Combined slurry copper scrap and concentrated copper scrap for treating azoles, metals and silica solids in wastewater

Abstract

A method of 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 of a semiconductor manufacturing facility and a concentrated copper scrap stream (CCW) from the semiconductor manufacturing facility, and introducing an oxidizing agent into the copper-containing solution, the copper catalyzing generating hydroxyl radicals from the oxidizing agent, the hydroxyl radical reacts with an organic compound.

Description

Technical Field

[0001] Aspects and embodiments disclosed herein relate to systems and methods for treating 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 wastewater using a modified Fenton's reagent utilizing copper from a combined waste stream of a semiconductor manufacturing facility as a catalyst.

[0002] Overview

[0003] According to one aspect, a method for removing organic compounds from a copper-containing solution is provided. The method includes generating the copper-containing solution from a mixture of wastewater from a copper chemical mechanical polishing (CMP) operation at a semiconductor manufacturing facility and a concentrated copper waste stream (CCW) from the semiconductor manufacturing facility, and introducing an oxidant into the copper-containing solution, wherein the copper catalyzes generation of hydroxyl radicals from the oxidant, and the hydroxyl radicals react with the organic compounds.

[0004] 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 generation of hydroxyl radicals from the oxidant.

[0005] In some embodiments, the method further comprises maintaining the pH of the copper-containing solution in the container at between about 2 and about 4.

[0006] In some embodiments, the method further comprises maintaining the temperature of the copper-containing solution in the vessel between about 55°C and about 65°C.

[0007] In some embodiments, introducing the oxidizing agent into the copper-containing solution comprises introducing hydrogen peroxide into the copper-containing solution.

[0008] In some embodiments, the method further comprises maintaining a hydrogen peroxide concentration in the copper-containing solution in the container at 250 mg / L or greater.

[0009] In some embodiments, the method further comprises obtaining the hydrogen peroxide from a waste stream from a semiconductor manufacturing facility.

[0010] In some embodiments, generating the copper-containing solution comprises mixing at least 1 part CCW to 25 parts CMP wastewater, or mixing at least 1 part CCW to 10 parts CMP wastewater.

[0011] In some embodiments, removing organic compounds from the copper-containing solution includes removing one or more azole compounds from the copper-containing solution.

[0012] In some embodiments, generating the copper-containing solution includes mixing CCW with CMP wastewater in an amount sufficient to provide 20 parts by weight of copper per part by weight of the one or more azole compounds.

[0013] In some embodiments, removing organic compounds from the copper-containing solution includes removing one or more of 1,2,4-triazole, 1H-Benzotriazole pyrazole, benzotriazole, 5-methyl-1H-benzotriazole (toluenetriazole), or 3-amino-1,2,4-triazole from the copper-containing solution.

[0014] According to another aspect, a system for removing organic compounds from wastewater from a semiconductor manufacturing facility is provided. The system includes 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 manufacturing facility; an oxidant source configured to introduce the oxidant into the wastewater in the vessel; and a pH adjusting chemical source configured to introduce the pH adjusting chemical into the wastewater in the vessel.

[0015] In some embodiments, the system further includes a pH monitor disposed within the container; and a controller configured to control the pH adjusting chemical source to introduce the pH adjusting chemical into the wastewater in the container 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 oxidant.

[0016] 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 between about 2 and about 4.

[0017] In some embodiments, the system further comprises a heater, and the controller is further configured to control the heater to maintain the temperature of the wastewater in the container between about 55°C and about 65°C.

[0018] 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 hydrogen peroxide concentration in the wastewater in the vessel at 250 mg / L or greater.

[0019] In some embodiments, the source of hydrogen peroxide comprises a waste stream from a semiconductor manufacturing facility.

[0020] In some embodiments, the wastewater comprises one or more anti-corrosives for copper, and the system is configured to decompose the anti-corrosives for copper using hydroxyl radicals generated by the oxidant, wherein copper acts as a catalyst in the generation of the hydroxyl radicals.

