Optical analyzer, optical analysis method, and composite analyzer

Abstract

To allow measurement of a wider wavelength range with a single light source unit, output multiple rays of light with a sufficient quantity, and efficiently perform simultaneous measurement at multiple points.SOLUTION: An optical analyzer irradiates optical cells storing samples with light, and detects light transmitted through the optical cells to analyze the samples. The optical analyzer comprises: a deuterium lamp and a halogen lamp that are light sources; a first light output port and a second light output port that output combined light of light from the deuterium lamp and light from the halogen lamp; and an optical fiber that is connected with the light output ports and splits the incident combined light and guides the light to the plurality of optical cells. A first optical fiber obtained by bundling a plurality of fiber groups branched to different destinations is connected to the first light output port. A second optical fiber obtained by laterally bundling a plurality of single core fibers branched to different destinations is connected to the second light output port.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an optical analysis device, an optical analysis method, and a combined analysis device for measuring the component concentrations of chemical solutions in, for example, semiconductor manufacturing processes. [Background technology]

[0002] As an example of a conventional analytical device, as shown in Patent Document 1, there is an optical analytical device that is connected to a pipe installed in a semiconductor manufacturing device and measures the concentration of a chemical solution (liquid sample) such as hydrofluoric acid (HF). This optical analytical device has an optical cell, a light source unit that irradiates light onto the optical cell, and a light detection unit that detects the light transmitted through the optical cell, and is configured to calculate the concentration of a predetermined component contained in the liquid sample contained in the optical cell by a calculation unit that receives a light intensity signal from the light detector. The light source unit has an optical output port that outputs light from the light source and an optical fiber connected to this optical output port, and the light from the light source is irradiated onto the optical cell via the optical fiber. The concentration obtained in this manner is used to control the concentration of the chemical solution flowing through the pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-139668 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned optical analysis device, it is desirable to be able to measure a wide wavelength range with one device. For this reason, for example, a light source unit that irradiates light may be provided with both a deuterium lamp that emits light in the ultraviolet region and a halogen lamp that emits light in the visible to infrared wavelength region as light sources, and multiple light output ports may be provided, and the light from the halogen lamp and the light from the deuterium lamp may be output from each light output port after being appropriately combined in accordance with the target measurement wavelength.

[0005] On the other hand, there is an increasing need for the above-mentioned optical analysis device to measure multiple points simultaneously, such as multiple points in a flow path, multiple tanks, etc. Conventionally, to measure multiple points simultaneously, a set of optical analysis devices must be installed at each measurement point, and the cost and installation space required for multiple devices are problems.

[0006] To solve this problem, it is conceivable to obtain multiple optical outputs from one optical output port in order to reduce the number of devices required for simultaneous measurement of multiple points. For example, one possible method is to connect a branching fiber to the optical output port.

[0007] Here, the problem with connecting a branch fiber to the optical output port of the light source unit is the amount of light. When using a branch fiber, multiple fibers corresponding to multiple branch destinations are arranged at the input end face of the optical fiber connected to the optical output port, but since the light from the light source that reaches the optical output port is shared by multiple fibers, the amount of light that reaches the branch destination is inevitably lower than when light is extracted by connecting a single fiber. Therefore, it is desirable to extract light efficiently from each optical output port.

[0008] The present invention has been made to solve all of the above-mentioned problems in one fell swoop, and its main objective is to enable measurement of a wide wavelength range using a single light source unit, and further to output multiple light beams with sufficient amounts of light, thereby enabling efficient simultaneous measurement of multiple points. [Means for solving the problem]

[0009] That is, the optical analysis device of the present invention is an optical analysis device that analyzes a sample by irradiating light onto an optical cell containing the sample and detecting the transmitted light, and is characterized in that it comprises a deuterium lamp and a halogen lamp as light sources, a first optical output port and a second optical output port that output a combined light of the light from the deuterium lamp and the light from the halogen lamp, and optical fibers connected to each of the optical output ports that branch the incident combined light and guide it to a plurality of the optical cells, wherein a first optical fiber formed by bundling a plurality of fiber groups having different branch destinations is connected to the first optical output port, and a second optical fiber formed by bundling a plurality of single-core fibers having different branch destinations side by side is connected to the second optical output port.

[0010] With this configuration, since there are multiple optical output ports that output a composite light of the ultraviolet light emitted from the deuterium lamp and the visible to infrared light emitted from the halogen lamp, it is possible to measure in a wide wavelength range from the ultraviolet to infrared range by detecting the light output from each optical output port with a photodetector having a suitable sensitivity wavelength range. For example, if the light output from the first optical output port is detected with a photodetector having a sensitivity wavelength range from the ultraviolet to visible range, it is possible to measure the ultraviolet to visible range. On the other hand, if the light output from the second optical output port is detected with a photodetector having a sensitivity wavelength range in the infrared range, it is possible to measure the infrared range.

