KR100883161B1 - Image processing device and the spatial distrbution evaluation method of paticle size using the same device - Google Patents

Abstract

An image processing apparatus and a method for evaluating distributional characteristics of particle size using the apparatus are provided. The method comprises the steps of preparing a container providing a space comprising a measurement plane, injecting incident light into the container, measuring a two-dimensional intensity distribution of scattered light scattered from particles present on the measurement plane, Processing the two-dimensional intensity distribution of the measured scattered light, and determining a spatial distribution of the size of particles present on the measurement plane.

Description

IMAGE PROCESSING DEVICE AND THE SPATIAL DISTRBUTION EVALUATION METHOD OF PATICLE SIZE USING THE SAME DEVICE}

1 is a block diagram for explaining a particle measuring device according to an embodiment of the present invention.

2 is a block diagram illustrating an image processing apparatus according to an exemplary embodiment.

3 to 7 are block diagrams illustrating a configuration of an image processor according to an exemplary embodiment of the present invention.

8 is a block diagram illustrating a configuration of a data converter according to an exemplary embodiment of the present invention.

9 and 10 are flowcharts of a method for evaluating distributional characteristics of particle size according to an embodiment of the present invention.

11 is a flowchart for explaining a step of converting a data format.

The present invention relates to an image processing apparatus and a method for evaluating distributional characteristics of particle size using the apparatus, and more particularly, an image for calculating spatial distribution of particle sizes by optically measuring two-dimensional scattered light from fine particles. A treatment apparatus and a method for evaluating the distributional characteristics of particle size using the apparatus.

In general, fabrication of semiconductor devices involves the use of plasma generated in a chamber, such as deposition, etching, and etch back. On the other hand, in the container in which the plasma is generated, fine dust particles in the range of tens to hundreds of nm may be generated, which may cause a decrease in yield and performance of the semiconductor device.

According to the prior art, the amount of dust particles generated inside the chamber can be monitored by an optical method. Meanwhile, as high performance and highly integrated semiconductor devices are required, a technology capable of providing information on spatial distribution of particle particles is required, but conventional technologies do not provide information on spatial distribution of particle particles.

An object of the present invention is to provide an image processing apparatus capable of providing information on the spatial distribution of particle particles present in a chamber.

One technical problem of the present invention is to provide a method for evaluating the distribution characteristics of particle size, which can provide information on the spatial distribution of particle particles present in the chamber.

In order to achieve the above technical problems, the image processing apparatus according to the present invention is disposed outside the container providing a space including the measurement plane, from the particles present on the measurement plane by the incident light incident into the container. A measurement unit configured to measure a two-dimensional intensity distribution of scattered light scattered, an image processor electrically connected to the measurement unit, and configured to process the two-dimensional intensity distribution of the measured scattered light, and output data of the image processor Particle size calculation unit for determining the spatial distribution of the size of the particles present on the measurement plane by using.

A method for evaluating the distributional characteristics of particle size according to the present invention comprises the steps of preparing a container that provides a space comprising a measurement plane, injecting incident light into the container, and the scattering of light scattered from the particles present on the measurement plane. Measuring a two-dimensional intensity distribution, processing the two-dimensional intensity distribution of the measured scattered light, and determining a spatial distribution of the size of particles present on the measurement plane.

Optical measurement method is used to measure the size of the fine particles generated in the plasma process. In this optical measuring method, incident light is incident into the container, and the scattered light by the particles is captured as an image using a measuring device, and the captured image is converted into a digital image. The converted digital image may be converted into a particle size through a data processing process.

The measuring device section includes a light detector. The two-dimensional intensity distribution of the scattered light of the light detector may include various noises. For example, since the plasma generates light by itself, the light detector may include image information (hereinafter, referred to as background noise) due to light generated in the plasma in addition to scattered light by the particles. In addition, the scattered light may fluctuate irregularly with time. The light detector may include information on irregular fluctuations over time (hereinafter, referred to as random noise). Image noise, including such background noise and random noise, interferes with the calculation of the exact particle size during data processing.