[0021] In some embodiments, the wastewater comprises one or more azole compounds, and the system is configured to decompose the one or more azoles using hydroxyl radicals generated by the oxidant, wherein copper acts as a catalyst in the generation of the hydroxyl radicals.

[0022] In some embodiments, the wastewater comprises one or more of 1,2,4-triazole, 1H-benzotriazolepyrazole, benzotriazole, 5-methyl-1H-benzotriazole (toluenetriazole), or 3-amino-1,2,4-triazole, and the system is configured to decompose the one or more of 1,2,4-triazole, 1H-benzotriazolepyrazole, benzotriazole, toluenetriazole, or 3-amino-1,2,4-triazole with hydroxyl radicals generated by an oxidant, wherein copper acts as a catalyst in the generation of hydroxyl radicals.

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

[0024] In some embodiments, the source of the wastewater is a copper CMP operation in a semiconductor manufacturing facility.

[0025] In some embodiments, the copper source comprises a copper plating operation in a semiconductor manufacturing facility. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component illustrated is represented by a like reference numeral. For clarity, not every component may be labeled. In the drawings:

[0028] Figure 1 The figure shows an example of a system as disclosed herein.

[0029] Details

[0030] Chemical mechanical polishing (CMP) planarization process involves a polishing slurry containing an oxidizing agent and an abrasive, a complexing agent, and other additives to remove and / or etch semiconductor wafers during the manufacturing process. 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 into the silicon wafer on the planarization workbench together with the polishing pad. Oxidizing agents and etching solutions are introduced to control the removal of materials. Deionized water rinsing is typically used to remove debris from the silicon wafer. UPW, demineralized water, and polishing water from reverse osmosis (RO) can also be used in semiconductor manufacturing facility tools to rinse silicon wafers.

[0031] Hydrogen peroxide (H2O2) oxidizing agent is often used to help dissolve copper from microchips. As a result, hydrogen peroxide (H2O2) can also be present in the byproduct polishing slurry wastewater at levels of about 300 ppm and higher.

[0032] In the manufacturing process of semiconductor devices, when copper wiring is installed, a large amount of wastewater containing an anti-corrosive agent for copper is discharged from the CMP step for polishing the copper surface. Therefore, it is necessary to treat the wastewater to prevent the discharge of undesirable pollutants into the environment.

[0033] Among copper corrosion inhibitors, azole-type copper corrosion inhibitors are particularly effective in preventing corrosion. However, azole-type copper corrosion inhibitors generally have a chemically stable structure and are not easily biodegraded. Therefore, when treating wastewater containing azole-type copper corrosion inhibitors discharged from the process, oxidants with high oxidizing power, such as ozone, ultraviolet rays, or hydrogen peroxide, or advanced oxidation processes combining these oxidants, are typically used to decompose the azole-type copper corrosion inhibitors, and the treated water is then discharged or collected.

[0034] However, as mentioned above, since azole-type copper corrosion inhibitors are chemically stable, even when using a highly oxidizing agent such as ozone, a large amount of the oxidizing agent must be added to oxidatively decompose the azole-type copper corrosion inhibitor, resulting in significant cost issues. In particular, with the increasing integration of semiconductor devices in recent years, the number of fine polishing steps has increased, and with this, the amount of polishing wastewater discharged has also increased. Consequently, the cost increase caused by the increased capacity of wastewater treatment equipment has become a problem.

[0035] Fenton's reagent is often used in the treatment of organic compounds. For every 0.3 parts of organic compound, Fenton's reagent can be produced by adding 10 parts of peroxide to 1 part of ferrous iron (ferrous sulfate).

[0036] Fenton's reagent is effective against some azoles, such as pyrazole. However, laboratory tests have shown that other forms of azoles, such as 1,2,4-triazole, do not break down when exposed to Fenton's reagent.