[0011] Furthermore, according to this configuration, since optical fibers that branch the output light are connected to each optical output port, multiple light beams can be output from each optical output port to perform simultaneous measurements at multiple points. By connecting different types of optical fibers to the first optical output port and the second optical output port, it becomes possible to output multiple beams of light with a wide wavelength range and sufficient light intensity.

[0012] For example, when the first optical output port is used for measuring the ultraviolet to visible light range as described above, it is desirable to output the light from the deuterium lamp and the halogen lamp with approximately the same light intensity, but since the deuterium lamp has a smaller original light intensity than the halogen lamp, it is necessary to efficiently extract the light from the deuterium lamp. Here, since the light emitting surface of the deuterium lamp is approximately circular, the image of the light from the deuterium lamp formed on the light input end face of the optical fiber is circular. Therefore, by using an optical fiber with an input end face that matches the circular light image, that is, by using a first fiber in which a group of multiple fibers is bundled together and multiple fibers are arranged in an approximately circular shape on the input end face, the light from the deuterium lamp can be efficiently extracted.

[0013] On the other hand, when using the second optical output port for measuring infrared light as described above, for example, only the amount of light from the halogen lamp needs to be considered. Since the light emitting surface (filament) of a halogen lamp is rectangular, the image of the light from the halogen lamp formed on the optical input end face of the optical fiber is horizontally elongated. Therefore, by using an optical fiber with an input end face that matches the horizontally elongated light image, that is, by using a second optical fiber in which multiple single-core fibers are bundled together horizontally, the light from the halogen lamp can be extracted efficiently and at low cost.

[0014] It is preferable that the optical analysis device has the first optical output port connected via the first optical fiber to a first photodetector having a sensitivity wavelength range in the ultraviolet to visible light range, and the second optical output port connected via the second optical fiber to a second photodetector having a sensitivity wavelength range in the infrared light range. In this way, the first optical output port can be used for measuring light in the ultraviolet to visible light range, and the second optical output port can be used for measuring light in the infrared range, thereby making it possible to obtain the aforementioned effects of the present invention more prominently.

[0015] Furthermore, it is preferable that the optical analysis device further includes an optical system that combines the light emitted from each of the lamps and guides it to each of the optical output ports, and that at the input end face of the first optical fiber, the multiple fibers that make up the multiple fiber groups are arranged in accordance with the shape of an image of light from the light source that is formed at the position of the input end face by the optical system. In this way, the multiple fibers that make up the multiple optical fiber groups are arranged to match the shape of the image of the light from the light source (e.g., a circular shape), thereby reducing light loss and enabling light to be output efficiently.

[0016] In the optical analyzer, it is preferable that a bundle diameter of the first optical fiber and an image size of the light from the light source are substantially the same at the input end face. In this way, the size of the optical fiber bundle diameter and the size of the light image are approximately the same, so that the loss of light can be reduced and the light can be output efficiently. In addition, the increase in cost due to increasing the number of fibers and increasing the bundle diameter can be suppressed.

[0017] In the optical analysis device, it is preferable that the first optical fiber is arranged such that the plurality of fiber groups are symmetrical with respect to a central axis at the input end face of the first optical fiber. In this way, it becomes possible to take in light almost evenly into a plurality of fiber groups, so that it becomes possible to irradiate almost the same amount of light onto the optical cells at the branching destinations of the respective groups.

[0018] Each of the plurality of fiber groups includes a central fiber that is a fiber passing through a central axis at an output end face after branching, and a plurality of surrounding fibers that are fibers that are arranged around the central fiber at the output end face after branching, The central fiber of each of the plurality of fiber groups is preferably disposed near a central axis on the input end face. In this way, a fiber that is located near the center of the input end face and that can take in strong light can be made the central fiber of each fiber group.

[0019] In the optical analysis device, it is preferable that the first optical fiber is a bundle of a dummy fiber that does not guide the light from the light source to the optical cell, together with the plurality of fiber groups. In this way, the strength of the optical fiber itself can be increased by providing the dummy fiber.