According to one embodiment of the present invention, the spatial noise of the exact particle size is determined by removing the background noise and the random noise from the two-dimensional intensity distribution of the scattered light.

Thus, by measuring the exact particle size, accurate monitoring of the fine particles generated in the plasma process is possible.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings. In understanding the drawings, it should be noted that like parts are intended to be represented by the same reference numerals as much as possible.

In addition, in the following description, numerous specific details, such as specific process flows, are described to provide a more general understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the present invention may be practiced without these specific details. And detailed description of known functions and configurations that are determined to unnecessarily obscure the subject matter of the present invention is omitted.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram for explaining a particle measuring device 400 according to an embodiment of the present invention.

Referring to FIG. 1, the particle measuring apparatus 400 may include a light emitter 110, first and second polarizers 120 and 150, a light converter 130, a measuring device 180, and an image processor ( 200, and a particle size calculator 300.

The light emitting unit 110 emits incident light B ₁ . Preferably, the incident light B ₁ may be laser light. The light emitter 110 may emit the laser light having a short wavelength to measure the size of the fine particles 145. The laser light may include a helium-neon laser or an argon (Ar) ion laser.

The first polarizer 120 polarizes the incident light B ₁ from the light emitter 110 in the first direction. The first polarizer 120 may include any one of a vertical direction polarizer and a parallel direction polarizer. Thus, the incident light beam (B ₁₎ a first pass through the polarization unit 120 may be polarized in any one of the incident light (B1) of the incident light in the vertical direction and a horizontal direction (B _1).

In addition, the first polarizer 120 may be a half lambda plate (λ / 2 plate). Each time the half lambda plate is rotated by 90 °, the incident light B ₁ may be alternately polarized by the half lambda plate into incident light in a vertical direction or incident light in a horizontal direction.

If the incident light B ₁ is light polarized in the horizontal direction, such as helium-neon laser light, the light emitting part is used to disperse the polarized light into two direction components (horizontal and vertical components) orthogonal to each other. The display device may further include a polarized beam splitter (not shown) provided between the 110 and the first polarizer 120. Therefore, the incident light B ₁ incident on the first polarizer 120 may be composed of two directional components perpendicular to each other.

At least one aperture I ₁ provided between the light emitter 110 and the first polarizer 120 to confirm the straightness of the incident light B ₁ is further included. The aperture I ₁ induces the straightness of the incident light B ₁ incident on the first polarizer 120.

The light converter 130 converts incident light B ₂ of the first direction component polarized by the first polarizer 120 into one-dimensional light B ₃ . The one-dimensional light B ₃ is irradiated into the plasma chamber 140.

The diaphragm I ₂ provided between the first polarizer 120 and the light converter 130 induces linearity of incident light having the first direction component.

The one-dimensional light B ₃ irradiated to the plasma chamber 140 collides with the particles 145 in the plasma chamber 140, and scattered light B ₄ is generated by the collision.

When the light emitter 110, the first polarizer 120, the light converter 130, and the plasma chamber 140 do not coincide with the traveling direction of the light, between the light generator 110 and the plasma chamber 140. At least one reflection mirror M is provided to change the path of the light.

The second polarizer 150 has the same direction component as the first polarizer 120. Therefore, when the first polarizer 120 is a vertical polarizer, the second polarizer 150 is a vertical polarizer. When the first polarizer 120 is a horizontal polarizer, the second polarizer 150 is a horizontal polarizer.

In addition, when the first polarizer 120 is a half lambda plate, the second polarizer 150 may be a half lambda plate that rotates by 90 ° in cooperation with the same direction component. Accordingly, the second polarizer 150 crosses the same direction components of scattered light B ₄ as the direction components polarized by the first polarizer 120.

In addition, when the first polarizer 120 includes a vertical polarizer and a horizontal polarizer, the second polarizer 150 has a polarizer that is interlocked with the direction component of the first polarizer 120. .

To confirm the scattering angle of the scattered light B ₄ , the apertures I ₃ and I ₄ provided between the light converting unit 130 and the second polarizing unit 150 are formed of scattered light B ₄ having a specific scattering angle. Induce straightness. The apertures I ₃ and I ₄ may be tubes.