[0037] As discussed above, azoles are often used as anti-corrosion additives in facilities that manufacture computer chips. These facilities also typically have high-strength copper-containing wastewater from the CMP process, which needs to be treated and disposed of after failure, bringing costs to the facility. In one embodiment, a waste copper stream is used to replace the iron in the Fenton reagent (Fenton-like reagent) to treat and degrade azole compounds in the wastewater. Tests have shown that 1,2,4-triazole, 1H-benzotriazole and methylbenzotriazole: 4,5-tolyltriazole (4,5Tolytriazole) can all be treated using copper-substituted Fenton reagents. In one test, it was found that waste hydrogen peroxide (which contains the azoles to be treated) and waste copper sulfate (which can be used to replace iron sulfate in the Fenton reaction) produced an oxidant-containing solution that successfully degraded the azoles.

[0038] In some embodiments, copper replaces iron in a modified Fenton reaction (referred to herein as a Fenton-like reaction). Waste copper streams from semiconductor production facilities can be used as a source of copper. Waste copper can be present in the effluent of a copper CMP process, which is referred to herein as slurry copper waste (SCW). More specifically, in some aspects and embodiments, a combined SCW and concentrated copper waste (CCW) stream can be used as a copper source for producing a Fenton-like reagent (using Cu instead of iron in a traditional Fenton reagent as a catalyst for producing hydroxyl radicals from H2O2) to treat azoles, metals (e.g., copper, cobalt, and iron), and silica solids in wastewater. In some embodiments, the two wastewaters are blended in a ratio of 1:25 (CCW:SCW) or greater, such as a ratio of 1:10 (CCW:SCW) or greater. In some embodiments, additional copper, such as copper 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 a Fenton-like reaction. In some embodiments, the combined CCW / SCW or the combined CCW / SCW after dosing with additional copper can contain 5,000 mg / L or more dissolved copper, e.g., 6,000 mg / L or 7,000 mg / L or more dissolved copper, or a ratio of up to 10:1, 15:1, or 20:1 or more by weight of copper:azoles in the wastewater to be treated.

[0039] 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 to about 200 mg / l or more total azoles, which are used as anti-corrosive agents 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 prior to discharge of the wastewater. These additional pollutants can be present at levels from about 0.01 wt% to about 1 wt%. The wastewater can also have a high background total organic carbon (TOC) concentration, of which total azoles constitute a portion of the TOC. For example, oxidants such as hydrogen peroxide (H2O2) are commonly used to help dissolve copper from microchips and can be present in CMP wastewater at concentrations exceeding 1,000 mg / L or 0.1 wt%.

[0040] U.S. regulatory agencies do not currently regulate maximum contaminant levels (MCLs) for azoles, but they are believed to have negative environmental impacts when discharged into open waterways. Recent evidence has indicated bioaccumulation of azoles in fish and toxic incidences of naturally occurring algal blooms, necessitating their removal from process waters prior to discharge.

[0041] As described in U.S. Patent No. 8,801,937, azole compounds are widely used as corrosion inhibitors for copper during silicon wafer processing in the semiconductor industry, the disclosure of which is incorporated herein by reference in its entirety for all purposes. 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, any derivatives thereof, amine salts thereof, and metal salts thereof. Examples of azole derivatives include compounds having a condensed ring of an azole ring and a benzene ring or the like, such as indazole, benzimidazole, benzotriazole, and benzothiazole, and also include derivatives thereof, such 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 the like. azoles, alkylaminosulfonylbenzotriazoles, mercaptobenzotriazoles, hydroxybenzotriazoles, nitrobenzotriazoles (e.g., 4-nitrobenzotriazole), halogenated benzotriazoles (e.g., 5-chlorobenzotriazole), hydroxyalkylbenzotriazoles, hydrogenbenzotriazoles, aminobenzotriazoles, (substituted aminomethyl)-tolyltriazole, carboxybenzotriazole, N-alkylbenzotriazoles, bisbenzotriazoles, naphthotriazoles, mercaptobenzothiazoles, aminobenzothiazole, amine salts thereof, and metal salts thereof.

