Apparatus for measuring flow particles

Abstract

This apparatus for measuring flow particles comprises: a laser light source generating a laser beam; a measurement cell irradiated with the laser beam and including a reference cell and a flow cell through which particles and a liquid sample pass; an optical switching unit which changes an optical path, between the reference cell and the flow cell; and a detector for detecting signals from the reference cell and the flow cell.

Description

Fluid particle measuring device

[0001] The present invention relates to a fluid particle measurement device. More specifically, it relates to a fluid particle measurement device including a light source and a fluid cell.

[0002]

[0003] Chemicals such as etchants, rinse agents, and developers may be used in the manufacturing process of electronic devices such as display device semiconductor devices. As the critical dimensions of the electronic devices decrease, higher purity chemicals are used.

[0004] For example, if the chemical substance contains nanoscale impurity particles, it may reduce the yield and reliability of the electronic device manufacturing process. For example, particles with a particle size of 100 nm or less, 50 nm or less, or even 10 nm in size need to be detected and managed in high-purity chemicals used in electronic device processes.

[0005] In order to detect particles within the chemical substance as a continuous process unit, the particles can be detected while continuously passing the chemical substance through a flow cell. For example, a detection signal can be generated via a light source while the particles are supplied / passed through the flow cell.

[0006] Particles can be dispersed within a liquid sample and fed into a flow cell. Noise can be generated by the liquid sample's medium, light scattering, etc. The intensity and frequency of the shock wave generated by the particle structure's excitation can also be interfered with by this noise, which can reduce detection reliability.

[0007] For example, Korean Patent Publication No. 10-1504061 discloses a sample measurement system using a laser light source.

[0008]

[0009] One object of the present invention is to provide a fluid particle measuring device having improved measurement precision and reliability.

[0010] One object of the present invention is to provide a method for measuring fluid particles with improved measurement precision and reliability.

[0011]

[0012] 1. A fluid particle measurement device comprising: a laser light source generating a laser beam; a measurement cell to which the laser beam is irradiated, the measurement cell including a reference cell and a flow cell through which particles and a liquid sample pass; an optical switching unit for changing an optical path between the reference cell and the flow cell; and a detector for detecting signals from the reference cell and the flow cell.

[0013] 2. A fluid particle measuring device, wherein in the above 1, the reference cell contains a medium, and the liquid sample passing through the fluid cell contains the medium and the particles.

[0014] 3. A fluid particle measuring device according to the above 1, wherein the reference cell and the fluid cell are arranged so that the laser beam passes continuously through the reference cell and the fluid cell.

[0015] 4. A fluid particle measuring device according to the above 3, wherein the optical conversion unit includes a mirror or prism that reflects a laser beam emitted from the reference cell and causes it to enter the fluid cell.

[0016] 5. A fluid particle measuring device according to 4 above, wherein the mirror includes a first mirror that reflects a laser beam emitted from the reference cell and a second mirror that causes the laser beam reflected from the first mirror to enter the fluid cell.

[0017] 6. A fluid particle measuring device according to 4 above, wherein the prism includes a first prism that reflects a laser beam emitted from the reference cell and a second prism that causes the laser beam reflected from the first prism to be incident on the fluid cell.

[0018] 7. A fluid particle measuring device according to 6 above, further comprising a refractive index matching layer disposed between the first prism and the reference cell, or between the second prism and the fluid cell.

[0019] 8. A fluid particle measuring device further comprising a lens disposed adjacent to at least one of the ends of the reference cell and the ends of the fluid cell in the above 1.

[0020] 9. In the above 8, the fluid particle measuring device includes a plurality of lenses arranged adjacent to both ends of the reference cell and both ends of the fluid cell, respectively.

[0021] 10. A fluid particle measuring device according to the above 9, further comprising a refractive index matching layer disposed between at least one of the lenses and the measuring cell.

[0022] 11. A fluid particle measuring device further comprising a partition wall disposed between the reference cell and the fluid cell in the above 1.

[0023] 12. A fluid particle measuring device further comprising a light absorbing layer disposed on surfaces facing the partitions of the reference cell and the fluid cell in the above 11.

