Concentration measuring device

Abstract

To provide a concentration measuring device.SOLUTION: A concentration measuring device according to one embodiment includes: a light emitting unit including a first light source for generating measuring light; a measuring unit for receiving first measuring light which is a part of the measuring light transmitted through a sample to be measured; and a reference measurement unit for receiving second measurement light which is a part of the measurement light not transmitted through the sample. An absorption amount of the sample is measured based on a light amount detected from the measurement unit and a light amount detected from the reference measurement unit, and chemical substance concentration of the sample is measured.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The following various embodiments relate to a concentration measuring device.

Background Art

[0002] Semiconductors are manufactured through various stages. For example, a chemical solution may be used in the etching process stage. Since the concentration of the chemical solution affects the quality of the semiconductor, the concentration of the chemical solution used in semiconductor manufacturing needs to be kept constant.

[0003] To manage the concentration of the chemical solution, the concentration of the chemical solution can be measured. For example, the concentration of the chemical solution can be measured by using a titration method or a method of determining the degree of light absorption. For example, Korean Patent Laid-Open No. 10-2021-0048111 discloses a concentration measuring device, its system, and a concentration measuring method.

[0004] The above-described background art is what the inventor retained or acquired during the derivation process of the present invention, and it cannot necessarily be said to be publicly known technology that was publicly disclosed to the general public before the filing of the present invention.

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object according to one embodiment is to provide a concentration measuring device for measuring the concentration of a chemical solution.

[0006] An object according to one embodiment is to provide a concentration measuring device that can maintain an appropriate temperature for measurement so as to obtain a reliable measurement result.

[0007] An object according to one embodiment is to provide a concentration measuring device that can monitor the degree of aging of device components.

[0008] An object according to one embodiment is to provide a concentration measuring device that can perform self-verification to determine the presence or absence of abnormalities.

Means for Solving the Problems

[0009] A concentration measuring device according to an embodiment includes a light emitting unit including a first light source that generates measurement light, a measurement unit that receives first measurement light that is a part of the measurement light transmitted through a sample to be measured, and a reference measurement unit that receives second measurement light that is a part of the measurement light that does not pass through the sample, measures an absorption amount of the sample based on an amount of light detected by the measurement unit and an amount of light detected by the reference measurement unit, and measures a chemical substance concentration of the sample.

[0010] The measurement unit can include a measurement photodiode sensor that receives the first measurement light and a first lens that focuses the first measurement light with the measurement photodiode sensor.

[0011] The reference measurement unit includes a reference photodiode sensor that receives the second measurement light and a second lens that focuses the second measurement light with the reference photodiode sensor, is located between the light emitting unit and the sample, and further includes a spectroscopic unit that separates the measurement light into the first measurement light and the second measurement light, and the spectroscopic unit may be a beam splitter that transmits the first measurement light and reflects the second measurement light.

[0012] A concentration measuring device according to an embodiment further includes a housing in which the light emitting unit, the measurement unit, and the reference measurement unit are disposed, and a constant temperature module disposed inside the housing and configured to maintain an internal temperature of the housing. The constant temperature module can include a sample supply pipe extending across at least a part of the housing, a heat sink connected to the first light source and configured to dissipate heat of the first light source, a temperature detection sensor configured to detect an internal temperature of the housing, and a fan configured to cool the inside of the housing.

[0013] A concentration measuring device according to an embodiment can further include a reflection mirror located between the beam splitter and the reference measurement unit and configured to direct the second measurement light toward the reference measurement unit.

[0014] The concentration measurement device according to one embodiment includes a light emitting unit including a first light source that generates measurement light, a measurement unit that receives the measurement light that passes through a sample that is the measurement target of the measurement light, and a verification unit that verifies an abnormal state of the measurement unit. The verification unit includes a second light source that generates verification light, and the second light source can be received by the measurement unit without passing through the sample.

[0015] The verification unit further includes an optical filter that filters light of a specific wavelength. The optical filter is located between the measurement unit and the sample. The optical filter transmits the measurement light and reflects the verification light toward the measurement unit. By comparing the amount of the verification light generated by the second light source with the amount of the verification light received by the measurement unit, an abnormal state of the measurement unit can be verified.

