TWI254033B - Method and apparatus for treating wastewater from copper chemical mechanical polishing - Google Patents

Abstract

A method and apparatus for treating wastewater from copper chemical mechanical polishing (Cu-CMP wastewater). A coagulant is diluted with a predetermined amount of wastewater from Cu-CMP. Next, the diluted coagulant and a large amount of Cu-CMP wastewater are introduced into a reaction tank respectively, such as to cause flocculation reaction of wastewater and coagulant. Next, the flocculated solution is introduced into a clarifier to mix with a coagulant aid, forming sludge. Finally, the sludge is removed and the treated water is discharged. According to the present invention, the sludge can also be recycled back to the clarifier. Thus, the difficultly-settled particles are settled by co-precipitation with sludge, which is helpful to flocculation of particles in wastewater. The present invention successfully treats Cu-CMP wastewater and the turbidity of the treated water reaches below 10 mg/L.

Description

1254033 β—No. 91118654 V. INSTRUCTION DESCRIPTION (1) Invention The present invention relates to a method and a device for treating steel chemical mechanical polishing wastewater, in particular to a technology for diluting a coagulant with wastewater and using a sludge to return to the official. A method and apparatus for treating copper chemical mechanical grinding wastewater.

Traditionally, aluminum has been used as an interconnect for semiconductor devices. For the flattening of the interconnect, a chemical mechanical polishing slurry (CMP slurry) is often used to smooth the aluminum wire by CMP. Since the slurry contains many high-hardness abrasive particles, it is necessary to treat the aluminum CM P wastewater for environmental protection considerations. After the completion of CMP, for the treatment of aluminum CMP wastewater, PAC (polyaluminum chloride) is generally used as a coagulant for coagulation sedimentation to form a small rubber feather (f 1 0 C ). Next, the polymer (ρ ο 1 y m e r ) is used as a coagulant, for example, an anionic powdery polymer, so that the formed rubber feathers are larger and heavier to facilitate settling. This PAC treatment method can successfully remove particles from aluminum CMP wastewater. Currently, copper is widely used as a copper interconnect for semiconductor interconnects. However, the treatment of copper CMP wastewater is still in its infancy. The inventors of the present invention have found that the use of a PAC treatment method conventionally used for treating aluminum CMP wastewater to treat copper CMP wastewater has no gel formation and cannot be successfully processed.

Copper CMP wastewater. OBJECT AND SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a method and apparatus for treating copper chemical mechanical polishing wastewater to solve the above problems, in order to successfully treat copper CMP wastewater, and the treated water can achieve a turbidity of less than 10 Mg/L.

0^03-8388TWFl · TSMC2002-0347 · Cathy.ptd Page 5 1254033 Case No. 91118654 月 Amendment V. Description of invention (2) The method for achieving this water includes the purpose of the invention. To dilute a coagulant and direct the dilution mill wastewater. Then, the above step of the reaction tank is mixed with a coagulant, and the treated water is prepared in addition to the above-mentioned treated copper chemical machine tank, in the tank, to help the present invention to mix a single mechanical grinding wastewater, a reaction In addition to the steps of the coagulant and the Dasheng; the spin-drying reaction, the mechanical grinding wastewater further comprises a granular copper chemical machine in the following wastewater for containing the coagulant, the copper chemistry located in the mixture, the present invention The coagulant and the inner part of the wastewater are used to make the sludge of the wastewater get sludge. Most to achieve a more method, in the step: the agglutination of the part. Mechanical grinding wastewater copper chemical mechanical grinding scrap copper chemical mechanical grinding wastewater a large amount of copper chemical mechanical research and coagulant production agglutination reverse introduction into a slow mixing sedimentation tank, remove the sludge, and the best treatment effect, the present invention will agglutinate The device for introducing the liquid into the slow mixed sediment and returning to the slow mixed sediment comprises: a nano-coagulant and a quantitative copper chemical machine dilution; and a mechanical grinding waste under the unit to accommodate the diluted water to make the two Mixing and producing a slow mixing tank, located in the coagulant and from the reaction tank and mixing the sediment tank to achieve the inclusion: the outlet pipe is located in the slow treated water for better treatment efficiency Downstream, for accommodating a waste water to mix the two to produce sludge; downstream of the mixed sedimentation tank for discharging the slow citrus fruit, the copper CMP wastewater treatment of the present invention

