KR100929868B1 - Particle Measuring System and Particle Measuring Method Using The Same - Google Patents

Abstract

Provide a particle measurement system. The measuring system includes a light emitting part for emitting incident light, a first polarizing part for polarizing incident light emitted from the light emitting part into a first direction component, and incident light of the first direction component polarized by the first polarizing part in one dimension. Detecting the scattered light of the first direction component passed by the light conversion unit for converting the light, the second polarizing unit for passing only the first direction component of the scattered light generated by the collision of the one-dimensional light and particles It includes a light detector for.

Plasma Particle Laser Scattering 2D

Description

Particle Measurement System and Method of Measuring Particle Using the Same

1 is a block diagram illustrating a particle measuring system used in a plasma process according to the prior art;

2 is a block diagram illustrating a particle measuring system used in a plasma process according to an embodiment of the present invention;

3A and 3B are detailed views for explaining light converters and scattered light of a particle measuring system according to embodiments of the present disclosure;

4 is a process flowchart for explaining a particle measuring method according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

10, 110: light emitting portion 20, 120: first polarizing portion

130: light conversion unit 132CL: cylindrical lens

132MI: first spherical mirror 132MIH: inlet

132MO: second spherical mirror 132MOH: outlet

134: convex lens 40, 140: plasma chamber

45, 145: particles 50, 150: second polarization portion

60, 160: light detector 70, 170: light receiver

180: chopper B ₁ : incident light

B ₂ : incident light of the first direction component B ₃ : one-dimensional light

B ₄ : Scattered Light B ₅ : Scattered Light of the First Directional Component

I ₁ , I ₂ , I ₃ , I ₄ , I ₅ : Aperture M: Reflective Mirror

PBS: Polarization Disperser

The present invention relates to a particle measuring system and a measuring method using the same, and more particularly, to a particle measuring system used in a plasma process and a measuring method using the same.

Semiconductor processing is mostly done in a plasma environment. Fine particles in the range of tens to hundreds of nm generated in the plasma process used in semiconductor processes such as deposition, etching, and planarization not only reduce the cleanliness of the process vessel in which the plasma process is performed, but also have patterns having similar line widths. It can stick to the phase and damage the pattern. Degradation of cleanliness and pattern damage inside the process vessel may seriously degrade the yield of the semiconductor process. Accordingly, monitoring of particles generated in the plasma process used in the semiconductor process is essential.

Laser Light Scattering is a method for determining the size of fine particles present in the plasma. The laser light scattering method irradiates a laser into the plasma to measure the ratio of the intensity between the vertically polarized component and the horizontally polarized component of the scattered light scattered by the particles present in the plasma at a specific scattering angle, and the horizontally polarized component of the scattered light and the horizontal It is a method of determining the size of particles scattering a laser through the ratio of the intensity between polarization components.

The intensity of the scattered light is a function that depends on the wavelength of the laser irradiated into the plasma, the scattering angle of the scattered light scattered by the particles, the direction component of the polarization and the size of the particle scattering the laser. Accordingly, if a scattered light is measured according to the direction component of polarization at a specific scattered angle using a laser having a wavelength, the scattered light intensity may be a function that depends only on the size of particles scattered by the laser. As a result, the size of the particles present in the plasma can be determined by determining the ratio of the intensity between them from the values of the vertically polarized light component and the horizontally polarized light component of the scattered light scattered by the particles.

Laser light scattering can be divided into Mie scattering and Rayleigh scattering. Microscattering can be applied when the particle size is large compared to the wavelength of the laser light, and Rayleigh scattering can be applied when the particle size is small compared to the wavelength of the laser light. Here, Rayleigh scattering can be obtained by first order approximation of non-scattering.

The non-scattering and Rayleigh scattering may satisfy Equation 1 below.

,

및

는 각각 입자의 반지름, 레이저 광의 파장 및 입자에 의해 산란된 레이저 광의 산란각이다.

및

는 각각 레이저 광의 수평 및 수직 방향 성분의 전기장을 나타내고,

및

는 레이저 광의 각각 수평 및 수직 방향 성분의 세기를 나타낸다.

,

And

Are the radius of the particle, the wavelength of the laser light and the scattering angle of the laser light scattered by the particle, respectively.

And

Represents the electric fields of the horizontal and vertical components of the laser light, respectively,

And

Denotes the intensity of the horizontal and vertical components, respectively, of the laser light.

, 수평 방향 성분의 전기장을

라 하고, 입자에 의해 산란된 레이저 광의 수직 방향 성분의 전기장을

, 수평 방향 성분의 전기장을

라고 하면, 입자로 입사되는 레이저 광과 입자에 의해 산란된 레이저 광 사이에는 아래 수학식 2와 같은 관계가 존재할 수 있다.The electric field of the vertical component of the laser light

The electric field of the horizontal component

The electric field of the vertical component of the laser light scattered by the particles

The electric field of the horizontal component

In this case, a relationship as shown in Equation 2 below may exist between the laser light incident on the particle and the laser light scattered by the particle.

,

,

및

는 미 산란의 산란각 함수들이다.

및

는 각각 산란된 레이저 광의 산란각 파수(wavenumber) 및 입자의 반지름과 관련된 벡터(vector) 값이다. 만약 입자가 구형일 경우,

및

성분은 0이 되고,

및

성분만 존재하게 된다.here

,

,

And

Are scattering angle functions of non-scattering.

And

Are the vector values associated with the scattering angle wavenumber of the scattered laser light and the radius of the particle, respectively. If the particles are spherical,

And

The component is zero,

And

Only the ingredients will be present.

