JP4472391B2 - Method for recycling used semiconductor polishing slurry - Google Patents

Description

  The present invention relates to a method for regenerating a semiconductor polishing slurry (hereinafter abbreviated as polishing slurry) used in a polishing step in a semiconductor manufacturing process, and in particular, metal ions contained in a used semiconductor polishing slurry. The present invention relates to a method for regenerating a used semiconductor polishing slurry in which metal ions such as iron, aluminum, copper, nickel, zinc, chromium, manganese, and tungsten, particularly tungsten ions, are mainly removed with chelate fibers.

  The semiconductor manufacturing process includes a process for making basic materials and manufacturing apparatus members such as glass for wafers, liquid crystals and masks, and a device manufacturing process for processing these materials to form elements and patterns.

  In recent years, with the increase in the speed of computers, semiconductor integrated circuits (ICs) used in computers have been required to have a higher degree of integration. In order to adapt to such high integration of ICs, it is indispensable to adopt a multilayer laminated structure together with miniaturization of wiring patterns.

  In order to employ a multilayer stack structure, the unevenness of each layer of the wafer itself and the multilayer stack structure as a base material is made smaller than before, and the coverage (step coverage) at the step portion during film formation is deteriorated and lithography is performed. It is necessary to avoid problems such as fluctuations in the coating thickness of the photoresist in the process.

  In order to eliminate the unevenness of each layer of such a multilayer laminated structure, the wafer as a base material and the surface of each layer formed on the wafer are polished using a polishing slurry.

  In addition, when forming contact holes or via holes by CVD (chemical vapor deposition) using tungsten W, or when embedding copper Cu in the damascene structure by plating, a tungsten film or copper film formed on the surface is used. The tungsten film or copper film formed on the surface leaving only the hole part and the damascene structure part is polished until it is flush with the surrounding insulating film. In this case as well, polishing using a polishing slurry is performed. .

  In general, a polishing step in a semiconductor manufacturing process is performed by bringing the surface of a wafer attached to a spindle into contact with a polishing pad on the surface of a rotary table and rotating the rotary table while supplying polishing slurry to the contact portion.

  The polishing slurry used in the polishing process in the semiconductor manufacturing process disperses abrasives such as fumed silica in ultrapure water, and depending on the purpose, components such as oxidizing agents such as hydrogen peroxide, iron salts, organic acids, etc. A special composition in which is dissolved is used.

  The wafer after the polishing process is cleaned with ultrapure water, and the used polishing slurry is stored in a recovery tank together with the cleaning liquid.

For example, in Patent Document 1, the concentration of the used polishing slurry collected in the recovery tank is adjusted by removing excess water with a ceramic filter, and the ionic components are removed by an ion exchange resin or the like. Insufficient components are replenished, and excessive particles such as removed polishing debris are removed through a particle size adjusting filter and reused as a polishing slurry.
JP-A-11-010540 JP-A-9-314466

  In the conventional polishing slurry regeneration method described above, the ion exchange resin used to remove the ionic component has the advantage that metal ions can be removed relatively easily, but the ion exchange group is a sulfonic acid group (a sulfonyl group). Alternatively, since it is a carboxylic acid group (carboxyl group), it is highly pH-dependent and has very poor metal ion adsorption selectivity. For example, if an alkali metal ion such as sodium ion or potassium ion is present, There is a drawback that the removal efficiency of the metal ions is significantly reduced.

Furthermore, since the tungsten CMP slurry waste liquid has a pH of 3.0 to 3.2, there is a problem that silica may be aggregated when an ion exchange resin mixed with a cation and an anion is used. That is, the point at which the zeta potential of the SiO ₂ particles becomes 0 (isoelectric point) is around pH 5, and the ion-exchange resin has a slower ion capture rate than the chelate fiber, so that the ion exchange zone is near the isoelectric point. Therefore, in the vicinity of the isoelectric point, the particle diameter of the SiO ₂ particles increases and tends to aggregate.

  Further, the ion exchange resin also has a problem that silica particles are adsorbed and inhibit the ion exchange treatment.