[0042] Figure 1 One embodiment of a system for treating azole-containing wastewater from a semiconductor manufacturing facility is schematically shown in FIG. A semiconductor manufacturing facility 110 typically includes hundreds of unit operations, three of which are located in Figure 1 is marked in. Figure 1 The unit operations identified in FIG. 1 are a copper CMP unit operation 120; a unit operation 130 that generates wastewater having a high concentration of dissolved copper, such as a copper plating operation; and a unit operation 140 that generates wastewater having a high concentration of hydrogen peroxide, such as one of the wafer cleaning unit operations within semiconductor fabrication facility 110. The disclosed system is configured to decompose organic contaminants, such as azoles, present in the wastewater from the copper CMP unit operation 120 using a Fenton-like reaction in which copper is used to catalyze the production of hydroxyl radicals from hydrogen peroxide. The hydroxyl radicals decompose the organic contaminants into less hazardous byproducts, such as nitrogen oxides (NO2 / NO3), carbon dioxide, and water, through oxidation.

[0043] Wastewater from CMP unit operation 120 is directed into vessel 150, for example, by pump P1. An oxidant, such as hydrogen peroxide, from an oxidant source 160 is added to the wastewater in vessel 150, for example, using another pump P4, in an amount and at a rate sufficient to maintain the hydrogen peroxide concentration in the vessel at a desired level (e.g., 300 mg / L or higher) to promote reactions that result in the decomposition of organic compounds in the wastewater. In some embodiments, the addition of oxidant from oxidant source 160 can be supplemented by, for example, adding wastewater containing hydrogen peroxide from unit operation 140 using pump P3. If the wastewater containing hydrogen peroxide from unit operation 140 contains sufficient hydrogen peroxide, hydrogen peroxide can be used as the sole source of hydrogen peroxide added to the wastewater in vessel 150.

[0044] In other embodiments, persulfates such as ammonium persulfate, potassium persulfate, and / or sodium persulfate may be used as the oxidant. The aspects and embodiments disclosed herein are not limited by the type of oxidant added to the treatment system. Upon reaction with the dissolved copper in vessel 150, peroxides generate hydroxyl radicals and peroxyhydroxyl radicals, while persulfates generate persulfate radicals.

[0045] A pH adjusting chemical source 170, such as a sulfuric acid source and / or a sodium hydroxide source, can add a pH adjusting agent to the wastewater in the 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., between 2 and 4 or approximately 3) to promote reactions that result in the decomposition of organic compounds in the wastewater.

[0046] A heater or heat exchanger 210 may also be present in the vessel and may be used to maintain the temperature of the wastewater in the vessel at a temperature suitable for promoting the decomposition of organic compounds, such as azoles, in the wastewater via a Fenton-like reaction within a desired timeframe. This temperature may be, for example, between 55° C. and 65° C. or approximately 60° C.

[0047] The wastewater from the CMP unit operation 120 may contain sufficient copper, such as copper sulfate, to catalyze the production of hydroxyl radicals from hydrogen peroxide in a Fenton-like reaction in the vessel 150, which will decompose one or more organic substances in the wastewater in the vessel 150. Byproducts of the decomposition of organic pollutants, such as nitrogen oxides (NO2 / NO3) and carbon dioxide, may exit the vessel 150 through the exhaust port V. The one or more organic substances may include one or more azoles, such as one or more of 1,2,4-triazole, 1H-benzotriazole, or tolyltriazole:4,5-toluenetriazole, that may be present in the wastewater from the CMP unit operation 120. The Fenton-like reagent for decomposing the azoles may be prepared by adding about 500 mg / l to about 3000 mg / l of an oxidizing agent, such as hydrogen peroxide or a persulfate, to about 50 mg / l to about 300 mg / l of a soluble copper compound, such as copper (Cu). 2+ ) sulfate).

[0048] Fenton-like reactions can occur according to chemical equations (1)-(3):

[0049] Cu 2+ + H2O2 → Cu 3+ + HO· + OH - (1)

[0050] Cu 3+ + H2O2 → Cu 2+ + HOO· + H + (2)

[0051] Cu 2+ + S2O8 2- → Cu 3+ + SO4 - + SO4 2- (3).

