JPH07120376A - Fine-particle measuring apparatus - Google Patents

Abstract

PURPOSE:To obtain the fine-particle measuring apparatus wherein the particle size and the number of particles of fine particles in which wave lengths of absorbed light are different and which are contained in an opaque solution like measuring sample are different. CONSTITUTION:A plurality of measuring units 8 which generate beams of wavelength-fixed measuring light are installed in a sample flow passage 5 for a foreign-body fine-particle measuring apparatus 10. Wavelengths of the beams of measuring light radiated form the units 8 are set so as to be different from each other. In addition, an absorption photometer 7 which detects the wavelength of light absorbed by a measuring sample 1 is installed in the sample flow passage 5. A detected wavelength by the photometer 7 and measured results by the measuring units 8 are sent to a system part 6. The control part 6 compares wavelengths of plural beams of measuring light from the measuring units 8 with the detected wavelength, it selects the measuring units 8 which generate the beams of light suitable for the sample 1, and it computes the particle size and the number of particles of foreign bodies in the sample 1 by using only the measured results by the selected units.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for measuring fine particles in a fluid, and more particularly to a technique which is particularly effective when applied to a measuring device for measuring the particle size and the number of foreign particles in a sample. The present invention relates to a technique useful for measuring the amount of foreign matter mixed in a liquid sample such as a resist used.

[0002]

2. Description of the Related Art Micron (μ) existing in pure water, chemicals, solutions such as photoresists used for manufacturing semiconductor devices
m) When measuring the particle size, the number of particles, the particle number distribution by particle size, etc. of foreign matter particles of the order, the measurement sample is irradiated with measurement light, and the scattered light generated at this time is detected to obtain the various data described above. There is known a device for measuring fine particles in liquid, which is designed to obtain In this submerged particle measuring apparatus, a sample flow path for allowing a measurement sample to pass at a constant speed is provided, and an optically transparent flow-through cell having chemical resistance is provided in the sample flow path. For this cell, measuring light (laser light) with a wavelength of several hundred nanometers (eg 632.8 nm)
The scattered light reflected from the fine particles at this time was measured as an electric signal by the light receiving element, and the particle size, the number of particles, etc. were calculated based on the measurement result. The measurement light used at this time has a fixed wavelength of one value so that scattered light of the same wavelength can be obtained, thereby improving the measurement accuracy of the fine particles.

[0003]

However, the present inventors have clarified that the above-mentioned technique has the following problems. That is, depending on the solution to be measured (measurement sample), there is a light absorption wavelength band unique to the solution. Therefore, when the wavelength fixed in the fine particle measuring device is included in this wavelength band, the irradiated measurement light is absorbed by the solution or the scattered light is absorbed, and the fine particle measurement is performed with high accuracy. You will not be able to do well. The present invention has been made in view of such circumstances, and even if the measurement sample is an opaque solution and light of a specific wavelength is absorbed by the light absorption wavelength band, the particles of fine particles in the sample are A main object of the present invention is to provide a fine particle measuring device capable of always measuring the diameter and the number of particles with high accuracy. The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0004]

The typical ones of the inventions disclosed in the present application will be outlined below. That is, the fine particle measuring apparatus of the present invention, the sample flow path to which the measurement sample is supplied, is provided with a plurality of irradiation means for generating the measurement light having a fixed wavelength, and the wavelength of the measurement light generated from each irradiation means. Are set to be different from each other.

[0005]

According to the above-mentioned means, the measurement sample can be irradiated with the measurement lights having different wavelengths.
The measurement light that does not belong to the light absorption band of the measurement sample is selected, and only the scattered light by this measurement light is measured to calculate the particle size and the number of particles of the fine particles in the sample. Therefore, with one measurement device, for multiple measurement samples with different light absorption bands,
It becomes possible to measure fine particles.

[0006]

【Example】

(First Embodiment) A first embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a configuration of a measurement wavelength variable type foreign matter in-liquid particle measuring apparatus 10 of this embodiment. As shown in this figure, a liquid measurement sample 1 in which foreign particles in a solution are measured is stored in a measurement sample tank 2. A gas (for example, N ₂ gas) pressurized from the pressurizing device 4 is introduced into the sample tank 2 through the pressurized gas introducing pipe 3, and the measurement sample 1 is operated by the action of the pressurized gas. It moves in the sample flow path 5. The operation of the pressurizing device 4 is controlled by a signal from a system control unit 6 described later, and as a result, the measurement sample 1 moves in the flow path 5 at a predetermined flow velocity. .

