Flow particle measuring apparatus and flow particle measuring method

Abstract

Disclosed are a flow particle measuring apparatus and a flow particle measuring method. The flow particle measuring apparatus comprises: a light source for generating a laser beam; a flow cell which is irradiated with the laser beam and through which a liquid sample including particles to be measured passes; a flow path for supplying the liquid sample to the flow cell; a flow meter that is coupled to the flow path and measures the flow rate of the liquid sample; and a temperature sensor for measuring the temperature around the flow cell or the light source.

Description

Fluid particle measuring device and fluid particle measuring method

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

[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] For example, information about particles can be obtained through the plasma generated when a laser beam collides with the particles. In this case, measurement accuracy and reliability can be affected by the output of the laser beam and the conditions of the liquid sample supplied to the flow cell.

[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 that generates a laser beam; and a flow cell through which the laser beam is irradiated and through which a liquid sample containing particles to be measured passes; a flow path that supplies the liquid sample to the flow cell; a flow meter coupled to the flow path that measures the flow rate of the liquid sample; and a temperature sensor that measures the temperature around the flow cell or the light source.

[0013] 2. A fluid particle measuring device according to the above 1, wherein the flow path includes a cell inlet through which the liquid sample is introduced into the flow cell and a cell outlet through which the liquid sample is discharged from the flow cell.

[0014] 3. A fluid particle measuring device according to the above 2, wherein the flow meter includes a first flow meter coupled to the cell outlet.

[0015] 4. A fluid particle measuring device according to the above 3, wherein the flow meter further includes a second flow meter coupled to the cell inlet.

[0016] 5. A fluid particle measuring device further comprising a flow valve coupled to the flow path together with the flow meter in the above 1.

[0017] 6. A fluid particle measuring device further comprising a flow control unit that controls the flow rate of the liquid sample supplied to the flow cell according to the flow rate measured from the flow meter in the above 1.

[0018] 7. A fluid particle measuring device according to the above 1, wherein the temperature sensor includes a first temperature sensor disposed adjacent to the fluid cell and a second temperature sensor disposed around the light source.

[0019] 8. A fluid particle measuring device further comprising a control unit that adjusts the output of the laser beam according to the temperature measured from the temperature sensor in the above 1.

[0020] 9. A method for measuring a flow particle, comprising: a step of analyzing a first correlation between temperature and plasma generation energy, and a second correlation between flow rate and plasma generation frequency; a step of irradiating a laser beam onto a flow cell through which a liquid sample including particles passes, to measure the temperature around the flow cell and the flow rate into the flow cell together with particle measurement; a step of deriving a temperature-derived plasma generation value from the first correlation according to the measured temperature and subtracting the value from the plasma generation value measured from the flow cell; and a step of adjusting the flow rate of the liquid sample supplied to the flow cell within a predetermined range set from the second correlation according to the measured flow rate.

[0021] 10. A method for measuring fluid particles, further comprising a step of controlling the temperature inside the fluid cell or the liquid sample according to the measured temperature in the above 9.

[0022] 11. A method for measuring fluid particles, further comprising a step of controlling the output of the laser beam irradiated onto the fluid cell according to the measured temperature in the above 9.

[0023]

[0024] A fluid particle measurement device according to embodiments of the present invention may include a temperature sensor positioned around a laser light source and / or a fluid cell. The temperature sensor can detect when the temperature of the fluid particle measurement device exceeds an appropriate range. Accordingly, the temperature within the fluid particle measurement device can be adjusted again or the output of the laser beam can be adjusted. Accordingly, an appropriate laser beam output for plasma generation in the fluid cell can be maintained.

[0025] Additionally, the temperature-derived value can be compensated for by the measured temperature or the temperature-derived value from the set laser output. Accordingly, the measurement precision and reliability of the fluid particle measurement device can be improved.

[0026] According to exemplary embodiments, a flow particle measurement device may include a flow meter coupled to a flow path of a flow cell. The flow meter may measure the flow rate of a liquid sample supplied to the flow cell, and if the flow rate deviates from an appropriate flow rate, the flow rate may be adjusted through a flow control unit. Accordingly, an appropriate flow rate for plasma generation in the flow cell may be continuously maintained.

[0027]

[0028] Figures 1 and 2 are schematic block diagrams showing a fluid particle measuring device according to exemplary embodiments.

[0029] Figure 3 is a schematic flowchart illustrating a method for measuring fluid particles according to exemplary embodiments.

[0030]

[0031] Embodiments of the present invention provide a fluid particle measurement device including a fluid cell and a light source. In addition, a particle measurement method using the fluid particle measurement device is provided.

[0032] 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, and 10 nm or less.

[0033] 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.

[0034] 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.

