Flow particle measurement apparatus

Abstract

This flow particle measurement apparatus comprises: a light source for generating a laser beam; a flow cell through which a liquid sample including particles passes; and a plurality of piezoelectric sensors disposed on one surface of the flow cell, thereby detecting a signal by means of plasma generated when the laser beam collides with the particles. The plurality of piezoelectric sensors extend in the direction parallel to the flow direction of the liquid sample inside 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] However, depending on the position of the particles within the flow cell, variations in the intensity of the detection signal may occur. For example, variations in the intensity and frequency of the shock wave generated when the particle structure is excited by the detection light may occur, resulting in a decrease in detection reliability and resolution.

[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 flow particle measurement device comprising: a light source generating a laser beam; a flow cell through which a liquid sample containing particles passes; and a plurality of piezoelectric sensors disposed on one surface of the flow cell to detect signals generated by plasma generated when the laser beam collides with the particles, the piezoelectric sensors extending in a direction parallel to the flow direction of the liquid sample within the flow cell.

[0013] 2. A fluid particle measuring device according to the above 1, wherein the piezoelectric sensors extend perpendicularly to the direction of incidence of the laser beam into the fluid cell when observed in a planar direction.

[0014] 3. A fluid particle measuring device in the above 1, wherein the piezoelectric sensors extend in the height direction of the fluid cell.

[0015] 4. A fluid particle measuring device in the above 1, wherein the piezoelectric sensors are respectively arranged on the first and second surfaces facing each other in the thickness direction of the fluid cell.

[0016] 5. A fluid particle measuring device in the above 4, wherein the piezoelectric sensors are arranged to overlap each other in the thickness direction of the fluid cell.

[0017] 6. A fluid particle measuring device further comprising an auxiliary piezoelectric sensor disposed on a different surface from the one surface of the fluid cell in the above 1.

[0018] 7. A fluid particle measuring device according to 6 above, wherein the auxiliary piezoelectric sensor is disposed on the surface of the fluid cell facing the direction in which the laser beam is incident on the fluid cell.

[0019] 8. A fluid particle measuring device according to 7 above, wherein the auxiliary piezoelectric sensor is respectively disposed on the third and fourth surfaces of the fluid cell facing the incident direction.

[0020] 9. A fluid particle measuring device in accordance with the above 8, wherein the auxiliary piezoelectric sensor disposed on the third surface and the auxiliary piezoelectric sensor disposed on the fourth surface overlap each other in the incident direction.

[0021] 10. A fluid particle measuring device according to 6 above, wherein a plurality of auxiliary piezoelectric sensors are repeatedly arranged along the flow direction on the surface.

[0022] 11. In the above 10, the auxiliary piezoelectric sensor is a fluid particle measuring device shorter than the piezoelectric sensor.

[0023] 12. A fluid particle measuring device according to 11 above, wherein the auxiliary piezoelectric sensor extends in a direction perpendicular to the extension direction of the piezoelectric sensor.

[0024] 13. A fluid particle measuring device in the above 1, wherein the piezoelectric sensors are directly attached to the fluid cell.

[0025]

[0026] According to embodiments of the present invention, a plurality of piezoelectric sensors extending parallel to the flow direction of a liquid sample may be positioned on a flow cell of a fluid particle measurement device. The piezoelectric sensors may be positioned adjacent to an area where particles are distributed along the particle flow direction. Accordingly, the overall detection intensity from the flow cell may be enhanced, and measurement coverage may be increased.

[0027] The piezoelectric sensor can extend along the length of the flow cell and be positioned perpendicular to the laser beam. This reduces the distance difference between the detection particles and the piezoelectric sensor. Furthermore, multiple parallel piezoelectric sensors can be positioned together to obtain a detection signal in which multiple detection intensities are equalized. This reduces the detection intensity difference due to the distance difference from the piezoelectric sensor.

[0028] In some embodiments, the piezoelectric sensor may also be positioned on the surface of the flow cell facing the direction of incidence of the laser beam. Therefore, the detection direction of the shock wave, which is transmitted substantially three-dimensionally, can be expanded, and the detection intensity can be further increased.

[0029]

[0030] FIG. 1 is a schematic block diagram illustrating a fluid particle measurement device according to exemplary embodiments.