  Patent Document 2 proposes a method of removing heavy metals in a semiconductor wafer polishing slurry using a chelate resin in order to improve the adsorption selectivity of metal ions.

  However, the chelate resin is in the form of beads or granules in which a chelate functional group is introduced into a polymer having a rigid three-dimensional crosslinked structure such as styrene-divinylbenzene, and selectively separates a trace amount of metal. Therefore, since the diffusion rate into the bead-like or granular chelate resin required for this is slow, there is a problem that the capture rate of metal ions is low.

  In other words, since the semiconductor polishing slurry contains a high concentration of abrasive and pH adjuster reaching several percent, a very small amount from the semiconductor polishing slurry with a chelate resin developed for selective separation in a general aqueous system. Even if the metal is selectively separated, there is a problem that the efficiency is deteriorated as a result.

  In response to this point, the present applicants previously proposed a polishing slurry refining material in which a functional group having a metal chelate-forming ability is immobilized on at least the surface of a fiber substrate, and applied for a patent ( Japanese Patent Application No. 2003-074581).

  The fiber base material (hereinafter abbreviated as chelate fiber) to which the functional group having the metal chelate-forming ability is immobilized has a large contact specific surface area per weight with the polishing slurry, so that the capture rate of metal ions is very high. However, there are disadvantages in that the performance tends to deteriorate and the pot life is short.

  As a result of diligent research to eliminate such difficulties, the present inventors have obtained the knowledge that the short lifetime of the chelate fiber is due to the oxidant dissolved in a small amount in the polishing slurry. That is, an oxidizing agent such as hydrogen peroxide is dissolved in a polishing slurry, particularly a polishing slurry for grinding a tungsten film, in order to oxidize the tungsten surface and facilitate polishing. The oxidizing agent acted on the functional group of the chelate fiber to deteriorate the metal ion capturing ability.

  The present invention has been made on the basis of such knowledge, and by removing the metal ions contained in the slurry by bringing the used semiconductor polishing slurry into contact with the chelate fiber, and adjusting the abrasive concentration and composition. In the method for regenerating a spent semiconductor polishing slurry, the slurry is subjected to an oxidant decomposition treatment before contacting the used semiconductor polishing slurry with a chelate fiber.

  In the present invention, the polishing slurry to be regenerated is as disclosed in JP-A-10-265766 and JP-A-11-116948, and specifically, for example, 0.02 μm or more. Particle size distribution (median diameter) Dispersed or dissolved components of fumed silica fine particles with a volume standard of about 0.15 μm and oxidizers such as hydrogen peroxide, ferric nitrate, organic acids and amino acids in water Is the target.

The following shows an example of the composition of the slurry before polishing.
Specific gravity 1.03
pH 2.0-2.2
Average particle size [μm] 0.14-0.15
W concentration [ppm] <10
Fe concentration [ppm] 60
Ti concentration [ppm] <0.1
B Concentration [ppm] <0.2
Na concentration [ppm] <0.1
Mg concentration [ppm] 0.6
Al concentration [ppm] 0.1
K concentration [ppm] <0.1
Ca concentration [ppm] 0.1
Mn concentration [ppm] 0.1
Cr concentration [ppm] 0.1
Mn concentration [ppm] 0.1
Ni concentration [ppm] <0.1
Cu concentration [ppm] <0.5
Zn concentration [ppm] <0.1
Pb concentration [ppm] <1
Co concentration [ppm] <0.1
Zr concentration [ppm] <0.1
Cr concentration [ppm] <10
TOC concentration [ppm] 160-230

  When the polishing slurry having the above composition is used in a polishing process, the concentration of a specific metal ion increases depending on the composition of the object to be polished, and in a state where the slurry is recovered in a recovery tank, cleaning water is also recovered. Therefore, it is diluted to lower the overall concentration.

  As the ceramic filter used for concentration of the used polishing slurry in the present invention, for example, a ceramic filter having a pore diameter of about 0.05 μm is used. When the used polishing slurry is passed through this ceramic filter, water and a part of the dissolved components are removed by passing through the pores of the ceramic filter, and the specific gravity of the used polishing slurry, which was 1.003, is 1. .033.

