MXPA00011851A - Removing metal ions from wastewater - Google Patents

Abstract

A novel process and apparatus are disclosed for cleaning wastewater containing metal ions in solution, hydrogen peroxide, and high solids, e.g., greater than about 50 mg/l particulate solids. A carbon adsorption column removes hydrogen peroxide in the wastewater feed containing high solids. A chemical precipitation unit removes the metal ions from solution. The process and apparatus remove metal ions such as copper from a high solids byproduct polishing slurry from the chemical mechanical polishing (CMP) of integrated circuit microchips to form an environmentally clean wastewater discharge.

Description

ELIMINATION OF METAL WATER IONS FROM DISPOSAL BACKGROUND OF THE INVENTION TECHNICAL FIELD The present invention relates to a method and apparatus for removing metal from waste water. In one aspect, this invention relates to a method and apparatus for removing copper ions from the waste water of a microchipping mechanical chemical buffer (CMP).

BACKGROUND The companies that manufacture microelectronic semiconductor pads (micropads) have developed advanced manufacturing procedures to reduce the size of the electronic circuitry in a micropastile to smaller dimensions. The smallest circuit dimensions involve individual minimum item sizes or minimum line widths in a single micro-chip. At smaller article size or smaller line width, typically in microscopic dimensions of about 0.2 to 0.5 microns, the adjustment of more computer logic components in the micropad is provided.

A new technology in semiconductor manufacturing involves the use of copper instead of aluminum and tungsten to create a copper chip circuitry on a silicon wafer. Copper has a lower electrical resistance than aluminum, thus providing a micropable that can be operated at much higher speeds. Copper is introduced into silicon ULSI and CMOS structures and is used as an interconnection material for channels and channels in these silicon structures. The ULSI silicon structures are integrated ultra-large scale integrated circuits containing more than 50,000 logic elements and more than 256 k memory bits. The CMOS silicon structures complementary metal-oxide semiconductor integrated circuits contain N-MOS and P-MOS transistors on the same substrate. For fully integrated multi-level micropacks, up to 6 levels, copper is currently the preferred interconnect material. A flattened mechanical chemical polisher (CMP) of the copper metal layers is used as part of the new advanced semiconductor manufacturing technology. The flattened mechanical chemical polisher produces a working surface of the substrate for the micro-chip. Current technology does not efficiently record copper, so the tools in semiconductor fabrication facilities employ a polishing step to prepare the surface of the silicon wafer.

The mechanical chemical polishing (CMP) of integrated circuits currently involves a flattening of microelectronic semiconductor wafers. A local flattening of the micro-chip is operated chemically and mechanically to uniform surfaces at a microscopic level of up to about 10 microns. { μm). A global flattening of the micro-chip extends over about 10 microns. { μm) and more. The mechanical chemical polishing flattening equipment is used to remove materials before a subsequent step of precision in the development of the integrated circuit. The mechanical chemical polishing (CMP) flattening process involves a polishing suspension composed of an oxidant, an abrasive, complexing agents and other additives. The polishing suspension is used with a polishing pad to remove excess copper in the wafer. Silicon, copper, and various tracers are removed from the silicon structure by chemical / mechanical suspension. The chemical / mechanical suspension is introduced into the silicon wafer on a flattening board together with the polishing pads. Oxidizing agents and etching solutions are introduced to control the removal of the material. Rinses with deionized water are often used to remove the waste from the wafer. Ultrapure water (UPW) of reverse osmosis (RO) and demineralized water can also be used in the tools in the facilities for the manufacture of semiconductors to rinse the silicon wafer.