The light receiving unit 170 measures the intensity of light B ₃ of one-dimensional that does not collide with the particle 145. The light receiving unit 170 may include a photodiode. The light receiving unit 170 measures the intensity of light B _{3 in} one dimension that does not collide with the particle 145, thereby averaging the particles 145 present on a specific surface (one side in two dimensions) in the plasma. Can also be found. The aperture I ₅ provided between the light receiving unit 170 and the light conversion unit 130 induces the linearity of the one-dimensional light B _{3 that} does not collide with the particle 145.

The measuring device unit 180 may include a light detector 160, a plasma vessel 140, and particles 145.

The light detector 160 blocks the two-dimensional intensity distribution of the scattered light B ₄ from irradiating the plasma chamber with the first image data IM1 as the instant image and the one-dimensional light B ₁ . The two-dimensional distribution of the background light photographed inside the plasma chamber may be sequentially stored as the second image data IM2 which is an instant image.

2 is a block diagram illustrating an image processing apparatus according to an exemplary embodiment.

Referring to FIG. 2, the image processing apparatus includes a measuring device unit 180 for measuring a two-dimensional intensity distribution of scattered light disposed around a container, an image processing unit 200 electrically connected to the measuring device unit 180, and The particle size calculator 300 may be electrically connected to the image processor 200.

The measuring device unit 180 is configured to measure the optical properties emitted from the particles present in the space inside the container. To this end, the measuring unit 180 may include a light detector 160 for measuring the scattered light scattered from the particles.

More specifically, the container provides a three-dimensional space including a predetermined two-dimensional measuring plane, and the measuring device unit 180 two-dimensionally scatters light emitted from particles present in the measuring plane. Configured to measure. According to the present invention, the scattered light may be a result of scattering of incident light (B ₁ ) emitted from the light emitting unit 110 by particles present on the measurement plane. It may be the plasma chamber 140 described with reference to, but the container to which the present invention can be applied is not limited thereto.

Meanwhile, the spatial position of the measurement plane may be defined by the light converter 130 or the reflective mirror M. For example, as shown in FIG. 1, when the traveling path of the incident light B ₁ reciprocates the space inside the container at different heights, this reciprocating traveling path of the incident light defines a two-dimensional plane. can do. According to another embodiment of the present invention, the light conversion unit 130 is a cylindrical lens for converting the incident light (B ₁ ) having a cross section of 0 dimension (that is, a point) to have a cross section of one dimension (that is, a line). It may be provided. In this case, the measurement plane may be defined as an intersection plane of the path of the incident light having the one-dimensional cross section defined by the cylindrical lens and the space inside the container. On the other hand, the above description of the measurement plane is only an example for explaining the technical idea of the present invention, the measurement plane may be variously modified by the type and arrangement of the optical components constituting the light conversion unit 130. have.

According to the present invention, the light detector 160 measures the optical characteristics of the scattered light scattered from the measurement plane in two dimensions and converts the optical signal into an electrical signal. To this end, the light detector 160 includes an imaging device having pixels arranged in one or two dimensions. The imaging device may be at least one of a charge coupled device (CCD), a video camera, and a multichannel photo multiplier tuber (PMT), and configured to measure the scattered light in color or black and white.

In addition, the measuring device unit 180 may further include an analog / digital converter. The A / D converter is configured to convert the electrical signal of the scattered light measured by the light detector 160 into digitized first image data IM1 and output the converted digital signal.

The image processor 200 is configured to process the two-dimensional intensity distribution of the measured scattered light to extract a polarization ratio distribution function (SPR). To this end, the image processing unit 200 may include a polarization ratio distribution function extraction unit 240 for extracting a polarization ratio distribution function (SPR) from the signal output from the measuring device unit 180 as shown in FIG. 3. Can be. The polarization ratio distribution function (SPR) represents a two-dimensional distribution of the ratio of the scattered light generated by incident lights having different polarizations.