The hydrogen peroxide decomposition treatment in the present invention is performed, for example, by the following method.
1) Irradiate the used polishing slurry with ultraviolet rays.
2) Contact the used polishing slurry with an oxidant decomposition catalyst.
3) The used polishing slurry is irradiated with ultraviolet rays and brought into contact with an oxidant decomposition catalyst.

  Usually, about 0.1 to 0.2% of hydrogen peroxide is dissolved in a used polishing slurry obtained by polishing a tungsten plug, but ultraviolet light having a wavelength of 254 nm is applied at 16 W per liter of the polishing slurry. When irradiated for 100 minutes, the hydrogen peroxide concentration is almost 0%. Further, as the hydrogen peroxide decomposition catalyst, activated carbon or other known catalysts can be used.

  In addition, also when ozone is used as an oxidizing agent added to a slurry, it can decompose | disassemble by the same method.

  The chelate fiber used in the present invention is obtained by immobilizing a functional group having a metal chelate forming ability on a fiber material, and has a high contact efficiency with metal ions, so that the capture rate of metal ions is very high. It has characteristics.

  Examples of the functional group having the ability to form a metal chelate immobilized on the fiber substrate in the present invention include aminocarboxylic acids (including aminopolycarboxylic acids), amines, hydroxylamines, phosphoric acids, and thio compounds. Groups are preferred. Of aminocarboxylic acids, iminoacetic acid and aminoacetic acid are used as aminomonocarboxylic acids, and nitrilotriacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, and glutamic acid are used as aminopolycarboxylic acids. Examples include diacetic acid, ethylenediamine disuccinic acid, and iminodiacetic acid. Examples of amines include ethylenediamine, diethylenetriamine, triethylenetetramine, polyethylene polyamine, polyethyleneimine, polyallylamine, pyrrole, polyvinylamine, and Schiff base. Examples of hydroxylamines include oxime, amidooxime, oxine (8-oxyquinoline), glucamine, dihydroxyethylamine, and hydroxamic acid. Examples of phosphoric acids include aminophosphoric acid and phosphoric acid. Examples of thio compounds include thiol, thiocarboxylic acid, dithiocarbamic acid, and thiourea.

  The type of the polymer used as a base material for the chelate-forming fiber used in the present invention is not particularly limited, and a material capable of being fiberized and having a metal chelate-forming ability introduced therein can be used alone or in combination. To use. For example, cellulose, polyvinyl alcohol, polyethyleneimine, polyester, polyvinyl chloride, polyacrylonitrile, polyamide, polyolefin and the like.

  Examples of the fibers used for the substrate include long-fiber monofilaments, multifilaments, short-fiber spun yarns, fabrics obtained by weaving or knitting these in a woven or knitted shape, and non-woven fabrics. It is also possible to use a fiber or a woven / knitted fabric obtained by compounding or blending fibers. Considering the contact efficiency with metal ions and the capturing speed as described above, the fiber used, particularly the single fiber diameter as a long fiber is preferably 1 to 500 μm, more preferably 5 to 200 μm, and the length is 10 mm. Longer ones are suitable.

  Furthermore, in order to increase the contact efficiency with the polishing slurry to be treated, it is also effective to use the base fiber in the form of short fibers. The preferable shape of the short fiber used here is 0.05 to 10 mm in length, preferably 0.1 to 3 mm, the single fiber diameter is about 1 to 500 μm, preferably 5 to 200 μm, and the aspect ratio is 1 About 1 to 600, preferably about 1.5 to 100. If necessary, a long fiber of more than 5 mm can be used.

  The long fiber type material has a feature that it can be easily processed into a sheet shape or a felt shape, while the short fiber type has a feature that the contact efficiency with the polishing slurry is higher than that of the long fiber type. When these characteristics are taken into consideration, the short fiber type is preferably used for the purpose of removing extremely low concentration metal ions in the polishing slurry as in the polishing process of wafer production. Further, in the polishing process of wafer manufacturing such as the CMP process of device manufacturing, it is not necessary to remove metal ions to a very low concentration (the metal ion concentration in the polishing slurry is generally 100 times or more), and chelate formation The long fiber type, which is easy to process so as to be easy to handle, is preferred for demands that require a large amount of metal ions to be loaded on the conductive fiber and the exchange frequency is relatively high.