[0016] The concentration measurement device according to one embodiment includes a light emitting unit including a first light source that generates measurement light, a verification unit including a second light source that generates verification light, a spectroscopic unit that is located between the light emitting unit and a sample that is the measurement target and splits the measurement light into first measurement light and second measurement light, a measurement unit that receives the first measurement light that passes through the sample, and a reference measurement unit that receives the second measurement light that does not pass through the sample. The absorption amount of the sample is measured based on the amount of light detected by the measurement unit and the amount of light detected by the reference measurement unit, and the chemical substance concentration of the sample is measured. The verification light verifies an abnormal state of the measurement unit. The measurement unit includes a measurement photodiode sensor, the reference measurement unit includes a reference photodiode sensor, the spectroscopic unit is a beam splitter that transmits the first measurement light and reflects the second measurement light, and an alternating alarm can be provided according to the degree of aging of the measurement photodiode sensor or the reference photodiode sensor.

Advantages of the Invention

[0017] The concentration measurement device according to one embodiment can measure the concentration of a chemical solution.

[0018] The concentration measurement device according to one embodiment can obtain reliable measurement results by maintaining an appropriate temperature for measurement.

[0019] The concentration measurement device according to one embodiment can monitor the degree of aging of device components.

[0020] The concentration measurement device according to one embodiment can perform self-verification to determine the presence or absence of abnormalities.

[0021] The effects of the concentration measurement device according to one embodiment are not limited to those mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

Brief Description of the Drawings

[0022]

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Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, the specific structural or functional descriptions disclosed herein are merely illustrative for the purpose of describing the embodiments, and the embodiments may be implemented in various different forms, and the present invention is not limited to the embodiments described herein. It should be understood that all modifications, equivalents, or alternatives to the embodiments are included within the scope of the rights.

[0024] The terms used in the embodiments are merely used for the purpose of explanation and are not to be construed as having an intention of limitation. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "including" or "having" indicate the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should not be construed as precluding the possibility of the existence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0025] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those of ordinary skill in the technical field to which this embodiment belongs. Commonly used pre-defined terms should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or overly formal sense unless clearly defined herein.

[0026] Also, in the description with reference to the accompanying drawings, regardless of the reference numerals in the drawings, the same components will be given the same reference numerals, and redundant descriptions thereof will be omitted. In the description of the embodiments, if the specific description of the related known technology is determined to obscure the gist of the embodiments unnecessarily, the detailed description thereof will be omitted.

[0027] In addition, when describing the components of the embodiment, terms such as first, second, A, B, (a), (b), etc. can be used. These terms are for distinguishing the components from other components, and the essence, order, or sequence of the components are not limited by these terms. When it is described that any component is "connected", "coupled", or "joined" to another component, it can be understood that the component is directly connected or joined to the other component, but another component can be "connected", "coupled", or "joined" between each component.

[0028] Components including functions common to the components included in any embodiment will be described using the same names in other embodiments. Unless otherwise stated, the descriptions given in any embodiment are also applicable to other embodiments, and specific descriptions within the overlapping scope will be omitted.

[0029] FIG. 1 is a perspective view of the external shape of a concentration measuring device 100 according to an embodiment, and FIG. 2 is a schematic view of the concentration measuring device 100 according to an embodiment.

[0030] The concentration measuring device 100 according to an embodiment includes a configuration as shown in FIG. 2, and the configuration shown in FIG. 2 may be housed at any position inside a housing 110 having the shape shown in FIG. 1.

[0031] Referring to FIG. 1, the shape of the housing 110 that can constitute the external shape of the concentration measuring device 100 according to an embodiment is various.

[0032] Referring to FIG. 2, a concentration measuring device 100 according to an embodiment includes a light emitting unit 120 that generates measurement light LM, a spectroscopic unit 130 that separates the measurement light LM into a first measurement light LM1 and a second measurement light LM2 that are part of the measurement light LM, a measurement unit 160 that receives the first measurement light LM1 that passes through the sample T to be measured, a reference measurement unit 170 that receives the second measurement light LM2 that does not pass through the sample T, a reflection mirror 140 that directs the second measurement light LM2 toward the reference measurement unit 170, a verification unit 180 that verifies an abnormal condition of the measurement unit 160, and a control unit (not shown) that controls the device.

[0033] The light emitting unit 120 includes a first light source 121 that generates the measurement light LM and a collimating lens 122 that allows the measurement light LM to pass through in parallel. Further, the first light source 121 may include an LED.

[0034] The wavelengths of the light generated by the first light source 121 are various. This will be described later.