및

성분은 각각 아래 수학식 3 및 수학식 4와 같다(Bohren and Huffman, 1983).At this time,

And

The components are shown in Equations 3 and 4, respectively (Bohren and Huffman, 1983).

및

은 각각 르장드르 다항식(Legendre polynomial)과 이의 미분식이다. 이때, 및

는 각각 아래 수학식 5 및 수학식 6과 같다.here

And

Are the Regendre polynomials and their derivatives, respectively. At this time, And

Are the same as Equations 5 and 6, respectively.

이고 그리고

은 복소수 값을 갖는 굴절 률(refractive index)이다.

및

은 각각 베셀(Bessel) 함수 및 한켈(Hankel) 함수와 관련된 항목이다.here

And

Is the refractive index with a complex value.

And

Are items related to the Bessel function and the Hankel function, respectively.

If the size of the particles is small compared to the wavelength of the laser light can be represented by Rayleigh scattering. This may be represented by Equations 7 and 8 below.

및

는 각각 입사된 레이저 광의 수평 및 수직 방향 성분의 세기이고,

는 상수이고,

는 측정되는 산란각 범위에 대한 체적값이고,

는 측정되는 산란각 범위에 대한 입체각(solid angle)이고, 그리고 은 입자의 밀도이다.

And

Are the intensities of the horizontal and vertical components of the incident laser light, respectively,

Is a constant,

Is the volume value for the scattering angle range being measured,

Is the solid angle over the scattering angle range being measured, and Is the density of the particles.

1 is a block diagram illustrating a particle measuring system used in a plasma process according to the prior art.

Referring to FIG. 1, the particle measuring system may include a light emitter 10, first and second polarizers 20 and 50, and a light detector 60.

The light emitter 10 may be for emitting incident light B ₁ . The light emitting unit 10 may be a laser light emitting device. Accordingly, the incident light B ₁ may be laser light.

At least one lens (not shown) may be further included to thin the incident light B ₁ emitted from the light emitter 10. The lens for thinning the incident light B ₁ may be a convex lens. The lens may be provided at any position between the light emitter 10 and the plasma chamber 40.

The first polarizer 20 may be for polarizing the incident light B ₁ emitted from the light emitter 10 into the first direction component. The first polarizer 20 may be a vertical component polarizer or a horizontal component polarizer. Accordingly, the incident light B ₁ passing through the first polarizer 20 may be polarized into incident light of a vertical component or incident light of a horizontal component.

If the incident light B ₁ is light polarized in a horizontal component, such as helium-neon laser light, the light emitting unit 10 is used to disperse the polarized light into two orthogonal components (horizontal and vertical components) that are perpendicular to each other. ) May further include a polarized beam splitter (PBS) provided between the first polarizer 20 and the first polarizer 20. Accordingly, the incident light B ₁ incident on the first polarizer 20 may be composed of two direction components perpendicular to each other.

In order to confirm the straightness of the incident light B ₁ , the light emitter 10 may further include at least one aperture or iris I ₁ provided between the light emitter 10 and the first polarizer 20. Accordingly, the incident light B ₁ incident on the first polarizer 20 may have straightness.

At least one aperture I ₂ provided between the first polarizer 20 and the plasma chamber 40 may be further included to confirm the straightness of the incident light B ₂ of the first directional component. Accordingly, the incident light B ₂ of the first direction component incident to the plasma chamber 40 may have straightness.

The incident light B ₂ of the first direction component polarized by the first polarizer 20 may be irradiated to the plasma chamber 40. The incident light B ₂ of the first directional component irradiated to the plasma chamber 40 may collide with the particles 45 in the plasma to generate scattered light B ₄ . Scattered light B ₄ can spread in all directions. The light detector 60 detects only the scattered light B ₄ having a specific scattering angle, so that the size of the particles 45 present at a specific site (a point in 0 dimension) in the plasma can be measured.

When the light generator 10, the first polarizer 20, and the plasma chamber 40 do not coincide with the traveling direction of the light, the light generator 10 and the plasma chamber 40 may be used to change the path of light. It may further include at least one reflective mirror (M). The reflecting mirror M may be mainly rotated with an ideal 45 degree angle.

The second polarizer 50 may be configured to pass only the first direction component of the scattered light B ₄ generated by the collision of the incident light B ₂ of the first direction component with the particles 45. The second polarizer 50 may have the same direction component as the first polarizer 20. When the first polarizer 20 is a vertical component polarizer, the second polarizer 50 may be a vertical component polarizer, and when the first polarizer 20 is a horizontal component polarizer, the second polarizer 50 may be used. May be a horizontal component polarizer.

At least one aperture I ₃ provided between the plasma chamber 40 and the second polarizer 50 may be further included to check the scattering angle of the scattered light B ₄ . Accordingly, the scattered light B ₄ incident on the second polarizer 50 may have a specific scattering angle.

The light detector 60 may be for detecting the scattered light B ₅ of the first directional component passed by the second polarizer 50. The light detector 60 may be a single-channel photomultiplier tube (PMT).

As hameu optical detector 60 are each measuring separately the intensity of the scattered light of the first direction component (B ₅₎ and the scattered light of the first direction component (B _5), the scattered light of the second direction component (not shown) perpendicular to, the The ratio of the intensity between the vertical component and the horizontal component of the scattered light B ₄ generated by the collision of the incident light B ₂ of the one-directional component with the particle 45 can be provided. Accordingly, it is possible to know the size of the particles 45 that collide with the incident light B ₂ of the first directional component to generate scattered light B ₄ .