BACKGROUND The Mechanical Chemical Polishing Flattening (CMP) process introduces copper into the process water, and government regulatory agencies are working on the wastewater discharge regulations of the mechanical chemical polishing (CMP) flattening process so strictly as the wastewater from the electrolysis processes, even when the flattening of CMP is not an electrolysis process. The copper ions in solution in the waste water must be removed from the byproduct of the polishing slurry to acceptably remove the waste water. The mechanical chemical polishing of the micro-chip produces a byproduct of the waste water from the "grinding" (polishing) suspension containing copper ions at a level of about 1 to 100 mg / l. The waste water by-product of the polishing slurry obtained from the micro-chip flattening also contains solids having sizes from about 0.01 to 1.0 μm at a level of about 500 to 2000 mg / l (500 to 2000 ppm). A hydrogen peroxide oxidant (H2O2) is typically used to help dissolve the copper in the micropad. In this way, hydrogen peroxide (H2O2) at a level of about 300 ppm and higher may also be present in the wastewater byproduct of the polishing suspension. A chelating agent such as citric acid or ammonia may also be present in the by-product of the polishing suspension to facilitate the maintenance of copper in solution. A waste water from the chemical / mechanical suspension will be discharged from the mechanical chemical polishing tool (CMP) at a flow rate of approximately 10 gpm, including rinsing streams. This waste water from the chemical / mechanical suspension will contain dissolved copper in a concentration of about 1 to 100 mg / l. Manufacturing facilities where multiple tools operate will typically generate a sufficient amount of copper to cause an environmental problem when discharging to the mouth of manufacturing facilities. A treatment program is needed to control the discharge of the copper present in the copper CMP wastewater before it enters the IPS wastewater treatment system manufacturing facilities. A conventional waste water treatment system in a semiconductor manufacturing facility often has pH neutralization and chloride treatment. A treatment system "at the end of the pipeline" typically does not contain equipment to remove heavy metals such as copper. An apparatus and method to provide a treatment at the point of origin for the removal of copper would solve the need to install a copper treatment system at the end of the expensive pipeline.