[0020] The optical analysis method of the present invention is an optical analysis method using an optical analysis device comprising a deuterium lamp and a halogen lamp as light sources, a first optical output port and a second optical output port for outputting a composite light of the light from the deuterium lamp and the light from the halogen lamp, and optical fibers connected to each of the optical output ports for branching the incident composite light and guiding it to a plurality of the optical cells, the optical analysis device irradiating the optical cell containing a sample and detecting the transmitted light, thereby analyzing the sample, characterized in that a first optical fiber formed by bundling a plurality of fiber groups having different branch destinations is connected to the first optical output port, and a second optical fiber formed by bundling a plurality of single-core fibers having different branch destinations side by side is connected to the second optical output port. Such an optical analysis method can achieve the same effects as those of the optical analysis device of the present invention described above.

[0021] Furthermore, the composite analytical device of the present invention measures the concentration of a component to be measured in a test liquid, and is characterized in that it comprises the optical analytical device described above, a conductivity meter that measures the conductivity of the test liquid or a pH meter that measures the pH of the test liquid, and a concentration calculation unit that calculates the concentration of the component to be measured by multivariate analysis using the optical absorption spectrum of the test liquid measured by the optical analytical device and the conductivity or pH of the test liquid measured by the conductivity meter or the pH meter as explanatory variables. Such a composite analytical device can achieve the same effects as the optical analytical device of the present invention described above. Effect of the Invention

[0022] According to the present invention as described above, it is possible to measure a wide wavelength range with a single light source unit, and further, it is possible to output a plurality of light beams with sufficient light intensity, and to efficiently perform simultaneous measurement of a plurality of points. [Brief description of the drawings]

[0023] [Figure 1] 1 is a diagram showing the overall configuration of an optical analysis device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing a schematic configuration of a light source unit according to the embodiment; [Diagram 3] 4A and 4B are diagrams illustrating the shapes of light images formed at each light output port in the embodiment. [Figure 4] FIG. 4 is a diagram showing the relationship between the bundle diameter of the first optical fiber and the image size of the deuterium lamp light in the embodiment. [Diagram 5] 6 is a diagram showing the relationship between the fiber diameter of the second optical fiber and the image size of the halogen lamp light in the embodiment. FIG. [Figure 6] 13 is a diagram showing the relationship between the bundle diameter at the light input end face of the first optical fiber and the image size of the light source according to another embodiment. FIG. [Figure 7] FIG. 11 is a diagram illustrating a configuration of a light source unit according to another embodiment. [Figure 8] FIG. 1 is a diagram showing the overall configuration of a composite analysis device including a light source analysis device of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] An optical analysis device 100 according to one embodiment of the present invention will now be described with reference to the drawings.

[0025] The optical analysis device 100 of this embodiment is used by being incorporated into, for example, a semiconductor manufacturing line, and measures the concentration of a chemical solution (liquid sample) used in, for example, a cleaning process in semiconductor manufacturing, and more specifically, is a spectrophotometer that measures the concentration by irradiating the liquid sample with light and measuring the absorbance of the liquid sample. Examples of chemical solutions include SC-1 (ammonia hydrogen peroxide solution), SC-2 (hydrochloric acid hydrogen peroxide solution), SPM (sulfuric acid hydrogen peroxide solution), FPM (hydrofluoric acid hydrogen peroxide solution), and BHF (buffered hydrofluoric acid solution).

[0026] 1, the optical analysis device 100 includes a light source unit 1, an optical cell 2 to which light emitted from the light source unit 1 is irradiated, a photodetector 3 to detect the light transmitted through the optical cell 2, and a calculation unit 4. In the optical analysis device 100, a liquid sample such as a drug solution is contained in the optical cell 2, the light emitted from the light source unit 1 is irradiated onto the optical cell 2, the light transmitted through the optical cell 2 is detected by the photodetector 3, and the calculation unit 4 receives a light intensity signal from the photodetector 3 and calculates the concentration of a predetermined component contained in the liquid sample. The concentration obtained in this manner is used to control the concentration of the drug solution, etc.

[0027] The optical cell 2 is, for example, a flow cell provided in a circulation path formed by a chemical piping connected to a chemical tank of a semiconductor cleaning device. The optical cell 2 may be an in-line flow cell directly incorporated in the piping in the semiconductor cleaning device. The material of the optical cell 2 is preferably sapphire when chemical resistance to hydrofluoric acid or the like is required, and is preferably quartz, which has better optical transparency, when chemical resistance is not required. The cell may be configured so that the wavelength range and absorbance to be measured can be selected for each chemical by changing the cell length.

[0028] The photodetector 3 includes a spectroscope that separates and detects the light transmitted through the optical cell 2. The optical absorption spectrum (spectroscopic spectrum) of the transmitted light is obtained by the photodetector 3. Note that the optical absorption spectrum in this embodiment is a concept that includes an absorbance spectrum obtained from the optical absorption spectrum of the transmitted light and the optical absorption spectrum of the incident light.