An ultraviolet / visible absorptiometer 7 is arranged in the flow path 5. The photometer 7 detects the wavelength of the light absorbed by the measurement sample 1 flowing in the flow channel, and the signal indicating the wavelength of the absorbed light is sent to the system controller 6.

The flow path 5 is further provided with a plurality of measuring units 8, 8, 8, ... And a flow rate measuring / adjusting section 9. These measuring units 8, 8 ... The part 9 constitutes a foreign particle measuring unit 10A.
Among these, a plurality of measurement units 8, 8, ... Includes an optically transparent measurement cell (flow-through cell) formed in the middle of the flow path 5 and a measurement light of a constant wavelength (flow-through cell). It is composed of a measurement light irradiation unit for irradiating a laser beam) and a scattered light detection unit for detecting scattered light after being irradiated on the foreign particle. Then, the measurement sample 1 that has flowed into the measurement cell is irradiated with the measurement light from the measurement light irradiation unit, the scattered light is detected by the scattered light detection unit, and a signal indicating the detection result. Are sent to the system control unit 6. In this case, in each of the measuring units 8, 8, ..., The light receiving element of the detecting section electrically detects the scattered state of the scattered light as a pulse signal. Then, based on the voltage value (amplitude) of this pulse signal and the frequency of occurrence, the system control unit 6 causes the particle size, the number of particles of the foreign particles contained in the sample 1, and the distribution of the number of particles for each stream size. Etc. are calculated.

By the way, the foreign particle measuring apparatus 10 of the present embodiment is provided with a plurality of measuring units 8, 8 ... Which generate measuring light having a fixed wavelength.
Each of the measuring lights generated for every 8 ... Is fixed to a constant value in advance so that the wavelengths thereof are different from each other. Then, the scattered light data obtained by the measurement lights having different wavelengths are sent to the system controller 6. The system control unit 6 recognizes the wavelength band absorbed by the measurement sample 1 detected by the absorptiometer 7, determines the wavelength band outside this band, and measures the measurement units 8, 8 ... The wavelength of light is compared with this wavelength range to determine which measuring unit is most suitable for measuring the foreign particle in the sample 1. And the one that was judged to be optimal
Only one or two or more pulse signals from the measurement units 8 are used as valid scattered light data, and the foreign particle of the measurement sample 1 is calculated using this data. In this case, depending on the processing method, the measurement light may use the signals from all the measurement units 8, 8, ... That do not belong to the wavelength band to calculate the foreign particle.

The flow rate measuring / adjusting section 9 has a function of measuring the moving speed of the measurement sample 1 in the channel and adjusting the moving speed to a constant value. In addition, adjustment of the flow velocity of the sample 1
This is performed by suction pressure feeding by the action of the vacuum state generating means provided in the adjusting section 9. As a result, as a whole of the apparatus 10, the flow rate control of the measurement sample 1 is performed by the action of the pressurizing apparatus 4 and the adjusting unit 9 described above. Then, the adjusted moving speed is sent to the system control unit 6 and is used for measuring the particle size of foreign matter particles and the number of particles. The moving speed / velocity of the sample 1 is appropriately adjusted by the flow rate measuring / adjusting unit 9 which receives a signal from the system control unit, and the moving speed of the sample is variously changed. By using this, it is possible to analyze the mixing state of the foreign particle in the sample 1 in more detail.

As described above in detail, according to the foreign particle measuring apparatus 10 of the first embodiment, depending on the type of the measurement sample 1, the particles of the measuring light having a wavelength other than the wavelength of the light absorbed by the sample are used. Since the measurement is performed, it becomes possible to perform accurate measurement of the foreign particle in any sample (particularly a semitransparent or opaque solution).

(Second Embodiment) Next, a second embodiment of the present invention will be described. FIG. 2 is a block diagram showing the configuration of the measurement wavelength variable foreign matter in-liquid particle measuring device 20 of the second embodiment. In the second embodiment, in place of the plurality of measurement units 8, 8, 8, ... Provided in the flow path 5 in the first embodiment, measurement light (laser light) of various wavelengths is emitted. The only difference from the first embodiment is that a tunable laser measuring unit 18 that can be used is provided. The measurement unit 18 has a configuration in which, when the optimum measurement light wavelength is set for the sample 1 based on a signal from the system control unit 16 described later, the wavelength does not change thereafter.
The measurement unit 18 and the flow rate measurement / adjustment unit 19 constitute a foreign particle measurement unit 20A.