[0031] FIG. 2 is a schematic perspective view illustrating a flow cell and a piezoelectric sensor of a flow particle measurement device according to exemplary embodiments.

[0032] FIG. 3 is a schematic cross-sectional view illustrating a flow cell and a piezoelectric sensor of a flow particle measurement device according to exemplary embodiments.

[0033] FIG. 4 is a schematic perspective view illustrating a flow cell and a piezoelectric sensor of a flow particle measuring device according to exemplary embodiments.

[0034] FIG. 5 is a schematic cross-sectional view illustrating a flow cell and a piezoelectric sensor of a fluid particle measurement 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 may 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, or 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 fluid cell (140), 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 shown 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 flow cell (140) 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 (135) before being irradiated to the flow cell (140). The focus of the first laser beam (B1) incident through the beam splitter (120) by the lens (135) can be adjusted to match the sample within the flow cell (140).

[0049] The lens (135) can adjust the irradiation area and / or focal length of the first laser beam (B1) incident on the flow cell (140). 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 (135) and the refractive index of the sample introduced into the flow cell (140). For example, the distance between the lens (135) and the flow cell (140) can be adjusted by the control unit (180) described below according to the focal length.

[0051] A liquid sample containing particles to be measured (target particles) 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), thereby enabling continuous real-time particle measurement.

[0052] 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).

[0053] 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).

[0054] 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).

[0055] When the first laser beam (B1) whose focal length is adjusted by the lens (135) collides with the flowing particles in the liquid sample within the flow cell (140), a plasma signal can be emitted.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] A detector (160) can be positioned adjacent to the flow cell (140) to measure the shock wave and / or flash.

[0060] 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.

[0061] In some embodiments, the detector (160) may further 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 positioned between the CCD camera and the flow cell (140) to allow flashes of a specific wavelength band to pass through.

[0062] In some embodiments, the piezoelectric sensor and the scintillation detector described above may each be positioned adjacent to the flow cell (140).

[0063] In some embodiments, the laser beam passing through the flow cell (140) may be blocked by the beam stopper (150). Accordingly, the laser beam passing through the flow cell (140) may be prevented from being scattered or reflected, thereby disrupting detection / measurement in the flow cell (140).

[0064] The operation / measurement mechanism of the above-described fluid particle measuring device (100) can be controlled as a whole by the control unit (180).

[0065] 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).

[0066] The control unit (180) may also move the lens (135) relative to the flow cell (140) to adjust the focal length of the first laser beam (B1).

[0067] 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.

[0068] FIG. 2 is a schematic perspective view illustrating a flow cell and a piezoelectric sensor of a flow particle measurement device according to exemplary embodiments.

[0069] In FIG. 2, the X direction may refer to the thickness direction of the flow cell (140), and the Y direction may refer to the height direction (or length direction) of the flow cell (140). In some embodiments, the Y direction may be the flow direction of the liquid sample in the flow cell (140). The Z direction may be the direction in which the laser beam is incident on and passes through the flow cell (140). The Z direction may be the width direction of the flow cell (140).

[0070] As shown in Fig. 2, a liquid sample may be injected (flow in) into the upper surface of the flow cell (140) and discharged (flow out) into the lower surface of the flow cell (140). The upper surface and the lower surface may be XZ planes of the flow cell (140).

[0071] The X-direction, Y-direction, and Z-direction may be substantially perpendicular to each other. For example, the length of the flow cell (140) in the Y-direction may be greater than the length in the Z-direction and the length in the X-direction, respectively. The length of a side of the flow cell (140) in the Y-direction (the height of the flow cell (140)) may be the largest among the lengths of the sides included in the flow cell (140). In one embodiment, the length of the flow cell (140) in the X-direction (the thickness of the flow cell (140)) may be less than the length in the Z-direction (the width of the flow cell (140)).

[0072] As illustrated in FIG. 2, the flow cell (140) may have a cubic shape (rectangular parallelepiped). However, the shape of the flow cell (140) may be appropriately changed, and may have a cylindrical shape, for example.

[0073] As described above, the detector (160) may include a piezoelectric sensor (162). The piezoelectric sensor (162) may be directly attached to the surface of the flow cell (140). The term “direct attachment” as used herein is used to encompass cases where the piezoelectric sensor (162) is in direct contact with the flow cell (140) and cases where it is attached via an adhesive. For example, “direct attachment” may be used to encompass cases where, in addition to an adhesive, an additional functional member / structure is disposed between the flow cell (140) and the piezoelectric sensor (162), or where an empty space (e.g., air) is formed between the piezoelectric sensor (162) and the flow cell (140).

