Defect inspection device

Abstract

The utility model discloses a defect inspection device, comprising a single light source emitting first light; a first beam splitter providing the first light onto a plurality of light paths; a first unit that is disposed on a first light path from the light source toward the sample holder and that irradiates the sample holder with first inspection light; a second unit disposed on a second light path from the light source toward the sample holder and configured to irradiate a second inspection light to the sample holder; a camera including a single image sensor that generates an image of a sample that is disposed on the sample holder and moves linearly by a time-delay integration method; and a detection section that detects a defect of the sample on the basis of the image received from the camera, at least one of the first unit and the second unit including an optical filter having a plurality of openings.

Description

Technical Field

[0001] The embodiment of the utility model relates to a defect inspection device. Background Art

[0002] Devices that inspect samples for defects by photographing them with a camera are being used in various ways. However, as the structure of samples to be inspected, such as high-resolution displays, becomes increasingly sophisticated, the time required to detect defects using inspection devices increases, and there is a problem of limited space when designing the structure of defect inspection devices. Utility Model Content

[0003] The present invention is to solve various problems including the above-mentioned problems and to provide a structure of a defect inspection device. The above-mentioned problems are illustrative and do not limit the scope of the present invention.

[0004] In one aspect of the present invention, a defect inspection device is disclosed, comprising: a single light source emitting a first light; a first beam splitter providing the first light to a plurality of light paths; a first unit arranged on a first light path from the light source toward a sample holder, irradiating the sample holder with a first inspection light; a second unit arranged on a second light path from the light source toward the sample holder, irradiating the sample holder with a second inspection light; a camera comprising a single image sensor for generating an image of a sample arranged on the sample holder and moving linearly by a time-delay integration method; and a detection unit for detecting a defect of the sample based on the image received from the camera, wherein at least one of the first unit and the second unit comprises an optical filter having a plurality of openings.

[0005] In one embodiment, the first inspection light and the second inspection light may simultaneously illuminate the sample holder, and the single image sensor of the camera includes: a first part, generating a first image of the sample taken by the first inspection light; and a second part, generating a second image of the sample taken by the second inspection light.

[0006] In one embodiment, the first unit may include: a first shielding plate that blocks a portion of the first light provided to the first light path; and the optical filter located between the first shielding plate and the sample holder.

[0007] In one embodiment, the second unit may include: a second shielding plate for blocking a portion of the first light provided to the second light path.

[0008] In one embodiment, the irradiation area of ​​the first inspection light and the irradiation area of ​​the second inspection light may be different from each other by the first shielding plate and the second shielding plate, respectively.

[0009] In one embodiment, the plurality of openings of the optical filter may include: a first opening located in a central portion; and a second opening located outside the first opening, and the first opening and the second opening have different shapes from each other.

[0010] In one embodiment, the first opening may have a semicircular shape in a plane.

[0011] In one embodiment, the second opening may have a semi-ring shape extending with a predetermined first width in a plane.

[0012] In one embodiment, the first opening may include a curved portion and a straight portion on a plane, and the second opening may include a first curved portion, a second curved portion located inside the first curved portion, and a straight portion connecting the first curved portion and the second curved portion.

[0013] In one embodiment, the first width of the second opening may be 1 / 8 to 1 / 6 of the maximum width of the first curved portion of the second opening.

[0014] In one embodiment, the length of the straight portion of the first opening may be 1 / 4 to 1 / 3 of the maximum width of the first curved portion of the second opening.

[0015] In one embodiment, the plurality of openings of the optical filter may include a first opening and a second opening spaced apart from each other, and the first inspection light may include a first component passing through the first opening of the optical filter and a second component passing through the second opening of the optical filter.

[0016] In one embodiment, the first component and the second component of the first inspection light may be different in at least one of an angle, a position, and a size.

[0017] In one embodiment, the defect inspection device may further include: at least one lens group located between the sample holder and the first unit and the second unit, and the first inspection light and the second inspection light are irradiated toward the sample holder through the at least one lens group respectively.

[0018] In one embodiment, the defect inspection device may further include: a sensor side optical filter, which allows the light reflected by the surface of the sample among the first inspection light and the light reflected by the surface of the sample among the second inspection light to pass through, and the sensor side optical filter is configured to be adjacent to the camera.

[0019] In one embodiment, the light reflected by the surface of the sample among the first inspection light and the light reflected by the surface of the sample among the second inspection light may be bent by a second beam splitter and travel toward the sensor-side optical filter.

[0020] In one embodiment, the camera may generate the first image of the sample based on the signal obtained from the first part, and generate the second image of the sample based on the signal obtained from the second part.

[0021] In one embodiment, when the sample includes defects, an image of the defects detected in the first image and an image of the defects detected in the second image may be different from each other.

[0022] In one embodiment, the detection unit may detect the defective position based on the first image and the second image.

[0023] In one embodiment, the single image sensor may further include: a dummy portion located between the first portion and the second portion.

[0024] (Effect of utility model)

[0025] According to the utility model, a device including a lighting and a camera can be provided to sufficiently ensure the working distance and generate a high-resolution image by a single scan of the sample to quickly detect defects. This effect is an example and the scope of the utility model is not limited by the above-mentioned effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The structure of a defect inspection device according to an embodiment of the present invention is schematically shown.

