KR101446061B1 - Apparatus for measuring a defect of surface pattern of transparent substrate - Google Patents

Abstract

The present invention relates to an apparatus to measure a defect in a surface pattern of a transparent substrate. More specifically, a substance having small reflectance is patterned on a transparent substrate to make reflectance of the transparent substrate close to 0, even if the reflectances of the transparent substrate and the patterned substance do not have a great difference, to relatively bring about an increase in the reflectance of the patterned substance and increase the reflectance contrast of the patterned substance and the transparent substrate, thereby measuring a surface pattern with higher detection accuracy or measuring the defect of the pattern.

Description

TECHNICAL FIELD [0001] The present invention relates to a device for measuring a defective surface pattern of a transparent substrate,

The present invention relates to an apparatus for measuring a surface pattern defect of a transparent substrate, in which a material having a small reflectivity is patterned on a transparent substrate so that the reflectance of the transparent substrate is made close to zero even if there is little difference in reflectivity between the transparent substrate and the patterned material It enhances the reflectivity of the pattern material relatively and raises the reflection contrast between the pattern material and the transparent substrate, thereby measuring the surface pattern with enhanced detection accuracy or measuring the defectiveness of the pattern.

1 is a conceptual diagram of a general scanning device.

1 includes a laser oscillating unit 10 for oscillating a laser beam, a beam splitting unit 90 for splitting a beam, a scanner 20 rotatably installed around a stationary point, And a condenser lens 7 for condensing a parallel laser beam whose traveling direction is adjusted by the scanner 10 in order to form a focus.

In this scanning method of the scanning device, a portion of the laser beam scanned by the laser oscillating portion 1 is transmitted through the beam splitting portion 90 in the y-axis direction, and the remaining portion of the beam passes through the positive and is reflected in the z-axis direction. The laser R2 transmitted through the beam splitter 30 is reflected by the scanner 10 to the multi-path beams R3, R4 and F5. The multi-path beams R3, R4 and F5 are collimated beams R6, R7 and R8 by the converging lens 20 to form a focus on the target plane TP. The beam reflected by the target plane forms a path to the beam dividing section 30 inversely (paths R6, R7 and R8, paths R3, R4 and F5 and path R2) 30, a part of the beam R9 is reflected in the negative z-axis direction and reaches the detection unit 6. [

The detection unit 6 measures the intensity of the reflected and returned laser beam and measures the image. Generally, the reflectance of glass or a transparent film is not 0%, and it has a low value but a small reflectance. (Hereinafter referred to as a "pattern material") such as ITO, graphene, carbon nanotube (CNT), or silver nano wire can be patterned on a transparent substrate such as glass or a transparent film have. Such a pattern material has a small difference in reflectivity of the transparent substrate, resulting in large contrast and low detection accuracy. Therefore, when the difference in reflectivity is not large, such as a transparent substrate and a pattern material, it is necessary to increase the contrast.

In order to distinguish materials such as transparent electrodes and the like having a large difference in refractive index between the transparent substrate such as glass and the transparent substrate formed on the surface of the transparent substrate, (Reflectance) compared to the conventional device.

The apparatus for measuring a surface pattern defect according to the present invention comprises a stage for arranging a transparent substrate having a pattern of another material on an upper surface thereof, a stage for irradiating the transparent substrate with light having an electric field parallel to the transparent substrate (p- An irradiating unit for irradiating the p-polarized light such that the p-polarized light is incident at a Brewster's angle according to a refractive index and a refractive index of a medium bounded by the transparent substrate, and a detector for determining whether the p- polarized light is reflected by the transparent substrate .

The apparatus for measuring a pattern defect of a transparent substrate according to the present invention can remove light reflected from any one of materials having little difference in reflectivity, thereby increasing the contrast between the two materials. Thereby, the pattern of the transparent substrate can be imaged or the defect of the pattern can be easily measured.