[0024] 13. A fluid particle measuring device according to the above 12, wherein the light absorbing layer includes an opening.

[0025] 14. A fluid particle measuring device according to 13 above, wherein the opening includes a first opening included in the light absorbing layer disposed on the surface of the reference cell and a second opening included in the light absorbing layer disposed on the surface of the fluid cell.

[0026] 15. In the above 14, the detector comprises a first detector that detects a signal from the reference cell through the first opening, and a second detector that detects a signal from the flow cell through the second opening, a fluid particle measuring device.

[0027]

[0028] According to embodiments of the present invention, a measurement cell to which a laser beam is irradiated may include a reference cell and a flow cell. A signal derived from a target particle can be obtained by correcting a medium-derived signal detected in the reference cell with a detection signal measured from the flow cell. Accordingly, noise derived from the medium can be removed to obtain a pure particle-derived signal.

[0029] In some embodiments, a laser beam can be continuously passed through a reference cell and a flow cell through a light conversion element such as a mirror or prism. Therefore, sufficient detection intensity can be secured without light loss due to light splitting.

[0030] In some embodiments, optical noise due to light scattering or the like can be additionally removed or reduced using a barrier and a light absorbing layer.

[0031]

[0032] FIG. 1 is a schematic block diagram illustrating a fluid particle measurement device according to exemplary embodiments.

[0033] FIGS. 2 to 8 are schematic cross-sectional views showing the structure of a measuring cell and a light conversion unit of a fluid particle measuring device according to exemplary embodiments.

[0034] FIGS. 9 to 11 are schematic cross-sectional views showing the arrangement / structure of a light blocking / light absorbing portion of a fluid particle measuring device according to exemplary embodiments.

[0035]

[0036] Embodiments of the present invention provide a fluid particle measurement device including a fluid cell and a light source.

[0037] The above-described fluid particle measuring device may be a device that calculates the number and size of fluid particles by detecting a shock wave or flash caused by plasma generated when a laser beam collides with fluid particles. According to exemplary embodiments, the fluid particle measuring device can measure the size and frequency (number) of nanoscale particles of 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 50 nm or less, 40 nm or less, 30 nm or less, 20 nm or less, and 10 nm or less.

[0038] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. However, the following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the contents of the invention described above, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited to the matters described in such drawings.

[0039] The terms “first,” “second,” “top,” “bottom,” “upper,” and “lower” used in this specification do not limit absolute positions or orders, but are used in a relative sense to distinguish different components or parts.

[0040] FIG. 1 is a schematic block diagram illustrating a fluid particle measurement device according to exemplary embodiments.

[0041] Referring to FIG. 1, a fluid particle measurement device (100) may include a light source (105), a measurement cell (140, 145), and a detector (160).

[0042] The light source (105) may be a laser light generating device. According to exemplary embodiments, a pulsed laser beam (B) may be generated from the light source (105). For example, the light source (105) may include an Nd:YAG pulsed laser beam light source having a wavelength in the range of 500 nm to 600 nm (e.g., 532 nm). The type and light wavelength of the light source (105) may be appropriately changed in consideration of the target particle to be measured and beam shaping described below.

[0043] In some embodiments, laser light generated from a light source (105) may pass through an optical diaphragm (110). The diameter or output of the laser light or laser beam may be adjusted through the optical diaphragm (110). For example, the diameter or output of the laser beam may be reduced through the optical diaphragm (110). In some embodiments, the optical diaphragm (110) may include an attenuator.

[0044] A laser beam generated from a light source (105) or a laser beam processed through an optical aperture (110) may be incident on a beam splitter (120). In some embodiments, the laser beam may be reflected through a mirror (115) and incident on the beam splitter (120).

[0045] The beam splitter (120) can pass some of the incident laser beam and reflect some of the incident laser beam. Some of the laser beam can be reflected by the beam splitter (120) and irradiated to the flow cell (140). Some of the laser beam can pass through the beam splitter (120) and irradiate to the energy detection unit (125).

[0046] For example, as illustrated in FIG. 1, a pulsed laser beam (B) can be split into a first laser beam (B1) and a second laser beam (B2) by a beam splitter (120). The first laser beam (B1) and the second laser beam (B2) can be irradiated to a flow cell (140) and an energy detection unit (125), respectively.