At least one aperture I ₄ provided between the second polarizer 50 and the light detector 60 may be further included to confirm the straightness of the scattered light B ₅ of the first directional component. Accordingly, the scattered light B ₅ of the first direction component incident to the light detector 60 may have linearity.

The light receiving unit 70 may further include a light receiving unit 70 for measuring the intensity of the incident light B ₂ of the first directional component that does not collide with the particle 45. The light receiving unit 70 may be a photo diode (PD). The light receiving unit 70 may measure the intensity of incident light B ₂ of the first direction component that does not collide with the particle 45.

Further comprising at least one aperture (I ₅ ) provided between the light receiving portion 70 and the plasma chamber 40 to confirm the straightness of the incident light (B ₂ ) of the first directional component that did not collide with the particles (45). can do. Accordingly, the incident light B ₂ of the first direction component incident to the light receiving unit 70 may have straightness.

The particle measuring system as described above may have a structure in which a laser having a diameter of about 4 mm or less is irradiated into the plasma to measure the intensity of scattered light using a short channel optical multiplier as a light detector at a specific scattering angle. Since the 0-dimensional light is used and the short-channel optical multiplier is used, only the size of particles existing at a specific site (a point in the 0-dimensional) in the plasma can be measured.

An object of the present invention is to provide a particle measuring system capable of monitoring the size and distribution of particles present in the plasma in two dimensions.

Another object of the present invention is to provide a particle measuring method capable of measuring the size and distribution of the particles present in the plasma in two dimensions.

In order to achieve the above technical problem, the present invention provides a particle measurement system. The measuring system includes a light emitting part for emitting incident light, a first polarizing part for polarizing incident light emitted from the light emitting part into a first direction component, and incident light of the first direction component polarized by the first polarizing part in one dimension. Detecting the scattered light of the first direction component passed by the light conversion unit for converting the light, the second polarizing unit for passing only the first direction component of the scattered light generated by the collision of the one-dimensional light and particles It may include a light detector for.

The incident light may be laser light.

The light emitting portion may be a laser light emitting device. Laser light emitting devices include ruby lasers, Q-switch endiyag lasers, ionic glass lasers, helium-neon lasers, neon ion lasers, argon ion lasers, krypton ion lasers, xenon ion lasers, fluorine excimer lasers, argon fluoride excimer lasers, Selected from krypton fluoride excimer laser, krypton chloride excimer laser, xenon fluoride excimer laser, xenon chloride excimer laser, gold vapor laser, copper vapor laser, nitrogen laser, helium-cadmium laser, gallium aluminum arsenide laser and gallium arsenide laser It can be one.

The first polarizer may be a first direction component polarizer or a second direction component polarizer orthogonal to the first direction component.

The first polarizer may be a half lambda plate.

The first polarizer includes a first directional component polarizer and a second directional component polarizer, and may further include a chopper provided between the light emitter and the first polarizer to select the directional component of the first polarizer.

The incident light is polarized light, and may further include a polarizing diffuser provided between the light emitting portion and the first polarizing portion to disperse the polarized light into two directional components orthogonal to each other.

The light converter may be a pair of spherical mirrors or cylindrical lenses.

The pair of spherical mirrors may include a first spherical mirror having an inlet for introducing incident light of the first directional component and a second spherical mirror having an outlet for extracting incident light of the first directional component.

The light converter may be a pair of spherical mirrors, and the one-dimensional light converted by the light converter may be multipath light.

The light converter may be the cylindrical lens, and the light converter may further include a convex lens.

The light converter may be the cylindrical lens, and the one-dimensional light converted by the light converter may be plate-shaped light.

The second polarizer may have the same directional component as the first polarizer.

The light detector may be a charge coupled device image sensor or a multichannel optical multiplier.

At least one aperture may be further provided between the light emitting unit and the light converting unit and between the light converting unit and the light detecting unit to check the linearity of the incident light and the scattering angle of the scattered light.

It may further include a light receiving unit for measuring the intensity of the one-dimensional light that does not collide with the particles. The light receiving unit may be a photodiode.

At least one aperture provided between the light receiving unit and the light conversion unit may be further included to confirm the linearity of the one-dimensional light that does not collide with the particles.

In addition, in order to achieve the above technical problem, the present invention provides a particle measuring method. The method includes emitting incident light from the light emitting part, polarizing the incident light from the first polarization part to the first direction component, converting incident light of the first direction component into the one-dimensional light in the light conversion part, one-dimensional Irradiating light to particles in the plasma chamber to generate scattered light, passing only the first directional component of the scattered light in the second polarizer, and detecting the scattered light of the first directional component in the light detector.

The incident light may be laser light.

The light emitting portion may be a laser light emitting device. Laser light emitting devices include ruby lasers, Q-switch endiyag lasers, ionic glass lasers, helium-neon lasers, neon ion lasers, argon ion lasers, krypton ion lasers, xenon ion lasers, fluorine excimer lasers, argon fluoride excimer lasers, Selected from krypton fluoride excimer laser, krypton chloride excimer laser, xenon fluoride excimer laser, xenon chloride excimer laser, gold vapor laser, copper vapor laser, nitrogen laser, helium-cadmium laser, gallium aluminum arsenide laser and gallium arsenide laser It can be one.

The first polarizer may be a first direction component polarizer or a second direction component polarizer orthogonal to the first direction component.

The first polarizer may be a half lambda plate.

The first polarizer includes a first directional component polarizer and a second directional component polarizer, and may further include a chopper provided between the light emitter and the first polarizer to select the directional component of the first polarizer.

The incident light is polarized light, and may further include a polarizing diffuser provided between the light emitting part and the first polarizing part to disperse the polarized light into two directional components orthogonal to each other.

