KR20130116986A - Particle complex characteristic measurement apparatus - Google Patents

Abstract

PURPOSE: A particle composite property measuring device is provided to enable the correction of the size distribution on a real time by correcting the size of particles grasped by observing images. CONSTITUTION: A particle composite property measuring device includes a main frame (10), a first chamber (30), a particle collection unit (50), a first detection unit (20), and a second detection unit (40). The main frame generates and collects electrons and maintains the vacuum state of the inside. The first chamber is joined to the main frame. The particle collection member is installed inside an internal space (31) of the first chamber. The first detection unit is installed on the first chamber to face the particle collection unit and optically measure the particles collected by the particle collection unit. The second detection unit is installed on the first chamber to face the particle collection unit and injects the particles into the particle collection unit. The particle collection unit performs a function of a stage for the first detection unit and collects the injected articles from the second detection unit.

Description

Particle Complex Characteristic Measurement Apparatus

The present invention relates to a particle composite characteristic measuring apparatus, and more particularly, to a particle composite characteristic measuring apparatus for measuring the size distribution, shape, and components of particles combining the function of a general SEM and the function of a PBMS into a single apparatus. will be.

Conventional techniques for measuring particle size distribution include Particle Beam Mass Spectrometer (PBMS), which includes an aerodynamic lens, an electron gun, an electrostatic deflector, and a Faraday cup. Faraday cup) and the like.

In the PBMS, the particles contained in the gas are concentrated and accelerated in the form of a beam in a low pressure environment, and charged to a saturated state. The charged particles enter the electric field to change its traveling path, The size distribution of the particles can be known.

In aerodynamic lenses, when an aerosol enters the inlet, particles are focused through the lens in several stages, and then focused and accelerated into the first vacuum chamber through the last accelerating nozzle. It is relatively light in comparison with the gas and is discharged by a turbo pump, and the particles are transferred to the electron gun. In the electron gun, electrons from the filament collide with the particle beam, and emit secondary electrons to charge to a positive state until saturation.

The electrostatic deflecting device is composed of a deflecting plate composed of about three sheets of meshes, and a positive (+) pole voltage is applied to a mash plate arranged in the middle to form an electric field. At this time, there may be a relationship between a specific-size particle and a specific voltage. For example, when a 1,000-V power supply is applied, when a 200-nm particle is a critical-size particle, do.

The Faraday cup is a simple metal substrate with electrodes connected to the back side. When the particles adhere to the Faraday cup, the positive ions held by the particles are transferred to the electrode, and the current value of the electrode is measured do.

However, according to the configuration of the general PBMS configured as described above, the concentration of the collected particles can be known by indirect estimation by measuring the current amount of the counter, but it is insufficient to know the exact value. Therefore, in order to measure an accurate value, it is necessary to measure the actual size of the particle by focusing the electron beam again with an electron lens and scanning the particle and imaging the amount of secondary electrons generated at this time. Through this operation, it is possible to correct the real-time size distribution by using and correcting the size of the particles observed in the image.

However, when measuring particle composite properties in this way, it is cumbersome to perform separate particle analysis using PBMS and image analysis using SEM (Scanning Electron Microscope). There is discomfort. It also has the disadvantage that real-time calibration is not possible.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an apparatus for measuring a particle composite characteristic and a method for measuring a particle composite characteristic using the same, the structure of which is improved to simultaneously perform a PBMS function and a SEM function in one equipment. The purpose is.

Particle measuring apparatus according to the present invention, the electron generation and focusing is made, the main frame for maintaining the interior in a vacuum; A first chamber coupled to the main frame; A particle collecting unit installed in an inner space of the first chamber; A first detection unit installed in the first chamber so as to face the particle collecting unit so as to optically measure the particles collected in the particle collecting unit; A second detection unit installed in the first chamber so as to face the particle collecting unit, and injecting particles into the particle collecting unit, wherein the particle collecting unit includes a role of a stage of the first detection unit, And at the same time performing a collecting role of the particles injected from the second detection unit.