[0047] The energy size of the second laser beam (B2) split by the beam splitter (120) can be measured through the energy detection unit (125). The energy size of the first laser beam (B1) incident on the measurement cell (140, 145) can be predicted or monitored with the energy measured through the energy detection unit (125).

[0048] The first laser beam (B1) can pass through a lens (130) before being irradiated to the measurement cell (140, 145). The focus of the first laser beam (B1) incident through the beam splitter (120) by the lens (130) can be adjusted to match the sample within the measurement cell (140, 145).

[0049] The lens (130) can adjust the irradiation area and / or focal length of the first laser beam (B1) incident on the measurement cell (140, 145). Accordingly, the detection performance for nanoparticles passing through the flow cell (140) can be improved.

[0050] The focal length can be appropriately adjusted by considering the collision point of the nanoparticles and the pulsed laser beam by the lens (130) and the refractive index of the sample introduced into the flow cell (140). For example, the distance between the lens (130) and the measurement cell (140, 145) can be adjusted by the control unit (180) described below according to the focal length.

[0051] According to exemplary embodiments, the measurement cell (140, 145) may include a flow cell (140) and a reference cell (145).

[0052] A liquid sample in which target particles to be measured are dispersed within a medium can be continuously supplied to the flow cell (140). As the liquid sample is supplied to the flow cell (140), a first laser beam (B1) is irradiated onto the flow cell (140), enabling continuous real-time particle measurement.

[0053] For example, the liquid sample can be supplied through the cell inlet (50) and the liquid sample can be discharged from the cell outlet (55).

[0054] In some embodiments, the flow of the liquid sample may be controlled by the flow control unit (170). For example, the flow rate or volume of the liquid sample passing through the flow cell (140) may be controlled by the flow control unit (170). In one embodiment, the flow control unit (170) may be controlled together with the control unit (180).

[0055] As illustrated in FIG. 1, the flow control unit (170) may be located on the path of the cell outlet (55). In one embodiment, the flow control unit (170) may also be located on the path of the cell inlet (50).

[0056] When the first laser beam (B1) collides with a fluid particle within a liquid sample within the fluid cell (140), a plasma signal may be emitted.

[0057] According to exemplary embodiments, the fluid particle measurement device (100) may be a measurement device using a laser-induced breakdown detection (LIBD) method. For example, when a pulsed laser beam collides with a nanoparticle, the energy level of the nanoparticle becomes excited, and then releases energy while returning to the ground state (or excited state). The released energy causes plasma or shock waves to be generated in the nanoparticle.

[0058] As described above, the energy of the laser beam required to generate laser-induced plasma increases in the order of solid, liquid, and gas. Accordingly, by selecting a laser beam of an appropriate wavelength, laser-induced plasma can be generated by rupturing only solid particles within a liquid sample, for example, in an aqueous solution.

[0059] The laser-induced plasma may generate a shock wave or flash. The shock wave and / or flash may vary depending on the properties of the nanoparticles contained in the liquid sample. The number and / or size of the nanoparticles may be predicted / calculated through the shock wave and / or flash.

[0060] The medium included in the liquid sample may be accommodated within the reference cell (145). In one embodiment, the medium may be included within the reference cell (145), and the target particles supplied to the flow cell (140) may not be included.

[0061] According to embodiments of the present invention, the first laser beam (B1) can pass through the reference cell (145) and the flow cell (140) sequentially and continuously. In one embodiment, the first laser beam (B1) can pass through the reference cell (145) and the flow cell (140) sequentially and continuously. In one embodiment, the first laser beam (B1) can also pass through the flow cell (140) and the reference cell (145) sequentially and continuously.

[0062] According to exemplary embodiments, the fluid particle measurement device (100) may include a light conversion unit (150) that converts an optical path between a reference cell (145) and a fluid cell (140). The design / structure of the reference cell (145), the fluid cell (140), and the light conversion unit (150) will be described in more detail below with reference to FIGS. 2 to 8.

[0063] A detector (160) can be positioned adjacent to the flow cell (140) to measure the shock wave and / or flash.