The light converter may be a pair of spherical mirrors or cylindrical lenses.

The pair of spherical mirrors may include a first spherical mirror having an inlet for introducing incident light of the first directional component and a second spherical mirror having an outlet for extracting incident light of the first directional component.

The light converter may be a pair of spherical mirrors, and the one-dimensional light converted by the light converter may be multipath light.

The light converter may be the cylindrical lens, and the light converter may further include a convex lens.

The light converter may be the cylindrical lens, and the one-dimensional light converted by the light converter may be plate-shaped light.

The second polarizer may have the same directional component as the first polarizer.

The light detector may be a charge coupled device image sensor or a multichannel optical multiplier.

At least one aperture may be further provided between the light emitting unit and the light converting unit and between the light converting unit and the light detecting unit to check the linearity of the incident light and the scattering angle of the scattered light.

It may further include a light receiving unit for measuring the intensity of the one-dimensional light that does not collide with the particles. The light receiving unit may be a photodiode.

At least one aperture provided between the light receiving unit and the light conversion unit may be further included to confirm the linearity of the one-dimensional light that does not collide with the particles.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the invention to those skilled in the art. Therefore, the shape of the elements in the drawings are exaggerated to emphasize a clearer description. In addition, since it is in accordance with the preferred embodiment, reference numerals presented in the order of description are not necessarily limited to the order. In the drawings, like reference numerals designate like elements that perform the same function.

2 is a block diagram illustrating a particle measuring system used in a plasma process according to an embodiment of the present invention.

Referring to FIG. 2, the particle measuring system may include a light emitter 110, first and second polarizers 120 and 150, a light converter 130, and a light detector 160.

The light emitting unit 110 may be for emitting incident light B ₁ . The light emitting unit 110 may be a laser light emitting device. Accordingly, the incident light B ₁ may be laser light. The laser light may have a wavelength of 800 nm or less. Accordingly, the laser light emitting device may be a ruby laser, a Q-switch Nd: YAG laser, an Er: glass laser, a helium-neon laser, a neon ( Ne) ion laser, argon (Ar) ion laser, krypton (Kr) ion laser, xenon (Xe) ion laser, fluorine (F ₂ ) excimer laser, argon fluoride excimer laser, krypton fluoride (KrF) Excimer Laser, Krypton Chloride (KrCl) Excimer Laser, Xenon Fluoride (XeF) Excimer Laser, Xenon Chloride (XeCl) Excimer Laser, Gold (Au) Vapor Laser, Copper (Cu) Vapor Laser, Nitrogen (N ₂ ) Laser, Helium It may be one selected from cadmium (HeCd) laser, gallium aluminum arsenide (GaAlAs) laser and gallium arsenide (GaAs) laser. Preferably, the laser light emitting device may have a low wavelength laser light output to measure the size of the fine particles 145. In general, a helium-neon laser or an argon ion laser can be used as the laser light emitting device.

At least one lens (not shown) may be further included to thin the incident light B ₁ emitted from the light emitter 110. The lens for thinning the incident light B ₁ may be a convex lens. Preferably, it may be a pair of convex lenses having different focal lengths. The lens may be provided at any position between the light emitter 110 and the light converter 130.

The first polarizer 120 may be for polarizing the incident light B ₁ emitted from the light emitter 110 into the first direction component. The first polarizer 120 may be a vertical component polarizer or a horizontal component polarizer. Accordingly, the incident light B ₁ passing through the first polarizer 120 may be polarized into incident light of a vertical component or incident light of a horizontal component. Alternatively, 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 can be cross-polarized by the half lambda plate into incident light of the vertical component or incident light of the horizontal component.

In addition, the first polarizer 120 may include a vertical component polarizer and a horizontal component polarizer. When the first polarizer 120 includes both a vertical component polarizer and a horizontal component polarizer, a light splitter (beam splitter) and a chopper provided between the light emitter 110 and the first polarizer 120 are provided. (chopper, 180) may further include. The light spreader may divide the incident light B ₁ into two paths. The chopper 180 may be configured to inject incident light B ₁ dispersed in two paths into a polarizing plate having a direction component selected from a vertical component polarizer and a horizontal component polarizer of the first polarizer 120, respectively.

If the incident light B ₁ is light polarized in a horizontal component, such as helium-neon laser light, the light emitting unit 110 is used to disperse the polarized light into two orthogonal components (horizontal and vertical components) that are perpendicular to each other. ) And a polarization diffuser provided between the first polarizer 120. Accordingly, the incident light B ₁ incident on the first polarizer 120 may be composed of two direction components perpendicular to each other.

At least one aperture I ₁ provided between the light emitting unit 110 and the first polarizing unit 120 may be further included to check the straightness of the incident light B ₁ . Accordingly, incident light B ₁ incident on the first polarizer 120 may have straightness.

The light converter 130 may be used to convert incident light B ₂ of the first direction component polarized by the first polarizer 120 into one-dimensional light B ₃ . The light converter 130 may be a pair of spherical mirrors or cylindrical lenses. For a detailed description of the one-dimensional light B ₃ emitted from the light conversion unit 130, refer to the description of FIGS. 3A and 3B below.

At least one aperture I ₂ provided between the first polarizer 120 and the light converter 130 may be further included in order to confirm the straightness of the incident light B ₂ of the first directional component. Accordingly, the incident light B ₂ of the first direction component incident to the light converter 130 may have straightness.