Taking into account the logistics of the equipment, as well as the characteristics to solve the waste, a copper treatment unit is needed at the point of origin, which is compact and can meet the discharge requirements of a single copper CMP tool. or a group of copper CMP tools. Iron sulfate (FeSO) or aluminum sulfate can be used (AI2 (SO4) 3) to coprecipitate the copper ions and produce a sediment. This precipitation process raises the pH to precipitate iron hydroxide and copper hydroxide with a residue of a waste water suspension with silica and alumina. The waste water by-product from the copper-containing polishing suspension of the CMP of semiconductor microelectronic pellets containing copper can pass through a microfilter to remove the solids in the form of a slurry of silica and alumina wastewater. The patent of E.U.A. do not. 3,301.54 ?, from Medford et al., Describes the treatment of etched acid solutions for copper-contaminated etching from the production of printed circuit boards. The waste water from the etching solutions is neutralized with sodium hydroxide. The patent of E.U.A. do not. 4, 010.099, Leach et al., Describes the extraction of copper by having it contact with an organic liquid ion exchange reagent. The patent of E.U.A. do not. 3,912,801, by Stephens, and the US patent. do not. 5,348,712, Marquis et al., Describe the extraction of metals with cyclic organic carbonates. The patent of E.U.A. do not. 3,440,036 from Spinney; the patent of E.U.A. do not. 3,428,449 to Swanson; and the patent of E.U.A. do not. 4,231, 888, by Dalton, describe the extraction of copper using organic oximes as the extraction agent. The material that penetrates from the microfilter containing penetrating copper ions can be reacted with sodium sulphide (NaS2) or an organic precipitation solution of a dithiocarbamate to precipitate the copper. The precipitation solution of dithiocarbamate is used to extract the copper ions from the complexing agent. The patent of E.U.A. do not. 5,346,627, Siefert et al., Discloses a method for removing metals from a fluid stream with a water-soluble ethylene ammonia dichloride polymer containing groups of dithiocarbamate salts to form complexes with the metals. In case hydrogen peroxide (H2O2) is present, the dithiocarbamate reacts with the hydrogen peroxide (H2O2) before the dithiocarbamate functions to extract the copper ions from the complexing agent. In this way, the hydrogen peroxide present in the precipitation step hinders the precipitation of copper, and a large amount of organic precipitation solution of dithiocarbamate will be required. The patent of E.U.A. do not. 5,559,515, from Misra et al., Describes the treatment of waste water containing heavy metal ions generated by the production of printed circuit boards (column 1, line 20, column 14, lines 40 to 42) and the elimination of copper waste water with dithiocarbamate to precipitate copper in the wastewater. Misra et al., Describe that various compounds can be used to form insoluble metal complexes with heavy metal ions. All have a greater attraction to metal ions than chelating agents that normally occur with metals in waste water. Such complex transforming agents include dithiocarbamates. These complexing agents are described as expensive (column 3, lines 33 to 48). Ferrous sulfate is described to replace toxic heavy metal ions that bind to chelating agents, but large amounts of ferrous ions may be required, which produces significant amounts of sediment (column 4, lines 16 to 49). Example V of Misra et al., Describes the influence exerted by chelating agents and ammonium ions in a cobr solution, 1 of 200 mg / l. Hydrogen peroxide is added as a strong oxidant. (Column 12, lines 37 to 41). The patent of E.U.A. do not. 5,298,168, by Guess, describes the removal of copper atoms using dithiocarbamate to precipitate copper from wastewater that has been filtered through carbon. Mercury is precipitated by dithiocarbamate (column 4, lines 30 to 50). Activated carbon is described (column 4, lines 58 and 59). The Guess patent describes that the heavy metals present in the solution, such as copper, compete with the mercury to obtain the carbamate in the formation of a stable complex for precipitation (column 7, lines 1 to 8). The patent of E.U.A. do not. 4,629,570, Kennedy, Jr., describes the cleaning of waste water (boiler cleaner) using dithiocarbamate as a copper precipitate and carbon filter. In the patent of E.U.A. do not. 4,629,570 to Kennedy, Jr., the chelated copper is removed by dithiocarbamates added in stoichiometric amounts to the amount of the dissolved copper (column 3, lines 18 to 26). The activated carbon can then be used (column 3, lines 27 to 30). The patent of E.U.A. do not. 3,923,471, Asano et al., In Example 3 a copper solution passes through a granular activated carbon column. The resistance of the fluid is measured and reported. The solution is then passed through an ion exchange resin column (U.S. Patent No. 3,923,741, column 6, lines 35 to 65). The patent of E.U.A. do not. 3,914, 374, by Koehler et al., Describes the removal of copper from the residue of acid nickel solutions by activated carbon that absorbs copper. The patent of E.U.A. do not. 5,464,605, Hayden, describes the removal of liquid peroxides by activated carbon. The practice of pretreatment for granulated activated carbon beds mainly requires the removal of contaminants such as excessive amounts of suspended solids. Suspended solids, including bacteria, in amounts exceeding about 50 mg / l, need to be removed before operating the carbon bed. Wastewater from non-copper CMP processes is generally discharged at the end of the semiconductor fabrication plant piping where the wastewater is neutralized prior to discharge. With the advent of copper technology, these suspension wastewaters will contain copper. Copper present at the mouth of manufacturing facilities can cause problems. Some manufacturing facilities must control the amount of suspended solids in the mouth. The accumulation of sediments in publicly owned receiving treatment facilities results in an increased cost for the disposal of municipal sediments and environmental problems to eliminate copper in the municipal sediment. The problems of biological toxicity in the municipal biological systems are caused by a mass load of copper. The limits of environmental discharge for copper result in not complying with the rules and regulations in the manufacturing facilities. A process and apparatus is necessary to remove the copper from the waste suspensions near the point of generation and allow the water without copper to discharge and neutralize in a conventional manner.

A method and apparatus is required to remove the copper ions from the solution for an acceptable disposal of waste water from the by-product of polishing slurries containing large amounts of suspended solids and to remove the copper ions from the solution containing large quantities of suspended solids efficiently and economically. An object of the present invention is to provide a novel method and apparatus for removing metal ions from the solution. An object of the present invention is to provide a novel method and apparatus for removing metal ions from the solution containing large amounts of suspended solids. An object of the present invention is to provide a novel method and apparatus for removing copper ions from the solution.