1 is a conceptual diagram of a general scanning device,
2 is a block diagram of an apparatus for measuring a surface pattern according to an embodiment of the present invention,
3 is a perspective view of a surface pattern measuring apparatus according to another embodiment of the present invention,
4 and 5 are perspective views of a surface pattern measuring apparatus according to another embodiment of the present invention, and Fig.
6 is a perspective view of a surface pattern measuring apparatus according to another embodiment of the present invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Also, the fact that the first component and the second component on the network are connected or connected means that data can be exchanged between the first component and the second component by wire or wirelessly.

Also, suffixes """ module "and" part "for components used in the following description are given only for convenience of description, It is not. Accordingly, the terms "module," "module," and " part " When such components are implemented in practical applications, two or more components may be combined into one component, or one component may be divided into two or more components as necessary.

In this description, the optical system may be an optical system or a combination of a plurality of optical systems. Also, whichever optical mechanism belongs to which optical system, this is merely an explanatory convenience, and any of the above optical mechanisms can constitute a separate system separately. Thus, it is not described specifically what optical system belongs to which optical system.

The transverse mode means the cross section of light that is perpendicular to the optical axis, i.e., the axis along which light travels. The transverse mode component means a light component of any one of the axes of the light. The first and second transverse mode directions are preferably perpendicular to each other. Hereinafter, the "first transverse mode direction" is an arbitrary axis perpendicular to the optical axis, and includes any one of the first axis, the first direction, the (x, y, z) Or in the direction, the longitudinal direction, the lateral direction, and the like. In particular, with respect to the longitudinal direction (vertical direction) and the lateral direction (horizontal direction), the longitudinal direction is a direction normal to the plane by the path of the laser beam, the lateral direction is the direction perpendicular to the longitudinal direction and the path direction of the laser beam Meaning or direction can be determined in relation to the ground. The "first transverse mode" means that the first axis (direction) component has the largest component. The first transverse mode component may also be referred to as the first component.

The cylindrical optical system may comprise a cylindrical optic. The cylindrical optic means a optic that has a curvature only in one direction and transmits or reflects the incident beam so as to condense or diffuse only in one-dimensional direction. The cylindrical lens means a transmissive type, and the cylindrical mirror means a reflective type. The cylindrical lens may have various shapes. For example, it may have a curvature only on one side (incidence surface or exit surface), or both sides (incidence surface and exit surface) may have a curvature.

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

2 is a block diagram of an apparatus for measuring a surface pattern according to an embodiment of the present invention.

2, a surface pattern measuring apparatus according to the present embodiment includes a stage 50 on which a substrate having a pattern formed of different materials is disposed on an upper surface thereof, a stage 50 for moving the substrate, an irradiation unit 1 for irradiating light onto the stage 50 And a detection unit 2 for detecting light emitted from the irradiation unit 1 and reflected by the stage 50. [

The substrate may be a transparent substrate made of a material such as glass or a transparent film. The material patterned on the substrate may be formed of a material having high transparency such as ITO, graphene, carbon nanotube (CNT), silver nano wire, or a combination thereof. That is, the difference between the reflectance and the transparency (refractive index) of the substrate and the patterned material (pattern material) may be small. The reflectivity of the substrate can be from 5 to 15%, and the reflectivity of the pattern material can be from 8 to 25%. The surface pattern measuring apparatus according to the present invention can distinguish the pattern material from the substrate even if the difference in reflectance between the substrate and the pattern material is within 10%. Further, the surface pattern measuring apparatus according to the present invention can measure even if the reflectance of the pattern material and the substrate is not substantially the same. In particular, the device according to the present invention can distinguish the pattern material from the substrate even if the difference in reflectivity of both materials is about 1% or more. The reflectivity referred to herein means the reflectivity according to vertical incidence.

The irradiating unit 1 may include a laser light source or an LED light source for emitting light. The irradiating unit 1 may further include a line beam generator for shaping the point light source type laser light source into a line beam. The line beam generator may include a scanner. The LED light source of the irradiation unit 1 may be included in the shaping unit 1 for emitting the light in the form of a line beam or for shaping the LED light source into a line beam. The forming unit may include a cylindrical optical system.