According to a preferred embodiment of the present invention, the particle collecting unit is provided with a metal substrate, it may be provided with a Faraday cup that is connected to the electrode on the back.

The first detection unit may include an electron detector (including a secondary electron and a back-scattered electron detector) and an x-ray detector.

In this case, the X-ray detector may be composed of any one of component analysis detectors using X-ray, such as Wave Length Dispersive X-ray Spectroscopy (WDS) or Energy Dispersed X-ray Spectroscopy (EDS).

The second detection unit includes a particle beam mass spectrophotometer (PBMS), a second chamber; A particle focusing unit for injecting an aerosol in which gas and particles are mixed into the second chamber; A nozzle for accelerating particles introduced through the particle focusing unit; An electron gun to charge particles accelerated in the nozzle; A deflection plate for applying only a specific voltage to classify only particles of a specific size among particles charged from the electron gun to saturation; And a particle injection unit for injecting particles of a predetermined size classified in the deflection plate into the particle collecting unit.

In the first chamber, the first and second detection units may be installed on the same surface.

The particle collecting unit may be inclined at a predetermined angle with respect to the electron trajectory generated by the main frame.

The particle collecting unit may be provided in any one of a concave shape and a flat shape so that particles injected from the second detection unit can be collected.

On the other hand, according to a preferred embodiment of the present invention, it may further include a pumping unit for maintaining the interior space of the first and second chamber in a vacuum state.

The pumping unit may include a first vacuum line connected with the first chamber; A second vacuum line connected to the second chamber; And one exhaust pipe for discharging air introduced through the first and second vacuum lines at once.

On the other hand, using the information optically measured in the first detection unit, the control unit for correcting the value measured in the second detection unit in real time; may further include a.

Particle composite characteristics measurement apparatus according to an embodiment of the present invention, the electron generation and focusing is made, the main frame for maintaining the interior in a vacuum; A first chamber coupled to the main frame; A particle collecting unit installed in an inner space of the first chamber; A first detection unit installed in the first chamber so as to face the particle collecting unit, the first detection unit including an electron detector and an x-ray detector for optically measuring the particles collected in the particle collecting unit; A second detection unit installed in the first chamber so as to face the particle collecting unit, the second detecting unit including a particle beam mass spectrometer (PBMS) for injecting particles into the particle collecting unit; And a controller configured to correct measured values in the second detection unit by using the detection information of the first detection unit, wherein the first chamber is set as a shared space of the first and second detection units, The particle collecting unit installed inside the first chamber simultaneously serves as a stage of the first detection unit and a particle collecting role injected from the second detection unit, and the first and second detection units are the same. Focusing the particle collecting unit in the direction.

According to the present invention, since one device can simultaneously implement the functions of the conventional particle beam mass spectrometer (PBMS) and the scanning electron microscope (SEM), the accuracy and convenience of the experiment can be improved and Various properties such as particle size, concentration, shape and composition can be analyzed.

In addition, since the electron beam is focused on the electron lens and scanned on the particles, the actual size of the particles can be observed by imaging the amount of secondary electrons generated at this time. It is possible to correct the size distribution with.

1 is a conceptual diagram of a particle composite characteristic measurement apparatus according to an embodiment of the present invention, and
2 is a flowchart according to a preferred embodiment of the present invention.

Hereinafter, a particle measuring apparatus according to a preferred embodiment of the present invention will be described with the accompanying drawings.

1 is a conceptual diagram of a particle composite characteristic measurement apparatus according to an embodiment of the present invention, and Figure 2 is a flow chart according to a preferred embodiment of the present invention.

Particle complex characteristic measurement apparatus according to the present invention, the main frame 10, the first detection unit 20, the first chamber 30, the second detection unit 40, the particle collecting unit 50 and the pumping unit ( 60).

The main frame 10 is installed in a direction substantially perpendicular to gravity, and is preferably provided in a substantially cylindrical shape. In addition, the main frame 10 may be configured to be airtightly processed, and a vacuum pipe for vacuum treatment may be installed to maintain the internal space of the main frame 10 in a vacuum state.