[0035] Figures 1 and 2 are schematic block diagrams illustrating a fluid particle measurement device according to exemplary embodiments. Figure 3 is a schematic flowchart illustrating a fluid particle measurement method according to exemplary embodiments.

[0036] Hereinafter, a fluid particle measuring device and a fluid particle measuring method using the same are described together with reference to FIGS. 1 to 3.

[0037] Referring to FIGS. 1 to 3, a fluid particle measurement device (100) may include a light source (105), a fluid cell (140), and a detector (160).

[0038] 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.

[0039] In some embodiments, the laser light generated from the light source (105) may pass through an attenuator (110). For example, the attenuator (110) may include an optical diaphragm. The output of the laser beam may be adjusted through the attenuator (110). For example, the output of the laser beam may be reduced through the attenuator (110).

[0040] A laser beam generated from a light source (105) or laser light processed through an attenuator (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).

[0041] 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) (e.g., the first energy detection unit).

[0042] 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.

[0043] 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).

[0044] The first laser beam (B1) can pass through a lens (130) 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 (130) can be adjusted to match the sample within the flow cell (140).

[0045] The lens (130) 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. In some embodiments, the lens (130) may be provided as a condenser lens.

[0046] 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 flow cell (140) can be adjusted by the control unit (180) described below according to the focal length.

[0047] 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.

[0048] 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).

[0049] 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).

[0050] 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).

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] A detector (160) can be placed around the flow cell (140) to measure the shock wave and / or flash.

[0056] In some embodiments, the detector (160) may include a camera, such as a CCD camera or a CMOS camera, which may be provided as a flash detector. In one embodiment, a filter may be placed between the camera and the flow cell (140) to block or pass flashes of a specific wavelength band.

[0057] 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.

[0058] For example, the piezoelectric sensor may be positioned adjacent to the flow cell (140). In some embodiments, the shock wave detector and the scintillation detector described above may each be positioned adjacent to the flow cell (140).

[0059] In some embodiments, the laser beam passing through the flow cell (140) may be introduced into an energy detection unit (150) (e.g., a second energy detection unit). The final energy after plasma generation may be measured through the energy detection unit (150).

[0060] The operation / measurement mechanism of the above-described fluid particle measuring device (100) can be controlled as a whole by the control unit (180).

[0061] 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).

[0062] The control unit (180) may also move the lens (130) relative to the flow cell (140) to adjust the focal length of the first laser beam (B1).

[0063] 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.

[0064] A fluid particle measuring device according to embodiments of the present invention may include a temperature sensor. According to exemplary embodiments, the temperature sensor may be positioned around the light source (105) and / or the flow cell (140) to measure or detect the temperature of the light source (105) or the surroundings of the light source (105) generated by the laser beam, and the temperature of the liquid sample within the flow cell (140).

[0065] In one embodiment, the correlation (first correlation) of the threshold energy at which induced discharge plasma is generated within the flow cell (140) depending on temperature can be analyzed (e.g., step S10 of FIG. 3). For example, the correlation between temperature and the threshold energy of the laser beam can be analyzed depending on the type or size of the particle.

[0066] Thereafter, the temperature-derived value derived from the correlation by temperature can be corrected or subtracted from the shock wave or flash intensity due to plasma generation in the flow cell (140) through the detector (160) (e.g., step S40a of FIG. 3).

[0067] In one embodiment, the temperature sensor may include a first temperature sensor (80) positioned adjacent to the flow cell (140). The temperature inside the flow cell (140) can be measured from the first temperature sensor (80) (e.g., step S30 of FIG. 3). From the correlation between the temperature and threshold energy described above, a temperature-derived value can be calculated from the measured temperature.

[0068] In one embodiment, the temperature sensor may include a second temperature sensor (90) positioned adjacent to the light source (105). For example, the correlation between temperature-dependent laser beam fluctuations can be analyzed. Thereafter, the temperature-induced fluctuation output can be compensated for in the set laser output. Accordingly, the laser output supplied for generating induced plasma in the flow cell (140) can be more precisely controlled (e.g., step S40c of FIG. 3).

[0069] In some embodiments, the temperature sensor may be used to detect when the temperature of the fluid particle measurement device exceeds an appropriate range. The temperature sensor may be used to re-regulate the temperature within the fluid particle measurement device (e.g., step S40b of FIG. 3 ) or to control the output of the laser beam via the control unit (180) (e.g., step S40c of FIG. 3 ). Accordingly, an appropriate laser beam output for plasma generation in the fluid cell (140) can be continuously maintained.

[0070] Figure 2 is a partially enlarged block diagram illustrating the arrangement / operation of the flow meter around the flow cell (140).

[0071] Referring to FIG. 2, a flow meter (200) may be coupled to a path through which a liquid sample is introduced and discharged into a flow cell (140). The flow rate of a liquid sample supplied to the flow cell (140) can be measured in real time through the flow meter (200) (e.g., step S30 of FIG. 3).