The one-dimensional light B ₃ generated by the light converter 130 may be irradiated to the plasma chamber 140. The one-dimensional light B ₃ irradiated to the plasma chamber 140 may collide with the particles 145 in the plasma to generate scattered light B ₄ . A detailed description of the scattered light B ₄ generated by the collision of the one-dimensional light B ₃ and the particles 145 may be described with reference to FIGS. 3A and 3B below.

When the light generator 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. It may further include at least one reflective mirror (M) for changing the path of the light. The reflecting mirror M may be mainly rotated with an ideal 45 degree angle.

The second polarizer 150 may be configured to pass only the first direction component of the scattered light B ₄ generated by the collision of the one-dimensional light B ₃ and the particles 145. The second polarizer 150 may have the same direction component as the first polarizer 120. When the first polarizer 120 is a vertical component polarizer, the second polarizer 150 may be a vertical component polarizer. When the first polarizer 120 is a horizontal component polarizer, the second polarizer 150 may be a vertical component polarizer. May be a horizontal component polarizer. Alternatively, 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 association with the same direction component. Accordingly, the second polarizer 150 may cross-pass the same direction component of scattered light B ₄ as the direction component polarized by the first polarizer 120.

In addition, when the first polarizer 120 includes a vertical component polarizer and a horizontal component polarizer, the second polarizer 150 may have a polarizer that is interlocked with the direction component of the first polarizer 120. . This means that the second polarizer 150 must have the same direction component as the direction component of the first polarizer 120 selected by the chopper 180 provided between the light emitter 110 and the first polarizer 120. Because. Accordingly, the direction components of the light passing through the first polarizer 120 and the light passing through the second polarizer 150 may be the same, and the scattered light of the direction component selected by the chopper 180 may be emitted from the light detector 160. Can be detected.

At least one aperture I ₃ provided between the light converter 130 and the second polarizer 150 may be further included to check the scattering angle of the scattered light B ₄ . Accordingly, the scattered light B ₄ incident to the second polarizer 150 may have a specific scattering angle.

The light detector 160 may be used to detect scattered light B ₅ of the first directional component passed by the second polarizer 150. The light detector 160 may be a charge coupled device (CCD) image sensor or a multi-channel light multiplier. The multichannel optical multiplier may be a two-dimensional array of the short channel optical multiplier. By using the charge coupled device image sensor or the multi-channel optical multiplier tube as the photo detector 160, collision of the particles 145 and the one-dimensional light B ₃ existing on a specific surface (one side in two dimensions) in the plasma Two-dimensional measurement of the scattered light (B ₄ ) generated by may be possible.

By the optical detector 160 is the scattered light of the first direction component (B ₅₎ and the measured intensity of the scattered light (not shown) of the second direction component perpendicular to the scattered light (B ₅₎ of the first direction component, respectively, or sequentially, It is possible to provide a ratio of the intensity between the vertical component and the horizontal component of the scattered light B ₄ generated by the collision of the one-dimensional light B ₃ and the particle 145. Accordingly, the size of the particles 145 colliding with the one-dimensional light B ₃ to generate the scattered light B ₄ can be known.

At least one aperture I ₄ provided between the second polarizer 150 and the light detector 160 may be further included to confirm the straightness of the scattered light B ₅ of the first directional component. Accordingly, the scattered light B ₅ of the first direction component incident to the light detector 160 may have linearity.

The light receiving unit 170 may further include a light receiving unit 170 for measuring the intensity of the one-dimensional light B _{3 that} does not collide with the particle 145. The light receiving unit 170 may be a photodiode. The light receiving unit 170 measures the intensity of the one-dimensional light B _{3 that} does not collide with the particle 145, thereby obtaining an average density of the particles 145 present on a specific surface (one side in two dimensions) in the plasma. Can be obtained.

It may further include at least one aperture (I ₅ ) provided between the light receiving unit 170 and the light conversion unit 130 to confirm the straightness of the one-dimensional light (B ₃ ) that did not collide with the particle 145. have. Accordingly, the one-dimensional light B ₃ incident to the light receiving unit 170 may have straightness.

Since the particle measuring system as described above irradiates the plasma with the one-dimensional light generated by the light converting unit, unlike the conventional method in which only the size of particles existing at a specific portion (a point of zero dimension) in the plasma can be measured. In addition, it is possible to measure the size and distribution of particles present on a specific surface (one side in two dimensions) in the plasma. Accordingly, in the plasma process used in the semiconductor process, the size and distribution of the particles depending on the position in the plasma may be two-dimensionally monitored by various factors such as the structure or physical action of the process vessel. .

3A and 3B are detailed views for explaining light converters and scattered light of a particle measuring system according to example embodiments.

Referring to FIG. 3A, the light converter 130 may include a pair of spherical mirrors 132MI and 132MO. A pair of spherical mirrors (132MI and 132MO) is incident on the first spherical mirror (132MI) and the incoming first direction component having an inlet opening (132MIH) for pulling the incident light (B ₂₎ of the first directional component (B ₂ ) it is possible to include a second spherical mirror (132MO) having an outlet (132MOH) for withdrawing a multi-path optical (B ₃₎ formed by the repetitive reflection of. The pair of spherical mirrors 132MI and 132MO may be concave mirrors facing each other.

By using the pair of spherical mirrors 132MI and 132MO included in the light conversion unit 130 to repeatedly reflect the first direction component incident light B ₂ in the height direction in the height direction, Path light B ₃ can be made. By adjusting the radius of curvature of the pair of spherical mirrors 132MI and 132MO, the number of paths of the multipath light B ₃ can be adjusted.