[0029] Thus, the optical analysis device 100 of this embodiment is configured to simultaneously irradiate light to a plurality of optical cells 2 using one light source unit 1, and to simultaneously measure a plurality of liquid samples. Specifically, the light source unit 1 has two optical output ports (a first optical output port 1P1 and a second optical output port 1P2) that output light. These two optical output ports are used to measure different wavelength ranges, with the first optical output port 1P1 being used to measure the ultraviolet light region to the visible light region, and the second optical output port 1P2 being used to measure the infrared light region. Optical fibers that branch the output light are connected to the two optical output ports 1P1 and 1P2, respectively. The light emitted from each of the optical output ports 1P1 and 1P2 is branched by the optical fiber and irradiated to each of the different optical cells 2. The light transmitted through each optical cell 2 is detected by the optical detector 3. The optical detectors 3 connected to the optical output ports 1P1 and 1P2 have different sensitivity wavelength ranges. Here, a photodetector 3 having a wavelength sensitivity range at least in the ultraviolet to visible light range is connected to the first light output port 1P1, and a photodetector 3 having a wavelength sensitivity range at least in the infrared light range is connected to the second light output port 1P2. The photodetector 3 connected to each of the light output ports 1P1 and 1P2 only needs to have a wavelength sensitivity range at least in the wavelength range exemplified, and may have a wavelength sensitivity range in other wavelength ranges. Also, "a photodetector is connected to the light output port" means that it is optically connected, and means that the light output from the light output port enters the photodetector via, for example, an optical fiber or the like.

[0030] Specifically, as shown in Fig. 2, the light source unit 1 includes a casing 1C, a plurality of light sources (a first light source 11 and a second light source 12) that are housed in the casing 1C and emit light of different spectra, a plurality of optical output ports (a first optical output port 1P1 and a second optical output port 1P2) that output the light emitted from each of the light sources 11 and 12, an optical system 13 that guides the light emitted from each of the light sources 11 and 12 to each of the optical output ports 1P1 and 1P2, and a plurality of optical fibers (a first optical fiber 14 and a second optical fiber 15) that are connected to each of the optical output ports 1P1 and 1P2. The first optical output port 1P1 and the second optical output port 1P2 are provided on one side wall of the casing 1C. Note that "emitting light of different spectra" means emitting light of which spectra are different from each other in at least a part of the wavelength range, and also includes emitting light of which spectra are different from each other in the entire wavelength range.

[0031] The first light source 11 emits light in the visible light range to the infrared light range, for example, and is specifically a halogen lamp.

[0032] The second light source 12 emits light in the ultraviolet region, for example, and is specifically a deuterium lamp.

[0033] The optical system 13 includes forward focusing lenses 131, 132 placed in front of the first light source 11 and the second light source 12, respectively, a first optical element 133 and a second optical element 134 that transmit and / or reflect incident light, and rear focusing lenses 135, 136 placed within or in front of the first optical output port 1P1 and the second optical output port 1P2, respectively, and that converge the incident light.

[0034] The forward focusing lenses 131, 132 are for adjusting the spread of the light emitted from the first light source 11 and the second light source 12. The two forward focusing lenses 131, 132 are arranged such that their optical axes coincide with the optical axes of the light sources 11, 12 and their optical axes intersect (for example, preferably perpendicular to each other, but not limited to this).

[0035] The first optical element 133 is disposed near an intersection CP where the optical axes of the forward collecting lenses 131 and 132 intersect. This first optical element 133 combines and emits light from the first light source 11 and the second light source 12. More specifically, this first optical element 133 transmits a part of the incident light and reflects a part of it, and is, for example, a beam splitter made of an uncoated quartz plate.

[0036] The first optical element 133 of this embodiment uses a non-coated quartz plate, and has optical properties in which the light transmittance (eg, about 85 to 95%) is higher than the light reflectance (eg, about 5 to 15%).

[0037] Here, the angle and position of the first optical element 133 are set so that the optical paths of the reflected light from the first light source 11 and the transmitted light from the second light source 12 are approximately the same. That is, in this first optical element 133, the reflected light from the first light source 11 and the transmitted light from the second light source 12 are combined. Here, the halogen lamp has a characteristic that the amount of light is greater than the amount of light from the deuterium lamp, and as described above, the first optical element 133 has an optical characteristic that the light reflectance is smaller than the light transmittance, so that the light from the first light source 11 reflected by the first optical element 133 and the light from the second light source 12 transmitted through the first optical element 133 are combined with an appropriate light amount balance. Then, a first optical output port 1P1 is provided on the optical path of this combined light (combined light), and the combined light (light in the ultraviolet light region to the infrared light region) of the reflected light from the first light source 11 and the transmitted light from the second light source 12 is output from the first optical output port 1P1.