Specifically, the measuring unit 18 includes the flow path 5
A measurement cell formed on the way, a wavelength tunable laser irradiation section for irradiating the cell with measurement light of various wavelengths (laser light), and a scattered light detection section for detecting scattered light obtained at the time of irradiation of the measurement light. Composed by. When the measurement sample 1 flowing from the sample tank 2 into the measurement cell through the sample flow path 15 is irradiated with the measurement light of the predetermined wavelength from the irradiation unit, the scattered light generated at this time is transmitted to the detection unit. Is detected as a pulse signal, and the scattered light data (pulse signal) obtained at this time is sent to the system control unit 16 to calculate the particle size of foreign matter particles in the sample 1, the number of particles, and the like.

The wavelength of the measuring light emitted from the measuring unit 18 is selected by a command signal from the system controller 16. That is, the system control unit 16 measures the wavelength of the light absorbed by the sample 1 based on the signal from the absorptiometer 7 installed in the sample flow path 15, and the measurement result is sent to the system control unit 16. send. Upon receiving the measurement result, the system control unit 16 determines the optimum wavelength (one wavelength that is not absorbed) for measuring the fine particles of the sample 1, and outputs a signal representing the wavelength to the wavelength tunable laser measurement unit 18 described above.
Send to. Then, based on this signal, the unit 18
Therefore, the sample is irradiated with the measurement light having the optimum wavelength for the particle measurement.

Also in this embodiment, similarly to the first embodiment, one measurement sample 1 is irradiated with measurement light of a plurality of wavelengths not belonging to the above wavelength band, and the scattering obtained at this time is obtained. The particle size of foreign particles, the number of particles, and the like may be calculated based on the data concerning the light. In addition, this second
The other structure of the embodiment is the same as the structure of the first embodiment described above, and the corresponding members are designated by the same reference numerals and the description thereof is omitted.

(Third Embodiment) Next, a third embodiment of the present invention will be described. In the third embodiment, the fine particle measuring mechanism (fine particle measuring unit 10A) in the first embodiment is diverted to a laser light scattering type absolute molecular weight measuring device.
The configuration is shown in the block diagram of FIG. In this laser light scattering type absolute molecular weight measuring apparatus 30, the eluent and the measurement sample enter the GPC apparatus 34 through the GPC (gel permeation chromatograph) eluent channel 32 and the measurement sample channel 33, respectively. ing. Then, in this third embodiment,
By the action of the molecular weight measuring unit (fine particle measuring unit) 30A,
The molecular weight of the substance contained in the eluent is measured.

That is, the GPC device 34 separates each component contained in the measurement sample and having different molecular weights from each other,
A GPC chromatograph reflecting the relative molecular weight can be obtained. Then, with respect to the eluate 31 sent from the GPC device 34 to the flow path 35, measurement of components in the liquid by the measurement units 38, 38 ... Arranged in the flow path 35 (molecular weight measurement of a substance in the liquid) Is done.

The measuring units 38, 38 ... Have substantially the same structure as the measuring units 8, 8 ... In the first embodiment, and each of the units 38, 38. (E.g., light) is applied to the eluate 31 to obtain scattered light data corresponding to the molecular weight of the substance contained in the eluate 31. Also in this case, the wavelength of the light absorbed by the eluent 31 is sent to the system control unit 36 by the absorptiometer 37 arranged in the flow path 35, and the control unit 36 receiving the wavelength absorbs the light. The wavelength band of the light to be recognized is recognized, the wavelength range not included in this band is recognized, and one or two or more desired measurement units 38 that emit the measurement light included in the wavelength range are selected. The calculation process is performed using only the scattered light data obtained. At this time, the eluate 31 flowing in the flow path 35 is
A constant flow velocity is achieved by the action of the flow velocity measurement / adjustment unit 39 that constitutes 0A, and the system control unit 36 calculates the molecular weight of the substance contained in the eluate 31 based on this velocity data.

FIG. 4 is a block diagram showing a modified example in which the fine particle measuring mechanism (fine particle measuring unit 20A) in the second embodiment is applied to a laser light scattering type absolute molecular weight measuring apparatus. In this modification, a wavelength tunable laser measurement unit 48 that generates measurement light of various wavelengths is used instead of the plurality of measurement units 38, 38 shown in FIG. The measurement unit 48 includes a flow rate measurement / adjustment unit 4
In cooperation with 9, a molecular weight measuring unit (fine particle measuring unit) 40A is configured.