An object of the present invention is to provide a novel method and apparatus for removing copper ions from solutions containing large amounts of suspended solids. An object of the present invention is to provide a novel method and apparatus for removing copper ions from the by-product solution of the polishing suspension so as to achieve acceptable disposal of waste water. Another object of the present invention is to provide a novel method and apparatus for removing copper ions from the solution from a by-product of the polishing suspension from the mechanical chemical buffer (CMP) of integrated circuits. A further objective of the present invention is to provide a novel method and apparatus for removing copper ions economically and efficiently from solutions containing large amounts of suspended solids. These and other objects and utilities of the present invention will be apparent to those skilled in the art considering the following detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE INVENTION The process and apparatus of the present invention removes metal ions from the waste water by providing a first step in a carbon adsorption bed to receive a waste water feed containing metal ions in solution, where the water supply waste contains solids with a size ranging from about 0.01 to 1.0 μm in a greater amount of about 50 mg / l, in combination with the provision of a second step of mechanical precipitation in the operation unit to receive the current of the product of the carbon bed from the carbon adsorption bed and to remove the metal ions from the solution. The process and apparatus of the present invention remove metal ions from the waste water containing solids in an amount greater than about 100 mg l, preferably in an amount greater than about 500 mg / l, for example, in an amount that It varies from about 500 to 200 mg / l. A wastewater feed containing hydrogen peroxide and metal ions in solution passes to the carbon column to reduce the concentration of the hydrogen peroxide and form a carbon bed spill that has lower hydrogen peroxide concentration levels. about 1 mg / l (1 ppm). In one aspect, the metal ions are copper ions. In one aspect, the metal ones are copper atoms at a concentration level ranging from about 1 to 100 mg / l. The chemical precipitation operating unit includes means for the copper ions in the stream of the carbon-bed product of the metal ions to make contact with an organic carbamate to precipitate the copper ions. In one embodiment, the organic carbamate includes dithiocarbamate. In an alternative embodiment, the chemical precipitation operating unit includes means for the copper poles in the carbon bed product stream to make contact with an inorganic iron sulphate (FeSO4) or aluminum sulfate (AI2 (SO4)). 3) to coprecipitate the copper ions at a neutral or high pH. The process and apparatus of the present invention function to remove metal from the waste water from a by-product of the polishing suspension. In a modality, the method and apparatus of the present invention function to remove metal ions, for example, as copper metal ions, from a waste water from a by-product of the polishing suspension from the mechanical chemical polishing (CMP) of micro-piles for precipitate the metal ions and form an environmentally clean water discharge product.

BRIEF DESCRIPTION OF THE DRAWING Figure 1 is a schematic diagram of procedure and apparatus of the present invention.