  In any case, virtually all of the chelate-forming functional groups introduced on the surface of thin fiber molecules effectively act to capture metal ions, so that it exhibits superior metal ion scavenging ability compared to chelate resins. To do.

  Moreover, it is also possible to use what made at least 1 part of the said acid type functional group alkali metal salt or ammonium salt according to pH of the semiconductor polishing slurry to process.

  The semiconductor polishing slurry refining material can be used alone, but depending on the properties of the semiconductor polishing slurry to be treated and the type of metal to be captured, different chelate-forming functional groups or Two or more kinds of different fiber base materials / shapes may be combined and laminated or mixed to form a layer.

  As a specific form applied to the method for purifying a semiconductor polishing slurry of the present invention, a module in which a container is fixedly filled with the above-mentioned chelating fibers for purification of a semiconductor polishing slurry. In this case, the semiconductor-forming slurry-purifying chelate-forming fiber is formed into a sheet or felt shape, placed in the flow path of the semiconductor polishing slurry, and the semiconductor polishing slurry is added to the fiber material formed into the sheet shape or felt shape. You may make it let liquid flow.

  Further, as another form, for example, short fiber-like chelate-forming fibers are filled so as to be flowable into a container having an inlet and an outlet of an abrasive slurry, and are not discharged out of the container with a filter or a strainer. Can be mentioned.

  In either method, while removing the metal ions present in the semiconductor polishing slurry to be processed, all the processed polishing slurry is supplied to the semiconductor polishing step, or at least part or all of the original polishing slurry is supplied to the original polishing slurry. After re-introducing into the semiconductor polishing slurry and circulation to further increase the metal ion removal level, the slurry can be supplied to the semiconductor polishing process.

  In this way, the used polishing slurry that has been subjected to concentration adjustment and removal of ionic components lacks additional components, such as consumption in the polishing process and removal as ionic components. It is necessary to do. Although the addition of such a deficient component can be added individually, it is not preferable to arrange a large number of pipes and nozzles for replenishing additives in the regeneration process in order to make the apparatus compact.

  Therefore, in the present invention, after the used polishing slurry is brought into contact with the chelate fiber, the composition is adjusted in advance so that the used polishing slurry has almost the same composition as the unused semiconductor polishing slurry. It is desirable to perform correction by adding a predetermined amount of the correction liquid. In determining the composition of the correction liquid, it is necessary to know the composition of the used polishing slurry after being brought into contact with the chelate fiber, but this composition can also be measured continuously or intermittently by a sensor or the like. However, when the same polishing operation is continuously performed over a long period of time, the composition of the polishing slurry is previously measured in detail by an analytical method, and based on the measurement result, an unused polishing slurry is added. The required amount may be adjusted in advance by determining the composition of the correction liquid having the same composition. The correction liquid may be adjusted to have the same composition as the unused polishing slurry by adding the same amount as that of the used polishing slurry, or the polishing liquid that is unused in a smaller amount or a larger amount. You may adjust so that it may become the same composition as the slurry for use. At this time, unused polishing slurry may also be replenished.

  According to this method, the correction liquid can be added with one pipe and one valve, so that the equipment can be simplified and reduced in size, and maintenance and control are facilitated.

  The regenerated polishing slurry which has been adjusted is reused by removing coarse abrasives and shavings through a particle size adjusting filter.

  In the semiconductor manufacturing process, especially in the process of polishing a hard metal surface, such as the polishing process of a semiconductor having a tungsten plug, the tungsten surface is oxidized by dissolving an oxidizing agent such as hydrogen peroxide in the polishing slurry. Polishing is performed.

  When the polishing slurry used in such a polishing step is recycled and brought into contact with the chelate fiber, the functional group having the chelate-forming ability of the chelate fiber is oxidized and the metal ion removal performance deteriorates.