Specifically, the incident light may be incident into the container with different polarization directions by using the first polarizer 120 described with reference to FIG. 1. In addition, the scattered light may be incident to the light detector 160 having different polarization directions by using the second polarizer 150 described with reference to FIG. 1. The polarization ratio distribution function SPR represents a ratio between the intensities of scattered light having different polarization directions incident to the light detector 160 at each point of the measurement plane.

On the other hand, even when there is no optical scattering between the incident light and the particles, as is known, background light determined by the temperature inside the container can be emitted from the container. Alternatively, if the vessel is a plasma chamber, plasma background light may be emitted from the vessel. The measurement device unit 180 and / or the image processor 200 may be configured to remove the effects of the background light. For example, the signal used to extract the polarization ratio distribution function (SPR) may be a result of subtracting the intensity of background light emitted from the container from the measured intensity of scattered light. In addition, the image processor 200 may be configured to perform a process of measuring the scattered light a plurality of times and averaging the scattered light in order to reduce an effect due to random noise generated during the measurement process. The process of extracting the polarization ratio distribution function (SPR) will be described in more detail later with reference to FIGS. 7 and 10.

According to an embodiment of the present invention, the measuring device unit 180 may be electrically connected to a computer (not shown) including a predetermined processing unit. The processing unit may be one or a combination of microprocessors, microcontrollers, digital signal processors and digital circuitry configured to process certain information. In this case, the processing unit may be used as the image processing unit 200.

The particle size calculator 300 is configured to process the polarization ratio distribution function (SPR) prepared by the image processor 200 to extract information about the size of the particles present on the measurement plane and their spatial distribution. .

Specifically, in the extraction process of the information on the particle size, a quantitative relationship between the polarization ratio and the particle size expressed through the Lorentz-scattering theory can be used. However, it is obvious that other theoretical or empirical data can be used as a quantitative relationship between the polarization ratio and the particle size for the extraction process. On the other hand, since the polarization ratio distribution function (SPR) is distributed data representing the polarization ratio at each point of the measurement plane, when the process of extracting information on the particle size from each point of the measurement plane is completed, the Information about the spatial distribution of particles present on the measurement plane can be obtained.

Meanwhile, according to an embodiment of the present invention, information on the spatial distribution of the particles obtained by the particle size calculator 300 may be visually displayed through a predetermined indicator. In addition, according to the present invention, the polarization ratio distribution function (SPR) may be measured in real time during the process. In this case, the indicator may be configured to represent a temporal change in the particle size distribution. Alternatively, the indicator may be configured to display a result obtained by temporally or spatially averaging information on the particle size distribution.

3 to 7 are block diagrams illustrating the components of the image processor 200 according to example embodiments.

As described above, the image processor 200 may include the polarization ratio distribution function extraction unit 240 as shown in FIGS. 3 to 7. The polarization ratio distribution function extractor 240 is configured to obtain an intensity ratio between scattered light having different polarization directions at positions of respective points of the measurement plane. Scattered light having different polarization directions may be measured with a time difference. Accordingly, the polarization ratio distribution function extracting unit 240 includes an information storage device for storing information on the two-dimensional intensity distribution of the scattered light and an arithmetic device for calculating the intensity ratio of scattered light having different polarization directions. can do.

According to other embodiments of the present disclosure, the image processor 200 may further include a data converter 210 as illustrated in FIGS. 4, 6, and 7. The data converter 210 is configured to easily convert the electrical signals IM1 and IM2 output from the measurement device unit 180 into data types Gr1 and Gr2 that are easily processed by the polarization ratio distribution function extractor 240. Configured to convert. Specifically, since the polarization ratio distribution function extractor 240 is configured to compare the intensities of the polarized light, the signals IM1 and IM2 output from the measurement device unit 180 are the polarization ratio distribution function extractor. It may not be easy to process at 240. For example, when the measuring device unit 180 is a color CCD, a process of removing information on color from the electrical signals IM1 and IM2 may be necessary. The data converter 210 may be configured to remove such unnecessary information, and FIG. 8, which will be described later, illustrates an embodiment of the data converter 210 to perform such a function.