DETAILED DESCRIPTION The method and apparatus of the present invention provides removal of metal ions through the combination of steps that include passing a waste water solution containing metal ions first through a carbon adsorption column, preferably without previous microfiltration or removal by ultrafiltration of suspended solids, to remove the hydrogen peroxide (H2O2) catalytically and then react the waste water solution containing the metal ions with an organic precipitation solution to remove the metal ions of the solution. In the present the solids are defined using Standard Methods 302 A, Preliminary Filtration for Metals (1985, le * 1 ed.): In an alternative embodiment, the waste water solution containing metal ions that pass from the carbon column they can be reacted with an inorganic precipitation solution to remove the metal ions from the solution. In one aspect, the method and apparatus of the present invention provide a novel method and apparatus for the removal of copper ions that includes passing a waste water solution containing copper ions first through a carbon column. , preferably without previous microfiltration or silica removal ultrafiltration, alumina suspension solids, to remove the hydrogen peroxide (H2O2) catalytically and subsequently react the waste water solution containing the copper ions with a dithiocarbamate to precipitate the copper. In one aspect the method and apparatus of the present invention provide a novel apparatus for the removal of copper ions which includes passing a solution of waste water containing copper ions first through a carbon adsorption column, preferably without micro-filtration / silica removal above, alumina suspension solids, to catalytically remove hydrogen peroxide (H2O2) and subsequently react the waste water solution containing the copper ions with an inorganic ferrous sulfate or aluminum sulfate to precipitate copper. The method and apparatus of the present invention provides a novel method and apparatus for the removal of copper from a byproduct of a wastewater solution of the copper-containing polishing suspension of the mechanical chemical buffer (CMP) of integrated circuits. of microelectronic semiconductor micropads. Now with reference to Figure 1, a schematic process diagram shows the metal removal method and apparatus of the present invention. A mechanical chemical polishing (CMP) leveling tool 10, for example, as in a chip manufacturing facility of integrated circuits, discharges a stream of waste water containing metal ions in solution, for example, as ions of copper in solution. The waste water stream containing copper ions also contains hydrogen peroxide at levels up to 300 ppm and above. Hydrogen peroxide is used as an oxidant to help dissolve the copper in the micropad. The waste water stream containing copper ions and hydrogen peroxide also contains suspended solids, eg, silica, alumina suspension solids, the nominal particle diameter size is about 0.01 to 1.0 μm and concentration about 50 mg / l (50 ppm) for example, on a scale of about 500 to 2000 mg / l (500 to 2000 ppm). The waste water stream 20 passes to the carbon 30 column. The carbon 30 column contains granulated activated carbon particles with a mesh size of about 8 x 40. A suitable carbon is an 8 x mesh 30 washed with acid available from US Filter Westes Coal - Arizona Inc. at Parker, Arizona. The hydrogen peroxide in the wastewater stream 20 passes downstream in the carbon column 30 and is adsorbed to the activated carbon granulated in the carbon column 30. A reverse flow stream 32 provides rinsing and regeneration of the column of carbon. carbon 30. A product stream 34 from the carbon column 30 containing copper ions in solution and grinding (polishing) solids from the carbon column 30 passes to a chemical unit of operation 40. The chemical feed stream 42 passes to a chemical feed, for example, an organic dithiocarbamate to the chemical operation unit 40 for precipitation and removal of the copper ions. The precipitated copper and some solids from the suspension can be removed through the discharge 44. The suspension of environmentally clean waste water passes through a waste water discharge 46 to a municipal waste 50. The waste water from CMP from Copper contains oxidants, dissolved copper, copper etchants, alumina particles, silica particles and sometimes a corrosion inhibitor. These constituents are contained in a bottom of deionized water. The following constituent concentrations are common.

Dissolved copper 5.0 mg / l Total suspended solids 1000.0 mg / l Oxidizing agents 300.0 mg / l Recorders 200.0 mg / l Complexing agents 400.0 mg / l 99% deionized water base + TDS 800 pH 6 to 7 Oxidizers as acid Nitric, hydrogen peroxide, ferric nitrate and ammonium persulfate are chemicals to improve the copper corrosion rate of a suspension. Other complexing agents such as citric acid or ammonium hydroxide help to burn copper. A group of multiple copper CMP tools generates about 100 gpm of wastewater. The waste water can be fed by gravity to an affluent collection tank which has a retention time, for example, of about 10 minutes. The collected CMP waste water can be pressurized in a lifting station before feeding to the method and apparatus of the present invention. Before practicing a real reduction, it was believed that the silica, alumina suspension solids would lock the bed and plug the carbon column in a matter of hours. However, it has been found that the method and apparatus of the present invention work surprisingly without becoming stuck and it has been observed that they operate for 10 days and more without increasing the pressure and without clogging. Hydrogen peroxide (H2O2) is catalytically broken down in the carbon column. A significantly lower amount of organic precipitation solution of dithiocarbamate is required to precipitate copper. The process and apparatus of the present invention removes hydrogen peroxide (H2O2) and dissolved copper ions from the by-product of the "ground" slurry (polishing) slurry from the integrated metal-etched chemical buffer (CMP) including chips. microelectronics of high-speed semiconductor integrated circuits containing copper metal.