[0064] In some embodiments, the detector (160) may include a camera, such as a charge-coupled device (CCD) camera, which may be provided as a flash detector. In one embodiment, a filter may be placed between the CCD camera and the measurement cells (140, 145) to allow flashes of a specific wavelength band to pass through.

[0065] In some embodiments, the detector (160) may include a piezoelectric sensor. The piezoelectric sensor may be provided as a shock wave detector. For example, the piezoelectric sensor may convert vibrations generated by the shock wave into electrical energy.

[0066] In some embodiments, the piezoelectric sensor and the flash detector described above may be positioned adjacent to the measurement cells (140, 145), respectively.

[0067] The detector (160) may include a first detector (160a) and a second detector (160b). The first detector (160a) may be positioned adjacent to the reference cell (145) to detect a shock wave or flash caused by plasma generated from the reference cell (145). The second detector (160b) may be positioned adjacent to the flow cell (140) to detect a shock wave or flash caused by plasma generated from the flow cell (140).

[0068] As described above, information about particles can be obtained by detecting the plasma generated when a laser beam collides with target particles within a liquid sample. However, trace amounts of impurities may also be present within the medium in which the target particles are dispersed, and these impurities can also generate plasma. This impurity-derived plasma can act as noise, reducing the reliability and precision of particle information.

[0069] According to the embodiments of the present invention described above, by passing a laser beam through a reference cell (145) containing a medium, a signal generated by plasma derived from impurities in the medium can be separately detected. A pure particle-derived signal can be obtained by subtracting or compensating a signal obtained from the reference cell (145) from a signal derived from plasma obtained from the flow cell (140).

[0070] According to exemplary embodiments, the first laser beam (B1) can be continuously passed through the reference cell (145) and the flow cell (140) without being split. Accordingly, a decrease in the amount of light can be prevented and a sufficient detection intensity can be maintained.

[0071] The operation / measurement mechanism of the above-described fluid particle measuring device (100) can be controlled as a whole by the control unit (180).

[0072] The control unit (180) can control the light source (105) and the flow control unit (170). For example, the control unit (180) can control the period or generation time of the pulse laser beam (B) generated from the light source (105). In addition, the flow control unit (170) can control the period or flow time of the liquid sample supplied to the flow cell (140) by the control unit (180).

[0073] The control unit (180) may also move the lens (130) relative to the measurement cell (140, 145) to adjust the focal length of the first laser beam (B1).

[0074] The control unit (180) can process the signal transmitted from the detector (160) to generate information on nanoparticles contained in the liquid sample. For example, the control unit (180) includes a signal amplifier, a digital signal converter, a Fourier transform unit, etc., and can determine the type, size, or number of nanoparticles by utilizing the frequency components, amplitude, etc. of the shock wave.

[0075] FIGS. 2 to 8 are schematic cross-sectional views showing the structure of a measuring cell and a light conversion unit of a fluid particle measuring device according to exemplary embodiments.

[0076] Referring to FIG. 2, the optical switching unit (150) may include a mirror (155). The laser beam passing through the reference cell (145) is reflected (for example, about 90) by the first mirror (155a). o After being reflected, it is reflected again by the second mirror (155b) (for example, about 90 o (reflected) and can be incident on the flow cell (140).

[0077] In some embodiments, lenses (152) may be positioned adjacent to at least one end of the laser beam of the measurement cell (140, 145) in the direction of travel. In one embodiment, lenses (152) may be positioned adjacent to both ends of the laser beam of the measurement cell (140, 145) in the direction of travel.

[0078] The laser beam can be focused onto the measurement cell (140, 145) and mirror (155) by the lens (152), and measurement errors due to light scattering, etc. can be reduced or suppressed.

[0079] In one embodiment, the lens (130) illustrated in FIG. 1 may be provided as a lens (152) adjacent to the incident surface of the reference cell (145).

[0080] Referring to FIG. 3, the lens (152) may be attached to the measuring cell (140, 145) and provided as a substantially integral single member.