The irradiating unit 1 can irradiate the stage 50 with the light in the p-polarized state with respect to the substrate or the stage 50. [ The p-polarized light means light parallel to the plane of the stage 50 on which an electric field is incident. The irradiating unit 1 may include a polarizer for passing only the p-polarized light among the irradiation light emitted from the light source or causing the irradiation light to be p-polarized so as to irradiate the p-polarized light. The polarizer may have a polarizer film (filter) that passes only p-polarized light or a wave plate that changes the polarization state of light passing therethrough. In the case of a general light source other than a laser light source, the polarizer preferably comprises a polarizing film. The wave plate is also called a phase retarder. When the electromagnetic wave passes through the wave plate, the polarization direction becomes the sum of the component parallel to the optical axis and the component perpendicular to the optical axis, and the vector sum of the two components changes according to the birefringence and thickness of the wave plate. The irradiation light may be polarized in a certain direction (laser light source), polarized in a certain direction (general light source) by the polarizing film, and then converted into p-polarized light to the substrate by the wave plate. The phase change rate of the light passing through the wave plate may be changed depending on the polarization direction of the light incident on the wave plate and the relationship with the substrate.

The irradiating unit 1 is arranged such that light having an electric field parallel to the substrate (hereinafter referred to as p-polarized light) is incident at a Brewster angle (Brewster angle) according to the refractive index of the substrate and the refractive index of a medium can do. The reflectance of the light irradiated on the substrate becomes close to 0 or 0 on the substrate, and the reflection is substantially eliminated.

The detection unit 2 is disposed in the reflection path of the light irradiated to the stage 50 so as to be coupled to the reflected light, and can detect the reflected light. The detection unit 2 may include a photo multiplier tube (PMT), a photodiode, or a CCD array for measuring light.

In this embodiment, the light irradiated to the substrate is not reflected, and the light irradiated to the pattern material is reflected. Therefore, the detection unit 2 can determine the presence or absence of the pattern material or the defect of the pattern by judging the presence or absence of the reflected light.

The transparency of the pattern material is high, and the intensity of light reflected by the pattern material may be small. However, since the detection unit 2 needs to detect the presence or absence of the reflected light, that is, the contrast ratio is high, it is possible to easily detect two materials that are contrasted even when the intensity of the reflected light is weak. The detection unit 2 may include an amplification unit for amplifying the intensity of the detected signal.

The detection unit 2 may further include a filter that transmits only the p-polarized light. Noise can be filtered out, and improved detection performance can be obtained.

In the present embodiment, the incident angle incident on the stage 50 by the irradiation unit 1 is determined by the refractive index of the substrate and the refractive index of the medium in contact therewith, but is not limited thereto. For example, the angle of incidence can be a Brewster's angle, depending on the refractive index of the patterned material and the refractive index of the medium in contact therewith. In this case, the light irradiated to the patterned material is not reflected.

The surface pattern measuring apparatus according to the present embodiment is not limited to the surface measurement of the substrate on which the pattern material is formed. For example, it is possible to measure the presence or absence of defects such as contaminants or flaws formed on the surface of the substrate.

3 is a perspective view of a surface pattern failure measuring apparatus according to another embodiment of the present invention. See FIG.

Referring to FIG. 3, the surface pattern failure measuring apparatus includes a stage 50 on which an object having low reflectivity is formed and on which a substrate having a different reflectivity from the formed material is disposed, a laser light source 10 for emitting a laser beam, A polarizer 30 to be p-polarized with respect to the stage 50, a scanner 20 which reflects the incident laser beam so that the path is continuously changed at a predetermined radiation angle in accordance with the scanner control signal, A first object lens 110 for changing the reflected laser beam into a parallel path beam, a first light receiving lens 210 for receiving the laser beam reflected by the stage 50, and a beam detector for detecting the presence or absence of the reflected beam .