0503-8388TWF1 : TSMC2002-0347 ; Cathy.ptd Page 6 1254033 Case No. 91118654 Year - Month Revision 5, Invention Description (3) A sludge guide back to the sludge to be returned to the slow mixing tank Helps agglomerate particles in wastewater. Alternatively, the apparatus for treating copper C Μ P wastewater of the present invention may further comprise: a sludge splitting device 'located downstream of the slow mixing sedimentation tank for dividing the sludge discharged from the slow mixed sedimentation tank into two parts and respectively introducing them a sludge return pipe and a sludge collection pipe, wherein the sludge return pipe can be used to guide a part of the sludge back into the slow mixing sedimentation tank to help agglomerate particles in the wastewater, and the sludge collection pipe can be used The other part of the sludge is introduced into a sludge concentration tank. EXAMPLES Figure 1 is a schematic view showing an apparatus for treating copper chemical mechanical polishing wastewater in accordance with a preferred embodiment of the present invention. Referring to FIG. 1 , the apparatus for treating copper chemical mechanical polishing wastewater comprises: a copper CMP wastewater supply device 1 , a wastewater separation device 20 , a mixing unit 30 , a reaction tank 4 , and a slow mixing tank. 5〇, a sludge splitting device 60, and an outflow pipe 7〇. First, copper CMp wastewater is supplied from the steel CMP wastewater supply unit iq. When the wastewater flows to the wastewater splitting device 20, the wastewater is divided into two parts. A small amount of waste water flows into the mixing unit 30 via the line 22 and the flow indicator 24, and most of the waste water flows into the reaction tank 4 through the line 26. The coagulant 32 enters the mixing unit 30 via a first flow control unit 34 (FC1) and is mixed with a small amount of copper CMP wastewater via line 22. The first flow control unit 34 can be used to control the flow of the coagulant 32 to the mixing unit 30. Thus, in the mixing unit 30, a small amount of copper CMP wastewater can be diluted

0503-8388OVF1 : TSMC2002-0347 : Cathy.ptd Page 7 1254033 Revision ____ Case No. 9in8fi54 V. Inventive Note (4) Coagulant. The reaction vessel 40 is diluted and simultaneously in the reaction tank 40. At this time, the rubber feather (f loc ). The sulphate is quickly passed into the 'most of the wastewater, and the wastewater and the coagulant will flow' through the line 36 to flow through the line 26 to produce an agglutination reaction, and the present invention uses a small amount of copper chemical mechanical polishing wastewater. Diluting the coagulant allows the coagulant to diffuse more evenly. Since the coagulant has been diluted with a portion of the copper CMp waste water, the coagulant is diluted into a small unit, so that the effective contact area of the coagulant with the particles in the copper CMP wastewater increases in the reaction tank 40,

The coagulant is capable of producing agglutination reaction with particles in the wastewater very uniformly. Further, since a small amount of waste water is mixed with the coagulant, the speed of introduction into the reaction tank is fast, so that the coagulant does not fail after entering the reaction tank 4 。. A coagulant suitable for the present invention may be a polymer, for example, may be polyacrylamide. Further, a small amount of copper CMP wastewater for diluting the coagulant may be a 5% to 10% by volume of a large amount of waste water introduced into the reaction tank.

In order to carry out a preferred agglutination reaction in the reaction tank 40, an acid (e.g., H2SO4) or an alkali solution (e.g., NaOH) may be used to adjust the pH of the wastewater. For example, the value of ρ Η of the wastewater in the reaction tank can be adjusted to an inspectivity, such as a p Η value between 8 and 1 1 ', which is between pH 9-10. Next, the aggregating liquid obtained in the reaction tank 40 is introduced into a slow mixing sediment tank 50. The coagulant 5 2 (for example, a polymer) can enter the slow mixing settling tank 50 via a second flow control unit 54 (FC2) to mix with the agglomerate to produce sludge (s 1 u dg e ). . The second flow control unit 54 can be used to control the flow of the coagulant 52 to the slow mixing chamber 50.

1254033 — Case No. 91 918 654 Revision 5, Invention Description (5) The sludge discharged from the slow mixing tank 50 can be divided into two parts by the sludge splitting device 6 and passed through the sludge return pipe 6 2 A part of the sludge is led back into the tank 50, and another sludge is introduced into a sludge concentration tank 6 6 via the sludge collection pipe 64. Some particles in the wastewater cannot be settled by agents such as coagulants or coagulants. The sludge introduced into the slow mixing tank 50 by the sludge return pipe 6 2 can capture small rubber feathers, and settle these difficult-to-precipitate particles by sludge co-precipitation to help agglomerate the particles in the wastewater. . Part of the sludge in the slow-mixing sedimentation tank 50 is led back through the sludge return pipe 62, and may account for 10% to 30% by weight of the total sludge discharged from the slow-mixing sedimentation tank. For example, the sludge introduced into the slow mixing tank 50 via the sludge return pipe 6 2 may account for 20%, and the sludge introduced into the sludge concentration tank 6 6 via the sludge collecting pipe 64 may be Accounted for 80%. Finally, the treated water is discharged via the outlet pipe 70, and the turbidity (t u r b i d i t y ) of the treated water of the present invention can reach 1 〇 m g / L, and the water quality is very good. Furthermore, PAC is traditionally used to treat aluminum CMP wastewater. Since PAC will dissociate in water, the treated water will have high conductivity and require further processing. As for the present invention, the use of a polymer to treat copper CMP wastewater does not have a high conductivity problem with the treated water, and no further treatment for lowering the conductivity is required. In summary, the present invention dilutes the coagulant with a small amount of copper CMP wastewater, so that the coagulant can be more uniformly diffused, so that the coagulant can more effectively agglutinate with the wastewater. Furthermore, the present invention directs the sludge back into the slow mixing sedimentation tank, and the difficult-to-precipitate particles can be settled by the co-precipitation of the sludge to help the agglomeration of the particles in the wastewater. Therefore, the present invention can successfully treat copper CMP wastewater and make