EXAMPLE A treatment study was conducted on a series of milling debris from a variety of mechanical chemical polishing operations (CMP) to produce integrated circuit semiconductor microelectronic chips. The treatments were carried out on the grinding residues of CMP received from various manufacturers of semiconductor chips from integrated circuits. The treatments were performed on the CMP milling waste to investigate and determine the removal of copper from an alumina suspension. A novel method and apparatus provide a first step of removal of carbon adsorption of hydrogen peroxide from a milling waste of flattening of CMP from a wafer combined with a second step of chemical precipitation of copper in complex in the milling waste of flattening of the wafer. The waste of the plating of the wafer contained many particulate alumina solids which, otherwise, that is, if it were not for the copper, could be discarded through the municipal sewer or drainage system.

The samples used during this example were CMP wastes associated with the development of computer micropacks. Various samples were used in the tests. Table 1 lists the samples.

TABLE 1 Samples received Source Label A CMP Label B CMP Label C CMP Label The carbon used throughout the carbon column test was Calgon RX with 8 x 40 mesh (batch 04033) available from Calgon Coal Co. in Pittsburgh, Pennsylvania. A suitable equivalent carbon is an 8 x 30 mesh washed with available U.S. Filter Westates Carbon-Arizona Inc. in Parker Arizona. The carbon was prepared by removing the gas and rinsing. Before the experiment, the carbon was conditioned by mixing it in deionized water for 10 minutes to allow gas removal and cleaning. The carbon was allowed to settle and suspended fine powders were decanted with a supernatant. This conditioning was repeated until the supernatant was clear and colorless with no visible suspensions. For column loading, the conditioned carbon was suspended and poured into a Plexiglas column having dimensions of approximately 2.54 cm in diameter and 15.24 cm in height. The depth of the final carbon bed was 91.44 cm. Deionized water was placed through the column counter to classify the carbon and remove any carbon dust from the residue. Three samples were placed through the carbon "A", "B" and "C" column, representing different manufacturing companies and separate facilities. One of the samples used during this test was a previously concentrated "A" suspension using a commercially available Membralox Silverback® micro filter purification system from U.S. Filter Wastewater Systems, Inc. in Warrendale, Pennsylvania. The concentrate was re-diluted with deionized water to simulate the characteristics "on reception". Hydrogen peroxide was added to all suspension samples to accurately simulate the expected concentrations of about 400 mg / l (400 ppm) total. The CMP suspension solutions containing hydrogen peroxide passed through the carbon filter bed without prior removal of any of the alumina, silica particles in the CMP suspension solutions. During this stage of the experiment, the influent pressure and hydrogen peroxide content were monitored. A peristaltic pump was used to transfer the sample from a 207.95 liter drum into the carbon column. Fluid velocity was monitored and perceived consistently throughout the experimental test. During the course of the experimental test operation, it was observed that gas bubbles would be forced out through the column of the spill tube at the bottom, instead of gassing up through the upper part of the carbon bed . This was consistent throughout the test of the experiment. In the first moments of the experiment, the flow stopped during the night. On several occasions the upper portion of the carbon bed dried. Retaining a larger liquid upper space before turning off the pump eliminating this undesirable condition. It is believed that the gasification continued while stationary, and subsequently the volume of the liquid decreased. After an initial period, a solution of ammonium citrate / copper was added to the suspension. Table 2 summarizes the results of the carbon column test.