The first detection unit 20 may include an electron detector 21 and an X-ray detector 22. The electron detector 21 can use the structure of the SEM (electron scanning microscope) previously known as it is. Documents related to the structure of the electron scanning microscope are specifically described in Korean Patent Application Laid-Open No. 2010-0095668 (published on September 1, 2010), and a detailed description thereof will be omitted.

In addition, the first detection unit 20 may further include a component analysis detector (WDS, EDS, etc.) module, and as illustrated, includes an X-ray detector 22. Detectors for component analysis (WDS, EDS, etc.) can be configured. The X-ray detector 22 is a device attached to an electron microscope to analyze a component of a sample, and a high-energy electron beam reacts with the specimen to display characteristic X-rays among various signals including the structure and chemical composition information of the specimen. can be used to analyze the composition of the specimen.

In the component analysis detector, qualitative analysis and quantification by measuring the wavelength and amount of the EDS and the characteristic X-rays using the energy of the characteristic X-rays generated during the deexcitation process generated in the atoms by the emission of the cabinet electrons by the particle beam. WDS for analysis.

EDS is the most widely used Si (Li) or Ge semiconductor device for X-ray detection, and it has the disadvantage of lowering the resolution of peak and precision in quantitative analysis, compared to WDS, but it is very simple to operate even for beginners. It has a short signal acquisition time and can be used widely because it can process a large amount of data.

In the first chamber 30, the first collecting unit 20 and the second detecting unit 40 to be described later are disposed on the same side, and the particle collecting unit installed in the internal space 31 of the first chamber 30. It is preferable that the first and second measurement units 20 and 40 are disposed at 50 in the same direction.

The internal space 31 of the first chamber 30 may be configured to maintain a vacuum state, and for this purpose, the first vacuum line 61 may be connected to the bottom surface side. At this time, the first vacuum line 61 is connected to a second vacuum line 62 which discharges the internal air of the second detection unit 40 to create a vacuum state, and exhausts the same to the pumping unit 60. It is desirable to be provided to perform the operation. In this case, the first and second vacuum lines 61 and 62 share the exhaust pipe 63, and the air in the first and second chambers 30 and 41 is one exhaust pipe 63. It is desirable to discharge it.

According to such a configuration, since it is not necessary to include a plurality of pumping units 60, the manufacturing cost can be reduced, and the equipment can be further miniaturized by sharing the exhaust flow path.

Meanwhile, as described above, the particle collecting unit 50 may be installed in the internal space 31 of the first chamber 30, and the particle collecting unit 50 may be installed at the main frame 10. It is preferable to arrange | position in the state which inclined predetermined angle (alpha) with respect to the electron trajectory (arrow A) emitted from a predetermined electron generation unit. At this time, the angle α is variable by a predetermined control unit, it is also possible for the user to manually adjust as needed.

According to a preferred embodiment of the present invention, the particle collecting unit 50 is preferably provided as a Faraday cup. The particle collecting unit 50 composed of the Faraday cup is a simple metal substrate, and has a structure in which electrodes are connected to the rear surface. When the particles are attached to the Faraday cup, the positive ions of the particles are transferred to the electrode. The current value of can be measured using a measuring instrument.

According to a preferred embodiment of the present invention, the particle collecting unit 50 provided with the Faraday cup is provided with a metal substrate, the electrode is connected to the back and the structure that can shield the external noise by using an insulator around the electrode It is preferable to have.

It is preferable that the second detection unit 40 is provided with PBMS equipment that is generally used, and the second chamber 41, the particle focusing unit 42, the nozzle 43, the electron gun 44, and the deflection are provided. A plate 45, and a particle injection section 46.

An interior of the second chamber 41 is connected to the second vacuum line 62, and the second vacuum line 62 is connected to the common vacuum pumping unit 60 together with the first vacuum line 61. Can be discharged to the outside.