0503-8388TWF1 · TSMC2002-0347 : Cathy.ptd Page 9 1254033 _ Case No. 91118654 修正 Amendment V. Description of invention (6) The turbidity of treated water is less than 1 〇 m g / L. BEST MODE FOR CARRYING OUT THE INVENTION Copper chemical mechanical polishing wastewater (C u - C Μ P wastewater) was treated using the apparatus shown in Fig. 1. The coagulant 3 2 used is a F S C ( Π 〇 c t a n t s t r ο n g c a t i ο η ) polymer coagulant which is allowed to flow into the mixing unit 30. The wastewater of 5% to 1% by volume of the total amount of Cu-CMP wastewater in the wastewater supply device 10 is taken into the mixing unit 30 to dilute the F S C polymer coagulant. Then, the diluted FSC polymer coagulant and the remaining large amount of Cu-CMP wastewater (i.e., 90% to 95% by volume of the total amount of Cu-CMP wastewater) are introduced into the reaction tank 40, respectively. Then, sodium hydroxide (N a 0 Η) and sulfuric acid (H 2 S 04) are injected into the reaction tank 40 to adjust the pH of the wastewater in the reaction tank 40 to pH 2 to 10-10. Then, the waste water in the reaction tank 40 is rapidly stirred for about 5 to 20 minutes to agglomerate the compound therein, particularly copper ions. Then, the agglomerate obtained in the reaction tank 40 is introduced into a slow mixing sediment tank 50. At this time, the polymer coagulant 52 is introduced into the slow-mixing precipitation tank 50, and mixed with the aggregating liquid to produce sludge. The sludge of 20% by weight of the total sludge discharged from the slow mixing tank 50 is led back to the slow mixing tank 50 via the sludge return pipe 6 2 to assist in the aggregation of the particles in the wastewater. Further, the remaining sludge discharged from the slow-mixing sedimentation tank 50 (i.e., the sludge of 80% by weight of the entire sludge) is introduced into the sludge concentration tank 66 via the sludge collecting pipe 64. The treated water discharged through the outflow pipe 70 is tested to find that the turbidity (Tu) of the treated water can reach 1 〇 mg/L, indicating that the water quality is very good.

0503-8388TWF1 ; TSMC2002-0347 ; Cathy.ptd Page 10 1254033 Case No. 91918654 Revision 5, Invention Description (7) Although the present invention has been disclosed in the preferred embodiments as above, it is not intended to limit the present invention. Any person skilled in the art will be able to make changes and refinements without departing from the spirit and scope of the invention, and the scope of the invention is defined by the scope of the appended claims.

0503-8388TWF1 ; TSMC2002-0347 : Cathy.ptd Page 11 1254033 Case No. 9Π18654 月 修正 Correction Schematic description of the drawings Fig. 1 is a schematic view showing an apparatus for treating copper chemical mechanical polishing wastewater according to a preferred embodiment of the present invention. Description of the label 10~ copper CMP wastewater supply device; 2 0~ waste water splitting device; 2 2~ pipeline; 2 4~ flow indicator; 26~ pipeline; 3 0~ mixing unit; 3 2~ coagulant; 4~first control unit; 36~ pipeline; 4 0~ reaction tank; 5 0~ slow mixing sedimentation tank; 5 2~ coagulant; 5 4~ second flow control unit 6 0~ sludge splitting device; 2 ~ sludge return pipe; 6 4 ~ sludge collection pipe; 6 6 ~ sludge concentration tank; 7 0 ~ outflow pipe.