[0074] According to exemplary embodiments, two or more piezoelectric sensors (162) may be disposed on one side of the flow cell (140). In one embodiment, a pair of piezoelectric sensors (162) may be disposed on the one side of the flow cell (140).

[0075] The piezoelectric sensors (162) may be arranged parallel to each other on the above-described surface. For example, the flow cell (140) has a rectangular parallelepiped shape with a height extending in the Y direction, and the piezoelectric sensors (162) may be arranged parallel to each other on the first surface (140a) of the flow cell (140).

[0076] Each of the piezoelectric sensors (162) may have a rod shape extending in the Y direction. Each of the piezoelectric sensors (162) may be parallel to the flow direction of the liquid sample within the flow cell (140).

[0077] In some embodiments, the direction of propagation (incident direction) of the laser beam in the flow cell (140) and the direction of extension of the piezoelectric sensor (162) may be substantially perpendicular to each other when observed in a planar direction (e.g., YZ plane direction).

[0078] As described above, a laser beam incident into the flow cell (140) may collide with particles within the liquid sample to generate plasma. A shock wave generated by the plasma may be detected by a piezoelectric sensor (162).

[0079] According to embodiments of the present disclosure, the piezoelectric sensor (162) is positioned parallel to the flow direction of the liquid sample, thereby increasing coverage of the flow of particles contained within the liquid sample. Accordingly, the detection frequency of particles colliding with the laser beam can be increased, and the detection speed can be improved as continuous particle detection is performed.

[0080] Additionally, as the piezoelectric sensor (162) extends in the height direction of the flow cell (140) and is positioned perpendicular to the laser beam, the distance deviation between the detection particles and the piezoelectric sensor (162) can be reduced.

[0081] Since a plurality of parallel piezoelectric sensors (162) are arranged adjacent to each other, a plurality of detection intensities can be obtained to obtain a detection signal with equalized detection intensities. Accordingly, the detection intensity deviation due to the difference in distance between the detected particle and the piezoelectric sensor (162) can be further reduced.

[0082] FIG. 3 is a schematic cross-sectional view illustrating a flow cell and a piezoelectric sensor of a flow particle measurement device according to exemplary embodiments.

[0083] Referring to FIG. 3, piezoelectric sensors (162) can be arranged to face each other with a flow cell (140) between them.

[0084] In some embodiments, the piezoelectric sensors (162) may be arranged on a first side (140a) and a second side (140b) of the flow cell (140) facing each other in the X direction. As illustrated in FIG. 2, a plurality of piezoelectric sensors (162) may be arranged parallel to each other on the first side (140a), and a plurality of piezoelectric sensors (162) may be arranged parallel to each other on the second side (140b).

[0085] In one embodiment, a pair of piezoelectric sensors (162) may be arranged parallel to each other on the first surface (140a), and a pair of piezoelectric sensors (162) may be arranged parallel to each other on the second surface (140b).

[0086] In one embodiment, the piezoelectric sensor (162) disposed on the first surface (140a) and the piezoelectric sensor (162) disposed on the second surface (140b) may overlap each other in the thickness direction (e.g., X direction) of the flow cell (140).

[0087] As described above, by arranging piezoelectric sensors (162) on opposing surfaces of the flow cell (140), the deviation in the detection distance of particles can be further reduced or leveled.

[0088] FIG. 4 is a schematic perspective view illustrating a flow cell and a piezoelectric sensor of a flow particle measuring device according to exemplary embodiments.

[0089] Referring to FIG. 4, the detector (160) of the fluid particle measuring device (100) may further include an auxiliary piezoelectric sensor (164).

[0090] According to exemplary embodiments, the auxiliary piezoelectric sensor (164) may be disposed on a surface of the flow cell (140) facing the incident direction of the laser beam. For example, the auxiliary piezoelectric sensor (164) may be disposed on a third surface (140c) of the flow cell (140). The third surface (140c) may correspond to the YX surface of the flow cell (140).