The substrate may be a transparent substrate made of a material such as glass or a transparent film. The material patterned on the substrate may be formed of a material having high transparency such as ITO, graphene, carbon nanotube (CNT), silver nano wire, or the like. That is, the difference between the reflectance and the transparency (refractive index) of the substrate and the patterned material (pattern material) may be small.

The laser light source 10 can oscillate a substantially parallel or converging laser beam. It is preferable that the beam emitted from the laser light source 10 is linearly polarized in one direction.

Polarizer 30 may cause the transmitted laser beam to be p-polarized with respect to stage 50. Generally, since the laser beam emitted from the laser light source 10 is linearly polarized in one direction, the polarizer 30 preferably includes a wave plate for changing the polarization state of the incident beam. Polarizer 30 may have a p-polarizer that allows only the p-polarized beam to be transmitted to stage 50 of the incoming laser beam.

In the present embodiment, the polarizer 30 is disposed on the path through which the beam emitted from the laser light source 10 is incident on the scanner 20, but is not limited thereto. For example, the beam incident on the scanner 20 can be arranged in a path where the beam is reflected.

The scanner 20 may deflect the incident laser beam so that the path is continuously changed within a certain radiation angle in accordance with the scanner control signal provided by the controller (not shown). Although shown in FIG. 3 as having three reflective paths, there are a number of reflective paths that are not shown. A reflected beam, which is reflected by the scanner 20 and changes its path continuously at a certain radiation angle, will be referred to as a radial multi-path (laser) beam or a deflection (laser) beam.

The scanner 20 may include a galvanometer, a polygon mirror, a resonant scanner, an acousto-optic deflector, and the like. The scanner 20 can be turned on / off according to the scanner control signal, or the deflection period can be changed.

The first object lens 110 is disposed on the path along which the multi-path beams by the scanner 20 travel. The first object lens 110 can be changed to a parallel multi-path beam (line beam) that advances the multi-path beams by the scanner 20 in parallel paths. For this purpose, when the focal point of the first object lens 110 is f, the distance between the first object lens 110 and the scanner 20 is preferably f. The parallel multi-path beam can form a scan line SL in a part of a target (a transparent substrate and a transparent pattern) on the stage 50.

The beam path length between the first object lens 110 and the pattern of the transparent substrate is preferably the focal distance f of the first object lens 110. [ This is because the intensity of the reflected light increases when the focus of the beam incident on the pattern is formed in the pattern. Since the height of the pattern is very small, the beam path length between the first object lens 110 and the transparent substrate may be f. The first object lens 110 may be a spherical convex lens or a cylindrical convex lens.

The first light receiving lens 210 may cause the incident parallel multi-path beams to be refracted to a specific position. The first light receiving lens 210 may be a spherical convex lens or a cylindrical convex lens, and the type thereof is preferably the same as that of the first object lens 110. For example, if the first object lens 110 is a spherical convex lens, the first light receiving lens 210 may also be a spherical convex lens.

And the detection unit may be disposed at a focal position in the direction of the transmission surface of the first light receiving lens. The detection unit may include a beam detector 220 for detecting the presence or absence of a beam reflected from the scan line SL on the stage 50. [ The detection unit may further include a p-polarizer 230 for removing noise, which transmits only the p-polarized beam to the stage 50 among the beams incident on the beam detector 220.

In this embodiment, the linearly polarized laser beam emitted from the laser light source 10 is p-polarized with respect to the stage 50 through the polarizer 30. [ The p-polarized beam is reflected by the scanner 20 as a radial multi-path beam, which passes through the first object lens 110 and becomes a parallel multi-path beam, So that the scan lines SL can be formed. The beam incident on the transparent substrate region of the scan line SL is not reflected and the beam incident on the pattern material region of the scan line SL is reflected and proceeds to the first light receiving lens 210. [ The first light receiving lens 210 allows the beam incident from the scan line SL to be coupled to the detection unit. The beam detector 220 can detect whether or not there is a beam passing through the p-polarized filter 230, extract a pattern image, or measure a pattern defect.