[0027] Figure 2 Schematic representation of the incident Figure 1 A first inspection light and a second inspection light of the sample holder.

[0028] Figure 3 Yes means Figure 1 A plan view of an image sensor included in a camera.

[0029] Figure 4 In the figure, (a) schematically shows the Figure 1 (b) schematically shows the structure from the first unit to the sample holder. Figure 1 The structure from the second unit to the sample holder.

[0030] Figure 5 It is a perspective view schematically showing an optical filter according to an embodiment of the present invention.

[0031] Figure 6 It is a cross-sectional view schematically showing an optical filter according to an embodiment of the present invention.

[0032] Figure 7 It is a plan view schematically showing an optical filter according to an embodiment of the present invention.

[0033] Figure 8 The components of the second inspection light that has passed through the optical filter according to one embodiment of the present invention are schematically shown.

[0034] Fig. 9 This is a conceptual diagram for explaining image generation using a TDI method by an image sensor of a camera of a defect inspection device according to an embodiment of the present invention.

[0035] Explanation of symbols:

[0036] 1: defect inspection device; 2: light source; 5: first lens group; BSP1: first beam splitter; P1: first unit; 13: first baffle plate; P2: second unit; 23: second baffle plate; 30: first optical filter; 41: second lens group; 43: third lens group; 54: sensor side optical filter; 71: sample holder; SP: sample; 100: image sensor. DETAILED DESCRIPTION

[0037] The present invention can have various changes and various embodiments, and specific embodiments are illustrated in the drawings and described in detail herein. Figure 1 The effects, features, and methods of achieving the effects and features of the present invention will become clear from the embodiments described in detail below. However, the present invention is not limited to the embodiments disclosed below, and the present invention can be implemented in various forms.

[0038] In the following embodiments, the terms "first" and "second" are not restrictive terms, but are used to distinguish one constituent element from other constituent elements.

[0039] In the following embodiments, a singular expression includes a plural expression unless there is a clear contrary meaning in the text.

[0040] In the following embodiments, terms such as including or having should be understood to refer to the existence of features or constituent elements recorded in the specification, and do not exclude the possibility of adding one or more other features or constituent elements in advance.

[0041] In the following embodiments, when a film, a region, a constituent element, etc. is located on or above another part, it includes not only the case where it is directly located on the other part, but also the case where other films, regions, constituent elements, etc. exist in between.

[0042] In this specification, "A and / or B" means A, B, or both A and B. In addition, in this specification, "at least one of A and B" means A, B, or both A and B.

[0043] In the following embodiments, the wiring extending in the "first direction or the second direction" refers not only to the case where the wiring extends in a straight line shape, but also includes the case where the wiring extends in a meandering shape or a curved shape along the first direction or the second direction.

[0044] In the following embodiments, "on a plane" refers to the case of looking down at the object part, and "on a cross section" refers to the case of observing a cross section of the object part vertically cut from the side. In the following embodiments, "overlap" includes overlap "on a plane" and "on a cross section".

[0045] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the accompanying drawings, the same reference numerals are given to the same or corresponding components.

[0046] Figure 1 The structure of a defect inspection device according to an embodiment of the present invention is schematically shown. Figure 2 Schematic representation of the incident Figure 1 A first inspection light and a second inspection light of the sample holder. Figure 3 Yes means Figure 1 A plan view of an image sensor included in a camera.

[0047] Reference Figure 1 The defect inspection device (hereinafter referred to as the inspection device) 1 is a device for inspecting defects of a sample SP that moves linearly, and can extract a plurality of images of the sample SP and inspect defects using the plurality of images.

[0048] The inspection device 1 may include a single light source 2. The single light source 2 may emit a first light (for example, white light). The first light emitted from the light source 2 may be incident on a first beam splitter BSP1. A first lens group 5 may be configured between the light source 2 and the first beam splitter BSP1. The first lens group 5 may include one or more lenses. The first light emitted from the light source 2 may pass through the first lens group 5 and be incident on the first beam splitter BSP1, and the first beam splitter BSP1 may provide the first light to a plurality of light paths. For example, a portion of the first light (hereinafter referred to as the 1-1 light) may be provided to the first light path through the first beam splitter BSP1. Another portion of the first light may be bent by the first beam splitter BSP1. For example, another portion of the first light (hereinafter referred to as the 1-2 light) may be reflected by the first beam splitter BSP1 and provided to a second light path different from the first light path.

[0049] The inspection device 1 may include a first unit P1 that outputs a first inspection light ISL1 and a second unit P2 that outputs a second inspection light ISL2. The first unit P1 may be arranged on a first light path from the light source 2 toward the sample holder 71. The second unit P2 may be arranged on a second light path from the light source 2 toward the sample holder 71. The first inspection light ISL1 and the second inspection light ISL2 outputted from the first unit P1 and the second unit P2, respectively, may be irradiated toward the sample holder 71 at the same time. A sample SP( Figure 2 ), the sample holder 71 can be linearly moved by the moving part 73. Sample SP ( Figure 2 ) can be fixedly arranged on the sample holder 71. Since the sample holder 71 is linearly moved by the moving part 73, in this specification, the sample SP ( Figure 2 ) can represent the linear movement of the sample holder 71.

