JP2014062771A - Apparatus and method for inspecting defect of transparent substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect only a surface defect by surely excluding influence of a rear defect even when a vertical movement of a thin transparent substrate occurs in inspection.SOLUTION: A transparent substrate defect inspection method for mounting an optically transparent substrate on a stage part movable in a plane, moving the stage part in one direction, applying light from an oblique direction to a surface of the substrate moved in the one direction on the stage part, detecting an image of light scattered on the substrate irradiated with the light, detecting a height of the substrate surface irradiated with the light, and detecting a defect on the substrate surface by processing a detection signal of the image of light scattered on the substrate and detected by the detector, the image of the scattered light of the defect of the substrate surface is detected by the detector by adjusting an incident angle of light applied from the oblique direction to the substrate surface on the basis of the detected height information of the substrate surface and aligning an imaging position of the scattered light image corresponding to a change in the height of the substrate surface to a position of the detector.

Description

  The present invention relates to a transparent substrate defect inspection apparatus and method for detecting a foreign matter adhering to the surface of a relatively thin transparent substrate or a defect such as a flaw or chipping on the surface separately from a foreign matter adhering to the back surface or a defect such as a flaw. .

  As background art of this technical field, there is an invention described in Japanese Patent Application Laid-Open No. 2004-037400 (Patent Document 1). The invention described in this gazette describes a technique for separately detecting front foreign matter and back foreign matter when inspecting adhered foreign matter on a transparent substrate at high speed. This is because the irradiation position of the front surface and the back surface of the substrate is shifted by irradiating the substrate with the laser from an oblique direction, and each detector for the front surface and the back surface depends on the irradiation position of the front surface and the back surface. Are combined with each other.

JP 2004-037400 A

  The method of separating and detecting the front and back foreign matter signals described in Patent Document 1 is such that the substrate is thick enough to reliably separate the focal position of the front surface and the back surface of the substrate in the detection optical system. This is effective when the vertical movement of the substrate is small. However, glass substrates used for liquid crystal displays, solar cells, and the like have become larger and thinner year by year, with respect to a 1.1 mm thick substrate as described in Patent Document 1, 0.5 mm or less, Furthermore, a substrate thinned to about 0.2 mm has been studied. Accordingly, the substrate is likely to bend on the stage of the inspection apparatus, and the vertical direction (the thickness direction of the substrate) is likely to shift depending on the inspection location of the substrate. Further, in the case where the foreign matter on the back surface is detected by the illumination light obliquely irradiated from the front surface side and the light transmitted through the substrate, the deviation of the irradiation position between the front surface and the back surface is reduced as the thickness is reduced. For this reason, with the configuration described in Patent Document 1, it is difficult to separate and detect the front and back foreign matter signals.

  When the height of the substrate surface fluctuates, as a method of correcting this height variation, the substrate height is monitored while the substrate is moved in a plane, and the substrate is placed according to the substrate height variation. It is conceivable to control the height of the stage to be moved in the vertical direction. However, with this method, when a relatively large substrate is inspected, the mass of the stage on which the substrate is placed is large, so the response speed for moving the stage up and down cannot follow the inspection, and the inspection throughput is not reduced. In addition, it is difficult to ensure sufficient height correction accuracy necessary for inspection.

  The present invention solves the above-mentioned problems of the prior art, and inspects for defects such as foreign matter adhering to the surface of a thin transparent substrate having a thickness of 0.5 mm or less, or about 0.2 mm, or wrinkles or chips on the surface. In addition, even if the substrate moves up and down during the inspection, the transparent substrate defect inspection apparatus and method which can detect only defects such as foreign matter and wrinkles on the surface by reliably eliminating the influence of foreign matters and wrinkles on the back surface. Is to provide.