[0091] The auxiliary piezoelectric sensor (164) may extend in a direction perpendicular to the piezoelectric sensor (162). In one embodiment, the auxiliary piezoelectric sensor (164) may extend in the thickness direction of the flow cell (140) (e.g., the X direction). The auxiliary piezoelectric sensor (164) may be shorter than the piezoelectric sensor (162).

[0092] In some embodiments, a plurality of auxiliary piezoelectric sensors (164) may be repeatedly arranged on the third surface (140c). For example, a plurality of auxiliary piezoelectric sensors (164) may be repeatedly arranged spaced apart from each other along the flow direction (e.g., Y direction).

[0093] By positioning the auxiliary piezoelectric sensor (164) in a direction facing the laser beam, the detection direction of the shock wave can be expanded. In addition, by securing detection intensities in multiple areas, deviations according to the detection distance can be further reduced or leveled.

[0094] FIG. 5 is a schematic cross-sectional view illustrating a flow cell and a piezoelectric sensor of a fluid particle measurement device according to exemplary embodiments.

[0095] Referring to FIG. 5, auxiliary piezoelectric sensors (164) can be arranged to face each other with the flow cell (140) between them.

[0096] In some embodiments, the auxiliary piezoelectric sensors (164) may be arranged on the third side (140c) and the fourth side (140d) of the flow cell (140) facing each other in the Z direction. As illustrated in FIG. 5, a plurality of auxiliary piezoelectric sensors (164) may be arranged parallel to each other on the third side (140c), and a plurality of auxiliary piezoelectric sensors (164) may be arranged parallel to each other on the fourth side (140d).

[0097] In one embodiment, the auxiliary piezoelectric sensor (164) disposed on the third surface (140c) and the auxiliary piezoelectric sensor (164) disposed on the fourth surface (140d) may overlap each other in the width direction (e.g., Z direction) of the flow cell (140).

[0098] As described above, by arranging auxiliary piezoelectric sensors (164) on surfaces facing each other in the incident direction of the laser beam of the flow cell (140), the detection coverage of particles can be increased while additionally reducing or equalizing the deviation of the detection distance.

Claims

1. A light source that generates a laser beam; a flow cell through which a liquid sample containing particles passes; and A fluid particle measurement device comprising a plurality of piezoelectric sensors disposed on one side of the fluid cell and detecting a signal generated by plasma when the laser beam collides with the particles, the piezoelectric sensors extending in a direction parallel to the flow direction of the liquid sample within the fluid cell.

2. A fluid particle measuring device according to claim 1, wherein the piezoelectric sensors extend perpendicularly to the direction of incidence of the laser beam into the fluid cell when observed in a planar direction.

3. A fluid particle measuring device according to claim 1, wherein the piezoelectric sensors extend in the height direction of the fluid cell.

4. A fluid particle measuring device according to claim 1, wherein the piezoelectric sensors are respectively arranged on the first and second surfaces facing each other in the thickness direction of the fluid cell.

5. A fluid particle measuring device according to claim 4, wherein the piezoelectric sensors are arranged to overlap each other in the thickness direction of the fluid cell.

6. A fluid particle measuring device according to claim 1, further comprising an auxiliary piezoelectric sensor disposed on a different surface from the one surface of the fluid cell.

7. A fluid particle measuring device according to claim 6, wherein the auxiliary piezoelectric sensor is disposed on a surface of the fluid cell facing the direction in which the laser beam is incident on the fluid cell.

8. A fluid particle measuring device according to claim 7, wherein the auxiliary piezoelectric sensor is respectively disposed on the third and fourth faces of the fluid cell facing the incident direction.

9. A fluid particle measuring device according to claim 8, wherein the auxiliary piezoelectric sensor disposed on the third surface and the auxiliary piezoelectric sensor disposed on the fourth surface overlap each other in the incident direction.

10. A fluid particle measuring device according to claim 6, wherein a plurality of auxiliary piezoelectric sensors are repeatedly arranged along the flow direction on the surface.

11. A fluid particle measuring device according to claim 10, wherein the auxiliary piezoelectric sensor is shorter than the piezoelectric sensor.

12. A fluid particle measuring device according to claim 11, wherein the auxiliary piezoelectric sensor extends in a direction perpendicular to the extension direction of the piezoelectric sensor.

13. A fluid particle measuring device according to claim 1, wherein the piezoelectric sensors are directly attached to the fluid cell.

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