Processed liquid evaluation method, processed liquid management method, processed liquid evaluation device, and processor

Abstract

To provide a processed liquid evaluation method with which it is possible to quickly manage whether a non-volatile impurity is included in a processed liquid processed by a filter device.SOLUTION: A processed liquid evaluation method includes a step of measuring, with a charged particle detector 16, a non-volatile impurity in a filter-processed liquid obtained by passing liquid to be processed through a filter device 10, and managing the non-volatile impurity in the filter-processed liquid.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for evaluating a treatment liquid, a method for managing a treatment liquid, an apparatus for evaluating a treatment liquid, and a treatment apparatus. [Background technology]

[0002] Filter devices are used, for example, to purify water, such as ultrapure water, and organic solvents used in semiconductor manufacturing processes. When a new filter is installed in a filter device and the flow of the liquid to be treated is started, or when the flow of the liquid to be treated is stopped and then resumed after a while, nonvolatile impurities may be mixed into the treated liquid from the filter inside the filter device, making it essential to manage the nonvolatile impurities in the treated liquid. Nonvolatile impurities that may be mixed into the treated liquid from the filter include metals, organic matter, and fine particles. Of these nonvolatile impurities, ICP-MS (inductively coupled plasma mass spectrometry) is typically used to analyze metals, GC (gas chromatography) is used to analyze organic matter, and a particle counter is typically used to analyze fine particles.

[0003] As described above, analyzing nonvolatile impurities in a treatment liquid requires multiple analytical instruments, and depending on the type of nonvolatile impurity, the analysis may take a long time. Therefore, in the past, it was difficult to quickly determine whether or not nonvolatile impurities were present in a treatment liquid treated by a filter device. The degree of contamination of each impurity in the treatment liquid varies over time. For example, at the start of the treatment liquid flow, organic matter and metals may be present in the treatment liquid. However, after a certain time has passed since the start of the treatment liquid flow, the organic matter may no longer be present, while the metals may still be present. Therefore, even if only organic matter is analyzed using an analytical instrument capable of relatively rapid analysis (e.g., GC), it may not be possible to determine whether or not nonvolatile impurities are present in the treatment liquid. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Chromatographic Science Journal, CHROMATOGRAPHY, Vol. 32 No. 3, pp. 161-170, 2011 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present disclosure is to enable quick management of whether or not nonvolatile impurities are contained in a treatment liquid that has been treated by a filter device. [Means for solving the problem]

[0006] A method for evaluating a treated liquid according to one aspect of the present disclosure is characterized by comprising a step of measuring non-volatile impurities in a filtered liquid obtained by passing a liquid to be treated through a filter device using a charged particle detector, and managing the non-volatile impurities in the filtered liquid.

[0007] In the above-described method for evaluating a treated liquid, it is preferable that the step includes passing the filtered liquid through a liquid chromatography column, and introducing the treated liquid discharged from the liquid chromatography column into the charged particle detector.

[0008] In the above-described method for evaluating a treated liquid, it is preferable that in the step, the filtered liquid is introduced directly into the charged particle detector without being passed through a liquid chromatography column.

[0009] In the above-described method for evaluating a treatment liquid, it is preferable that the nonvolatile impurities are quantified from the measurement results of the charged particle detector using a calibration curve method.

[0010] Furthermore, a method for managing a treatment liquid, which is one aspect of the present disclosure, is characterized in that it manages the start-up conditions of the filter device based on the measurement results of the charged particle detector obtained by the method for evaluating the treatment liquid or the quantification results of the non-volatile impurities obtained by the method for evaluating the treatment liquid.

[0011] Furthermore, a method for managing a treatment liquid according to one aspect of the present disclosure is characterized in that, when the measurement result of the charged particle detector obtained by the treatment liquid evaluation method or the quantification result of the non-volatile impurities obtained by the treatment liquid evaluation method is equal to or greater than a predetermined value, the start-up operation of the filter device is continued, and when the measurement result of the charged particle detector obtained by the treatment liquid evaluation method or the quantification result of the non-volatile impurities obtained by the treatment liquid evaluation method is less than a predetermined value, the start-up operation of the filter device is terminated.

[0012] Furthermore, a treatment liquid evaluation device according to one aspect of the present disclosure is characterized by including a charged particle detector that measures non-volatile impurities in a filtered liquid obtained by passing a liquid to be treated through a filter device.