[0081] In one embodiment, lenses (152) may be attached to the incident and exit surfaces of both ends of the reference cell (145) in the direction of propagation of the laser beam, respectively. In one embodiment, lenses (152) may be attached to the incident and exit surfaces of both ends of the flow cell (140) in the direction of propagation of the laser beam, respectively.

[0082] Referring to FIG. 4, the optical conversion unit (150) may include a prism (157). The laser beam passing through the reference cell (145) is reflected (for example, about 90) by the first prism (157a). o After being reflected, it is reflected again (for example, about 90) by the second prism (157b). o (reflected) and can be incident on the flow cell (140).

[0083] The first prism (157a) can be coupled to the emission surface of the reference cell (145). The second prism (157b) can be coupled to the incidence surface of the flow cell (140).

[0084] In some embodiments, as described with reference to FIG. 3, lenses (152) may be positioned adjacent to opposite ends of the measurement cells (140, 145). In this case, the prism (157) may be spaced apart from one end of the measurement cell (140, 145), and the lens (152) may be positioned between the lens (152) and the measurement cell (140, 145).

[0085] Referring to FIG. 5, a lens (152) may be coupled or attached to one surface of a measurement cell (140, 145) to which a prism (157) is not coupled. In one embodiment, a lens (152) may be attached to the incident surface of the reference cell (145) and the exit surface of the flow cell (140), respectively.

[0086] Referring to FIG. 6, a refractive index matching layer (153) may be disposed between the prism (157) and the measurement cells (140, 145). In one embodiment, the refractive index matching layer (153) may be formed between the exit surface of the reference cell (145) and the first prism (157a), and may be formed between the incident surface of the flow cell (140) and the exit surface of the second prism (157b).

[0087] Light loss or light scattering due to the difference in refractive index at the interface between the measuring cell (140, 145) and the light conversion unit (150) can be prevented by the refractive index matching layer (153).

[0088] Referring to FIG. 7, as described above, a lens (152) may be attached to one end of a measuring cell (140, 145) facing a prism (157). A refractive index matching layer (153) may be placed between the lens (152) and the measuring cell (140, 145).

[0089] In one embodiment, a refractive index matching layer (153) may be formed between the incident surface of the reference cell (145) and the lens (152). A refractive index matching layer (153) may be formed between the exit surface of the flow cell (140) and the lens (152).

[0090] Referring to FIG. 8, as described with reference to FIG. 3, the light switching unit (150) includes a mirror, and a lens (152) can be coupled to the ends of the measuring cells (140, 145).

[0091] A refractive index matching layer (153) may be formed between the ends of the measuring cells (140, 145) and the lens (152). In one embodiment, the refractive index matching layer (153) may be formed at both ends of the reference cell (145) and both ends of the flow cell (140), respectively.

[0092] FIGS. 9 to 11 are schematic cross-sectional views showing the arrangement / structure of a light blocking / light absorbing portion of a fluid particle measuring device according to exemplary embodiments.

[0093] Referring to FIG. 9, a partition wall (190) may be placed between the reference cell (145) and the flow cell (140). The partition wall (190) may prevent scattered light from mixing between the reference cell (145) and the flow cell (140). In addition, the mixing of scattered light generated from the lens (152) into the reference cell (145) and the flow cell (140) may also be blocked by the partition wall (190).

[0094] A light absorbing layer (192) may be disposed on the surface of the measuring cell (140, 145). In some embodiments, the light absorbing layer (192) may be disposed on the surface facing the partition wall (190) of the measuring cell (140, 145). For example, in FIG. 9, a light absorbing layer (192) may be disposed on the upper surface of the reference cell (145) and the lower surface of the flow cell (140), respectively.

[0095] As the light absorption layer (192) covers the measurement cell (140, 145), it is possible to prevent detection performance disturbance or deterioration due to scattered light generated by impurities or particles within the measurement cell (140, 145).

[0096] The partition wall (190) and the light absorbing layer (192) are provided as light blocking / light absorbing parts and may include materials having light blocking / absorbing properties, such as metal materials, resin materials, and ceramic materials.

[0097] Referring to FIG. 10, a light absorbing layer (192) may be disposed on each of the two surfaces of the measuring cells (140, 145). For example, the light absorbing layer (192) may be disposed on the surface adjacent to the partition wall (190) of the measuring cells (140, 145).