[0038] On the other hand, a second optical element 134 is disposed on the optical path of the light from the first light source that has been transmitted through the first optical element 133. This second optical element 134 is a reflecting mirror such as a plane mirror that reflects the incident light. A second optical output port 1P2 is provided on the optical path of the light from the first light source 11 that has been reflected by this second optical element 134, and transmitted light (light in the visible light range to infrared light range) from the first light source 11 is output from the second optical output port 1P2.

[0039] Since light from the second light source 12 reflected by the first optical element 133 also reaches this second light output port 1P2, strictly speaking, the second light output port 1P2 emits a combined light (ultraviolet light region to infrared light region) that is a combination of the transmitted light from the first light source 11 and the reflected light from the second light source 12. However, as described above, the light amount of the deuterium lamp is smaller than the light amount of the halogen lamp, and the first optical element 133 has optical characteristics in which the light reflectance is smaller than the light transmittance, so that most of the light that reaches the second light output port 1P2 is the transmitted light from the first light source 11.

[0040] The two rear focusing lenses 135, 136 are respectively provided between the optical path between the first optical element 133 and the first optical output port 1P1 and the optical path between the first optical element 133 (and further the second optical element 134) and the second optical output port 1P2.

[0041] In this way, the first light output port 1P1 and the second light output port 1P2 output a composite light in which the light from the halogen lamp, which is the first light source 11, and the light from the deuterium lamp, which is the second light source 12, are mixed in different ratios. Since the halogen lamp, which is the first light source 11, has a rectangular light emitting surface (filament), and the deuterium lamp, which is the second light source 12, has a substantially circular light emitting surface, a rectangular image formed by the light from the first light source 11 and a circular image formed by the light from the second light source 12 are overlapped with each other at each of the light output ports 1P1 and 1P2, as shown in FIG. 3. The optical system 13 of this embodiment is configured to form a circular light image formed by the second light source (deuterium lamp) 12 in an overlapping manner within the rectangular light image formed by the first light source (halogen lamp) 11.

[0042] A first optical fiber 14 and a second optical fiber 15 that branch the incident light and output it to a plurality of branch destinations are connected to the first optical output port 1P1 and the second optical output port 1P2, respectively.

[0043] The first optical fiber 14 is a bundle of multiple fibers, and is a so-called bundle type. In the first optical fiber 14, multiple fibers are arranged in the cladding with almost no gaps.

[0044] Specifically, the first optical fiber 14 outputs light input from the first optical output port 1P1 to a plurality of different branch destinations, and light is output from a plurality of fibers at each branch destination. More specifically, the first optical fiber 14 has a plurality of fiber groups (first fiber group 14A, second fiber group 14B) with different branch destinations and a dummy fiber group 14C for reinforcement, bundled together in its clad. The first fiber group 14A and the second fiber group 14B are each composed of the same number of fibers (7 in this case), and the dummy fiber group 14c is composed of a plurality of dummy fibers (5 in this case).

[0045] 4A and 4B are diagrams showing the fiber configurations of the first optical fiber 14 at (a) the optical input end face, (b) the optical output end face 1, and (c) the optical output end face 2. As shown in FIG. 4A, at the optical input end face, a plurality of fibers are arranged closely without gaps in accordance with the shape of the inner wall of the clad (circular in plan view). The plurality of fibers constituting the first fiber group 14A and the second fiber group 14B are arranged symmetrically with respect to the central axis P1 of the first optical fiber 14. The fibers constituting the dummy fiber group 14C are arranged symmetrically with respect to the central axis P1 in the first optical fiber 14.

[0046] Furthermore, as shown in FIGS. 4(b) and 4(c), at each light output end face after branching, the fibers constituting the first fiber group 14A and the fibers constituting the second fiber group 14B are arranged in a symmetrical relationship.

[0047] As shown in Fig. 4(b) and (c), each of the multiple fiber groups 14A and 14B includes one central fiber (denoted as A1 or B1) that passes through the central axis at the output end faces 1 and 2 after branching, and multiple (six) surrounding fibers (denoted simply as A and B) that are fibers arranged around the central fiber at the output end faces 1 and 2. As shown in Fig. 4(a), the central fiber included in each of the multiple fiber groups 14A and 14B is arranged near the central axis P1 of the optical fiber 14 at the input end face. Here, one dummy fiber is arranged on the central axis P1 of the optical fiber 14, and multiple central fibers are arranged adjacent to this dummy fiber.