[0052] Persulfate and Cu 2+ Oxidation or Cu 3+ The hydroxyl radicals, peroxyhydroxyl radicals, and persulfate radicals formed by the reduction of azoles can react with azoles in the CMP wastewater and decompose the azoles into primarily nitrogen oxides (NO2 / NO3), carbon dioxide, and water. Without wishing to be bound by any particular theory, the decomposition of nitrogen-containing organic molecules such as azoles can occur via the reaction shown in Equation 4:

[0053] C x N y H z + OH· → CO2 + NO3 + H2O (4).

[0054] One or more sensors or monitors, such as temperature sensors, pH sensors, ORP sensors, chemical concentration sensors, etc., collectively represented by "S", can be present in the container 150 and in contact with the wastewater in the container. The one or more sensors S can communicate with the controller 190. The controller 190 can be a conventional computer including a conventional processor, such as the one from Intel Corporation. processor and runs a conventional operating system, such as one from Microsoft 1 and is programmed to perform the functions disclosed herein. The controller may optionally be or include a specially programmed controller, such as an application specific integrated circuit (ASIC) programmed to perform the functions disclosed herein. The controller 190 is programmed or otherwise configured to control the pH adjustment chemical source 170 to introduce the pH adjustment chemical into the wastewater in the vessel 150 in an amount and at a rate sufficient to maintain the pH of the wastewater at a level at which the copper catalyzes the production of hydroxyl radicals by the oxidant. The controller 190 may also control the operation of the heat exchanger or heater 210 and any of the pumps P1-P7 to control, for example, the introduction of wastewater from the CMP unit operation 120, the introduction of oxidant from the oxidant source 160, the introduction of CCW from the unit operation 130, the introduction of wastewater containing hydrogen peroxide from the unit operation 140, the introduction of the make-up copper solution from the source 200, and the removal of treated wastewater from the vessel 150.

[0055] In some embodiments, the wastewater (SCW) from the CMP unit operation 120 may not contain sufficient copper to catalyze the production of sufficient hydroxyl radicals to decompose the organic contaminants in the wastewater from the CMP unit operation 120 to the desired lowest possible level. Therefore, additional copper can be added to the wastewater in the vessel 150 from, for example, the unit operation 130 that produces the wastewater (CCW) having a high concentration of dissolved copper, via pump P2 operated by controller 190. As described above, in some embodiments, the two wastewaters can be blended or introduced into the vessel 150 in a ratio of 1:25 (CCW:SCW) or greater, such as a ratio of 1:10 (CCW:SCW) or greater. In some embodiments, additional copper, such as copper in the form of a copper sulfate solution, can be added to the combined CCW / SCW from a make-up copper solution source 200, such as 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 the combined CCW / SCW after dosing with additional copper can contain 5,000 mg / L or more dissolved copper, e.g., 6,000 mg / L or 7,000 mg / L or more dissolved copper, or a ratio of up to 10:1, 15:1, or 20:1 or more by weight of copper:azoles in the wastewater to be treated.

[0056] Wastewater in vessel 150, from which organic compounds have been removed by Fenton-like decomposition as disclosed herein, can exit the vessel and be directed, for example, by pump P6, to a post-treatment system 180. Post-treatment system 180 can be used to remove residual copper and other undesirable components from the partially treated wastewater exiting vessel 150 using methods known in the art, and can produce treated water that can be discharged to the environment, recycled, or sent for further treatment or disposal.