The particle focusing unit 42 is an aerosol (mixing of gas and particles) focusing mechanism generally made of an aerodynamic lens or the like, and can focus an aerosol made of gas and particles into the center of the electron gun 43. The particle focusing unit 42 is generally composed of an aerodynamic lens, but is not limited thereto. Any particle concentrating unit may be used as long as the particle focusing unit 42 may focus gas and particles simultaneously.

The nozzle 43 accelerates the gas and particles introduced through the particle focusing unit 42 to the electron gun 44.

The electron gun 44 charges the gas including the particles introduced through the nozzle 43 until it is saturated.

The deflection plate 45 (deflector) is used to classify the size of the particles, and loads a specific voltage to the load, and delivers only particles of a specific size to the particle collecting unit 50 side. In this case, the deflection plate 45 is preferably configured so that the particle trajectory included in the aerosol introduced through the particle focusing unit 42 can be vertically changed, but is not limited thereto. Depending on the configuration, it is also possible to adjust the angle automatically or manually so that the particle collecting unit 50 can be accurately focused.

The particle injection unit 46 injects the particles having a predetermined size classified through the deflection plate 45 into the particle collecting unit 50.

A feature of the present invention configured as described above is to use the functions of the existing SEM and PBMS integrated into a single equipment, for this purpose, the particle collecting unit provided with a Faraday cup installed in the first chamber 30 ( 50, the particles introduced through the second detection unit 40 composed of the PBMS, etc. adhere to each other, the cations of the particles are transferred to the electrode installed on the back of the particle collecting unit 40, the electrode The detected current value is measured by a predetermined measuring instrument, and together with this, the particle collecting unit 50 is used as a stage of the electron detector 21.

In addition, the particles scanned by the particle collection unit 40, using the electron and X-ray detector 20, the particle size distribution of the particles through the imaging process can be observed by the measurer in real time. In this case, when there is a difference between the value of the particle size observed with the naked eye and the value of the particle size measured using the measuring instrument, the output value of the measuring instrument may be corrected by using a predetermined controller. In this way, the particle size can always be measured accurately.

2 is a flow chart for schematically explaining the operation of the particle composite characteristic measurement apparatus according to the present invention.

As shown, it may be composed of optical measuring steps made on the first detection unit 20 side to perform the SEM role, and particle injection steps made on the second detection unit 40 side to perform the PBMS role. .

In the first detection unit 20, electrons are generated (S10), and the generated electrons are focused (S20) in the particle collecting unit 50, which serves as a stage with particles supplied from the second detection unit 40. Collide the particles (S30).

When the electrons collide with the particles, secondary electrons and scattering electrons (especially backscattered electrons) are emitted (S50), and the shape and size of the particles can be measured through the detection of the electrons (S51), and at the same time X-rays Is emitted (S40), it is possible to measure the chemical composition of the particles using the emitted X-rays (S41).

On the other hand, on the second detection unit 40 side, particles are injected into the internal space 31 of the first chamber 30 through the particle focusing unit 42 in the trajectory of the arrow B (see FIG. 1). That is, the particle focusing unit 42 introduces an aerosol in a state where gas and particles are mixed into the second chamber 41 (S110). The introduced particles are charged and focused (S120), and the particles are accelerated by separating the gas and the particles from the nozzle 43 (S130), and the particles transferred to the deflection plate 45 are filtered only for particles of a predetermined size. (S140), the particle injection unit 46 is injected into the particle collecting unit 50 to perform a stage role (S150). When particles are collected in the particle collecting unit 50 (S160), the collected particles may be optically detected at the first detection unit 20, and information such as particle concentration may be detected through current measurement. (S161).

According to the present invention configured as described above, the electrode of the particle collecting unit 50 can determine the particle concentration by the amount of current measured, the shape of the particles collected by the particle collecting unit 50 is secondary electron and Since the optical detector 20 composed of a backscattered electron detector or the like can be used to optically grasp and the components can be analyzed using energy dispersive X-ray spectroscopy, the optical distribution, shape and composition of the particles can be determined at once. Of course, the size distribution can be identified at once.