[0048] Here, the size and position of the optical system 13 and the insertion depth of the first optical fiber 14 are set so that, at the first optical output port 1P1, the bundle diameter D (i.e., the inner diameter of the cladding that contains the multiple fiber groups) at the optical input end face of the first optical fiber 14 is approximately the same as the size of the image of light from the light source (deuterium lamp) 12 formed (imaged) at the position of the optical input end face by the optical system 13. Here, "approximately the same bundle diameter and optical image size" does not only mean completely the same, but also means a range that includes a difference of, for example, within ±20%, preferably within ±10%. It is preferable that the optical image size is slightly larger than the bundle diameter.

[0049] On the other hand, the second optical fiber 15 is a so-called single-core branch type optical fiber that is configured by bundling a plurality of (here, two) single-core fibers side by side. This second optical fiber 15 outputs the light input from the second optical output port 1P2 to a plurality of different branch destinations, and the light is output from a single-core fiber composed of one fiber core at each branch destination. FIG. 5 is a diagram showing the fiber configuration of the second optical fiber 15 at (a) the optical input end face, (b) the optical output end face 1, and (c) the optical output end face 2. As shown in FIG. 5(a), at the optical input end face, two single-core fibers 15D and 15E before branching are arranged side by side. Then, as shown in FIG. 5(b) and (c), these two single-core fibers are connected to each optical output end face.

[0050] This second optical fiber 15 is connected to the second optical output port 1P2 so that the direction in which the two single-core fibers are arranged coincides with the longitudinal direction of the image of the first light source (halogen lamp) 11 formed at the position of the optical input end face by the optical system 13.

[0051] According to the optical analysis device 100 equipped with the light source unit 1 of this embodiment configured in this manner, the device is equipped with a plurality of optical output ports 1P1, 1P2 which output a combined light of the ultraviolet light emitted from the deuterium lamp 12 and the visible to infrared light emitted from the halogen lamp 11, and the light output from the first optical output port 1P1 is detected by a photodetector 3 having a sensitivity wavelength range from the ultraviolet to visible light range, while the light output from the second optical output port 1P2 is detected by a photodetector 2 having a sensitivity wavelength range in the infrared range. Therefore, the first optical output port 1P1 can be used to perform measurements in the ultraviolet to visible light range, and the second optical output port 1P2 can be used to perform measurements in the infrared range, making it possible to perform measurements in a wide wavelength range according to the purpose.

[0052] Furthermore, since optical fibers 14, 15 for branching the output light are connected to the optical output ports 1P1, 1P2, a plurality of light beams can be output from each of the optical output ports 1P1, 1P2, allowing simultaneous measurement of a plurality of points.

[0053] By connecting a bundle-type optical fiber in which the fiber arrangement at the input end face is approximately circular to the first optical output port 1P1 used for measuring the ultraviolet to visible light range, the light from the deuterium lamp 11, which has a smaller light output than the halogen lamp 12, can be efficiently extracted, and the light from the deuterium lamp 12 and the halogen lamp 11 can be output with approximately the same amount of light, and the light from each lamp 11, 12 can be output with sufficient light output even at each output end face after branching.

[0054] On the other hand, the second optical output port 1P2, which is used for measuring the infrared light range and for which only the amount of light from the halogen lamp 11 needs to be considered, is connected to a single-core branched optical fiber in which the fiber arrangement shape at the input end face is long horizontally, making it possible to efficiently extract the light from the halogen lamp while keeping costs down, and also making it possible to output a sufficient amount of light from the halogen lamp 11 at each output end face after branching.

[0055] The present invention is not limited to the above-described embodiment. For example, in the above embodiment, in the first optical output port 1P1, the bundle diameter D at the optical input end face of the first optical fiber 14 and the size of the image of the light from the light source (deuterium lamp) 12 formed (imaged) at the position of the optical input end face by the optical system 13 are configured to be substantially the same, but this is not limited thereto. In other embodiments, as shown in Fig. 6, the bundle diameter D at the optical input end face of the first optical fiber 14 may be configured to be larger than the image size of the light from the light source (deuterium lamp) 12.

[0056] In other embodiments, the circular light image produced by the second light source (deuterium lamp) 12 does not have to be formed so as to overlap with the rectangular light image produced by the first light source (halogen lamp) 11. For example, a part of the light image produced by the first light source 11 and a part of the light image produced by the second light source 12 may overlap with each other, or the light image produced by the first light source 11 may be completely contained within the light image produced by the second light source 12.

[0057] In the above embodiment, the light emitted from the first light source 11, which is a halogen lamp, is extracted from only one direction by the optical system 13, but this is not limited to the above. In other embodiments, by utilizing the characteristic of a halogen lamp that emits light in various directions, it is possible to use an optical system other than the optical system 13 to extract and output light from other directions, as shown in Fig. 7, for example.