[0035] The spectroscopic unit 130 is located, for example, between the light emitting unit 120 and the sample T, and the spectroscopic unit 130 can transmit the first measurement light LM1 and reflect the second measurement light LM2. On the other hand, those skilled in the art will understand that the distinction between the first measurement light LM1 and the second measurement light LM2 is a relative concept based on transmission and reflection.

[0036] Further, the spectroscopic unit 130 may be a beam splitter 131 that transmits the first measurement light LM1 and reflects the second measurement light LM2. The beam splitter 131 may have various orientations with respect to the measurement light LM. For example, the beam splitter 131 may be oriented to transmit the first measurement light LM1 that is part of the measurement light LM and reflect the second measurement light LM2 that is part of the measurement light LM. For example, the beam splitter 131 may be oriented so that the incident measurement light LM is not totally reflected.

[0037] On the other hand, the sample T to be measured may be disposed in the sample unit 150. The sample T can be supplied to the sample unit 150 via a pipe (not shown) provided from the outside.

[0038] The measurement unit 160 includes a measurement photodiode sensor 162 that receives the first measurement light LM1 and a first lens 161 that focuses the first measurement light LM1 on the measurement photodiode sensor 162.

[0039] The measurement photodiode sensor 162 may be a photodiode sensor that can convert an optical signal into an electrical signal. For example, the measurement photodiode sensor 162 can convert the amount of the received first measurement light LM1 into an electrical signal and transmit it to a control unit (not shown).

[0040] The first lens 161 can focus the first measurement light LM1 on the measurement photodiode sensor 162 in order to cause the measurement photodiode sensor 162 to receive the first measurement light LM1. The first lens 161 may be a lens in various forms. For example, the first lens 161 may be a spherical lens or an aspherical lens.

[0041] The reflection mirror 140 may be provided between the beam splitter 131 and the reference measurement unit 170. The reflection mirror 140 may be a mirror in various forms. For example, the reflection mirror 140 may be a flat mirror and may reflect all of the incident second measurement light LM2 in parallel.

[0042] The reference measurement unit 170 includes a reference photodiode sensor 172 that receives the second measurement light LM2 and a second lens 171 that focuses the second measurement light LM2 on the reference photodiode sensor 172.

[0043] The reference photodiode sensor 172 may be a photodiode sensor that can convert an optical signal into an electrical signal. For example, the reference photodiode sensor 172 may convert the amount of the received second measurement light LM2 into an electrical signal and transmit it to a control unit (not shown).

[0044] The second lens 171 may focus the second measurement light LM2 on the reference photodiode sensor 172 in order to cause the second measurement light LM2 to be received by the reference photodiode sensor 172. The second lens 171 may be a lens in various forms. For example, the second lens 171 may be a spherical lens or an aspherical lens.

[0045] FIG. 3 shows the concentration measurement principle of the concentration measurement device 100 according to an embodiment. Hereinafter, the concentration measurement principle of the concentration measurement device 100 according to an embodiment will be described.

[0046] Referring to FIG. 3, a part of the configuration of the concentration measurement device 100 according to an embodiment is shown. After light is generated by a light source corresponding to the light emitting unit 120, the light is transmitted through the sample T. The transmitted light is received by a detector corresponding to the measurement unit 160. Here, depending on the concentration of hydrogen peroxide water (H2O2) or sulfuric acid (H2SO4) in the sample T, the degree of light absorption can change. Therefore, based on the amount of light before transmission and the amount of light after transmission, the absorption amount of the sample T can be measured to measure the chemical substance concentration of the sample T.

[0047] FIG. 4 shows the measurement mode of the concentration measurement device 100 according to an embodiment.

[0048] Referring to both FIG. 2 and FIG. 4, the concentration measurement device 100 according to an embodiment can separate the same measurement light LM into two partial lights of the same wavelength by a beam splitter 131 that splits the measurement light LM into a first measurement light LM1 and a second measurement light LM2, and cause them to be received by the measurement unit 160 and the reference measurement unit 170, respectively.

[0049] The first measurement light LM1 passes through the sample T and a part of it is absorbed, while the second measurement light LM2 does not pass through the sample T and is not absorbed at all. Since the light quantity after absorption through the first measurement light LM1 is known and the light quantity of the measurement light LM itself that is not absorbed through the second measurement light LM2 is known, the first measurement light LM1 and the second measurement light LM2 can be compared to measure the absorption amount. Through such an absorption amount, the concentration measuring device 100 can conclusively measure the chemical substance concentration of the sample T.