[0050] The first inspection light ISL1 output from the first unit P1 may be irradiated toward the sample holder 71 through at least one lens group (for example, the second lens group 41 and the third lens group 43). A second beam splitter BSP2 may be disposed between the first unit P1 and the second lens group 41, and the first inspection light ISL1 may pass through the second beam splitter BSP2 and travel toward the second lens group 41. The first inspection light ISL1 may travel toward the sample holder 71 on a line coaxial with the optical axes of the second lens group 41 and the third lens group 43. The second lens group 41 and the third lens group 43 may each include one or more lenses.

[0051] The second inspection light ISL2 output from the second unit P2 may be irradiated toward the sample holder 71 through the second lens group 41 and the third lens group 43. The aforementioned second beam splitter BSP2 may be disposed between the second unit P2 and the second lens group 41, and the second inspection light ISL2 may be bent by the second beam splitter BSP2. For example, the second inspection light ISL2 may be reflected by the second beam splitter BSP2 and travel toward the second lens group 41. The second inspection light ISL2 may travel toward the sample holder 71 on a line coaxial with the optical axes of the second lens group 41 and the third lens group 43.

[0052] The first inspection light ISL1 and the second inspection light ISL2 may be coaxial illumination that travels toward the sample holder 71 on a line coaxial with the optical axes of the second lens group 41 and the third lens group 43 .

[0053] The first inspection light ISL1 and the second inspection light ISL2 may be irradiated toward the sample holder 71 at the same time, but may irradiate different areas on the sample holder 71. Figure 2 As shown, the first inspection light ISL1 may illuminate the first area S1 of the sample holder 71, and the second inspection light ISL2 may illuminate the second area S2 of the sample holder 71. The first area S1 as the illumination area of ​​the first inspection light ISL1 and the second area S2 as the illumination area of ​​the second inspection light ISL2 may be different from each other. For example, the first area S1 and the second area S2 may be adjacent to each other but not overlap.

[0054] The sample SP may pass through the first area S1 and the second area S2 by the linear movement of the sample holder 71. The positions of the areas irradiated by the first inspection light ISL1 and the second inspection light ISL2 (i.e., the first area S1 and the second area S2) may be fixed relative to the linear movement of the sample holder 71. As a non-limiting embodiment of the present invention, when the sample SP moves along Figure 2 In the case of traveling in the horizontal direction, the sample SP may pass through the second region S2 and the first region S1 at different times from each other.

[0055] As the sample SP passes through the second region S2 and the first region S1, the light reflected by the sample SP may pass through Figure 1 The eyepiece portion 45 and the sensor side optical filter 54 are shown and directed toward the camera 60. For example, the light reflected by the sample SP can pass through the eyepiece portion 45 and be bent in the third beam splitter BSP3 to travel to the fourth lens group 51 and the fifth lens group 52, be bent in the image lens 53 and pass through the sensor side optical filter 54 and the cathode ray tube lens 55 and directed toward the camera 60.

[0056] The camera 60 may include a single image sensor, which may include multiple parts that receive light that is different from each other. Figure 3 As shown, the image sensor 100 may include a first portion 110 and a second portion 120 , each having a predetermined area but spaced apart from each other.

[0057] The first portion 110 and the second portion 120 may each include a plurality of pixels P capable of receiving light. For example, the first portion 110 may include a plurality of pixel lines, each of which may include a plurality of pixels P arranged along a direction. Similarly, the second portion 120 may have a pixel line structure. As an embodiment, each pixel P may be approximately 5 micrometers (μm) by 5 micrometers (μm) in horizontal direction and vertical direction, but the aforementioned numerical values ​​are illustrative, and the size of the pixel P may be changed in various ways.

[0058] The image sensor 100 may include a gap (eg, a dummy portion 140) between two adjacent portions of the first portion 110 and the second portion 120. The dummy portion 140 may include a pixel P, but may not generate an image (or signal) for inspecting a defect of the sample SP.

[0059] The first part 110 can utilize the first inspection light ISL1 ( Figure 2 ) to receive the light reflected by the sample SP to scan the sample SP, and the second part 120 can use the second inspection light ISL2 ( Figure 2 ) to receive the light reflected by the sample SP so as to scan the sample SP. Figure 2 ) may not be received by the first portion 110, and the light obtained by the first inspection light ISL1 ( Figure 2 )The light obtained may not be received by the second part 120.

[0060] The image sensor 100 can generate an image of a sample SP that moves linearly on the sample holder 71 by a time delay integration (TDI) method. For the same sample SP, the first part 110 can generate a first image, and the second part 120 can generate a second image. The first image obtained by the first inspection light ISL1 output from the first unit P1 can be formed by the light received by the first part 110. The second image obtained by the second inspection light ISL2 output from the second unit P2 can be formed by the light received by the second part 120.

[0061] like Figure 2As shown, as the sample SP passes through the first area S1 and the second area S2, the single image sensor 100 can generate a plurality of images (e.g., the first image and the second image) through the first part 110 and the second part 120. Such first and second images can be provided to the detection unit 80, and the detection unit 80 can detect defects of the sample SP based on the first and second images.

[0062] Figure 4 In the figure, (a) schematically shows the Figure 1 (b) schematically shows the structure from the first unit to the sample holder. Figure 1 The structure from the second unit to the sample holder.