[0072] If the flow rate of the liquid sample is excessively reduced, the number of particles present in the flow cell (140) may excessively increase. Accordingly, the frequency of plasma generation from the flow cell (140) may excessively increase.

[0073] If the flow rate of the above liquid sample increases excessively, the number of particles present in the flow cell (140) may decrease excessively. Accordingly, the frequency of plasma generation from the flow cell (140) may decrease excessively.

[0074] According to exemplary embodiments, the correlation between the flow rate and the plasma generation frequency (second correlation) can be analyzed (e.g., step S20 of FIG. 3), and an appropriate flow rate range can be set based on the correlation. While the flow rate of the liquid sample in the flow cell (140) is measured in real time through the flow meter (200) (e.g., step S30 of FIG. 3), if the flow rate is out of the above-mentioned range, the flow rate can be adjusted in real time through the flow rate control unit. The flow rate control unit may include a flow rate valve such as a solenoid valve (e.g., step S50 of FIG. 3).

[0075] The flow meter (200) may be coupled to the cell inlet (50) and / or the cell outlet (55). According to preferred embodiments, the flow meter (200) may include a first flow meter (210) coupled to the cell outlet (55). The flow rate of the liquid sample discharged from the flow cell (140) may be measured in real time through the first flow meter (210), and the flow rate of the liquid sample may be adjusted through the first flow valve (215) based on the measurement result.

[0076] As described above, by coupling the flow meter and valve to the cell outlet (55), the flow rate of the liquid sample can be controlled while suppressing contamination of the liquid sample by the flow meter and valve.

[0077] In some embodiments, the flow meter (200) may include a second flow meter (220) coupled to the cell inlet (50). The flow rate of a liquid sample introduced into the flow cell (140) through the second flow meter (220) can be measured in real time, and the flow rate of the liquid sample can be adjusted through the second flow valve (225) based on the measurement result.

[0078] The operation of the flow valve (215, 225) can be controlled through the flow control unit (170).

[0079] The first temperature sensor (80) may be positioned adjacent to or in contact with the flow cell (140). As described above, the internal temperature of the flow cell (140) or the temperature of the liquid sample within the flow cell (140) may be measured in real time through the first temperature sensor (80). The temperature-derived value at the temperature measured from the temperature-energy correlation may be corrected / subtracted from the measured plasma detection value (e.g., steps S30 and S40a of FIG. 3).

Claims

1. A light source that generates a laser beam; and A flow cell through which a liquid sample containing particles to be measured passes while the laser beam is irradiated; A path for supplying the liquid sample to the above flow cell; A flow meter coupled to the above-mentioned euro to measure the flow rate of the liquid sample; and A fluid particle measuring device comprising a temperature sensor for measuring the temperature around the fluid cell or the light source.

2. A fluid particle measuring device according to claim 1, wherein the flow path includes a cell inlet through which the liquid sample is introduced into the flow cell and a cell outlet through which the liquid sample is discharged from the flow cell.

3. A fluid particle measuring device according to claim 2, wherein the flow meter comprises a first flow meter coupled to the cell outlet.

4. A fluid particle measuring device according to claim 3, wherein the flow meter further comprises a second flow meter coupled to the cell inlet.

5. A fluid particle measuring device according to claim 1, further comprising a flow valve coupled to the flow path together with the flow meter.

6. A flow particle measuring device according to claim 1, further comprising a flow control unit that controls the flow rate of the liquid sample supplied to the flow cell according to the flow rate measured from the flow meter.

7. A fluid particle measuring device according to claim 1, wherein the temperature sensor includes a first temperature sensor disposed adjacent to the fluid cell and a second temperature sensor disposed around the light source.

8. A fluid particle measuring device according to claim 1, further comprising a control unit that adjusts the output of the laser beam according to the temperature measured by the temperature sensor.

9. A step of analyzing the first correlation between temperature and plasma generation energy, and the second correlation between flow rate and plasma generation frequency; A step of irradiating a laser beam onto a flow cell through which a liquid sample containing particles passes, thereby measuring the temperature around the flow cell and the flow rate into the flow cell together with particle measurement; A step of deriving a temperature-derived plasma generation value based on the measured temperature from the first correlation and subtracting it from the plasma generation value measured from the flow cell; and A method for measuring a flow particle, comprising the step of controlling the flow rate of the liquid sample supplied to the flow cell within a predetermined range set from the second correlation according to the measured flow rate.

10. A method for measuring fluid particles, further comprising the step of controlling the temperature inside the fluid cell or the liquid sample according to the measured temperature in claim 9.

11. A method for measuring fluid particles, further comprising the step of controlling the output of the laser beam irradiated onto the fluid cell according to the measured temperature in claim 9.

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