[0050] Here, depending on the type of solution, since a specific solution can absorb a large amount of light of a specific wavelength, it is possible to select light of an appropriate wavelength according to the type of the sample T solution to be measured. The light of an appropriate wavelength for an aqueous hydrogen peroxide solution and a sulfuric acid solution will be described below.

[0051] FIG. 5 shows the transmittance for each wavelength of light with respect to hydrogen peroxide water.

[0052] Referring to FIG. 5, the x-axis represents the wavelength and the y-axis represents the transmittance. If the transmittance is high at a specific wavelength, it means that absorption of light by the solution is not satisfactorily performed at that specific wavelength.

[0053] It can be seen that in the ultraviolet region of about 275 nm, the degree of light transmission varies greatly depending on the concentration difference of hydrogen peroxide water (for example, 3.7%, 1.85%, and 0.92%). Therefore, when measuring the concentration of hydrogen peroxide water in the solution, measurement light in the ultraviolet region (for example, the measurement light LM in FIG. 4) may be used.

[0054] Referring to FIG. 6, the x-axis represents the wavelength and the y-axis represents the transmittance. If the transmittance is high at a specific wavelength, it means that absorption of light by the solution is not satisfactorily performed at that specific wavelength.

[0055] It can be seen that in the infrared region of about 2200 nm, the degree of light transmission varies greatly depending on the concentration difference of sulfuric acid (for example, 1 to 10%). Therefore, when measuring the concentration of sulfuric acid in the solution, measurement light in the infrared region (for example, the measurement light LM in FIG. 4) may be used.

[0056] FIG. 7 shows the verification mode of the concentration measuring device 100 according to one embodiment.

[0057] Referring to FIG. 7, the verification unit 180 includes a second light source 181 that generates verification light LC and an optical filter 182 that filters light of a specific wavelength. The verification light LC may be received by the measurement photodiode sensor 162 of the measurement unit 160 without passing through the sample T.

[0058] The optical filter 182 may be provided between the sample unit 150 and the measurement unit 160.

[0059] Also, the optical filter 182 allows the measurement light LM to pass through so as not to affect the measurement light LM in the measurement mode shown in FIG. 4, and reflects the verification light LC toward the measurement unit 160 so that it can function only for the verification light LC in the verification mode.

[0060] For example, the optical filter 182 may be a band-pass filter. For example, the optical filter 182 may be a band-pass filter that allows light in the infrared and ultraviolet regions used as the measurement light (e.g., the measurement light LM in FIG. 4) to pass through and reflects light in the intermediate region.

[0061] Therefore, the verification light LC may be light in the region between infrared and ultraviolet. For example, the verification light LC may be light having a wavelength between 240 nm and 2200 nm. For example, the verification light LC may be light having a wavelength of about 515 nm.

[0062] In the verification mode, the measurement light LM may not be generated from the first light source 121, and the verification light LC may be generated only by the second light source 181. Thereafter, the verification light LC is received by the measurement photodiode sensor 162 of the measurement unit 160 by the optical filter 182, and the amount of the verification light LC generated by the second light source 181 and the amount of the verification light LC received by the measurement unit 160 are compared to verify an abnormal condition of the measurement unit 160. For example, when there is an abnormality in the measurement photodiode sensor 162, a value different from the amount of the verification light LC generated is measured, and when there is no abnormality in the measurement photodiode sensor 162, the same value as the amount of the verification light LC generated is measured.

[0063] FIG. 8 shows the content related to the aging measurement of the concentration measuring device 100 according to an embodiment. For example, the concentration measuring device 100 may include a display (not shown) capable of displaying information, and the information as shown in FIG. 8 is displayed on the display.

[0064] Regarding the aging measurement, the specifications of the sensor, the life, the usage time, the amount of light measured by the reference measurement unit 170, etc. can be displayed.

[0065] An alarm may be provided when the amount of light measured is reduced by a preset ratio compared to the amount of light initially measured by the reference measurement unit 170.

[0066] On the other hand, since the concentration measurement is performed by comparing the light that does not pass through the sample T (for example, the second measurement light LM2 shown in FIG. 4) and the light that passes through the sample T (for example, the first measurement light LM1 shown in FIG. 4), a reliable value can be obtained regardless of the aging of the sensor.

[0067] Further, the concentration measuring device 100 according to an embodiment may include a thermostatic module (not shown) disposed inside the housing. Since the light absorption amount of the solution can change according to the temperature change, the thermostatic module can maintain the temperature for an appropriate environment for measurement.