  In order to solve the above-described problems, in the present invention, a defect inspection apparatus for a transparent substrate is mounted on a stage portion on which an optically transparent substrate is placed and movable in a plane, and the stage portion is placed on the stage portion. An illumination optical system that irradiates light on the surface of an optically transparent substrate from an oblique direction, and a detector that detects an image of light scattered by the optically transparent substrate irradiated with light by the illumination optical system Scattered light detection optical system, height detection system for detecting the height of the surface of the optically transparent substrate irradiated with light by the illumination optical system, and optically transparent substrate detected by the scattered light detection optical system A signal processing unit that processes the detection signal of the light scattered by the light source, a stage unit, an illumination optical system unit, a scattered light detection optical system unit, a height detection system, and a control unit that controls the signal processing unit. The control unit is designed to detect the height of the optically transparent substrate surface detected by the height detection system. A substrate that is optically transparent to the detector of the scattered light detection optical system by controlling the illumination optical system based on the information and adjusting the incident angle of the light that irradiates the surface of the optically transparent substrate from an oblique direction. The image of the surface of was projected.

  Further, in order to solve the above-described problems, in the present invention, a transparent substrate defect inspection apparatus is mounted on a stage unit on which an optically transparent substrate is mounted and movable in a plane, and the stage unit. Illumination optical system for irradiating light on the surface of the optically transparent substrate from an oblique direction, and a detector for detecting an image of light scattered by the optically transparent substrate irradiated with light by the illumination optical system Scattered light detection optical system, height detection system for detecting the height of the surface of an optically transparent substrate irradiated with light by the illumination optical system, and optically transparent detected by the scattered light detection optical system A signal processing unit that processes a detection signal of light scattered by a substrate, a control unit that controls a stage unit, an illumination optical system unit, a scattered light detection optical system unit, a height detection system, and a signal processing unit, The control unit determines the height of the optically transparent substrate surface detected by the height detection system. The scattered light detection optical system is controlled based on the information, and the image formation position of the scattered light image and the position of the detector of the scattered light detection optical system according to the change in the height of the surface of the optically transparent substrate are determined. I tried to match.

  Further, in order to solve the above-described problems, in the present invention, an optically transparent substrate is placed on a stage part movable in a plane and moved in one direction, and moved in one direction on this stage part. The surface of the optically transparent substrate is irradiated with light from an oblique direction, the image of the light scattered by the optically transparent substrate irradiated with this light is detected by a detector, and the optically irradiated light The height of the surface of the transparent substrate is detected, and the detection signal of the image of light scattered by the optically transparent substrate detected by the detector is processed to detect defects on the surface of the optically transparent substrate. In the defect inspection method for a transparent substrate, the incident angle of light irradiated from an oblique direction to the surface of the optically transparent substrate is adjusted based on the detected height information of the surface of the substrate, or optically transparent Position and detector of scattered light image according to the change of surface height of various substrates By combining the position and to detect the image of the scattered light of the defect in the optically transparent substrate surface detector.

  According to the present invention, even in the inspection of foreign matter on a large, thin transparent substrate, regardless of the vertical movement caused by substrate deflection on the stage, it is possible to reliably eliminate the influence of foreign matter on the backside of the substrate and detect only surface foreign matter. Become. Thereby, quality control of a liquid crystal display and a solar cell can be performed reliably, and productivity can be significantly improved.

It is a block diagram which shows the schematic structure of the transparent substrate adhesion foreign material inspection apparatus of Example 1. FIG. FIG. 3 is a block diagram of a detection optical system for explaining the principle of signal exclusion of foreign substances on the backside of the substrate according to the first embodiment. FIG. 3 is a block diagram of a detection optical system for explaining the principle of optical path change when the transparent substrate rises in Example 1. FIG. 3 is a block diagram of a detection optical system for explaining the principle of the influence correction of the substrate height change according to the first embodiment. FIG. 3 is a block diagram of a detection optical system for explaining the principle of operation of the first embodiment. 3 is a flowchart illustrating a flow of inspection in the first embodiment. FIG. 6 is a block diagram of a detection optical system for explaining the effect of the inspection according to the first embodiment. It is a block diagram which shows the schematic structure of the transparent substrate adhesion foreign material inspection apparatus of Example 2. FIG. In Example 2, it is a defect map which shows the board | substrate test | inspection result when not controlling the inclination angle of a mirror. In Example 2, it is a defect map which shows the board | substrate test | inspection result at the time of controlling the inclination angle of a mirror. It is a block diagram which shows the schematic structure of the inspection apparatus of the transparent substrate of Example 3. FIG. It is a block diagram which shows the schematic structure of the inspection apparatus of the transparent substrate of Example 4. FIG. It is a block diagram which shows the schematic structure of the inspection apparatus of the transparent substrate of Example 5. FIG. It is a block diagram which shows the schematic structure of the inspection apparatus of the transparent substrate of Example 6. FIG. It is a block diagram which shows the schematic structure of the inspection apparatus of the transparent substrate of Example 7. FIG. It is a block diagram which shows the schematic structure of the inspection apparatus of the transparent substrate of Example 2. FIG. 6 is a cross-sectional view of a transparent substrate showing the types of defects detected in Example 2. FIG. 10 is a flowchart showing portions different from those in the first embodiment in the inspection flow in the second embodiment. 10 is a flowchart illustrating a flow of defect classification processing in the second embodiment.