According to still another exemplary embodiment of the present invention, as illustrated in FIGS. 5 to 7, the image processing unit 200 may include a subtraction unit 220 and a memory unit in order to remove the effect of the background light inside the container. 250) may be further included. Specifically, the memory 250 stores information on the two-dimensional intensity distribution of the measured scattered light. The subtractor 220 subtracts the information on the two-dimensional intensity distribution of the measured background light from the information on the two-dimensional intensity distribution of the scattered light. In other words, the subtractor 220 calculates the magnitude of the scattered light minus the intensity of the background light at a position corresponding to each point of the measurement plane. Accordingly, the data output from the subtractor 220 is information Gc about the two-dimensional distribution of the net intensity of the scattered light (hereinafter, the net scattered light intensity distribution) from which the effect of the background light is removed. It is composed. In this case, as described above, in order to extract the polarization ratio distribution function (SPR), it is necessary to compare the intensities of scattered light having different polarization directions, and the net scattered light intensity distributions use scattered light having different polarization directions. It is obtained by.

According to still another embodiment of the present invention, as shown in FIG. 7, the image processor 200 may further include an average value calculator 240 to reduce random noise generated during the measurement process.

The average value calculator 230 sequentially receives information on the two-dimensional intensity distribution of the measured scattered light corresponding to the number of reference frames, and averages the information on the two-dimensional intensity distribution of the measured scattered light. Calculate (Ga)

The reference frame number may be set to a predetermined value. The reference frame number may be five frames. However, the reference frame number may be set to a larger number of frames according to the performance of the CCD camera or the video camera included in the light detector 160.

Meanwhile, all blocks included in the image processor 200 illustrated in FIG. 2 mean functional separation, and do not mean physical separation. In addition, the image processor 200 illustrated in FIG. 2 may be designed as an image processor implemented in a single chip form consisting of logic circuits. Also, the image processor 200 illustrated in FIG. 2 may be a specialized image processing computer rather than a single chip.

In addition, the image processing process by the image processing unit 200 shown in FIG. 2 is implemented in the form of software operated by a general purpose computer such as a special purpose hardware form or a tool control computer or a combination of the hardware form and the software form Can be.

Referring to FIG. 8, the data converter 210 may include a data receiver 212, a color converter 214, and a gray data generator 216.

The data receiver 212 is configured to convert the first image data IM1 and the second image data IM2 into digitized first image data ID1 and second image data ID2, respectively.

The color converter 214 converts the first image data ID1 and the second image data ID2 into first color space data YCrCb1 and second color space data YCrCb1 including luminance information, respectively. Configured to convert.

The gray data generator 216 is configured to convert the first color space data YCrCb1 and the second color space data YCrCb1 into first gray data Gr1 and second gray data Gr2, respectively. .

According to the present invention, the data receiver 212 may include a frame grabber capable of capturing an image of the two-dimensional intensity distribution of the scattered light.

The frame grabber (not shown) may be configured to convert the first image data IM1 from the light detector 160 into various general digital file formats such as TIF, BMP, JPEG, and GIF. Also, the first image data ID1 may be digital file formats including R (red), G (green), and B (blue) information.

The color converter 214 may receive the first image data ID1 in units of frames. The first image data ID1 may be converted into the first color space data YCrCb1 using a color space conversion algorithm. The first color space data YCrCb1 may include first luminance data Y1 including luminance information, first color difference data Cr1 including color difference information, and second color difference data Cb1. On the other hand, the gradation data generating unit 216 sets the gradation level corresponding to the luminance information included in the first luminance data Y1 among predetermined gradation intervals (for example, 256 gradations) as the first gradation data Gr1. It can be configured to convert and output.

9 is a flowchart of a method for evaluating distributional characteristics of particle size, in accordance with an embodiment of the present invention.

Referring to FIG. 9, in the method for evaluating the distribution characteristics of particle size, preparing a container providing a space including a measurement plane (S100), and incident light into the container, the particles present on the measurement plane Measuring the two-dimensional intensity distribution of the scattered light from (S200), processing the measured two-dimensional intensity distribution of the scattered light (S300), and determines the spatial distribution of the size of the particles present on the measurement plane It includes a step (S400).