According to the present invention, since the used semiconductor polishing slurry is brought into contact with the oxidant decomposition catalyst or irradiated with ultraviolet rays and then brought into contact with the chelate fiber to remove metal ions, the chelate fiber has The functional group having chelate-forming ability is not deteriorated by the action of the oxidizing agent, and the chelate fiber has a high ion capture rate and immediately passes near the isoelectric point, so that SiO ₂ is less likely to cause aggregation of fine particles. Over time, good metal ion removal performance is maintained.

  As described above, according to the present invention, since the metal ions are removed from the used polishing slurry by using the chelate fiber, the oxidizing agent contained in the used polishing slurry is decomposed. The deterioration of the chelate fiber is suppressed, the metal ion removal performance can be maintained in a good state for a long time, and the pot life can be extended.

  Next, embodiments of the present invention will be described.

FIG. 1 is a configuration diagram of a first embodiment of the present invention.
This embodiment is composed of a tank 1 for storing used polishing slurry, cleaning waste liquid after polishing, etc., a ceramic filter (or acid resistant) having a pore diameter of 0.05 μm that concentrates by removing moisture from the used polishing slurry. Organic film) 2, a tank with an ultraviolet device (or a tank with an oxidizer decomposition device) 3 equipped with an ultraviolet irradiation device with a wavelength of 254 nm, a chelate fiber treatment device 4, a composition adjustment tank 5 and a particle size adjustment filter 6 in the flow path. Along the way, they are installed in order.

  In this embodiment, the polishing slurry or the like supplied to the tank 1 is sent to the ceramic filter 2, and excess moisture is filtered and concentrated in the process of passing through the ceramic filter 2.

  Next, this polishing slurry is sent to the tank 3 with an ultraviolet device, where hydrogen peroxide dissolved in about 0.1 to 0.2% is decomposed. Then, the polishing slurry from which the hydrogen peroxide has been removed is sent to the chelate fiber treatment device 4 where the metal ions and organic ions are removed, and further added in advance in the composition adjusting tank 5 so as to be the same as the unused polishing slurry. An amount of correction liquid having the same composition and pH is added, and finally, particles having an excessive particle size are removed by the particle size adjusting filter 6 and supplied again to the polishing apparatus as a slurry for regenerated polishing.

  The tank 3 with an ultraviolet device may be a tank provided with a catalyst for catalytically decomposing an oxidant.

The above is an example in which the used polishing slurry is concentrated and then metal ions are removed, but the present invention is not limited to such a configuration example. For example, the following configuration can be adopted.
○ Tank 1 → Tank with UV irradiation device (or tank with oxidizer decomposition device) 3 → Filter → Ceramic filter (or acid-resistant organic film) 2 → Chelate fiber treatment device 4 → Composition adjustment tank 5 → Particle size adjustment filter 6
In the case of this configuration, W colloidalized by ultraviolet irradiation and hydrogen peroxide is removed by a filter, so that the load on the chelate fiber treatment device is reduced.

Moreover, the following structure can also be taken as needed.
○ Tank 1 → Tank with UV irradiation device (or tank with oxidizer decomposition device) 3 → Ceramic filter (or acid-resistant organic film) 2 → Chelate fiber treatment device 4 → Composition adjustment tank 5 → Particle size adjustment filter 6
○ Tank 1 → Tank with UV device (or tank with oxidizer decomposition device) 3 → Chelate fiber treatment device 4 → Ceramic filter (or acid-resistant organic film) 2 → Composition adjustment tank 5 and particle size adjustment filter 6

  Next, examples embodying the present invention will be described.

The drainage of the abrasive used in the flattening process was regenerated as follows.
Water and the silica abrasive in the abrasive were separated by a ceramic filter membrane (hereinafter referred to as a filter) made of Al ₂ O ₃ as a support and coated with ZrO ₂ on the surface. The pore size of this filter is 0.05 μm. By using this filter, the abrasive density of the abrasive drainage liquid is increased. That is, the abrasive grains are concentrated. The circulating flow rate to the ceramic filter is 4 m / sec per ceramic filter, and about 35 L / h of permeated water can be obtained. The permeated water was drained during this regeneration operation.