[0013] Furthermore, a processing device according to one aspect of the present disclosure is characterized in that it comprises a filter device through which the liquid to be processed is passed, and a charged particle detector that measures non-volatile impurities in the filtered liquid obtained by passing the liquid to be processed through the filter device. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to quickly manage whether or not impurities are contained in the treatment liquid that has been treated by the filter device. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a processing apparatus according to an embodiment of the present invention. [Figure 2] FIG. 1 is a block diagram showing a configuration of a charged particle detector. [Figure 3]FIG. 10 is a diagram showing the transition of peak areas in the spectrum obtained by measuring the filtered liquid with a charged particle detector. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes an embodiment of the present invention. The embodiment is an example of implementing the present invention, and the present invention is not limited to the embodiment.

[0017] Fig. 1 is a schematic diagram showing an example of a processing apparatus according to this embodiment. The processing apparatus 1 shown in Fig. 1 includes a filter device 10 and a processing liquid evaluation device 12. A pipe 14a is connected to the inlet of the filter device 10, and a pipe 14b is connected to the outlet of the filter device 10. The processing liquid evaluation device 12 includes a charged particle detector 16, and a pipe 14c branching from the pipe 14b is connected to the charged particle detector 16.

[0018] The treatment process for a liquid to be treated using the treatment device 1 shown in Figure 1 will be described. The liquid to be treated contains impurities that can be removed by the filter device 10, such as ionic impurities and fine particles. The liquid to be treated is passed through the filter device 10 via pipe 14a. At this time, the liquid to be treated is filtered by the filter installed in the filter device 10, and the impurities in the liquid to be treated are removed. The liquid to be treated from which the impurities have been removed is discharged from the filter device 10 to pipe 14b as a treated liquid (hereinafter referred to as the filtered liquid).

[0019] The liquid to be treated is not particularly limited, and examples thereof include water, sugar solutions, organic solvents, etc. Examples of organic solvents include alcohols such as isopropyl alcohol, methanol, and ethanol; ketones such as cyclohexanenone, methyl isobutyl ketone, acetone, and methyl ethyl ketone; alkene-based organic solvents such as 2,4-diphenyl-4-methyl-1-pentene and 2-phenyl-1-propene; N-methylpyrrolidone; and mixed organic solvents thereof. The organic solvent may be either a polar organic solvent or a nonpolar organic solvent. Furthermore, the polar organic solvent may be either a protic polar organic solvent or an aprotic polar organic solvent.

[0020] The liquid to be treated contains metal impurities such as elements such as Li, B, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Mo, Ag, Cd, Sn, Sb, Ba, W, Au, Pb, and Pt, and these metal impurities exist in the form of ionic impurities, colloidal or monodispersed fine particles, or complexes. The water to be treated also contains anionic impurities such as sulfate ions, nitrate ions, chloride ions, boron, fluorine, and organic acids such as formic acid and acetic acid.

[0021] The material of the filter installed in the filter device 10 is not particularly limited, and known materials can be used. Examples of resins include polyamides such as nylon (e.g., 6-nylon and 6,6-nylon); polyolefins such as polyethylene (e.g., UPE: ultra-high molecular weight polyethylene, HDPE: high-density polyethylene) and polypropylene; polystyrene; polyimide; polyamideimide; poly(meth)acrylate; polyfluorocarbons such as polytetrafluoroethylene, perfluoroalkoxyalkane, perfluoroethylenepropene copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, polychlorotrifluoroethylene, polyvinylidene fluoride, and polyvinyl fluoride; polyvinyl alcohol; polyester; cellulose; cellulose acetate; and the like. These polymers can be used alone or in combination of two or more. In addition to resins, diatomaceous earth, glass, and the like may also be used. Alternatively, a polymer (such as nylon-grafted UPE) in which polyamide (such as nylon-6 or nylon-6,6) is graft-copolymerized onto polyolefin (such as UPE (ultra-high molecular weight polyethylene)) may be used as the filter material.

[0022] The filter may be a surface-treated filter. The surface treatment method is not particularly limited, and known methods can be used. Examples of surface treatment methods include chemical modification treatment, plasma treatment, hydrophobic treatment, coating, gas treatment, and sintering.

[0023] Plasma treatment is preferred because it hydrophilizes the filter surface. The water contact angle on the filter surface hydrophilized by plasma treatment is not particularly limited, but the static contact angle at 25°C measured with a contact angle meter is preferably 60° or less, more preferably 50° or less, and even more preferably 30° or less.

[0024] The chemical modification treatment is preferably a method of introducing ion exchange groups into the filter. That is, the filter is preferably a filter having ion exchange groups. Examples of the ion exchange groups include cation exchange groups and anion exchange groups. Examples of the cation exchange groups include sulfonic acid groups, carboxyl groups, and phosphate groups, and examples of the anion exchange groups include quaternary ammonium groups.