  The present invention detects the height of the substrate surface, and scattered light generated from defects such as foreign matter adhering to the surface side of the substrate or wrinkles, chips, dents on the substrate surface according to the detected height change, By adopting a configuration that allows detection without being affected by the scattered light generated on the back side of the substrate, foreign matter adhering to the surface side of the substrate, defects such as wrinkles, chips, dents, etc. were attached to the back side. The present invention relates to a transparent substrate defect inspection apparatus and method which can be reliably detected by separating them from defects such as foreign matter, wrinkles and chips.

  Hereinafter, examples will be described with reference to the drawings.

In the present embodiment, an example of an apparatus for inspecting a foreign substance on a transparent substrate will be described.
FIG. 1 is an example of a configuration diagram illustrating a basic configuration of a detection optical system 100 of a defect inspection apparatus for a transparent substrate according to the present embodiment. 1 is a laser light source, 2 is a lens, 3 is a laser, 4 is a mirror, 5 is a variable angle mechanism, 6 is an incident laser, 7 is a transparent substrate, 8 is a transmission laser, 9 is a reflection laser, and 10 is a position sensitive detector. , 11 is scattered light, 12 is an objective lens (actually a lens system composed of a plurality of lenses, but is shown as a single lens to simplify the display), 13 is a detector, 14 is a surface foreign matter, 15 is a surface foreign matter image, 18 is a stage on which the transparent substrate 7 is placed and is movable in the XY plane, 21 is a signal processing unit for processing the detection signal output from the detector 13, The control unit 22 controls the stage 18 and also receives the output from the signal / position sensitive detector 10 processed by the signal processing unit 21 to control the variable angle mechanism 5. The reference numeral 23 denotes the inspection output from the control unit. To display results and enter inspection conditions Which is the input-output unit. Θin is an incident angle, and θdet is a detection angle.

  In the configuration of the detection optical system 100 shown in FIG. 1, the laser 3 generated from the laser light source 1 controlled by the control unit 22 becomes a beam collimated by the lens 2. This beam is reflected by the mirror 4 whose angle is controlled by the angle variable mechanism 5 and irradiates the surface 71 of the transparent substrate 7 as an incident laser 6 at an incident angle θin from an oblique direction. A part of the incident laser 6 is refracted on the surface 71 of the transparent substrate 7 to become the transmission laser 8, and the rest is reflected on the surface 71 of the transparent substrate 7 to become the reflection laser 9. The reflected laser 9 is received by a position sensitive detector 10 in which a plurality of light receiving elements (pixels) are arranged one-dimensionally or two-dimensionally. The objective lens 12 and the detector 13 are arranged in a positional relationship such that an image of the irradiation position of the incident laser 6 on the transparent substrate 7 is transferred to the element surface of the detector 13. If the surface foreign matter 14 is present on the surface 71 of the transparent substrate 7, scattered light 11 is generated from the surface foreign matter 14, and the scattered light 11 incident on the objective lens 12 is transferred onto the detector 13 by the objective lens 12. An image 15 is formed. Therefore, it is possible to confirm the presence of the surface foreign matter 14 by processing the signal of the detector 13 together with the position information of the stage 18 by the signal processing unit 21 and displaying it on the monitor of the input / output unit 23. It is also possible to compare the signal of the detector 13 with a preset threshold value and detect a signal larger than this threshold value as a defect.