The decomposition and removal of H ₂ O ₂ contained in the abrasive drainage was performed using an ultraviolet irradiation facility (hereinafter referred to as UV) capable of irradiating a wavelength of 0.25 μm. The UV lamp used was 16W. The H ₂ O ₂ concentration in the drainage liquid of 1 L abrasive is about 0.2 wt%. The H ₂ O ₂ concentration was determined by diluting the abrasive effluent and exposing it to a hydrogen peroxide test paper (0-50 ppm measurable) by changing the color. The H ₂ O ₂ could be completely decomposed to 0% by irradiation with UV for about 100 minutes. Incidentally, in this embodiment, to see the relationship between the degradation of the ultraviolet irradiation time and H ₂ O _2, was measured for the concentration of H ₂ O ₂ for every predetermined time has elapsed from the start of irradiation, after 30 minutes 0.1 %, 0.05% after 60 minutes, and 0.15% after 80 minutes.

The removal of tungsten (hereinafter referred to as W) impurities contained in the abrasive drainage liquid uses chelate fibers. The chelate fiber used is a fiber described in Japanese Patent Application No. 2003-074581. The W impurity concentration in the abrasive drainage is about 50 to 180 ppm. 5 kg of chelate fiber CG-50 was packed in a cylindrical container of 150φ length 850 mm. This product (metrate) was passed at a flow rate of 0.3 L / min to remove W impurities to <10 ppm. In the analysis of W concentration, after removing silica abrasive grains with a UF film, the sample is sent to inductively coupled plasma to ionize and measure the spectrum of Auger electrons emitted (ICP-AES).
Thereafter, ferric nitrate, organic acid, and amino acid were added to the metrate treatment solution. Further, 30 L of a new abrasive was added and the pH was measured after stirring. HNO ₃ was added to adjust to pH 2.0-2.2. After the chemical was added, the particle size was adjusted using a CMPure 205 (2 μm removed by 50%, 5 μm removed by 90%) filter. Circulation was performed at a flow rate of 7 L / min, and processing was performed in which 100 L abrasive was changed 50 times.

  After regeneration of the abrasive, the liquid was sampled, the particle size distribution was measured with LA-920 manufactured by HORIBA, and the number of particles of 0.5, 1.0 μm or more was measured with Accusizer-780 manufactured by ParticleSizing System.

As a result of analyzing the back liquid from which the silica abrasive grains were removed with the UF film by ICP-AES, the metal impurity concentration was the same as that of the new abrasive as shown in Table 1 below, and the amount of metal impurities was the same. there were.

It is a block diagram which shows the structure of one embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Tank, 2 ... Ceramic filter, 3 ... Tank with ultraviolet device, 4 ... Chelate fiber processing apparatus, 5 ... Composition adjustment tank, 6 ... Grain size adjustment filter

Claims (9)