[0057] Aspects and embodiments disclosed herein also relate to methods for removing organic compounds such as one or more azoles from copper-containing solutions, such as wastewater from a chemical mechanical polishing unit operation of a semiconductor manufacturing facility, using a Fenton-like reagent. The copper-containing solution can be produced from a mixture of wastewater from a copper chemical mechanical polishing (CMP) operation of a semiconductor manufacturing facility and a concentrated copper waste stream (CCW) from a semiconductor manufacturing facility. The method may include introducing an oxidant into the copper-containing solution, wherein the copper catalyzes the production of hydroxyl radicals by the oxidant, and the hydroxyl radicals react with the organic compound. The pH of the copper-containing solution in the container can be maintained at a level at which the copper catalyzes the production of hydroxyl radicals by the oxidant, such as between 2 and 4. The temperature of the copper-containing solution in the container can be maintained between about 55° C. and about 65° C. Introducing the oxidant into the copper-containing solution can include introducing hydrogen peroxide into the copper-containing solution. The concentration of hydrogen peroxide in the copper-containing solution in the container can be maintained at 250 mg / L or higher. Hydrogen peroxide can be obtained from a waste stream from a semiconductor manufacturing facility. Generating the copper-containing solution may include mixing at least 1 part CCW with 25 parts CMP wastewater or mixing at least 1 part CCW with 10 parts CMP wastewater. Generating the copper-containing solution may include combining CCW with CMP wastewater in amounts sufficient to provide 10 parts by weight of copper per 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 tolyltriazole:4,5-toluenetriazole from the copper-containing solution.

[0058] Example 1

[0059] CMP slurry wastewater (slurry copper waste - SCW) and wastewater with high Cu concentration (concentrated copper waste - CCW) from semiconductor production facilities, as well as a 25:1 mixture of SCW and CCW, were analyzed and found to contain the contaminants listed in Table 1 below:

[0060] Table 1 - SCW and CCW wastewater analysis

[0061]

[0062] Tests were conducted to determine whether the amount of copper present in a 25:1 mixture of SCW and CCW was sufficient to catalyze the production of sufficient hydroxyl radicals to decompose the 1,2,4-triazole present in the mixture. Details of the test conditions and results are presented in Table 2 below:

[0063] Table 2 - Decomposition of azoles using a Fenton-like reaction in SCW:CCW mixtures

[0064]

[0065] 1 Sodium bisulfate - decomposing H2O2

[0066] The pH of the blended sample (962 mL SCW + 38 mL CCW) was 3.0. A cumulative dose of 1,680 mg / L of H2O2 produced a 90% TOC removal rate and a residual azole level of 0.38 mg / L (99% removal) over a 120-minute reaction time. These results were achieved without the addition of iron and demonstrate that copper, already present in wastewater streams from semiconductor manufacturing facilities, can be used as a catalyst for a Fenton-like reaction to successfully remove organic pollutants, including azoles, from those same wastewater streams.

[0067] Example 2

[0068] Further testing was conducted to evaluate whether the Fenton-like reaction disclosed herein could successfully decompose organic compounds such as azoles from wastewater from semiconductor manufacturing facilities under simulated worst-case scenarios of pollutant concentrations in the wastewater. Additional 1,2,4-triazole was spiked into wastewater mixtures of 25:1 SCW:CCW and 10:1 SCW:CCW to produce wastewater mixtures having the copper and azole concentrations shown in Table 3 below.

[0069] Table 3 - Simulated worst-case wastewater mixtures

[0070] Approximate concentration 25:1 test 10:1 test Copper (mg / L) 670 1,659 Azoles (mg / L) 350 350

[0071] The test conditions and results for TOC removal from simulated worst-case wastewater are shown in Table 4 below.

[0072] Table 4 - Test Conditions and Results for TOC Removal from Simulated Worst-Case Wastewater

[0073]

[0074] The 10:1 blend removed more TOC than the 25:1 blend, but still only removed 32% of TOC. Another Fenton-like reaction test was conducted to determine the copper-to-azole ratio required to achieve approximately 70% TOC removal, which should correspond to over 90% azole removal. The copper-to-azole ratio was extrapolated from the above results relative to TOC removal and the required copper concentration was determined to be ~7,000 mg / L, with a copper / azole ratio of approximately 20 by weight.

[0075] This type of Fenton reaction test was conducted by spiking a 25:1 blend containing approximately 690 mg / L Cu and 6,330 mg / L Cu (9,582 mg / L CuSO4). The results are shown in Table 5 for comparison along with the same blend sample without copper spike.