Accordingly, the light incident to the plasma chamber 140 may be multipath light B ₃ approaching one dimension. The multipath light B ₃ incident to the plasma chamber 140 may collide with the particles 145 present in the plasma to generate scattered light B ₄ . Scattered lights B ₄ can spread in all directions. Among them, only the scattered light B ₄ having a specific scattering angle is detected by the light detecting unit 160 of FIG. 2, and thus the size and distribution of the particles 145 present on a specific surface (one side of the secondary circle) in the plasma. Can be measured.

Referring to FIG. 3B, the light converter 130 may include a cylindrical lens 132CL. The light converter 130 may further include a convex lens 134.

By using the cylindrical lens 132CL included in the light conversion unit 130, the plate-shaped one-dimensional light B ₃ is spread by spreading the first-dimensional component incident light B _{2 in the} form of a sheet. Can be made. The convex lens 134 may serve to change the one-dimensional light B ₃ having a shape spread by the cylindrical lens 132CL into a plate-shaped one-dimensional light B ₃ having a constant height.

Accordingly, the light incident to the plasma chamber 140 may be a plate-shaped one-dimensional light B ₃ . The plate-shaped one-dimensional light B ₃ incident to the plasma chamber 140 may collide with the particles 145 present in the plasma to generate scattered light B ₄ . Scattered lights B ₄ can spread in all directions. Among them, only the scattered light B ₄ having a specific scattering angle is detected by the light detector 160 of FIG. 2, thereby determining the size and distribution of the particles 145 present on a specific surface (one side in two dimensions) in the plasma. It can be measured.

4 is a process flowchart for explaining a particle measuring method according to an embodiment of the present invention.

Referring to FIG. 4, the incident light is emitted from the light emitting unit (S110), the incident light is polarized (S120) from the first polarization unit to the first direction component, and the incident light of the first direction component is emitted from the light conversion unit. Converting to one-dimensional light (S130), generating scattered light by irradiating the one-dimensional light with particles in the plasma chamber (S140), passing only the first direction component of the scattered light in the second polarizer (S150), and The light detecting unit may include detecting scattered light of the first directional component (S160).

Emitting incident light from the light emitting unit (S110) may be to emit incident light such as laser light from a light emitting unit such as a laser light emitting device. The laser light may have a wavelength of 800 nm or less. Accordingly, the laser light emitting device is a ruby laser, Q-switch endiyag laser, iaglas laser, helium-neon laser, neon ion laser, argon ion laser, krypton ion laser, xenon ion laser, fluorine excimer laser, argon fluoride Excimer laser, krypton fluoride excimer laser, krypton chloride excimer laser, xenon fluoride excimer laser, xenon chloride excimer laser, gold vapor laser, copper vapor laser, nitrogen laser, helium cadmium laser, gallium aluminum arsenide laser and gallium arsenide laser It may be one selected from. Preferably, the laser light emitting device may have a low wavelength laser light output to measure the size of the fine particles 145. In general, a helium-neon laser or an argon ion laser can be used as the laser light emitting device.

Polarizing the incident light from the first polarizer to the first direction component (S120) polarizes the incident light incident on the first polarizer to the incident light of the vertical component or the incident light of the horizontal component using a vertical component polarizer or a horizontal component polarizer. It may be. Alternatively, the first polarizer may be a half lambda plate. Each time the half lambda plate is rotated by 90 °, the incident light can be cross-polarized by the half lambda plate into incident light of the vertical component or incident light of the horizontal component.

In addition, the first polarizer may include a vertical component polarizer and a horizontal component polarizer. When the first polarizer includes both the vertical component polarizer and the horizontal component polarizer, the light polarizer and the chopper may be further provided between the light emitter and the first polarizer. The light splitter can split the incident light into two paths. The chopper may be for injecting incident light dispersed in two paths into a polarizing plate having a direction component selected from a vertical component polarizing plate and a horizontal component polarizing plate, respectively.

If the incident light is light polarized in a horizontal component, such as helium-neon laser light, between the light emitter and the first polarizer to disperse the polarized light into two orthogonal components (horizontal and vertical components) that are orthogonal to each other It may further comprise a polarizing diffuser provided in. Accordingly, the incident light incident on the first polarizer may be composed of two direction components orthogonal to each other.

The conversion of incident light of the first direction component into the one-dimensional light in the light conversion unit (S130) is performed by using the pair of spherical mirrors or cylindrical lenses included in the light conversion unit for the incident light of the 0-dimensional first direction component. It may be to convert to light.

The light converter may include a pair of spherical mirrors. The pair of spherical mirrors have a first spherical mirror having an inlet for introducing incident light of the first directional component and a first outlet having an outlet for extracting multipath light formed by repetitive reflection of the incident light of the first directional component introduced therein. It may include two spherical mirrors. The pair of spherical mirrors may be concave mirrors facing each other.

By using the pair of spherical mirrors included in the light conversion unit to repeatedly reflect the 0-dimensional first-direction component incident light in the height direction, multipath light closer to one dimension may be generated. By adjusting the radius of curvature of the pair of spherical mirrors, the number of paths of the multipath light can be adjusted.

Alternatively, the light conversion unit may include a cylindrical lens, and the light conversion unit may further include a convex lens. The plate-shaped one-dimensional light may be made by spreading the first-dimensional component incident light in the 0-dimensional to the plate shape by using the cylindrical lens included in the light conversion unit. The convex lens may serve to convert the one-dimensional light having a form spread by the cylindrical lens into a plate-shaped one-dimensional light having a constant height.

The generation of the scattered light by irradiating the one-dimensional light to the particles in the plasma chamber (S140) may be to generate the scattered light by colliding the one-dimensional light irradiated into the plasma chamber with the particles in the plasma.