The embodiments of the present invention described above and shown in the drawings should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art will be able to modify the technical idea of the present invention in various forms. Accordingly, such improvements and modifications will fall within the scope of the present invention as long as they are obvious to those skilled in the art.

10; Main frame 20; First detection unit
21; Electronic detectors (secondary electrons, backscattered electrons, etc.)
22; X-ray (X-ray) detector
30; First chamber 31; Inner space
40; Second detection unit 41; The second chamber
42; Particle focusing unit 43; Nozzle
44; PBMS electron total 45; Deflection plate
46; Particle injection unit 50; Particle Collection Unit
60; Pumping unit 61; 1st vacuum line
62; Second vacuum line 63; Exhaust pipe
A; Electron trajectory B; Particle trajectory

Claims (11)

Electron generation and focusing is made, the main frame for maintaining the interior in a vacuum;
A first chamber coupled to the main frame;
A particle collecting unit installed in an inner space of the first chamber;
A first detection unit installed in the first chamber so as to face the particle collecting unit so as to optically measure the particles collected in the particle collecting unit;
And a second detection unit installed in the first chamber so as to face the particle collecting unit and injecting particles into the particle collecting unit.
The particle collecting unit, the particle composite characteristics measuring apparatus characterized in that at the same time performs the role of the stage of the first detection unit, and the collecting role of particles injected from the second detection unit.
The method of claim 1, wherein the particle collecting unit,
It is provided with a metal substrate, the particle composite characteristic measurement apparatus provided with a Faraday cup that is connected to the electrode on the back.
The method of claim 1, wherein the first detection unit,
An apparatus for measuring particle composition characteristics, comprising an electron detector and an x-ray detector.
The method of claim 1, wherein the second detection unit,
Particle Beam Mass Spectrometer (PBMS),
A second chamber;
A particle focusing unit for injecting an aerosol in which gas and particles are mixed into the second chamber;
A nozzle for accelerating particles introduced through the particle focusing unit;
An electron gun to charge particles accelerated in the nozzle;
A deflection plate for applying only a specific voltage to classify only particles of a specific size among particles charged from the electron gun to saturation; And
And a particle injection unit for injecting particles of a predetermined size sorted by the deflection plate into the particle collecting unit.
The method of claim 1, wherein the first chamber,
And said first and second detection units are provided on the same surface.
The method of claim 1, wherein the particle collecting unit,
Particle composite characteristic measurement apparatus characterized in that inclined at a predetermined angle with respect to the electron trajectory generated in the main frame.
The method of claim 6, wherein the particle collecting unit,
Particle composite characteristic measurement apparatus characterized in that it is provided in any one of a concave shape and a flat shape so that the particles injected from the second detection unit can be collected.
5. The method of claim 4,
And a pumping unit which maintains the first and second chamber internal spaces in a vacuum state.
The method of claim 8, wherein the pumping unit,
A first vacuum line connected to the first chamber;
A second vacuum line connected to the second chamber; And
And one exhaust pipe for discharging the air introduced through the first and second vacuum lines at a time.
The method of claim 1,
And a controller for correcting in real time the value measured by the second detection unit using the information optically measured by the first detection unit.
Electron generation and focusing is made, the main frame for maintaining the interior in a vacuum;
A first chamber coupled to the main frame;
A particle collecting unit installed in an inner space of the first chamber;
A first detection unit installed in the first chamber so as to face the particle collecting unit, the first detection unit including an electron detector and an x-ray detector for optically measuring the particles collected in the particle collecting unit;
A second detection unit installed in the first chamber so as to face the particle collecting unit, the second detecting unit including a particle beam mass spectrometer (PBMS) for injecting particles into the particle collecting unit; And
And a controller configured to correct the measured value in the second detection unit by using the detection information of the first detection unit.
The first chamber is set as a shared space of the first and second detection units, and the particle collecting unit installed inside the first chamber serves as a stage of the first detection unit and is injected from the second detection unit. Simultaneously perform the role of collecting particles,
And said first and second detection units focus said particle collecting unit in the same direction.

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