[0058] Further, the optical analysis device 100 of other embodiments is not limited to an apparatus that analyzes a liquid sample such as a chemical liquid, and may also analyze a gas sample such as a gas.

[0059] Furthermore, the optical analysis device 100 described above may be applied to a combined analysis device 400 that measures the concentration of a predetermined component contained in a liquid sample using the optical absorption spectrum of the liquid sample and a characteristic value of the liquid sample measured electrochemically. Hereinafter, one embodiment of such a combined analysis device 400 will be described with reference to FIG.

[0060] <Device configuration> The combined analytical device 400 measures the concentration of a measurement target component contained in a liquid sample, such as a chemical liquid used in, for example, a semiconductor manufacturing device. This combined analytical device 400 is provided, for example, in a chemical liquid pipe that supplies the chemical liquid, and measures the concentration of the measurement target component in the chemical liquid. The concentration thus obtained is used to control the concentration of the chemical liquid, etc. The chemical liquid is a mixed chemical liquid (mixed sample) of two or more components, and may include, for example, a component that becomes conductive when dissolved, a component that does not become conductive, or a component that is a hydrogen ion (H + ) contains components that are correlated with

[0061] 7, the composite analyzer 400 includes an optical measurement unit (specifically, the optical analyzer) 100 that measures the optical absorption spectrum of a liquid sample, an electrochemical measurement unit 200 that electrochemically measures a characteristic value of the liquid sample, and an information processing device 300 that processes measurement information obtained from the optical measurement unit 100 and the electrochemical measurement unit 200. The characteristic value is a physical property value that is correlated with the concentration of a component to be measured contained in the liquid sample.

[0062] As described above, the optical measurement unit 100 is an absorbance meter that irradiates a liquid sample with light to measure the absorbance of the liquid sample. The optical cell 2 housed therein is provided in a first sample flow path L1 formed by a chemical liquid pipe (not shown) connected to a chemical liquid tank T of a semiconductor manufacturing device, for example.

[0063] The electrochemical measurement section 200 of this embodiment includes a conductivity meter 210 that measures the conductivity (electrical conductivity) of a liquid sample, and a pH meter 220 that measures the pH of the liquid sample.

[0064] Specifically, the conductivity meter 210 applies an AC voltage between two electrodes 211, 212 and measures the conductivity (electrical conductivity) of the liquid sample based on the flowing current. The conductivity meter 210 of this embodiment is provided on the upstream or downstream side of the optical measurement unit 100 in the first sample flow path L1 in which the optical measurement unit 100 is provided. Note that the conductivity meter 210 may be of an AC 4-pole type or an electromagnetic induction type, in addition to an AC 2-pole type. The conductivity meter 210 may also be provided in a sample flow path other than the first sample flow path L1.

[0065] The pH meter 220 measures the pH of the liquid sample based on the potential difference generated between the pH glass electrode (working electrode) 221 and the reference electrode 222. The pH meter 220 of this embodiment is provided in a second sample flow path L2 formed by a chemical liquid pipe (not shown) connected to the chemical liquid tank 5, separate from the first sample flow path L1. The pH meter 220 may be provided in the first sample flow path L1, for example, on the upstream side or downstream side of the optical measurement unit 100.

[0066] The information processing device 300 calculates the concentration of a measurement target component in a liquid sample using the optical absorption spectrum (or absorbance spectrum) obtained by the optical measurement unit 100, the conductivity obtained by the conductivity meter 210, and the pH obtained by the pH meter 220. The information processing device 300 is a computer having a CPU, a memory, an input / output interface, an AD converter, output means such as a display, and input means such as a keyboard. The CPU and peripheral devices work together to fulfill the function of the concentration calculation unit 310 based on a component concentration calculation program stored in the memory.

[0067] Specifically, the concentration calculation unit 310 calculates the concentration of the measurement target component by multivariate analysis using the optical absorption spectrum and characteristic values ​​(conductivity and pH) as explanatory variables. Note that possible multivariate analyses include multiple regression analysis (MLR or ILS), principal component regression analysis (PCR), least squares method (CLS), partial least squares method (PLS (PLS1 or PLS2)), etc.

[0068] Here, the concentration calculation unit 310 performs a first or second derivative process on the optical absorption spectrum and performs multivariate analysis using the derivative values ​​as explanatory variables. The concentration calculation unit 310 also performs multivariate analysis using the values ​​of each of a plurality of wavelengths in the optical absorption spectrum as explanatory variables.

[0069] Specifically, the concentration calculation section 310 calculates the concentration of the measurement target component by multivariate analysis using the following formula.