[0063] Reference Figure 1 , Figure 4 (a) and (b), the first light emitted from the single light source 2 can be split by the first beam splitter BSP1 ( Figure 1 ) is provided to multiple optical paths (for example, a first optical path and a second optical path). The first unit P1 can be configured on the first optical path to output a first inspection light ISL1. The second unit P2 can be configured on the second optical path to output a second inspection light ISL2. At least one of the first unit P1 and the second unit P2 may include an optical filter having a plurality of openings. The optical filter having a plurality of openings may cause the light passing therethrough to include a plurality of light components. The plurality of light components may respectively be components that have passed through different openings among the plurality of openings. The positions, sizes, shapes, etc. of the plurality of openings may be different. At least one of the angles, positions, and sizes of the illumination of the plurality of light components may be different. That is, the light that has passed through the optical filter having a plurality of openings may exhibit different optical conditions from each other according to the number, position, size, and shape of the plurality of openings. Below, refer to Figures 5 to 8 The specific description will be given later.

[0064] This embodiment shows a case where one of the first unit P1 and the second unit P2 includes an optical filter having multiple openings. For example, the first unit P1 may not include an optical filter, and the second unit P2 may include an optical filter having multiple openings (for example, the first optical filter 30). However, the present invention is not limited to this. In other embodiments, the first unit P1 and the second unit P2 may each include an optical filter having multiple openings.

[0065] Reference Figure 1 and Figure 4(a), the first unit P1 may include a 1-1 lens group 11, a first shielding plate 13, and a 1-2 lens group 15 arranged on the first light path of the first light emitted from the light source 2. As an embodiment, the 1-1 lens group 11 may be arranged in the first beam splitter BSP1 ( Figure 1 ) and the first shielding plate 13, and the first shielding plate 13 can be arranged between the 1-1 lens group 11 and the 1-2 lens group 15.

[0066] The 1-1 lens group 11 and the 1-2 lens group 15 may include more than one lens. As described above, a portion of the first light emitted from the light source 2 (i.e., the 1-1 light) may be provided to the first light path in the first beam splitter BSP1. The 1-1 light may pass through the 1-1 lens group 11 and the first baffle plate 13 between the 1-1 lens group 11 and the 1-2 lens group 15, thereby traveling toward the 1-2 lens group 15. The first baffle plate 13 may block a portion of the 1-1 light that has passed through the 1-1 lens group 11, allowing the remaining portion of the light to pass through. The first baffle plate 13 may be a baffle plate coated with a non-reflective coating, for example, a stainless steel (SUS) plate coated with a non-reflective coating. The first baffle plate 13 may be used to control the reflection of the light in the front reference lens 11. Figure 2 The position of the first region S1 and / or the size of the first region S1 are described.

[0067] Reference Figure 1 As an embodiment, the first unit P1 may include a first mirror 17 and a 1-3 lens group 19. The 1-1 light (the first inspection light ISL1 ( Figure 1 )) can be reflected by the first mirror 17 and travel toward the 1st-3rd lens group 19. The 1st-3rd lens group 19 may include more than one lens. The first inspection light ISL1( Figure 1 ) can pass through the 1st to 3rd lens groups 19 and then move toward the second lens group 41 and the third lens group 43, and can pass through the third beam splitter BSP3.

[0068] As previously referred to Figure 2 As described above, the first inspection light ISL1 can illuminate the first area S1 of the sample holder 71. Since the sample SP disposed on the sample holder 71 is linearly moved by the moving part 73, the image sensor 100 ( Figure 3 ) (e.g., the first portion 110, Figure 3 ) records the image for sample SP.

[0069] The first inspection light ISL1 irradiated to the sample SP may be reflected by the sample SP. The light reflected by the sample SP may pass through the eyepiece portion 45 and the sensor-side optical filter 54 and be directed toward the camera 60. For example, the light reflected by the sample SP may pass through the eyepiece portion 45, the third beam splitter BSP3, the fourth lens group 51, the fifth lens group 52, the image lens 53, the sensor-side optical filter 54, and the cathode ray tube lens 55 and be directed toward the camera 60.

[0070] The light that has passed through the sensor-side optical filter 54 (ie, the light including the information on the sample SP) can be as follows: Figure 1 As shown, the camera 60 moves toward the image sensor 100 ( Figure 3 ) (e.g., the first portion 110, Figure 3 ) can generate a first image by the aforementioned light.

[0071] In the case where there is a bad structure in the sample SP, the reflection in the bad structure and the reflection in the normal structure may be different. For example, the light reflected by the bad structure may reach the image sensor 100 ( Figure 3 ) (e.g., the first portion 110 ( Figure 3 )). For example, in the first part 110 ( Figure 3 )In the first image generated, the defect may appear relatively dark and the periphery of the defect may appear bright.

[0072] Reference Figure 1 and Figure 4 (b), the second unit P2 may include a 2-1st lens group 21, a second shielding plate 23, a 2-2nd lens group 25 and a first optical filter 30 arranged on the second light path of the first light emitted from the light source 2. As an embodiment, the 2-1st lens group 21 may be arranged in the first beam splitter BSP1 ( Figure 1 ) and the second shielding plate 23, the second shielding plate 23 can be arranged between the 2-1st lens group 21 and the 2-2nd lens group 25. The 2-2nd lens group 25 can be arranged between the second shielding plate 23 and the first optical filter 30.