One-dimensional light incident into the plasma chamber may collide with particles present in the plasma to generate scattered light. Scattered light can spread in all directions. By detecting only the scattered light having a specific scattering angle in the light detector, it is possible to measure the size and distribution of the particles present on a specific surface (one side in two dimensions) in the plasma.

Passing only the first direction component of the scattered light in the second polarizing unit (S150) is the incident light of the vertical component or the horizontal component using the same vertical component polarizing plate or horizontal component polarizing plate that is incident to the second polarizing unit as the first polarizing unit It may be polarized by the incident light of the component. The second polarizer may have the same directional component as the first polarizer. When the first polarizer is a vertical component polarizer, the second polarizer may be a vertical component polarizer, and when the first polarizer is a horizontal component polarizer, the second polarizer may be a horizontal component polarizer. Alternatively, when the first polarizer is a half lambda plate, the second polarizer may be a half lambda plate that rotates by 90 ° in association with the same direction component. As a result, the second polarizer can cross-pass the same direction component of scattered light as the direction component polarized by the first polarizer.

In addition, when the first polarizer includes a vertical component polarizer and a horizontal component polarizer, the second polarizer may have a polarizer that is interlocked with the direction component of the first polarizer. This is because the second polarizing portion should have the same directional component as that of the first polarizing portion selected by the chopper provided between the light emitting portion and the first polarizing portion. Accordingly, the direction components of the light passing through the first polarization portion and the light passing through the second polarization portion may be the same, and the scattered light of the direction component selected by the chopper may be detected by the light detector.

The display apparatus may further include at least one aperture provided between the light converter and the second polarizer to determine the scattering angle of the scattered light. Accordingly, the scattered light incident on the second polarizer may have a specific scattering angle.

The detecting of the scattered light of the first directional component by the light detector (S160) may be detecting the scattered light of the first directional component by using a charge coupled device image sensor or a multi-channel optical multiplier included in the light detector. The multichannel optical multiplier may be a two-dimensional array of the short channel optical multiplier. By using a charge coupled device image sensor or a multichannel optical multiplier as a light detector, two-dimensional measurement of scattered light generated by collision of particles existing on a specific surface (one side in two dimensions) and one-dimensional light in the plasma This may be possible.

The light detector measures the intensity of the scattered light of the first directional component and the scattered light of the second directional component orthogonal to the scattered light of the first directional component, respectively, or sequentially, so that the vertical direction of the scattered light generated by the collision of the one-dimensional light and the particles. It is possible to provide the ratio of the intensity between the component and the horizontal component. Accordingly, the size of particles that collide with the one-dimensional light to generate scattered light can be known.

In addition, the light receiving unit may further include measuring the intensity of the one-dimensional light that does not collide with the particles. The light receiving unit may be a photodiode. The light receiving unit measures the intensity of the one-dimensional light that does not collide with the particles, thereby obtaining an average density of particles existing on a specific surface (one side in two dimensions) in the plasma.

Unlike the conventional method of measuring particles as described above, since the one-dimensional light generated by the light conversion unit is irradiated into the plasma, only the size of particles existing at a specific portion (a point in the 0-dimensional) in the plasma can be measured. In addition, it is possible to measure the size and distribution of particles present on a specific surface (one side in two dimensions) in the plasma. Accordingly, in the plasma process used in the semiconductor process, the size and distribution of the particles depending on the position in the plasma can be monitored two-dimensionally by various factors such as the structure or physical action of the process vessel.

By using the particle measurement system using the one-dimensional light according to the embodiments of the present invention described above, it is possible to effectively monitor the size and distribution of particles present in the plasma in two dimensions. Accordingly, the manufacturing yield of the semiconductor manufacturing process can be improved.

In addition, by using the particle measuring method using the one-dimensional light according to the embodiments of the present invention, it is possible to measure the size and distribution of the particles present in the plasma in two dimensions. Accordingly, by effectively monitoring the particles present in the plasma, the yield of the semiconductor manufacturing process can be improved.

As described above, according to the present invention, it is possible to effectively monitor the size and distribution of particles present in the plasma in two dimensions. Accordingly, the manufacturing yield of the semiconductor manufacturing process can be improved.

In addition, according to the present invention it is possible to measure the size and distribution of the particles present in the plasma in two dimensions. Accordingly, by effectively monitoring the particles present in the plasma, the yield of the semiconductor manufacturing process can be improved.

Claims (38)