[0070]

number

[0071] where Abs i (Absorbance) is the differential processing of the optical absorption spectrum, and is the value for each of multiple wavelengths (λ1, λ2, . . . λn). In addition, the coefficient a i , b, and c are the concentration regression coefficients for wavelength λi, conductivity, and pH, respectively. The concentration regression coefficients correspond to the weights of each explanatory variable. Furthermore, k is a calibration curve obtained in advance, and S is the measurement data (actual measurement data) of the liquid sample from the optical measurement unit 100 and the electrochemical measurement unit 200. Here, the calibration curve is obtained by multivariate analysis of the measurement data from the optical measurement unit 100 and the electrochemical measurement unit 200 obtained when a standard sample with a known concentration is measured, using the above formula. When using two explanatory variables, absorbance and conductivity, simply enter zero into the pH term in the above equation 1. When using two explanatory variables, absorbance and pH, simply enter zero into the conductivity term in the above equation 1.

[0072] In addition, various modifications and combinations of the embodiments may be made as long as they do not go against the spirit of the present invention. [Explanation of symbols]

[0073] 100...Optical analyzer 1 Light source unit 11...1st light source 12...Second light source 13...Optical system 14 First optical fiber 15 Second optical fiber 1P1: First optical output port 1P2: Second optical output port 2. Optical Cell 3. Photodetector

Claims

1. An optical analysis device that analyzes a sample by irradiating light onto an optical cell containing the sample and detecting the transmitted light, a deuterium lamp and a halogen lamp as light sources; a first optical output port and a second optical output port for outputting a composite light of the light from the deuterium lamp and the light from the halogen lamp; an optical fiber connected to each of the optical output ports, branching the incident combined light and guiding it to a plurality of the optical cells; a first optical fiber, which is a bundle of a plurality of fiber groups each having a different branch destination, is connected to the first optical output port; In the optical analysis device, a second optical fiber formed by bundling a plurality of single-core fibers having different branch destinations side by side is connected to the second optical output port.

2. the first optical output port is connected via the first optical fiber to a first photodetector having a wavelength sensitivity range from an ultraviolet light region to a visible light region; 2. The optical analysis device according to claim 1, wherein the second optical output port is connected via the second optical fiber to a second photodetector having a wavelength sensitivity range in the infrared light region.

3. an optical system that combines the light emitted from each of the lamps and guides the combined light to each of the optical output ports; 3. The optical analysis device according to claim 1, wherein the plurality of fibers constituting the plurality of fiber groups are arranged at the input end face of the first optical fiber in accordance with the shape of an image of light from the light source formed at the position of the input end face by the optical system.

4. 4. The optical analyzer according to claim 3, wherein the bundle diameter of the first optical fiber and the image size of the light from the light source are substantially the same at the input end face.

5. 3. The optical analysis device according to claim 1, wherein the first optical fiber is arranged such that the plurality of fiber groups are symmetrical with respect to a central axis at the input end face of the first optical fiber.

6. each of the plurality of fiber groups includes one central fiber that is a fiber passing through a central axis of the output end face after branching, and a plurality of peripheral fibers that are fibers arranged around the central fiber at the output end face after branching; The optical analysis device according to claim 5 , wherein the central fiber of each of the plurality of fiber groups is disposed near a central axis on the input end face.

7. 3. The optical analyzer according to claim 1, wherein the first optical fiber is a bundle of dummy fibers that do not guide the light from the light source to the optical cell, together with the plurality of fiber groups.

8. an optical analysis method using an optical analysis device comprising a deuterium lamp and a halogen lamp as light sources, a first optical output port and a second optical output port for outputting a composite light of the light from the deuterium lamp and the light from the halogen lamp, and optical fibers connected to each of the optical output ports for branching the incident composite light and guiding it to a plurality of optical cells, the optical analysis method comprising: irradiating the optical cells containing a sample with light and detecting the transmitted light to analyze the sample, the method comprising: a first optical fiber formed by bundling a plurality of fiber groups each having a different branch destination is connected to the first optical output port; The optical analysis method further comprises connecting a second optical fiber, which is a bundle of multiple single-core fibers arranged side by side and branched to different destinations, to the second optical output port.

9. A method for measuring the concentration of a target component in a sample, The optical analysis device according to claim 1 ; a conductivity meter for measuring the conductivity of the sample or a pH meter for measuring the pH of the sample; and a concentration calculation unit that calculates the concentration of the component to be measured by multivariate analysis using the optical absorption spectrum of the sample measured by the optical analysis device and the conductivity or pH of the sample measured by the conductivity meter or the pH meter as explanatory variables.

Images