4 and 5 are perspective views of a surface pattern measuring apparatus according to another embodiment of the present invention. See FIGS. 2 and 3. FIG. A detailed description of the corresponding components will be omitted.

4 and 5, the surface pattern measuring apparatus includes a stage 50 for placing a substrate having a pattern on which a material having a different reflectivity is formed, a laser light source 10 for emitting a laser beam, A scanner 20 that reflects the incident laser beam so that the path is continuously changed at a predetermined radiation angle in accordance with the scanner control signal, a laser 20 that is reflected by the scanner 20, A cylindrical optical system for changing the beam into a parallel path beam, a first light receiving lens 210 for receiving the laser beam reflected by the stage 50, and beam detecting portions 220 and 230 for detecting the presence or absence of the reflected beam .

The substrate may be a transparent substrate made of a material such as glass or a transparent film. The material patterned on the substrate may be formed of a material having high transparency such as ITO, graphene, carbon nanotube (CNT), silver nano wire, or the like. That is, the difference between the reflectance and the transparency (refractive index) of the substrate and the patterned material (pattern material) may be small.

It is preferable that the cylindrical optical system of the surface pattern measurement apparatus shown in FIG. 4 includes a cylindrical concave mirror 120.

The cylindrical optical system of the surface pattern measurement apparatus shown in Fig. 5 preferably includes a cylindrical concave mirror 120 and a planar mirror 130. Fig. The arrangement order of the cylindrical concave mirror and the flat mirror may be changed.

Spherical lenses have different thicknesses in the center and outline. The polarization of the laser beam passing through the spherical lens is not uniform. That is, it may be difficult to make the reflectance in the scan line SL zero. However, when the cylindrical mirror is used, the polarization nonuniformity due to the difference in the thickness of the medium does not occur.

4, the linearly polarized laser beam emitted from the laser light source 10 is p-polarized with respect to the stage 50 through the polarizer 30. [ The p-polarized beam is reflected by the scanner 20 into a radially multipath beam. The radial multi-path beam is reflected by the cylindrical concave mirror 120 and proceeds to the parallel multi-path beam. To this end, the beam path length of the scanner 20 and the cylindrical concave mirror 120 is preferably substantially the same as the focal length of the cylindrical concave mirror 120. The parallel multi-path beam forms a scan line SL on the target on the stage 50. The beam incident on the transparent substrate region of the scan line SL is not reflected and the beam incident on the pattern material region of the scan line SL is reflected and proceeds to the first light receiving lens 210. [ The first light receiving lens 210 allows the beam incident from the scan line SL to be coupled to the detection unit. The beam detector 220 can detect whether there is a beam passing through the p-polarized filter 230, and extract the pattern image.

5, the linearly polarized laser beam emitted from the laser light source 10 is p-polarized with respect to the stage 50 through the polarizer 30. [ The p-polarized beam is reflected by the scanner 20 into a radially multipath beam. The radial multi-path beam is reflected by the cylindrical concave mirror 120 and proceeds to the parallel multi-path beam. To this end, the beam path length of the scanner 20 and the cylindrical concave mirror 120 is preferably substantially the same as the focal length of the cylindrical concave mirror 120. The planar mirror 130 reflects the beam reflected by the cylindrical concave mirror 120 toward the stage 50. The smaller the angle of incidence of the cylindrical concave mirror 120, the better the beam is formed. However, if the angle of incidence is made small, it is difficult to arrange the components. The planar mirror 130 can be used to make the arrangement of the components more freely. The parallel multi-mirror beam reflected by the planar mirror 130 forms a scan line SL on the target on the stage 50. [ The beam incident on the transparent substrate region of the scan line SL is not reflected and the beam incident on the pattern material region of the scan line SL is reflected and proceeds to the first light receiving lens 210. [ The first light receiving lens 210 allows the beam incident from the scan line SL to be coupled to the detection unit. The beam detector 220 detects whether there is a beam passing through the p-polarized filter 230, and can detect a pattern image or measure a pattern defect.