  FIG. 2 illustrates a configuration for eliminating the scattered light detection signal from the substrate backside foreign matter in the detection signal from the detector 13 without detecting the scattered light from the substrate backside foreign matter in this embodiment. is there. In FIG. 2, the display of the stage 18, the signal processing unit 21, the control unit 22, and the input / output unit 23 is omitted in order to simplify the description. In FIG. 2, 16 is a back surface foreign material, 17 is an image of the back surface foreign material formed by the objective lens 12, and other symbols are the same as those in FIG. Although the incident laser 6 is refracted according to Snell's law after being incident on the transparent substrate 7, it is the same that the transmitted laser 8 is inclined with respect to the normal of the surface 71 of the transparent substrate 7. The irradiation position of the back surface 72 is on the right side of the front surface. Therefore, when the back surface foreign material 16 exists on the back surface 72 of the transparent substrate 7, a part of the scattered light 11 from the back surface foreign material 16 passes through the objective lens 12, but the back surface foreign material image 17 is formed. The position to be performed is a position on the left side of the detector 13. Therefore, by installing the detector 13 at a position that includes the position where the front surface foreign object image 15 is formed and does not include the position where the rear surface foreign material image 17 is formed, the back surface foreign object is formed on the back surface 72 of the transparent substrate 7. Even if 16 is present, the detection signal output from the detector 13 that has detected the surface foreign object image 15 does not change. Thereby, it is possible to remove the influence of the back surface foreign matter 16 attached to the back surface 72 side of the transparent substrate 7 that is not subject to inspection, and the surface foreign material 14 attached to the front surface 71 side of the target transparent substrate 7. It is possible to selectively detect only.

  FIG. 3 shows the change of the optical path when the transparent substrate 7 in this embodiment rises and the height changes. The same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals. In the transparent substrate 7, the broken line indicates the original height in the same state as in FIG. 1, the solid line indicates the rising direction, and the arrow indicates the rising direction. As the transparent substrate 7 rises, the position where the transmission laser 8 reaches the back surface 72 of the transparent substrate 7 shifts to the left as compared with the case shown in FIGS. For this reason, when the back surface foreign matter 16 ′ is present on the left side from the position shown in FIG. 2, the back surface foreign material 16 is irradiated with the transmission laser 8 and is incident on the objective lens 12 among the scattered light generated from the back surface foreign material 16. The transmitted scattered light 11 enters the detector 13. Further, at the height of the transparent substrate 7 indicated by the solid line, the position of the reflection laser 9 incident on the position sensitive detector 10 is shifted in the direction of the arrow as compared with the case of FIGS. If the pixels of the position sensitive detector 10 are arranged in the direction of the arrow, the height of the transparent substrate 7 can be obtained from the pixel number having the maximum signal intensity.

  FIG. 4 is a diagram illustrating a configuration for correcting the influence of the height variation of the transparent substrate 7 in the present embodiment. The same number is attached | subjected about the same component as FIGS. The height of the transparent substrate 7 is changed in the same manner as in FIG. 3, but is controlled by the angle variable mechanism 5 to rotate the mirror 4 in the direction of the arrow, from the same angle as in FIG. 3 shown by the broken line to the angle shown by the solid line. It has changed. Thereby, the incident position of the incident laser 6 on the front surface 71 of the transparent substrate 7, the position where the transmission laser 8 reaches the rear surface 72 of the transparent substrate 7, and the reflection position of the reflected laser 9 from the front surface 71 of the transparent substrate 7 are all. Shift to the right. Therefore, even if the back surface foreign matter 16 exists at the same position as shown in FIG. 3 as indicated by the dotted line 16 ′, it is no longer irradiated with the transmission laser 8. Further, even if the back surface foreign matter 16 is indicated by a solid line, the scattered light generated from the back surface foreign matter 16 is present at a position where the transmission laser 8 reaches the back surface 72 of the transparent substrate 7 (a position passing through the back surface 72 of the transparent substrate 7). The position where the back surface foreign object image 17 formed by the scattered light that has entered and transmitted through the objective lens 12 is located on the left side of the detector 13 that is arranged in accordance with the position where the front surface foreign object image 15 is formed. It becomes. Therefore, even if the back surface foreign material 16 exists on the back surface 72 of the transparent substrate 7, the back surface foreign material image 17 is not detected by the detector 13, and the signal of the detector 13 does not change. Thereby, regardless of the height fluctuation of the transparent substrate 7, it is possible to remove the influence of the back surface foreign matter 16 of the transparent substrate 7 that is not the object of inspection, as in the case shown in FIG. Only the surface foreign matter 14 of the substrate 7 can be selectively detected.