According to an embodiment of the present invention, the determining of the spatial distribution of the particle size may include determining the size distribution of the particles present on the measurement plane by using the relationship between the polarization ratio distribution function and the particle size. It may include.

According to an embodiment of the present invention, the relation between the polarization ratio distribution function and the particle size may be a relation by Lorentz-Scattering theory.

According to an embodiment of the present invention, the polarization ratio distribution function may be data representing the intensity of the scattered light at each position on the traveling path of the incident light.

According to an embodiment of the present invention, the vessel may be a plasma processing chamber loaded with a substrate, and the measurement plane may be a plane perpendicular to the substrate.

According to one embodiment of the present invention, the incident light has a path reciprocating the measurement plane at different heights, thereby scanning the measurement plane in two dimensions.

10 is a flowchart of a method for evaluating distributional characteristics of particle size, in accordance with an embodiment of the present invention.

Referring to FIG. 10, in the method for evaluating the distribution characteristic of particle size, preparing a container providing a space including a measurement plane (S100), and incident light into the container, the particles present on the measurement plane Measuring the two-dimensional intensity distribution of the scattered light from (S200), processing the measured two-dimensional intensity distribution of the scattered light (S300), and determines the spatial distribution of the size of the particles present on the measurement plane It includes a step (S400).

Measuring the two-dimensional intensity distribution of the scattered light (S200) may be repeated for a predetermined reference frame to remove random noise. To this end, a predetermined reference frame value N may be determined and an initial state state may be set (S10).

Measuring the two-dimensional intensity distribution of the scattered light (S200) is a first incident light having a different polarization direction and a second incident light incident into the container, the first scattered from the particles present on the measurement plane Measuring two-dimensional intensity distributions of the scattered light and the second scattered light (S210), and processing the two-dimensional intensity distribution of the measured scattered light (S300) is the two-dimensional of the first and second scattered light Processing the red intensities to obtain a polarization ratio distribution function (S360). The first incident light and the first scattered light may be vertically polarized light, and the second incident light and the second scattered light may be horizontally polarized light.

According to one embodiment of the invention, the first incident light and the second incident light may be incident into the container in turn. That is, the first incident light and the second incident light may be incident into the container in sequence at a first time interval, but the first time interval may be 0 second to 10 sec.

According to a modified embodiment of the present invention, the step of measuring the two-dimensional intensity distribution of the scattered light (S200) is to block the incident light in the interior of the container, and measuring the two-dimensional distribution of background light ( S212), and processing the measured two-dimensional intensity distribution of the scattered light (S300) is a two-dimensional intensity distribution of the background light in the two-dimensional intensity distributions of the first scattered light and the second scattered light The method may further include extracting two-dimensional distributions of the first net scattered light and the second net scattered light (S330). Accordingly, background noise is removed from the two-dimensional intensity distributions of the first and second net scattered light.

In detail, the step S210 of measuring the two-dimensional intensity distributions of the first scattered light and the second scattered light may be performed by the imaging device. The imaging device converts the two-dimensional distribution of the first and second scattered light into an electrical signal, converts the converted electrical signal into first image data IM1 having a digital signal form, and outputs the first signal. The image data IM1 may be divided into the vertical first image data IM1 and the horizontal first image data IM1 according to the polarization state.

Similarly, measuring the two-dimensional intensity distributions of the background light (S212) may be performed by the imaging device. The imaging unit may convert the two-dimensional distribution of the background light into an electrical signal, and convert the converted electrical signal into second image data IM2 having a digital signal form and output the converted signal.

Processing the measured two-dimensional intensity distribution of the scattered light (S300) is a step of converting the data format of the measured two-dimensional intensity distribution of the scattered light (S320) and the two-dimensional intensity distribution of the measured background light Converting the data format (S322), subtracting the two-dimensional distribution of the measured background light from the measured two-dimensional intensity distribution of the scattered light to obtain a two-dimensional intensity distribution of the net scattered light (S330), the net The method may include repeating the two-dimensional intensity distribution of the scattered light a plurality of times (S340), averaging the two-dimensional intensity distribution of the net scattered light (S350), and obtaining a polarization ratio distribution function (S360).