6 is a perspective view of a surface pattern measuring apparatus according to another embodiment of the present invention. See FIG.

Referring to FIG. 6, the surface pattern measuring apparatus includes a stage 50 for placing a substrate having a pattern on which a material having a different reflectivity is formed, a light source 15 for emitting light, A second object lens 115 for parallelizing the light transmitted through the polarizer 35, a second object lens 115 for receiving light by the stage 50, A lens 215, and a beam detecting unit for detecting the presence or absence of reflected light.

The substrate may be a transparent substrate made of a material such as glass or a transparent film. The material patterned on the substrate may be formed of a material having high transparency such as ITO, graphene, carbon nanotube (CNT), silver nano wire, or the like. That is, the difference between the reflectance and the transparency (refractive index) of the substrate and the patterned material (pattern material) may be small.

The light source 15 preferably emits a line beam or a radial light in a one-dimensional form. In order to emit light in the form of a line beam, the light source 15 may include a plurality of LEDs, and a plurality of LEDs may be arranged on a straight line, or one side may be coupled to each of the plurality of LEDs, The optical fiber can be provided. The light source 15 may include a cylindrical optical system, particularly a cylindrical convex lens, for forming a narrow line beam.

The polarizer 35 may include a polarizing filter that transmits only the light polarized in a predetermined direction among the incident light. The polarizer 35 may further include a wave plate for changing the polarization direction so as to be p-polarized with respect to the stage 50.

The second object lens 115 changes the radial light emitted from the light source 15 into parallel light. For this purpose, when the focal point of the second objective lens 115 is f2, the optical path length between the second objective lens 115 and the light source 15 is preferably f. The parallel light can form a scan line SL in a part of a target (a transparent substrate and a transparent pattern) on the stage 50. The second object lens 115 may be a spherical convex lens or a cylindrical convex lens.

And the second light receiving lens 215 may cause the incident parallel multi-path beams to be refracted to a specific position. The second light receiving lens 215 may be a spherical convex lens or a cylindrical convex lens. It is preferable that the second light receiving lens 215 is a optical unit corresponding to the second object lens 115. [

And the detection unit may be disposed at a focal position in the direction of the transmission surface of the first light receiving lens. The detection unit may include a beam detector 225 for detecting the presence or absence of a beam reflected from the scan line SL on the stage 50. [ The detection unit may further include a p-polarizer 235 for removing noise, which transmits only the p-polarized beam to the stage 50 among the beams incident on the beam detector 225.

In this embodiment, the radial light emitted from the light source 15 passes through only the p-polarized light with respect to the stage 50 through the polarizer 35. [ The p-polarized light is transmitted through the second object lens 115 and becomes parallel light, so that the scan line SL can be formed on the target on the stage 50. The light incident on the transparent substrate region of the scan line SL is not reflected and the light incident on the pattern material region of the scan line SL is reflected to proceed to the second light receiving lens 215. The second light receiving lens 215 allows the light incident from the scan line SL to be coupled to the detection unit. The beam detector 225 can detect whether there is light passing through the p-polarized filter 235, and extract the pattern image.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

1: irradiation part 2: detection part
10: laser light source 15: light source
20: scanner 30, 35: polarizer
50: stage

Claims (16)