0503-8388TWF1 ; TSMC2002-0347 ; Cathy.ptd Page 12

Claims (1)

...τ Case No. 91118654: V:: Years and months corrections 六 ϋ ϋ Μ Μ · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Waste water method 4 · Method for applying wastewater 5 · For example, the method of wastewater treatment is to guide the wastewater to a 10% by volume ratio. 6. The following steps: The method of wastewater treatment: The condensation of medium particles 7. The method of mixing waste water In the treatment of copper chemistry of copper chemical coagulant and inside, so that the waste water step is obtained, and the sludge is produced, and the scope of the patent is discharged, wherein the scope of the patent is mixed, wherein the scope of the patent is mixed, wherein the assistance The scope of the patent, which is used to enter the reaction tank) Please patent the range, in the agglomeration will be part of the sludge. The patent scope, wherein the guide body discharges all mechanical grinding wastewater, comprising: mechanically grinding wastewater to dilute a coagulant; a large amount of copper chemical mechanical polishing wastewater respectively and coagulating agent to generate agglutination reaction; Slowly mix the sedimentation tank with a mud; and treated water. The copper chemical mechanical polishing agent described in item 1 is a polymer. The copper chemical mechanical polishing agent described in item 2 is polyacrylamide. The copper chemical mechanical polishing agent described in item 1 is a polymer. The copper chemical mechanical polishing dilution coagulant described in item 1 is quantified by copper chemical mechanical research and development of a large amount of copper chemical mechanical polishing wastewater by 5% to the treatment of copper chemical mechanical polishing liquid introduced into the slow mixing precipitation tank After the inside, it also includes returning the slow mixing chamber to help the copper chemical mechanical grinding back to the slow mixing tank in the wastewater mentioned in item 6 to account for 10% to 30% of the slow sludge. %weight ratio. 0503-8388TWF] : TSMC2002-0347 : Cathy.ptd Page 13 Π 54033 Case No. 91118654 $ 'Application for Patent Range Month Revision 8. The method for treating copper chemical mechanical grinding wastewater as described in claim 7 After the diluted coagulant is introduced into a reaction tank, the method further comprises the steps of: adjusting the p Η value of the wastewater in the reaction tank to between 8 and 11. 9) The method for treating copper chemical mechanical polishing wastewater according to claim 8 of the patent application, after introducing the diluted coagulant into a reaction tank, further comprising the steps of: adjusting the pH of the wastewater in the reaction tank to 9 Between 10 and 10. 1 0 · A device for treating steel chemical mechanical grinding wastewater, comprising: a mixing unit for accommodating a coagulant and a predetermined amount of copper chemical mechanical grinding wastewater to make the coagulant diluted; Downstream of the mixing unit, the diluted coagulant and a large amount of steel chemical mechanical grinding wastewater are mixed to form an agglutination reaction; a slow mixing sediment tank is located downstream of the reaction tank to accommodate a help The coagulant and the waste water from the reaction tank are mixed to produce sludge; and an outflow pipe is located downstream of the slow mixing sedimentation tank for discharging the treated water from the slow mixing tank. 1 1 The apparatus for treating copper chemical mechanical polishing wastewater as described in claim 0, further comprising a first flow control unit located upstream of the mixing unit for controlling the flow of the coagulant to the mixing unit. 1 2 · The apparatus for treating copper chemical mechanical grinding wastewater according to claim 1 of the patent application, further comprising a second flow control unit located upstream of the slow mixing sedimentation tank for controlling the coagulant to the slow mixing The flow rate of the sedimentation tank. 1 3 ·Research on copper chemical mechanical research as described in item 1 of the patent application scope 0503-8388TWF1 ; TSMC2002-0347 ; Cathy.ptd Page 14 1254033 Case No. 91 1 18654 Lunar New Year Amendment Six, the application for patented range of wastewater treatment equipment, including: The mixing unit and the upstream of the reaction tank, divided into two The wastewater is passed to the mixed water to flow into the reaction tank. The copper chemical mechanical research and development wastewater separation device described in the above-mentioned item is located in the chemical mechanical grinding wastewater unit for copper, and is divided into a large amount of waste. The apparatus for the first grinding wastewater of the patent scope includes: The sludge return pipe is used to guide the sludge back into the slow mixing sedimentation tank to help agglomerate the particles in the wastewater. 1 5 . The apparatus for treating copper chemical mechanical polishing wastewater according to claim 10 of the patent scope, further comprising: downstream of the slow mixing sedimentation tank, which is to be introduced into two parts and separately introduced into a sludge to be part of The sludge is led back to the agglutination of the slow mix, and the sludge collection pipe can be used in a sludge concentration tank. a sludge splitting device, located in a sludge splitting pipe and a sludge collecting pipe discharged from the slow mixing sedimentation tank, wherein the sludge conducting pipe can be used in the sedimentation tank to help the waste water to contaminate another part Mud into one 0503-8388TWF1 : TSMC2002-0347 ; Cathy.ptd Page 15