The wavelength of the measuring light from the measuring unit 48 is determined based on the signal from the system controller 46. That is, the system control unit 46 receives a signal indicating the wavelength band of the light absorbed by the eluent 31 from the absorptiometer 37, and measures the measurement light (laser light) of one wavelength that does not belong to this band by the above measurement. It is generated in the unit 48 and the molecular weight of the substance in the eluate 31 is calculated. Also in this modification, similarly to the third embodiment, one kind of eluent 31 is selected with measurement light of two or more wavelengths that do not belong to the above wavelength band, and the measurement light is sequentially irradiated. The molecular weight of the substance contained in the eluate may be calculated based on a plurality of data concerning the scattered light obtained at this time. The other structure of this modification is the same as the structure of the third embodiment described above, and the corresponding members are designated by the same reference numerals and the description thereof is omitted.

As described above, according to the foreign particle measuring apparatus (absolute molecular weight measuring apparatus) using the particle measuring section of the above-mentioned embodiment, the system control section determines the solution (eluent) to be measured. Recognize the wavelength band of the light to be absorbed,
Since the particle size (molecular weight) and the number of particles are measured using only the scattered light data from the measurement unit that emits the measurement light not included in this band, one measurement device can measure a plurality of light absorption bands having different light absorption bands. The particle size (molecular weight) of fine particles and the number of particles in various kinds of solutions can always be calculated accurately.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say. For example, in the first and third embodiments, the scattered light data from the plurality of measurement units is appropriately selected by the system control unit to perform particle measurement, but based on the signal from the system control unit, The operation of the measurement unit that is not suitable for measurement may be stopped.

In the above description, the invention mainly made by the present inventor has been applied to the foreign particle measuring apparatus and the absolute molecular weight measuring apparatus which are the fields of application in the background, but the invention is not limited thereto. However, it can be generally used for measuring the size, content, etc. of substances contained in a fluid.

[0024]

The effects obtained by the representative one of the inventions disclosed in the present application will be briefly described as follows. That is, the measurement of the fine particles contained in the semitransparent or opaque solution can be performed by one measuring device, and the throughput is improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a measurement wavelength variable type foreign matter in-liquid particle measuring device 10 of a first embodiment.

FIG. 2 is a block diagram showing a configuration of a measuring wavelength variable foreign matter in-liquid particle measuring device 20 of a second embodiment.

FIG. 3 is a block diagram showing an example in which the fine particle measuring mechanism in the first embodiment is diverted to a laser light scattering type absolute molecular weight measuring apparatus.

FIG. 4 is a block diagram showing an example in which the fine particle measuring mechanism in the second embodiment is diverted to a laser light scattering type absolute molecular weight measuring apparatus.

[Explanation of symbols]

 1 Liquid Measurement Sample 5 Sample Flow Path 6 System Control Section 7 Ultraviolet / Visible Absorptiometer 8 Measurement Unit 10 Measurement Wavelength Variable Foreign Particle Particle Measuring Device 10A Foreign Particle Particle Measuring Section (Particle Measuring Mechanism) 18 Wavelength Variable Laser Measuring Unit

Claims (3)

[Claims] 1. A sample passing through a sample flow path is irradiated with measuring light, scattered light generated during irradiation is detected, and the particle size of the fine particles in the sample, that is, the number of particles is determined based on the detection result. In the fine particle measuring device for measuring, the sample flow path is provided with a plurality of irradiation means for generating measurement light having a fixed wavelength, and the wavelengths of the measurement light generated from the respective irradiation means are set to be different from each other. A particle measuring device characterized in that 2. The sample light passing through the sample flow path is irradiated with measuring light, scattered light generated at the time of irradiation is detected, and the particle size of the fine particles in the sample, that is, the number of particles is determined based on the detection result. In the fine particle measuring device for measuring, the sample flow path is provided with an irradiating means for generating variable wavelength measuring light. 3. A wavelength measuring unit installed in the sample flow path for detecting the wavelength of light absorbed by the sample, and the irradiation unit irradiates the wavelength based on the wavelength measured by the wavelength measuring unit. The control means for selecting a measurement light and calculating the particle size and the particle amount based on the measurement result of the scattered light related to the selected measurement light is included. Particle measuring device.