[0068] The constant temperature module may include a sample supply pipe (not shown) extending across at least a part of the housing (e.g., the housing 110 shown in FIG. 1), a heat sink (not shown) connected to a first light source (e.g., the first light source 121 shown in FIG. 2) to dissipate the heat of the first light source, a temperature detection sensor (not shown) for detecting the internal temperature of the housing, and a fan (not shown) for cooling the inside of the housing.

[0069] The sample supply pipe may be connected to, for example, a sample section (e.g., the sample section 150 shown in FIG. 2) to supply a sample to the sample section. The extension path of the sample supply pipe is various. For example, inside the housing, a part of the sample supply pipe may be extended linearly, a part may be curved, and a part may be wound. By forming a long sample supply path inside the housing for the visual target supply pipe, the temperature of the sample may be kept the same as or close to the temperature set inside the housing.

[0070] The heat sink can dissipate the heat that may be generated when the first light source generates measurement light.

[0071] The temperature detection sensor can detect the internal temperature of the housing and provide temperature information for controlling the operation of the fan. For example, the temperature detection sensor may include a Peltier element. If the internal temperature of the housing measured by the Peltier element is higher than the set temperature, the fan can be operated to keep the internal temperature of the housing close to the set temperature.

[0072] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to the above-described embodiments, and those having ordinary knowledge in the art can apply various technical modifications and variations based on the above. For example, the described technology may be executed in an order different from the described method, and / or the components such as the described system, structure, device, circuit, etc. may be combined or assembled in a form different from the described method, or replaced or substituted by other components or equivalents, and appropriate results can still be achieved.

[0073] Therefore, the scope of the present invention is not limited to the disclosed embodiments, but is defined by equivalents such as those equivalent to the claims.

Claims

1. A light emitting unit including a first light source that generates measurement light in the infrared region, a measurement unit that receives first measurement light, which is part of the measurement light that passes through a sample to be measured, a reference measurement unit that receives second measurement light, which is part of the measurement light that does not pass through the sample, a verification unit that verifies an abnormal condition of the measurement unit, and including, the sample is a sulfuric acid solution, measuring the absorbance of the sample based on the amount of light detected by the measurement unit and the amount of light detected by the reference measurement unit, and measuring the concentration of sulfuric acid in the sample, the verification unit includes a second light source that generates verification light, the second light source is received by the measurement unit without passing through the sample, the measurement unit, a measurement photodiode sensor that receives the first measurement light, a first lens that focuses the first measurement light with the measurement photodiode sensor, A concentration measuring device comprising.

2. The reference measurement unit, a reference photodiode sensor that receives the second measurement light, a second lens that focuses the second measurement light with the reference photodiode sensor, The concentration measuring device according to claim 1, comprising.

3. Further including a spectroscopic unit located between the light emitting unit and the sample, which separates the measurement light into the first measurement light and the second measurement light, The spectroscopic unit is a beam splitter that transmits the first measurement light and reflects the second measurement light. The concentration measuring device according to claim 1.

4. A housing in which the light emitting unit, the measurement unit, and the reference measurement unit are disposed inside, a constant temperature module disposed inside the housing to maintain the internal temperature of the housing, and further including, the constant temperature module, a sample supply pipe extending across at least a part of the housing, a heat sink connected to the first light source to dissipate heat of the first light source, a temperature detection sensor that detects the internal temperature of the housing, a fan that cools the inside of the housing, The concentration measuring device according to claim 1, comprising.

5. Further including a reflection mirror located between the beam splitter and the reference measurement unit to direct the second measurement light toward the reference measurement unit. The concentration measuring device according to claim 3.

6. The verification unit further includes an optical filter that filters light of a specific wavelength, An optical filter is positioned between the measurement unit and the sample, and the optical filter transmits the measurement light and reflects the verification light toward the measurement unit. The concentration measurement device according to claim 1, wherein an abnormal condition of the measurement unit is verified by comparing the amount of the verification light generated by the second light source with the amount of the verification light received by the measurement unit. **Claim 7** Further comprising a spectroscopic unit positioned between the light emitting unit and a sample to be measured, the spectroscopic unit splitting the measurement light into first measurement light and second measurement light. The reference measurement unit includes a reference photodiode sensor. The spectroscopic unit is a beam splitter that transmits the first measurement light and reflects the second measurement light. The concentration measurement device according to claim 1, wherein an alarm for replacement is provided according to the degree of aging of the measurement photodiode sensor or the reference photodiode sensor.

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