[0076] Table 5 - TOC Removal from Simulated Worst Case Wastewater with Supplemented Copper

[0077]

[0078] Adding copper at the beginning of the test greatly improved TOC removal, indicating that a copper / azole ratio of 20 or higher can provide successful decomposition of organic compounds in the combined SCW:CCW wastewater via Fenton-like reactions.

[0079] The words and terms used herein are for descriptive purposes and should not be considered limiting. As used herein, the term "more than one / plurality" refers to two or more items or components. The terms "comprising," "including," "carrying," "having," "containing," and "involving," whether in the written description or in the claims and the like, are open-ended terms, meaning "including but not limited to." Therefore, the use of such terms is intended to encompass the items listed thereafter and their equivalents, as well as additional items. With respect to the claims, only the transitional terms "consisting of" and "consisting essentially of" are closed transitional terms or semi-closed transitional terms, respectively. The use of ordinal terms such as "first," "second," "third," and the like in the claims that modify claim elements does not, by itself, imply any priority, precedence, or order of one claim element relative to another claim element, or the temporal order in which the acts of the method are performed, but rather serves merely as a marker to distinguish one claim element having a certain name from another element having the same name (but using ordinal terms) to distinguish the claim elements.

Claims

1. A method for removing organic compounds from a copper-containing solution, the method comprising: producing the copper-containing solution from a mixture of wastewater from a copper chemical mechanical polishing (CMP) operation at a semiconductor manufacturing facility and a concentrated copper waste stream (CCW) from a semiconductor manufacturing facility; as well as An oxidizing agent is introduced into the copper-containing solution, and the copper catalyzes the generation of hydroxyl radicals from the oxidizing agent, which react with the organic compound.

2. The method of claim 1 , further comprising maintaining the pH of the copper-containing solution in the container at a level at which the copper catalyzes the generation of the hydroxyl radicals from the oxidant.

3. The method of claim 2, further comprising maintaining the pH of the copper-containing solution in the container between about 2 and about 4.

4. The method of claim 1 , further comprising maintaining the temperature of the copper-containing solution in the container between about 55°C and about 65°C.

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

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

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

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

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

10. The method of claim 9, wherein generating 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 part by weight of the one or more azole compounds.

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

12. A system for removing organic compounds from wastewater from a semiconductor manufacturing facility, the system comprising: a container 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 manufacturing facility; an oxidant source configured to introduce the oxidant into the wastewater in the container; as well as A pH adjusting chemical source is configured to introduce the pH adjusting chemical into the wastewater in the container.

13. The system of claim 12, further comprising: a pH monitor disposed within the container; as well as A controller is configured to control the pH adjusting chemical source to introduce the pH adjusting chemical into the wastewater in the container in an amount and at a rate sufficient to maintain the pH of the wastewater at a level at which the copper catalyzes the generation of hydroxyl radicals from the oxidant.

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 container in an amount and at a rate sufficient to maintain the pH of the wastewater between about 2 and about 4.

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

16. 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 hydrogen peroxide concentration in the wastewater in the container at 250 mg / L or greater.

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

18. The system of claim 12, wherein the wastewater contains one or more anti-corrosion agents for copper, and the system is configured to decompose the anti-corrosion agents for copper with hydroxyl radicals generated by the oxidizing agent, wherein the copper acts as a catalyst in the generation of the hydroxyl radicals.

19. The system of claim 12, wherein the wastewater comprises one or more azole compounds, and the system is configured to decompose the one or more azoles using hydroxyl radicals generated by the oxidant, wherein the copper acts as a catalyst in the generation of the hydroxyl radicals.

20. The system of claim 12, wherein the wastewater comprises one or more of 1,2,4-triazole, 1H-benzotriazole pyrazole, benzotriazole, 5-methyl-1H-benzotriazole (toluenetriazole), or 3-amino-1,2,4-triazole, and the system is configured to decompose the one or more of 1,2,4-triazole, 1H-benzotriazole pyrazole, benzotriazole, toluenetriazole, or 3-amino-1,2,4-triazole with hydroxyl radicals generated from the oxidant, wherein the copper acts as a catalyst in the generation of the hydroxyl radicals.

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

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

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

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