11 is a flowchart for explaining a step of converting a data format.

Referring to FIG. 11, in operation S320, the data format of the measured two-dimensional intensity distribution of the scattered light is converted into the first image data in digital form. S320a), converting the first image data into first color space data including luminance information using a color space conversion algorithm (S320b), and converting the first color space data into first grayscale data. It may include at least one step of the data conversion step (S320c).

Since the data format of the measured scattered light and the data format of the measured background light may be converted using the data converter 210 described above with reference to FIG. 8, a detailed description thereof will be omitted.

Referring back to FIG. 10, the step S330 of extracting the secondary distributions of the first net scattered light and the second net scattered light may include the two-dimensional distribution of the background light in the two-dimensional intensity distribution of the first scattered light. By subtracting the two-dimensional distribution of the first net scattered light, subtracting the two-dimensional distribution of the background light from the two-dimensional intensity distribution of the second scattered light, the two-dimensional distribution of the second net scattered light Can be extracted.

The polarization ratio distribution function is determined as a ratio of two-dimensional intensities of the averaged first and second scattered light, wherein the two-dimensional intensities of the averaged first and second scattered light are two of the first and second scattered light. The method may include measuring the dimensional intensity distributions repeatedly (S340) and averaging the two-dimensional intensity distributions of the first scattered light and the second scattered light (S350). The repeated measuring (S340) and the averaging step (S350) is to remove the random noise.

According to a modified embodiment of the present invention, measuring the two-dimensional intensity distribution of the measured scattered light (S200) is a step of measuring the two-dimensional intensity distributions of the first and second scattered light (S310) and the background light And a step S312 of measuring a two-dimensional intensity distribution, and processing the two-dimensional intensity distribution of the measured scattered light (S300) to extract a two-dimensional intensity distribution of the first and second net scattered light. Step S330 and extracting the polarization ratio distribution function may be included (S360).

According to a modified embodiment of the present invention, the step of measuring the two-dimensional intensity distribution of the scattered light (S200) is a step of measuring the two-dimensional intensity distributions of the first and second scattered light (S210) and the two-dimensional of the background light Including the intensity distribution (S212), and processing the two-dimensional intensity distribution of the measured scattered light (S300) is a step of transforming the data (S320), two of the first and second net scattered light The method may include extracting a dimensional intensity distribution (S330) and extracting a polarization ratio distribution function (S360).

On the other hand, "comprises / comprising" as used herein is used to specify the presence of a feature, integral, step or component of the present invention, but one or more other features, integrals, steps, components It does not exclude the presence of additional groups or hearing.

According to the image processing apparatus and the method for evaluating the distribution characteristics of the particle size using the apparatus according to the present invention as described above, it is possible to provide information on the spatial distribution of the particles of particles present in the chamber. In addition, the spatial distribution of the exact particle size can be measured by removing random noise and / or background noise from the two-dimensional intensity distribution of the scattered light. As a result, accurate monitoring of the fine particles generated in the plasma process is possible.

Claims (18)