[0025] The method for introducing ion exchange groups is not particularly limited, but may involve irradiating the filter with ionizing radiation (such as α-rays, β-rays, γ-rays, X-rays, and electron beams) to generate active moieties (radicals). After this irradiation, the filter is immersed in a monomer-containing solution to graft polymerize the monomer onto the filter. As a result, the polymer obtained by polymerization of the monomer is grafted onto the filter. The generated polymer can be contacted with a compound containing anion exchange groups or cation exchange groups to introduce ion exchange groups into the polymer.

[0026] The pore size of the filter is not particularly limited, and may be, for example, in the range of 1 nm to 300 nm, 1 nm to 200 nm, 1 nm to 20 nm, 1 nm to 10 nm, or 1 nm to 5 nm.

[0027] Examples of the filter include a porous membrane formed by sintering powder of resin or the like, and a fiber membrane formed by a method such as electrospinning, electroblowing, or meltblowing.

[0028] The filtered liquid obtained from the filter device 10 may contain nonvolatile impurities. For example, when a new filter is installed in the filter device and the flow of the liquid to be treated is started, or when the flow of the liquid to be treated is stopped and then resumed after a while, nonvolatile impurities adhering to the filter may be mixed into the filtered liquid, or nonvolatile impurities may be eluted from the filter and mixed into the filtered liquid. Furthermore, nonvolatile impurities may be mixed into the filtered liquid if the liquid to be treated contains a large amount of nonvolatile impurities. Therefore, it is important to manage the impurities in the filtered liquid in order to use a purified filtered liquid with few impurities. Nonvolatile impurities that may be mixed into the filtered liquid include metals, organic matter, and fine particles.

[0029] The following describes a method for evaluating the treated solution to control non-volatile impurities in the filtered treated solution.

[0030] A portion of the filtered liquid discharged from the filter device 10 passes through a pipe 14c and is introduced into a charged particle detector 16. Non-volatile impurities in the filtered liquid are measured by the charged particle detector 16.

[0031] FIG. 2 is a block diagram showing the configuration of a charged particle detector. The configuration of the charged particle detector shown in FIG. 2 is an example, and is not limited thereto; conventionally known charged particle detectors can be used. The charged particle detector 16 shown in FIG. 2 includes a nebulizer 20, a drying tube 22, a mixing chamber 24, a collector 26, an electrometer 28, and a detection unit 30. Measurement of nonvolatile impurities using the charged particle detector 16 is performed, for example, as follows: The filtered liquid discharged from the filter device 10 is atomized by the nebulizer 20 with nitrogen or air, preferably nitrogen, as a carrier gas, to form droplets. The droplets are sent to the drying tube 22, and as they pass through the drying tube 22, the solvent in the droplets evaporates, forming residual particles of the nonvolatile impurities in the droplets. The residual particles are sent to the mixing chamber 24, where they collide with positively charged nitrogen gas and become positively charged. The stream of positively charged residual particles moves to collector 26, where the charge imparted to the residual particles is measured as a current value by electrometer 28. Then, detection unit 30 creates and stores a spectrum with the retention time on the horizontal axis and the current value (signal intensity) detected by the electrometer on the vertical axis.

[0032] Since the current value measured by the electrometer is proportional to the amount of detected residual particles, i.e., the total amount of nonvolatile impurities (total amount of metals, organic matter, fine particles, etc.), the presence or absence of nonvolatile impurities in the filtered solution can be monitored by the area of ​​the peaks in the spectrum generated by the detection unit 30. Specifically, the area of ​​the peaks in the spectrum generated by the detection unit 30 is calculated. The peak area is then compared with a preset value. If the peak area is equal to or greater than the preset value, it is determined that nonvolatile impurities are present in the filtered solution. If the peak area is less than the preset value, it is determined that nonvolatile impurities are not present in the filtered solution. Such monitoring of nonvolatile impurities in the filtered solution based on the measurement results (i.e., peak areas) from the charged particle detector 16 can be performed by an operator, or by a computing device provided in the processed solution evaluation device 12.

[0033] By using the charged particle detector 16, metals, organic matter, particulates, and the like can be measured as nonvolatile impurities as a whole, eliminating the need for multiple analyzers. Furthermore, the measurement time is short. Therefore, based solely on the measurement results of nonvolatile impurities using the charged particle detector 16 (i.e., peak area), it is possible to quickly determine whether or not impurities are present in the filtered liquid.