[0073] The 2-1 lens group 21 and the 2-2 lens group 25 may include more than one lens. As described above, a portion of the first light emitted from the light source 2 (i.e., the 1-2 light) may be provided to the second light path in the first beam splitter BSP1. The first light provided to the second light path may pass through the 2-1 lens group 21 and the second baffle plate 23 between the 2-1 lens group 21 and the 2-2 lens group 25, thereby traveling toward the 2-2 lens group 25. The second baffle plate 23 may block a portion of the 1-2 light that has passed through the 2-1 lens group 21, and allow the remaining portion of the light to pass.

[0074] The area covered by the second shielding plate 23 may be different from the area covered by the first shielding plate 13. For example, the first shielding plate 13 may cover one side of the two side areas with the optical axis as the center (for example, Figure 4 The left area in (a) of FIG. 1 ), and the second shielding plate 23 can shield one side of the two side areas with the optical axis as the center (for example, Figure 4 The right area in (b) of FIG. 1 ). By using the second shielding plate 23, the reference Figure 2 The position of the second region S2 and / or the size of the second region S2 are described. The second shielding plate 23 may be a metal plate coated with a non-reflection coating (for example, a stainless steel (SUS) plate coated with a non-reflection coating).

[0075] The 1-2 light having passed through the 2-1st lens group 21, the second shielding plate 23, and the 2-2nd lens group 25 may pass through the first optical filter 30. The first optical filter 30 may be a filter having a plurality of apertures.

[0076] Reference Figure 1 As an embodiment, the second unit P2 may include a second mirror 27 and a 2-3 lens group 29. The second mirror 27 may be disposed between the 2-2 lens group 25 and the 2-3 lens group 29, and the 2-3 lens group 29 may be disposed between the second mirror 27 and the first optical filter 30. The 1-2 light having passed through the second shielding plate 23 may be reflected by the second mirror 27 after passing through the 2-2 lens group 25, thereby traveling toward the 2-3 lens group 29. The 1-2 light having passed through the 2-3 lens group 29 may pass through the first optical filter 30.

[0077] The 1-2 light (ie, the second inspection light ISL2 ( Figure 2 )) can be achieved through the second beam splitter BSP2 ( Figure 1 ) and moves toward the second lens group 41 and the third lens group 43, and passes through the third beam splitter BSP3.

[0078] like Figure 1 As shown, the first inspection light ISL1 and the second inspection light ISL2 traveling toward the sample holder 71 on a line coaxial with the optical axes of the second lens group 41 and the third lens group 43 can be reflected by the first shielding plate 13 of the first unit P1 and the second shielding plate 23 of the second unit P2. Figure 2 As shown, different areas are illuminated from each other.

[0079] As previously referred to Figure 2As described above, the second inspection light ISL2 can illuminate the second area S2 of the sample holder 71. The sample SP disposed on the sample holder 71 is linearly moved by the moving part 73. Therefore, as the sample SP moves, the image sensor 100 ( Figure 3 ) (e.g., the second portion 120, Figure 3 ) records the image for sample SP.

[0080] The second inspection light ISL2 irradiated to the sample SP may be reflected by the sample SP. The light reflected by the sample SP may pass through the eyepiece portion 45, the third beam splitter BSP3, the fourth lens group 51, the fifth lens group 52, the image lens 53, the sensor side optical filter 54 and the cathode ray tube lens 55 toward the camera 60.

[0081] The light that has passed through the sensor-side optical filter 54 (ie, the light including the information on the sample SP) can be as follows: Figure 1 As shown, the camera 60 moves toward the image sensor 100 ( Figure 3 ) (e.g., the second portion 120, Figure 3 ) can generate a second image by the aforementioned light.

[0082] In the case where there is a bad structure in the sample SP, the reflection in the bad structure may be different from the reflection in the normal structure. Unlike the 1-1 light provided to the first light path, the 1-2 light provided to the second light path passes through the first optical filter 30, so the second inspection light ISL2 ( Figure 1 ) can be irradiated under optical conditions different from the first inspection light ISL1. Therefore, even if the same defect is detected, the image sensor 100 ( Figure 3 ) (e.g., the second portion 120, Figure 3 )The second image generated may be different from the first image.

[0083] Figure 5 is a perspective view schematically showing an optical filter according to an embodiment of the present invention. Figure 6 is a cross-sectional view schematically showing an optical filter according to an embodiment of the present invention. Figure 7 Schematically shows a plan view of an optical filter according to an embodiment of the present invention. Figure 8 The components of the second inspection light that has passed through the optical filter according to one embodiment of the present invention are schematically shown. Figures 5 to 7 express Figure 1 and Figure 4 The first optical filter 30, Figure 8Each component of the second inspection light ISL2 that has passed through the first optical filter 30 is shown.