[0098] In some embodiments, a light absorbing layer (192) may be disposed on the upper and lower surfaces of the reference cell (145) and the upper and lower surfaces of the flow cell (140) in FIG. 9, respectively.

[0099] Referring to FIG. 11, the light absorbing layer (192) may include an opening. A signal emitted from the measuring cell (140, 145) may be detected through the opening.

[0100] In some embodiments, the light absorbing layer (192) disposed on the upper surface of the reference cell (145) may include a first opening (192a). The light absorbing layer (192) disposed on the lower surface of the flow cell (140) may include a second opening (192b).

[0101] The first detector (160a) is arranged to overlap the first opening (192a) in the thickness direction and can detect a signal from the reference cell (145). The second detector (160b) is arranged to overlap the second opening (192b) in the thickness direction and can detect a signal from the flow cell (140).

[0102] According to exemplary embodiments, the fluid particle measurement device (100) may further include a cell mount on which a measurement cell (140, 145) is mounted. The above-described partition wall (190) and light absorbing layer (192) may be included as a component or a member of the cell mount.

[0103] For example, the cell mount includes cell insertion grooves formed between the partition wall (190) and the light absorbing layer (192), and a measurement cell (140, 145) can be inserted into the cell insertion grooves. The cell mount includes side covers covering both ends of the measurement cell (140, 145), and the side covers can each include an optical aperture through which a laser beam is incident and emitted.

Claims

1. A light source that generates a laser beam; A measuring cell including a reference cell and a flow cell through which particles and liquid samples pass, wherein the laser beam is irradiated; an optical switching unit that changes the optical path between the reference cell and the flow cell; and A fluid particle measuring device comprising a detector for detecting signals from the reference cell and the fluid cell.

2. A fluid particle measuring device according to claim 1, wherein the reference cell includes a medium, and the liquid sample passing through the fluid cell includes the medium and the particles.

3. A fluid particle measuring device according to claim 1, wherein the reference cell and the fluid cell are arranged so that the laser beam passes continuously through the reference cell and the fluid cell.

4. A fluid particle measuring device according to claim 3, wherein the optical conversion unit includes a mirror or prism that reflects a laser beam emitted from the reference cell and causes it to enter the fluid cell.

5. A fluid particle measuring device according to claim 4, wherein the mirror includes a first mirror that reflects a laser beam emitted from the reference cell and a second mirror that causes the laser beam reflected from the first mirror to enter the fluid cell.

6. A fluid particle measuring device according to claim 4, wherein the prism includes a first prism that reflects a laser beam emitted from the reference cell and a second prism that causes the laser beam reflected from the first prism to be incident on the fluid cell.

7. A fluid particle measuring device according to claim 6, further comprising a refractive index matching layer disposed between the first prism and the reference cell, or between the second prism and the fluid cell.

8. A fluid particle measuring device according to claim 1, further comprising a lens disposed adjacent to at least one of the ends of the reference cell and the ends of the fluid cell.

9. A fluid particle measuring device according to claim 8, wherein the lens comprises a plurality of lenses arranged adjacent to both ends of the reference cell and both ends of the fluid cell, respectively.

10. A fluid particle measuring device according to claim 9, further comprising a refractive index matching layer disposed between at least one of the lenses and the measuring cell.

11. A fluid particle measuring device according to claim 1, further comprising a partition wall disposed between the reference cell and the fluid cell.

12. A fluid particle measuring device according to claim 11, further comprising a light absorbing layer disposed on surfaces of the reference cell and the fluid cell facing the partitions.

13. A fluid particle measuring device according to claim 12, wherein the light absorbing layer includes an opening.

14. A fluid particle measuring device according to claim 13, wherein the opening comprises a first opening included in the light absorbing layer disposed on the surface of the reference cell and a second opening included in the light absorbing layer disposed on the surface of the fluid cell.

15. A fluid particle measuring device according to claim 14, wherein the detector comprises a first detector for detecting a signal from the reference cell through the first opening, and a second detector for detecting a signal from the fluid cell through the second opening.

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