TABLE 2 CARBON COLUMN TEST The results in Table 2 showed that the carbon could remove the hydrogen peroxide from the CMP suspension solutions without entrapping the alumina, silica particles inside the filter bed. The novel method and apparatus of the present invention have applications for the precipitation and removal of metal ions other than copper from wastewater solutions of chemical flattening. The novel process and apparatus of the present invention have applications for the precipitation and removal of metal ions such as copper, gold, platinum, palladium, iron, cobalt, nickel, ruthenium, rhodium, silver, osmium, iridium, and mixtures of the same. Preferred embodiments of the method and apparatus of the present invention have applications for the precipitation and removal of metal ions such as copper and gold. The method and apparatus of the present invention removes metal ions from the waste water by providing a carbon bed to receive a waste water feed containing metal ions in solution, where the waste water feed contains solids with sizes that they vary from about 0.01 to 1.0 μm in a greater amount of about 100 mg / l, in combination with the provision of a chemical precipitation operation unit to receive a stream of carbon bed product from the carbon bed and to remove the metal ions from the solution. The process and apparatus of the present invention remove metal ions from waste water containing solids in an amount greater than about 500 mg / l, for example from an amount ranging from about 500 to 2000 mg / l. A wastewater feed containing hydrogen peroxide and metal ions in solution is passed to the carbon column to reduce the concentration of hydrogen peroxide and form a spill carbon bed having hydrogen peroxide concentration levels , preferably at a lower level of about 1 mg / l (1 ppm). In one aspect, the metal ions are copper ions. In one aspect, metal ions are copper ions at a concentration level ranging from about 1 to 100 mg / l. The chemical precipitation operating unit includes means for the metal particles in the product stream of the carbon bed to make contact with an organic carbamate to precipitate the copper atoms. In one embodiment, the organic carbamate includes dithiocarbamate. In an alternative embodiment, the chemical precipitation operating unit includes means for the metal poles in the product stream of the carbon bed to make contact with an inorganic iron sulphate (FeSO4) or aluminum sulfate (Al2 (SO4). ) 3) to precipitate copper ions. The process and apparatus of the present invention function to remove metal ions from the waste water of a by-product of the polishing suspension. In one embodiment, the method and apparatus of the present invention functions to remove metal ions, for example copper metal ions, from a waste water from a by-product of the polishing suspension from the mechanical chemical polisher (CMP) of the integrated circuits to precipitate metal ions and form a discharge product of environmentally clean water. By "environmentally clean" is meant a waste water discharge stream to a municipal waste water treatment plant in such a way that the waste water discharge stream contains copper ions at concentrations of less than about 0.5 mg / l (0.5 ppm). Although the invention has been described in conjunction with various embodiments, it will be understood that various alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. In this way, this invention is intended to encompass said alternatives, modifications and variations all falling within the spirit and scope of the appended claims.

Claims (20)

NOVELTY OF THE INVENTION CLAIMS

1. - A method for removing metal ions from waste water comprising: (a) providing a carbon bed for receiving a waste water feed containing metal ions in solution, wherein said waste water feed contains solids with a size that varies from about 0.01 to 1.0 μm in a greater amount of about 50 mg / l; and (b) providing a chemical precipitation operating unit to receive a product stream in a carbon bed from said carbon bed and to remove said metal from the solution.

2. The process for removing metal ions from waste water according to claim 1, wherein said waste water contains solids in an amount greater than about 100 mg / l.

3. The process for removing metal ions from waste water according to claim 1, wherein said waste water contains solids in an amount ranging from about 500 to 2000 mg / l.

4. The method for removing metal from waste water according to claim 1, further characterized in that it comprises passing a feed of waste water containing hydrogen peroxide and metal ions in solution to said waste water column. carbon to reduce the concentration of said hydrogen peroxide and form a spill carbon bed having concentration levels of hydrogen peroxide of less than about 1 mg / l (1 ppm).

5. The process for removing metal ions from waste water according to claim 4, wherein said metal ions comprise copper ions.

6. The process for removing metal ions from waste water according to claim 5, wherein said waste water contains copper ions at a level ranging from about 1 to 100 mg / l.

7. The method for removing metal from the waste water according to claim 5, wherein said step for providing a chemical precipitation operation unit comprises the metal ions in said product stream of carbon bed. of metal ions make contact with an organic carbamate to precipitate said copper ions.