[0034] The frequency of measuring nonvolatile impurities using the charged particle detector 16 may be, for example, once every 10 seconds to 60 minutes during the start-up period of the filter device 10. The start-up period refers to the period from when a new filter is installed in the filter device 10 and the flow of the treated liquid begins, or from when the flow of the treated liquid is stopped and then resumed after a while, until it is confirmed that the filtered liquid no longer contains nonvolatile impurities. Furthermore, after the start-up period of the device has elapsed, the frequency of measuring nonvolatile impurities using the charged particle detector 16 may be, for example, once every day to once every month. The start-up of the filter device 10 refers to reducing unintended discharge (elution or deposits) from the filter at the beginning of the flow of liquid through the filter (or when the flow is restarted after a stop) and achieving a steady state. For example, in the filter device 10, the treated liquid discharged from the filter is discharged from the pipe 14b without being supplied to a point of use until the start-up period is complete.

[0035] The amount of nonvolatile impurities in the filtered liquid may be quantified based on the measurement results of the nonvolatile impurities using the charged particle detector 16. The amount of nonvolatile impurities is preferably quantified by a calibration curve method. An example of the procedure for the calibration curve method is described below. (1) As described above, the peak area in the spectrum of nonvolatile impurities obtained by the charged particle detector 16 is determined. (2) Prepare multiple standard solutions containing different concentrations of a substance soluble in the liquid to be treated. For example, if the liquid to be treated is isopropyl alcohol, a preferred soluble substance is LiBr. In other words, prepare multiple isopropyl alcohol solutions containing different concentrations of LiBr. (3) The standard solution is analyzed by the charged particle detector 16 in the same manner as described above, and a calibration curve showing the relationship between the peak area of ​​the obtained spectrum and the concentration of LiBr is prepared. (4) Using the calibration curve prepared in (3), convert the peak area determined in (1) into the concentration of nonvolatile impurities. The quantitative determination of such non-volatile impurities may be carried out by an operator, or may be carried out by a computing device provided in the treatment liquid evaluation device 12 .

[0036] In this embodiment, the filtered liquid discharged from the filter device 10 may be introduced directly into the charged particle detector 16, or the filtered liquid may be passed through a liquid chromatography column, and the treated liquid discharged from the liquid chromatography column may be sequentially introduced into the charged particle detector 16. In the former case, all nonvolatile impurities contained in the filtered liquid can be measured. In the latter case, the nonvolatile impurity components are separated by the liquid chromatography column, and each component of the nonvolatile impurities contained in the filtered liquid can be measured. The liquid chromatography column may be appropriately selected depending on the components of the nonvolatile impurities, and conventionally known columns such as gel filtration columns, cation exchange columns, and anion exchange columns can be used.

[0037] The method for managing the treatment liquid in this embodiment is characterized by managing the start-up conditions of the filter device 10 based on the measurement results (i.e., peak area) of the charged particle detector 16 obtained by the above-described treatment liquid evaluation method or the quantification results of non-volatile impurities in the filter treatment liquid. For example, the start-up conditions may be managed by continuing the start-up operation of the filter device 10 when the peak area or amount of non-volatile impurities calculated by measuring the non-volatile impurities in the filter treatment liquid with the charged particle detector 16 is equal to or greater than a predetermined value, and terminating the start-up operation when the peak area or amount of non-volatile impurities falls below the predetermined value. Alternatively, the start-up conditions may be managed by terminating the start-up operation when the most recent value of the peak area or amount of non-volatile impurities calculated over time becomes equivalent to the immediately preceding value (within a predetermined range) or when the same value is obtained multiple times in a row. [Example]

[0038] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to the following examples.

[0039] Isopropyl alcohol (Kanto Chemical, EL-UM) was passed through a filter device (Optimizer D (model number: CWSF0S2S3M)) at a flow rate of 100 mL / min, and the filtered solution was measured at regular intervals using a charged aerosol detector, and the peak areas in the resulting spectrum were measured. The filter installed in the filter device was an Entegris Optimizer UPE (pore size: 5 nm). The measurement conditions using the charged aerosol detector were as follows: <Measurement conditions> Mobile phase: isopropanol / ultrapure water = 50 / 50 Flow rate: 0.5mL / min Charged particle detector: Vanquish CAD H (Thermo Scientific TM Vanquish TM Flex UHPLC System)

[0040] FIG. 3 shows the transition of peak area in the spectrum obtained by measuring the filter-treated liquid with a charged particle detector. As shown in FIG. 3, the peak area in the obtained spectrum decreased with the passage of isopropyl alcohol, and when the passage time of isopropyl alcohol reached 120 minutes, the peak area in the obtained spectrum became 0. In other words, when the passage time of isopropyl alcohol reached 120 minutes, it was confirmed that non-volatile impurities were no longer contained in the filter-treated liquid. In this way, in the examples, it is possible to quickly manage whether or not impurities are contained in the filter-treated liquid. Note that, when it is confirmed that non-volatile impurities are no longer contained in the filter-treated liquid, it is desirable to terminate the start-up of the filter device and then proceed to actual operation of the filter device.