[0084] Reference Figures 5 to 7 , the first optical filter 30 may include a plurality of apertures. As an embodiment, the first optical filter 30 may include a first aperture 31 and a second aperture 32. The first aperture 31 and the second aperture 32 of the first optical filter 30 may be spaced apart from each other. For example, the first aperture 31 and the second aperture 32 of the first optical filter 30 may be arranged to be spaced apart from each other on the inner side of the circular light shielding area. Figures 5 to 7 FIG. 4 shows a case where the first optical filter 30 includes two openings, but the present invention is not limited thereto. As another embodiment, the first optical filter 30 may include more than three openings.

[0085] The positions, sizes, shapes, etc. of the plurality of openings of the first optical filter 30 may be different. For example, the first opening 31 may be arranged at the center of the first optical filter 30. On a plane, the first opening 31 may be a semicircular opening. The first opening 31 may include a semicircular arc-shaped curved portion 31-1 and a straight portion 31-2.

[0086] The second opening 32 may be spaced apart from the first opening 31. For example, the second opening 32 may be located at a position further outward than the first opening 31 from the center of the first optical filter 30. The second opening 32 may have a shape different from the first opening 31. For example, on a plane, the second opening 32 may have a half-ring shape extending with a certain first width. Such a second opening 32 may include a first curved portion 32-1, a second curved portion 32-2 further inward than the first curved portion 32-1, and a straight portion 32-3 connecting the first curved portion 32-1 and the second curved portion 32-2. The first curved portion 32-1 and the second curved portion 32-2 of the second opening 32 may have an arc shape of a semicircle.

[0087] In one embodiment, the first and second curved portions 32-1 and 32-2 of the second opening 32 may be arranged in a direction opposite to the curved portion 31-1 of the first opening 31. The straight portion 32-3 of the second opening 32 may be arranged on substantially the same line as the straight portion 31-2 of the first opening 31.

[0088] In one embodiment, the length W2 of the straight portion 31 - 2 of the first opening 31 may be 1 / 4 to 1 / 3 of the maximum width W1 of the first curved portion 32 - 1 of the second opening 32 .

[0089] In one embodiment, the first width W3 of the second opening 32 (or the length of the straight portion 32 - 3 ) may have a size of 1 / 8 to 1 / 6 of the maximum width W1 of the first curved portion 32 - 1 of the second opening 32 .

[0090] In one embodiment, the maximum width W1 of the first curved portion 32 - 1 of the second opening 32 may represent a diameter of the first curved portion 32 - 1 having an arc shape of a semicircle.

[0091] Reference Figure 5 and Figure 8 , the 1-2 light (ie, the second inspection light ISL2) passing through the first optical filter 30, Figure 1 ) may include multiple light components. The multiple light components may be components that have passed through different openings among the multiple openings. The number of the multiple light components may be determined according to the number of the multiple openings. For example, the second inspection light ISL2 ( Figure 1 ) may include a first component ISL2a and a second component ISL2b. The first component ISL2a of the second inspection light ISL2 may be a component that has passed through the first opening 31 of the first optical filter 30. The second component ISL2b of the second inspection light ISL2 may be a component that has passed through the second opening 32 of the first optical filter 30.

[0092] At least one of the angles, positions, and sizes of the multiple light components passing through the first optical filter 30 may be different. For example, at least one of the angles, positions, and sizes of the first component ISL2a and the second component ISL2b of the second inspection light ISL2 may be different. The optical conditions of such multiple light components may be different according to the positions, sizes, and shapes of the multiple openings respectively corresponding to them. For example, the first component ISL2a of the second inspection light ISL2 may be illuminated at a different angle than the second component ISL2b due to the different shapes of the first opening 31 and the second opening 32 of the first optical filter 30.

[0093] The second inspection light ISL2 may irradiate the aforementioned second area S2 of the sample holder 71 . Figure 8is a cross section of the sample holder 71, representing a portion of the second area S2. The irradiation area of ​​the second inspection light ISL2 may include an irradiation area of ​​the first component ISL2a and an irradiation area of ​​the second component ISL2b. The first component ISL2a of the second inspection light ISL2 may irradiate the first portion S2a of the second area S2, and the second component ISL2b of the second inspection light ISL2 may irradiate the second portion S2b of the second area S2. The irradiation area of ​​the first component ISL2a of the second inspection light ISL2 may be connected to the irradiation area of ​​the second component ISL2b of the second inspection light ISL2. For example, although not shown in the figure, on a plane, the first component ISL2a of the second inspection light ISL2 may pass through the first opening 31 in the central portion of the first optical filter 30 and irradiate the central portion of the second area S2 irradiated by the second inspection light ISL2. That is, the first portion S2a of the second area S2 may be located in the central portion of the second area S2. The second component ISL2b of the second inspection light ISL2 may irradiate the outer contour of the second area S2 irradiated by the second inspection light ISL2 through the second opening 32 of the outer contour of the first optical filter 30. That is, the second portion S2b of the second area S2 may be located at the outer contour of the second area S2. In some embodiments, the irradiation area of ​​the first component ISL2a of the second inspection light ISL2 may also overlap with the irradiation area of ​​the second component ISL2b of the second inspection light ISL2.