A plasma chamber containing particles; A light emitting part for emitting incident light; A first polarizer configured to polarize the incident light emitted from the light emitter into a first direction component; A light converter converting incident light of the first direction component polarized by the first polarizer into one-dimensional light; A second polarizer configured to pass only the first direction component of the scattered light generated by the collision of the one-dimensional light with the particles; And A light detector for detecting scattered light of the first directional component passed by the second polarizer, The light conversion unit is a pair of spherical mirrors or cylindrical lenses, The light detector detects light scattered in the two-dimensional plane defined in the plasma chamber by the one-dimensional light, The first polarizing unit and the second polarizing unit are interlocked with each other to change the first directional polarization component to extract the particle size and distribution two-dimensionally by using ratios of the different first directional polarization components. Particle measurement system. The method of claim 1, And said incident light is laser light. The method of claim 1, And the light emitting unit is a laser light emitting device. The method of claim 2, The light emitting unit is a ruby laser, Q-switch endiyag laser, iaglas laser, helium-neon laser, neon ion laser, argon ion laser, krypton ion laser, xenon ion laser, fluorine excimer laser, argon fluoride excimer laser, krypton Fluoride excimer laser, krypton chloride excimer laser, xenon fluoride excimer laser, xenon chloride excimer laser, gold vapor laser, copper vapor laser, nitrogen laser, helium-cadmium laser, gallium aluminum arsenide laser and gallium arsenide laser Particle measurement system characterized in that. The method of claim 1, And said first polarizing part is a first direction component polarizing plate or a second direction component polarizing plate orthogonal to the first direction component. The method of claim 1, And said first polarizer is a half lambda plate. The method of claim 5, The first polarizer comprises the first directional component polarizer and the second directional component polarizer, And a chopper provided between the light emitting portion and the first polarizing portion to select a directional component of the first polarizing portion. The method of claim 1, The incident light is polarized light, And a polarizing diffuser provided between said light emitting portion and said first polarizing portion to disperse said polarized light into two directional components orthogonal to each other. delete The method of claim 1, The pair of spherical mirrors are: A first spherical mirror having an inlet for introducing incident light of the first directional component; And And a second spherical mirror having an outlet for extracting incident light of the first directional component introduced therein. The method of claim 1, The light conversion unit is the pair of spherical mirrors, And the one-dimensional light converted by the light conversion unit is multipath light. The method of claim 1, The light conversion unit is the cylindrical lens, The light conversion unit further comprises a convex lens. The method of claim 1, The light conversion unit is the cylindrical lens, And the one-dimensional light converted by the light conversion unit is a plate-shaped light. The method of claim 1, And said second polarizing part has the same directional component as said first polarizing part. The method of claim 1, And the light detector is a charge coupled device image sensor or a multi-channel optical multiplier. The method of claim 1, And at least one aperture provided between the light emitting part and the light converting part and between the light converting part and the light detecting part, respectively, in order to check the straightness of the incident light and the scattering angle of the scattered light. Particle Measuring System. The method of claim 1, And a light receiving unit for measuring the intensity of the one-dimensional light that does not collide with the particles. The method of claim 17, And the light receiving part is a photodiode. The method of claim 17, And at least one aperture provided between the light receiving unit and the light conversion unit to confirm the straightness of the one-dimensional light that does not collide with the particles. Emitting incident light from the light emitting portion; Polarizing the incident light in a first direction component in a first polarizer; Converting the incident light of the first directional component into one-dimensional light by a light conversion unit; Irradiating the one-dimensional light onto particles in the plasma chamber to produce scattered light; Passing only the first directional component of the scattered light in a second polarizer; And Detecting the scattered light of the first directional component in a light detector; The light conversion unit is a pair of spherical mirrors or cylindrical lenses, The light detector detects light scattered in the two-dimensional plane defined in the plasma chamber by the one-dimensional light, The first polarizing unit and the second polarizing unit are interlocked with each other to change the first directional polarization component to extract the size and distribution of the particles two-dimensionally using ratios of the different first directional polarization components. A particle measuring method. The method of claim 20, And the incident light is laser light. The method of claim 20, And the light emitting unit is a laser light emitting device. The method of claim 22, The laser light emitting device is a ruby laser, Q-switch endiyag laser, iaglas laser, helium-neon laser, neon ion laser, argon ion laser, krypton ion laser, xenon ion laser, fluorine excimer laser, argon fluoride excimer laser Among, krypton fluoride excimer laser, krypton chloride excimer laser, xenon fluoride excimer laser, xenon chloride excimer laser, gold vapor laser, copper vapor laser, nitrogen laser, helium-cadmium laser, gallium aluminum arsenide laser and gallium arsenide laser Particle measuring method characterized in that the selected one. The method of claim 20, The said 1st polarizing part is a 1st direction component polarizing plate or a 2nd direction component polarizing plate orthogonal to a 1st direction component, The particle measuring method characterized by the above-mentioned. The method of claim 20, And said first polarizing portion is a half lambda plate. The method of claim 24, The first polarizer comprises the first directional component polarizer and the second directional component polarizer, And a chopper provided between the light emitting portion and the first polarizing portion to select a directional component of the first polarizing portion. The method of claim 20, The incident light is polarized light, And a polarizing diffuser provided between the light emitting portion and the first polarizing portion to disperse the polarized light into two directional components orthogonal to each other. delete The method of claim 20, The pair of spherical mirrors are: A first spherical mirror having an inlet for introducing incident light of the first directional component; And And a second spherical mirror having an outlet for extracting incident light of the first directional component introduced therein. The method of claim 20, The light conversion unit is the pair of spherical mirrors, And the one-dimensional light converted by the light conversion unit is multipath light. The method of claim 20, The light conversion unit is the cylindrical lens, The light converting unit further comprises a convex lens. The method of claim 20, The light conversion unit is the cylindrical lens, The one-dimensional light converted by the light conversion unit is a particle measuring method, characterized in that the plate-shaped light. The method of claim 20, And said second polarizing part has the same directional component as said first polarizing part. The method of claim 20, And the light detector is a charge coupled device image sensor or a multi-channel optical multiplier. The method of claim 20, And at least one aperture provided between the light emitting part and the light converting part and between the light converting part and the light detecting part, respectively, in order to check the straightness of the incident light and the scattering angle of the scattered light. Particle Measurement Method. The method of claim 20, Particle measuring method further comprises a light receiving unit for measuring the intensity of the one-dimensional light that does not collide with the particles. The method of claim 36, The light receiving unit is a particle measuring method, characterized in that the photodiode. The method of claim 37, wherein And at least one aperture provided between the light receiving unit and the light conversion unit to confirm the linearity of the one-dimensional light that does not collide with the particles.

Images