8. The process for removing metal ions from the waste water according to claim 5, wherein said step for providing a chemical precipitation operation unit comprises that said carbon-bed product stream metal products make contact with the dithiocarbamate to precipitate said copper ions.

9. The process for removing metal ions from the waste water according to claim 5, wherein said step for providing a chemical precipitation operation unit comprises said metal ion streams of the carbon bed product making contact with iron sulfate (FeSO4) or aluminum sulfate (Al2 (SO) 3) to coprecipitate said copper ions.

10. The process for removing metal ions from waste water according to claim 5, wherein said waste water feed comprises a by-product of the polishing suspension.

11. The method for removing metal ions from waste water according to claim 10, wherein said waste water feed comprises a by-product of the polishing suspension of the mechanical chemical polishing (CMP) of integrated chip micropacks.

12. An apparatus for removing metal ions from waste water, comprising: (a) a carbon bed for receiving a waste water feed containing metal ions in solution, wherein said waste water feed contains solids with a size that varies from about 0.01 to 1.0 μm in a higher amount of about 100 mg / l; and (b) a chemical precipitation operation unit for receiving a stream of carbon bed product from said carbon bed and for removing said metal ions from the solution.

13. An apparatus for removing metal ions from waste water according to claim 12, further characterized in that said waste water contains solids in an amount greater than about 500 mg / I.

14. - The apparatus for removing metal ions from waste water according to claim 12, wherein said waste water contains hydrogen peroxide and said product stream of carbon bed has hydrogen peroxide concentration levels less than about 1 mg / l (1 ppm).

15. The apparatus for removing metal ions from the waste water according to claim 14, wherein said waste water comprises a by-product of the polishing suspension and said metal ions comprise copper in said by-product of the waste. polishing suspension.

16. The apparatus for removing metal ions from waste water according to claim 15, wherein said waste water comprises a by-product of the polishing suspension of the mechanical chemical polishing (CMP) of integrated circuits and said Metal comprise copper ions at a level on a scale of 1 to 100 mg / l.

17. The apparatus for removing metal ions from waste water according to claim 15, wherein said chemical precipitation operation unit comprises organic chemical means for said metal products of the product stream of the carbon bed. make contact with an organic carbamate to precipitate said copper ions.

18. The apparatus for removing metal from the wastewater according to claim 15, wherein said chemical precipitation operating unit comprises organic chemical means for said metal products in the product stream of wastewater. carbon make contact with the dithiocarbamate to precipitate said copper ions.

19. The apparatus for removing metal from waste water according to claim 15, wherein said chemical precipitation operation unit comprises inorganic chemical means for said metal ions to flow from the product of the carbon bed. contact with iron sulphate (FeSO4) or aluminum sulfate (A (SO4) 3) to coprecipitate said copper ions.

20. A method for removing copper ions in a by-product of the polishing suspension of waste water from mechanical chemical polishing (CMP) of integrated circuit micropads comprising: (a) providing a carbon bed to receive a feed of wastewater slurry by-product polishing from the mechanical chemical polishing (CMP) of integrated circuits, said waste water feed from the by-product of the slurry suspension contains hydrogen peroxide and copper ions in solution at a level that varies by from 1 to 100 mg / l to reduce the concentration of said hydrogen peroxide and form a spill product stream of the carbon bed having concentration levels of hydrogen peroxide of less than about 1 mg / l (1 ppm), wherein said waste water feed of the by-product of the polishing suspension additionally contains solids with a size ranging from about 0.01 to 1.0 μm in one greater amount of about 500 mg / l; (b) providing a chemical precipitation operating unit to receive a stream of carbon bed product from said carbon bed and to remove said copper ions from the solution; (c) passing a waste water feed of the by-product of the polishing suspension containing copper ions in solution from the mechanical chemical polishing suspension (CMP) of integrated chip micropads to said carbon column; (d) causing the copper ions in said product stream of the carbon bed to contact an organic carbamate in said chemical precipitation operation unit to precipitate said copper particles and form a discharge product of environmentally clean water.