[0094] The second inspection light ISL2 that has passed through the first optical filter 30 may be reflected by the sample SP. The light reflected by the sample SP may be directed toward the camera 60 ( Figure 1 ) moves, the image sensor 100 of the camera 60 ( Figure 3 ) (e.g., the second portion 120, Figure 3 ) can generate a second image based on the light. The second image may include multiple parts corresponding to multiple light components. For example, the second image may include multiple parts corresponding to the first component ISL2a of the second inspection light ISL2 reflected by the sample SP after being irradiated to the sample SP and the second component ISL2b of the second inspection light ISL2.

[0095] In the case where there is an undesirable structure in the sample SP, the reflection in the undesirable structure may be different from the reflection in the normal structure. The second inspection light ISL2 having passed through the first optical filter 30 may illuminate the second area S2 to be consistent with the first inspection light ISL1 ( Figure 1 ) are irradiated under different optical conditions. The second part 120 ( Figure 3 )The second image generated may be different from the first image.

[0096] For example, the second part 120 ( Figure 3) may include a first portion based on the first component ISL2a of the second inspection light ISL2 and a second portion based on the second component ISL2b of the second inspection light ISL2. In the first portion of the second image, the defect may appear relatively dark and the periphery of the defect may appear bright. In the second portion of the second image, the defect may appear relatively bright and the periphery of the defect may appear dark.

[0097] In one embodiment, the first part of the second image based on the first component ISL2a of the second inspection light ISL2 may be similar to the first image based on the first inspection light ISL1, in that the defect appears relatively bright and the periphery of the defect appears dark, but the type or number of defects detected may be different. For example, the first component ISL2a of the second inspection light ISL2 may focus on irradiating the central portion as a part of the second area S2, while the first inspection light ISL1 may irradiate the entire first area S1. The first part of the second image may have a difference in depth, etc. compared to the first image. Depending on the situation, the type or number of defects detected based on the first part of the second image may be different from the type or number of defects detected based on the first image.

[0098] Fig. 9 This is a conceptual diagram for explaining image generation using a TDI method by an image sensor of a camera of a defect inspection device according to an embodiment of the present invention.

[0099] Reference Fig. 9 The first portion 110 of the image sensor 100 may include a plurality of pixel lines C11, C12, C13, ..., C1n. The aforementioned pixel lines C11, C12, C13, ..., C1n may be driving stages for time delay integration (TDI).

[0100] According to the linear movement of the sample SP, the pixel lines C11, C12, C13, ..., C1n can respectively obtain signals for the image of the sample SP at different times. For example, the signal for the first part SP1 of the sample SP received by the first pixel line C11 at the first moment, the signal for the first part SP1 of the sample SP received by the second pixel line C12 at the second moment, ... and the signal for the first part SP1 of the sample SP received by the nth pixel line C1n at the nth moment can be accumulated to generate an image for the first part SP1 of the sample SP. In the manner described above, a first image for the entire sample SP can be generated.

[0101] Just as the first part 110 generates the first image by the aforementioned TDI method, the second part 120 may generate the second image by the TDI method.

[0102] Fig. 9 In other words, the first portion 110 and the second portion 120 may be configured to be spaced apart from each other in a direction intersecting the linear moving direction of the sample SP (e.g., in a direction intersecting the linear moving direction of the sample SP). Fig. 9 The two ends of the first and second electrodes are parallel to each other in the longitudinal direction (in the middle), but the present invention is not limited to this.

[0103] As another embodiment, the first portion 110 and the second portion 120 may also be spaced apart from each other and spaced apart from each other along a direction intersecting the linear moving direction of the sample SP. For example, the first portion 110 and the second portion 120 may be configured to be spaced apart from each other along the linear moving direction of the sample SP (e.g., Fig. 9 In this case, each driving stage of the camera 60 for performing time delay integration (TDI) may include a portion of the first portion 110 and a portion of the second portion 120.

[0104] As a comparative example of the present invention, in the case of a relatively low-resolution defect inspection device using an area array camera, the distance between the camera and the sample (hereinafter referred to as the working distance) can be sufficiently ensured, but in order to inspect a sample SP having a very fine structure such as a display providing a high-resolution image, a high-resolution camera must be used. In this case, the aforementioned working distance is shortened, and since the working distance is shortened, it is difficult to ensure space for irradiating the first inspection light and the second inspection light that travel toward the sample at different incident angles.

[0105] However, according to the reference Figures 1 to 9 In the described embodiment, the first inspection light ISL1 and the second inspection light ISL2 travel along the same axis as the second lens group 41 and the third lens group 43, and the light reflected by the sample SP can travel along the same axis as the second lens group 41 and the third lens group 43, so as to be received by the camera 60, thereby ensuring a sufficient working distance between the sample SP and the camera 60.

[0106] According to an embodiment of the utility model, the first unit P1 has a first baffle plate 13, and the second unit P2 has a second baffle plate 15, so that the first inspection light ISL1 and the second inspection light ISL2 traveling toward the sample holder 71 along the same axis as the second lens group 41 and the third lens group 43 can simultaneously illuminate different areas from each other.

[0107] According to an embodiment of the utility model, a single light source 2 is included, and at least one of the first unit P1 and the second unit P2 is provided with a first optical filter 30 as an optical filter including a plurality of apertures, so that a plurality of inspection lights (e.g., a first inspection light ISL1 and a second inspection light ISL2) with different optical conditions can be irradiated to the sample SP. Therefore, a defect inspection device that can inspect various defects while simplifying the equipment can be provided.