A substrate on which a pattern of another material is formed, the substrate being different in reflectivity from the pattern material;
Polarized light such that light having an electric field parallel to the substrate (p-polarized) toward the substrate is incident at a Brewster's angle according to a refractive index of the substrate and a refractive index of a medium bounded by the substrate; And
And a detector for detecting light reflected by the substrate,
The irradiation unit
A laser light source for emitting a laser beam;
A scanner for reflecting the incident laser beam so that the path is continuously changed in accordance with a scanner control signal at a predetermined radiation angle;
A polarizer disposed in any one of a path through which the laser beam is incident to the scanner and a path through which the laser beam is reflected by the scanner, so that the laser beam is p-polarized with respect to the substrate; And
And a cylindrical concave mirror for refracting the p-polarized laser beam in a first direction,
Wherein an angle between the first direction and a normal of the substrate is a Brewster's angle according to a refractive index of the substrate and a medium bounded by the substrate,
Characterized in that the cylindrical concave mirror is so reflected that the degree of polarization of the p-polarized laser beam incident is uniform. A substrate on which a pattern of another material is formed, the substrate being different in reflectivity from the pattern material;
Polarized light such that light having an electric field parallel to the substrate (p-polarized) toward the substrate is incident at a Brewster's angle according to a refractive index of the substrate and a refractive index of a medium bounded by the substrate; And
And a detector for detecting light reflected by the substrate,
The irradiation unit
A laser light source for emitting a laser beam;
A scanner for reflecting the incident laser beam so that the path is continuously changed in accordance with a scanner control signal at a predetermined radiation angle;
A polarizer disposed in any one of a path through which the laser beam is incident to the scanner and a path through which the laser beam is reflected by the scanner, so that the laser beam is p-polarized with respect to the substrate; And
And a second optical system for refracting the p-polarized laser beam in a first direction,
Wherein an angle between the first direction and a normal of the substrate is a Brewster's angle according to a refractive index of the substrate and a medium bounded by the substrate,
The second optical system
A first reflector for reflecting a beam reflected from the scanner at a first acute angle; And
And a second reflector for reflecting the beam reflected by the first reflector at a second acute angle and for reflecting the beam at the second acute angle to the first direction,
Wherein one of the first and second reflecting portions is one of a planar mirror and a cylindrical concave mirror and the other one of the first and second reflecting portions is the other one of the planar mirror and the cylindrical concave mirror,
Characterized in that the cylindrical concave mirror is so reflected that the degree of polarization of the p-polarized laser beam incident is uniform. 3. The method according to claim 1 or 2,
Wherein the detection unit analyzes the detected light to extract a pattern of the substrate or to judge whether or not the pattern is defective. 3. The method according to claim 1 or 2,
The irradiation unit
A light source that emits one-dimensional light; And
And a polarizer for causing the one-dimensional light to be p-polarized with respect to the substrate,
Wherein:
A target lens disposed in a reflection path where the general light having the same path as that of the p-polarized light generated by the polarizer is reflected by the substrate to converge the general light to a specific position; And
And a photographing unit that detects p-polarized light having passed through the object lens. 5. The method of claim 4,
The light source emits a fan-shaped light,
Wherein the irradiating unit further comprises a first optical system for converting p-polarized sector-shaped light by the polarizer into p-polarized parallel light that proceeds in a predetermined direction and irradiating the p-polarized parallel light to the substrate. 5. The method of claim 4,
Wherein the detecting section further comprises a p-polarizing filter disposed between the object lens and the photographing section and allowing only the light p-polarized with respect to the substrate to pass through the photographing section. 3. The method according to claim 1 or 2,
Wherein the detection unit includes a beam detector for detecting whether a p-polarized laser beam incident on the substrate is reflected by the substrate. delete delete delete delete delete delete 3. The method according to claim 1 or 2,
Wherein the cylindrical concave mirror changes a radial beam that is emitted at a focus position into a parallel beam,
Wherein the path length of the beam reflected by the cylindrical concave mirror to the substrate is equal to the distance of the focal point. 3. The method according to claim 1 or 2,
Wherein the substrate is one of a glass and a transparent film,
Wherein the pattern material comprises at least one of ITO, graphene, carbon nanotube (CNT), and silver nano wire. 3. The method according to claim 1 or 2,
Wherein the difference between the reflectance of the substrate and the reflectance of the pattern material is 1 to 10%.

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