Preparing a container providing a space comprising a measurement plane; Injecting incident light into the vessel to define the measurement plane through reflection and to measure a two-dimensional intensity distribution of scattered light scattered from particles present on the measurement plane; Processing the two-dimensional intensity distribution of the measured scattered light; And Determining a spatial distribution of the size of particles present on the measurement plane. The method of claim 1, Measuring the two-dimensional intensity distribution of the scattered light is to enter the first incident light and the second incident light having a different polarization direction into the container, the first scattered light and the first scattered light from the particles present on the measurement plane Measuring two-dimensional intensity distributions of the scattered light; Processing the two-dimensional intensity distribution of the measured scattered light includes processing the two-dimensional intensities of the first and second scattered light to obtain a polarization ratio distribution function. Assessment Methods. The method of claim 2, Measuring the two-dimensional intensity distribution of the scattered light further comprises the step of measuring the two-dimensional intensity distribution of the background light in the state of blocking the incident light entering the inside of the container, The processing of the measured two-dimensional intensity distribution of the scattered light includes: subtracting the two-dimensional intensity distribution of the background light from the two-dimensional intensity distributions of the first scattered light and the second scattered light, thereby obtaining the first net scattered light and the second net. And extracting the two-dimensional distributions of the scattered light. The method of claim 2, The polarization ratio distribution function is determined as a ratio of two-dimensional intensities of the averaged first and second scattered light, Processing the two-dimensional intensity distribution of the measured scattered light Repeatedly measuring the two-dimensional intensity distributions of the first scattered light and the second scattered light several times; And And averaging two-dimensional intensity distributions of the first scattered light and the second scattered light. The method according to any one of claims 2 to 4, Processing the two-dimensional intensity distribution of the measured scattered light And converting the data format of the measured two-dimensional intensity distribution of the scattered light. The method of claim 5, wherein Converting the data format of the two-dimensional intensity distribution of the measured scattered light Converting the measured two-dimensional intensity distribution of the scattered light into first image data in digital form; Converting the first image data into first color space data including luminance information using a color space conversion algorithm; And And at least one step of converting the first color space data into first gray level data. The method of claim 2, Determining the spatial distribution of the size of the particles And determining the size distribution of the particles present on the measurement plane by using the relationship between the polarization ratio distribution function and the particle size. The method of claim 7, wherein The relationship between the polarization ratio distribution function and the particle size is a relational expression based on Lorentz-scattering theory. The method of claim 2, And wherein the polarization ratio distribution function expresses the intensity of the scattered light as a function of the respective positions on the propagation path of the incident light. The method of claim 2, The first incident light and the second incident light are incident to the inside of the container in sequence at a first time interval, The first time interval is more than 0 seconds to 10 seconds or less, characterized in that the distribution characteristic evaluation of the particle size. The method of claim 1, The vessel is a plasma processing chamber loaded with a substrate, And said measuring plane is a plane perpendicular to said substrate. The method of claim 1, The incident light has a path for reciprocating the measurement plane at different heights, thereby scanning the measurement plane in two dimensions. A two dimensional intensity distribution of scattered light scattered from particles present on the measurement plane defined via reflection defined by reflection by incident light incident into the container, the space providing a space including a measurement plane Measuring device unit; An image processor electrically connected to the measurement device to process the two-dimensional intensity distribution of the measured scattered light; And And a particle size calculator configured to determine a spatial distribution of sizes of particles existing on the measurement plane by using output data of the image processor. The method of claim 13, The measuring device unit has a two-dimensional intensity distribution of the first scattered light and the second scattered light scattered from the particles present on the measurement plane by the first incident light and the second incident light having different polarization directions incident into the container. Is configured to measure And the image processor includes a polarization ratio distribution function extracting unit configured to extract the polarization ratio distribution function by processing two-dimensional intensities of the first and second scattered light beams. The method of claim 14, The measuring device unit measures the two-dimensional distribution of the background light emitted from the container, The image processor may further include a subtractor configured to extract the two-dimensional distributions of the first net scattered light and the second net scattered light by subtracting the two-dimensional distribution of the background light from the two-dimensional distribution of the first scattered light and the second scattered light. Image processing apparatus, characterized in that. The method of claim 14, The image processor may include a data converter configured to convert a data format of the measured two-dimensional intensity distribution of the scattered light; And And at least one of an average value calculator for calculating an average value of the measured two-dimensional intensity distributions of the scattered light. The method of claim 16, The data conversion unit A data receiver configured to convert the two-dimensional intensity distribution of the measured scattered light into first image data in a digital data format; A color conversion unit configured to convert the first image data into first color space data including luminance information using a color space conversion algorithm; And And at least one of grayscale data generating units configured to convert the first color space data into first grayscale data. The method of claim 14, The measuring device includes a light detector, The optical detector includes any one of a charge coupled device image sensor, a video camera, and a multichannel photo multiplayer tube.

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