[0108] According to an embodiment of the present invention, a single image sensor 100 is as shown in FIG. Figure 3 As described above, the sample SP is divided into a plurality of parts (for example, the first part 110 and the second part 120) and the inspection light (the first inspection light ISL1 and the second inspection light ISL2) of different conditions is irradiated in accordance with each part, so that a plurality of images of the sample SP can be obtained by a single scan. Therefore, the sample SP can be inspected accurately and quickly for defects by only a single scan.

[0109] According to the embodiment of the present invention, a single image sensor 100 is divided to generate images in a plurality of parts, so when the detection unit 80 performs defect inspection, it is easy to match or extract the coordinates of the defect position, and the defect of the sample can be quickly inspected.

[0110] The utility model described above is described with reference to the embodiments shown in the drawings, but this is only an example, and those skilled in the art should be able to understand that various modifications and variations of the embodiments can be achieved. Therefore, the true technical protection scope of the utility model should be determined by the technical ideas of the claims.

Claims

1. A defect inspection device, characterized in that: include: A single light source emits the first light; a first beam splitter, providing the first light onto a plurality of light paths; A first unit is arranged on a first light path from the light source toward the sample holder, and irradiates a first inspection light toward the sample holder; a second unit, arranged on a second light path from the light source toward the sample holder, irradiating the sample holder with a second inspection light; a camera including a single image sensor for generating an image of a sample disposed on the sample holder and moving linearly in a time-delayed integration manner; as well as a detection unit that detects a defect of the sample based on the image received from the camera, At least one of the first unit and the second unit includes an optical filter having a plurality of openings.

2. The defect inspection device according to claim 1, characterized in that: The first inspection light and the second inspection light simultaneously illuminate the sample holder, The single image sensor of the camera comprises: A first part, generating a first image of the sample photographed by the first inspection light; and The second part generates a second image of the sample captured by the second inspection light.

3. The defect inspection device according to claim 1 or 2, characterized in that: The first unit comprises: a first shielding plate, blocking a portion of the first light provided to the first light path; and The optical filter is located between the first shielding plate and the sample holder.

4. The defect inspection device according to claim 3, characterized in that: The second unit includes a second shielding plate configured to block a portion of the first light provided to the second light path.

5. The defect inspection device according to claim 4, characterized in that: An irradiation area of ​​the first inspection light and an irradiation area of ​​the second inspection light are different from each other by the first shielding plate and the second shielding plate, respectively.

6. The defect inspection device according to claim 1 or 2, characterized in that: The plurality of openings of the optical filter include: A first opening located in the central portion; and a second opening, located outside the first opening, The first opening and the second opening have shapes different from each other.

7. The defect inspection device according to claim 6, characterized in that: In a plane, the first opening has a semicircular shape.

8. The defect inspection device according to claim 7, characterized in that: In a plane, the second opening has a semi-ring shape extending with a predetermined first width.

9. The defect inspection device according to claim 8, characterized in that: In a plane, the first opening includes a curved portion and a straight portion. The second opening includes a first curved portion, a second curved portion located inside the first curved portion, and a straight portion connecting the first curved portion and the second curved portion.

10. The defect inspection device according to claim 9, characterized in that: The first width of the second opening has a size of 1 / 8 to 1 / 6 of the maximum width of the first curved portion of the second opening.

11. The defect inspection device according to claim 9, characterized in that: The length of the straight portion of the first opening has a size of 1 / 4 to 1 / 3 of the maximum width of the first curved portion of the second opening.

12. The defect inspection device according to claim 3, characterized in that: The plurality of openings of the optical filter include a first opening and a second opening that are spaced apart from each other, The first inspection light includes a first component that has passed through the first opening of the optical filter and a second component that has passed through the second opening of the optical filter.

13. The defect inspection device according to claim 12, characterized in that: The first component and the second component of the first inspection light are different in at least one of an angle, a position, and a size.

14. The defect inspection device according to claim 1 or 2, characterized in that: Also includes: at least one lens assembly located between the sample holder and the first unit and the second unit, The first inspection light and the second inspection light are irradiated toward the sample holder through the at least one lens group, respectively.

15. The defect inspection device according to claim 14, characterized in that: Also includes: a sensor-side optical filter that allows the light reflected by the surface of the sample among the first inspection light and the light reflected by the surface of the sample among the second inspection light to pass therethrough, The sensor-side optical filter is arranged adjacent to the camera.

16. The defect inspection device according to claim 15, characterized in that: The light reflected by the surface of the sample among the first inspection light and the light reflected by the surface of the sample among the second inspection light are bent by a second beam splitter and travel toward the sensor-side optical filter.

17. The defect inspection device according to claim 2, characterized in that: The camera generating the first image of the sample based on the signal obtained from the first portion, The second image of the sample is generated based on the signal obtained from the second portion.

18. The defect inspection device according to claim 17, characterized in that: In the case where the sample includes a defect, an image of the defect detected in the first image and an image of the defect detected in the second image are different from each other.

19. The defect inspection device according to claim 17, characterized in that: The detection unit detects the position of the defect based on the first image and the second image.

20. The defect inspection device according to claim 2, characterized in that: The single image sensor further includes a dummy portion located between the first portion and the second portion.

Images