In the method for reclaiming a used semiconductor polishing slurry, which comprises contacting the used semiconductor polishing slurry with a chelate fiber to remove metal ions contained in the slurry, and adjusting the concentration and composition of the abrasive.
A method for regenerating a used semiconductor polishing slurry, comprising subjecting the used slurry for polishing a semiconductor to an oxidant decomposition treatment before contacting the used slurry with a chelate fiber.   2. The used semiconductor polishing according to claim 1, wherein the oxidizing agent decomposition treatment comprises contacting the used semiconductor polishing slurry with an oxidizing agent decomposition catalyst and / or irradiating the used semiconductor polishing slurry with ultraviolet rays. 3. Slurry regeneration method.   The composition adjustment is performed in advance so that the used semiconductor polishing slurry is brought into contact with the chelate fiber, and then the used semiconductor polishing slurry has almost the same composition as the unused semiconductor polishing slurry. The method for reclaiming a used semiconductor polishing slurry according to claim 1 or 2, which is performed by adding a correction liquid.   The composition adjustment is performed in advance so that the used semiconductor polishing slurry is brought into contact with the chelate fiber, and then the used semiconductor polishing slurry has almost the same composition as the unused semiconductor polishing slurry. The method for reclaiming a used semiconductor polishing slurry according to claim 1 or 2, which is carried out by adding a correction fluid and an unused semiconductor polishing slurry.   5. The used semiconductor polishing according to claim 1, wherein the adjustment of the abrasive concentration is performed by passing a used semiconductor polishing slurry through a ceramic filter and filtering a part of the dispersion medium. Slurry regeneration method. A concentration step of removing a part of the dispersion medium with respect to the abrasive by passing the used semiconductor polishing slurry through a ceramic filter or an organic film;
Contacting the used semiconductor polishing slurry that has undergone the concentration step with an oxidant decomposition catalyst and / or irradiating the used semiconductor polishing slurry with ultraviolet rays; and
A metal ion removing step of bringing the used semiconductor polishing slurry that has undergone the oxidant decomposition step into contact with the chelate fiber;
A correction liquid and / or a composition adjusted in advance so that the used semiconductor polishing slurry that has undergone the metal ion removal step has the same composition as that of the unused semiconductor polishing slurry. A composition adjustment step of adding a correction liquid and an unused semiconductor polishing slurry at a predetermined ratio;
A method for regenerating a used semiconductor polishing slurry, comprising: a particle size adjusting step of filtering the used semiconductor polishing slurry that has undergone the composition adjusting step with a particle size adjusting filter. Contacting the used semiconductor polishing slurry with an oxidant decomposition catalyst and / or irradiating the used semiconductor polishing slurry with ultraviolet rays; and
Metal ion removal step of bringing the used semiconductor polishing slurry that has undergone the oxidant decomposition step into contact with the chelate fiber,
A concentration step of removing a part of the dispersion medium by passing the used semiconductor polishing slurry that has undergone the metal ion removal step through a ceramic filter or an organic film;
Correction liquid and / or correction that has been pre-adjusted to the used semiconductor polishing slurry that has undergone the concentration step so that the used semiconductor polishing slurry has substantially the same composition as the unused semiconductor polishing slurry. A composition adjusting step of adding a liquid and unused semiconductor polishing slurry at a predetermined ratio;
A method for regenerating a used semiconductor polishing slurry, comprising: a particle size adjusting step of filtering the used semiconductor polishing slurry that has undergone the composition adjusting step with a particle size adjusting filter. Contacting the used semiconductor polishing slurry with an oxidant decomposition catalyst and / or irradiating the used semiconductor polishing slurry with ultraviolet rays; and
A filtration step of filtering the used semiconductor polishing slurry that has undergone the oxidant decomposition step with an oxidation-resistant filter capable of removing aggregated particles;
A concentration step of removing a part of the dispersion medium by passing the used semiconductor polishing slurry that has undergone the filtration step through a ceramic filter or an organic film;
Metal ion removal step of bringing the used semiconductor polishing slurry that has undergone the concentration step into contact with the chelate fiber;
A correction liquid and / or a composition adjusted in advance so that the used semiconductor polishing slurry that has undergone the metal ion removal step has substantially the same composition as the unused semiconductor polishing slurry. A composition adjustment step of adding a correction liquid and an unused semiconductor polishing slurry at a predetermined ratio;
A method for regenerating a used semiconductor polishing slurry, comprising: a particle size adjusting step of filtering the used semiconductor polishing slurry that has undergone the composition adjusting step with a particle size adjusting filter. Contacting the used semiconductor polishing slurry with an oxidant decomposition catalyst and / or irradiating the used semiconductor polishing slurry with ultraviolet rays; and
A concentration step of removing a part of the dispersion medium by passing the used semiconductor polishing slurry that has undergone the oxidant decomposition step through a ceramic filter or an organic film;
Metal ion removal step of bringing the used semiconductor polishing slurry that has undergone the concentration step into contact with the chelate fiber;
A correction liquid and / or a composition adjusted in advance so that the used semiconductor polishing slurry that has undergone the metal ion removal step has substantially the same composition as the unused semiconductor polishing slurry. A composition adjustment step of adding a correction liquid and an unused semiconductor polishing slurry at a predetermined ratio;
A method for reclaiming a used semiconductor polishing slurry, comprising: a particle size adjusting step of filtering the used semiconductor polishing slurry that has undergone the composition adjusting step with a particle size adjusting filter.

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