[0041] [Note] (1) A method for evaluating a treated liquid, comprising a step of measuring non-volatile impurities in a filtered liquid obtained by passing the liquid to be treated through a filter device using a charged aerosol detector, and managing the non-volatile impurities in the filtered liquid. (2) The method for evaluating a treated liquid described in (1) above, characterized in that in the process, the filtered liquid is passed through a liquid chromatography column, and the treated liquid discharged from the liquid chromatography column is introduced into the charged particle detector. (3) The method for evaluating a treated liquid according to (1) above, wherein in the step, the filtered liquid is introduced directly into the charged particle detector without passing through a liquid chromatography column. (4) The method for evaluating a processing liquid according to any one of (1) to (3) above, wherein the nonvolatile impurities are quantified from the measurement results of the charged particle detector using a calibration curve method. (5) A method for managing a treatment liquid, characterized by managing start-up conditions of the filter device based on the measurement results of the charged particle detector obtained by the treatment liquid evaluation method described in any one of (1) to (3) above or the quantification results of the non-volatile impurities obtained by the treatment liquid evaluation method described in (4) above. (6) If the measurement result of the charged particle detector obtained by the method for evaluating a treatment liquid described in any one of (1) to (3) above or the quantitative result of the non-volatile impurities obtained by the method for evaluating a treatment liquid described in (4) above is equal to or greater than a preset value, continuing the start-up operation of the filter device, A method for managing a treatment liquid, characterized in that, when the measurement result of the charged particle detector obtained by the treatment liquid evaluation method described in any one of (1) to (3) above or the quantification result of the non-volatile impurities obtained by the treatment liquid evaluation method described in (4) above is less than a preset value, the start-up operation of the filter device is terminated. (7) A treatment liquid evaluation device comprising a charged particle detector for measuring nonvolatile impurities in a filtered liquid obtained by passing a liquid to be treated through a filter device. (8) a filter device through which the liquid to be treated passes; a charged particle detector for measuring non-volatile impurities in a filtered liquid obtained by passing the liquid to be treated through the filter device. [Explanation of symbols]

[0042] 1 treatment device, 10 filter device, 12 treatment liquid evaluation device, 14a to 14c piping, 16 charged particle detector, 20 nebulizer, 22 drying tube, 24 mixing chamber, 26 collector, 28 electrometer, 30 detection unit.

Claims

1. A method for evaluating a treated liquid, comprising a step of measuring non-volatile impurities in a filtered liquid obtained by passing the liquid to be treated through a filter device using a charged aerosol detector, and managing the non-volatile impurities in the filtered liquid.

2. 2. The method for evaluating a treated liquid according to claim 1, wherein in the step, the filtered liquid is passed through a liquid chromatography column, and the treated liquid discharged from the liquid chromatography column is introduced into the charged particle detector.

3. 2. The method for evaluating a treated liquid according to claim 1, wherein in the step, the filtered liquid is introduced directly into the charged particle detector without passing through a liquid chromatography column.

4. 2. The method for evaluating a processing liquid according to claim 1, wherein the nonvolatile impurities are quantified from the measurement results of the charged particle detector using a calibration curve method.

5. A method for managing a processing liquid, characterized by managing the start-up conditions of the filter device based on the measurement results of the charged particle detector obtained by the processing liquid evaluation method of claim 1 or the quantification results of the non-volatile impurities obtained by the processing liquid evaluation method of claim 4.

6. When the measurement result of the charged particle detector obtained by the method for evaluating a treatment liquid according to claim 1 or the quantitative result of the non-volatile impurities obtained by the method for evaluating a treatment liquid according to claim 4 is equal to or greater than a preset value, the start-up operation of the filter device is continued; A method for managing a processing liquid, characterized in that if the measurement result of the charged particle detector obtained by the processing liquid evaluation method of claim 1 or the quantification result of the non-volatile impurities obtained by the processing liquid evaluation method of claim 4 is less than a predetermined value, the start-up operation of the filter device is terminated.

7. A treatment liquid evaluation device comprising a charged particle detector for measuring nonvolatile impurities in a filtered liquid obtained by passing a liquid to be treated through a filter device.

8. a filter device through which the liquid to be treated passes; a charged particle detector for measuring non-volatile impurities in a filtered liquid obtained by passing the liquid to be treated through the filter device.

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