  FIG. 5 is a diagram illustrating the operation of this embodiment. 3 is a laser, 4 is a mirror, 6 is an incident laser, 7 is a transparent substrate, 9 is a reflection laser, 10 is a position sensitive detector, and θin and θin ′ are incident angles. The angle of the mirror 4 is adjusted by the angle variable mechanism 5, but the illustration of the angle variable mechanism 5 is omitted in FIG. 5 for simplicity of explanation. Here, the solid line of the transparent substrate 7 indicates the reference position of the surface 71, the broken line indicates the position after the change, and Δz indicates the amount of change in the height of the transparent substrate 7. Hm is the height from the reference position of the surface 71 of the transparent substrate 7 to the mirror 4, Lm is the distance from the mirror 4 to the irradiation position 73 before the height change, and Ld is the position sensitive type from the irradiation position 73 before the height change. The distance to the detector 10 is shown.

When the transparent substrate 7 rises by Δz, the irradiation position 73 before the height change shifts by Δx to the irradiation position 73 ″ after the height change. Here, as the most preferable arrangement of this embodiment, Lm = Ld, and the detection surface of the position sensitive detector 10 is set perpendicular to the surface 71 of the transparent substrate 7. In this case, the deviation Δh of the reflection laser 9 incident position on the position sensitive detector 10 is equal to 2 · Δz. That is, from Δh measured by the position sensitive detector 10
Δz = Δh / 2 (Equation 1)
Is required.

Further, the incident angle θin when the transparent substrate 7 is at the reference position (position before the height change: the position shown by the solid line in FIG. 5) is
θin = tan ⁻¹ (Lm / Hm) (Equation 2)
It is.

In order to set the irradiation position shift Δx to 0 when the transparent substrate 7 rises by Δz, it is necessary to change the angle of the mirror 4 by being driven by the angle variable mechanism 5 so as to be the optical path of the broken line 9 ′ in the figure. is there. The incident angle θin ′ at this time is
θin ′ = tan ⁻¹ {Lm / (Hm−Δz)}
= Tan ⁻¹ [tan θin · {1 + Δz / (Hm−Δz)}] (Equation 3)
It becomes.

  The swing angle Δm of the mirror 4 is obtained as follows.

Δm = (θin′−θin) / 2
= (Tan ⁻¹ [tan θin · {1 + Δz / (Hm−Δz)}] − θin) / 2
... (Equation 4)
That is, it is possible to determine the swing angle Δm of the mirror 4 by monitoring the shift Δh in the incident position of the reflection laser 9 ″ to the position sensitive detector 10.

(Equation 4) may be approximated as follows. That is, the substrate height variation Δz is generally on the order of 1 mm or less, and Hm is very small compared to tens of mm in general.
Δm≈ [tan ⁻¹ {tan θin · (1 + Δz / Hm)} − θin] / 2
... (Equation 5)
And can be approximated. Furthermore, according to the first order approximation,

tan ⁻¹ {tan θin · (1 + Δz / Hm)}

≈θin + sin (2 · θin) / 2 · (Δz / Hm) (Equation 6)
It becomes. That is, Δm≈sin (2 · θin) · (Δz / Hm) / 4 (Expression 7)
And can be approximated.

  In accordance with the above, when the mirror 4 is swung by the angle Δm and the incident laser 6 ′ and the reflected laser 9 ′ are in the broken line state, the deviation Δh of the incident position of the reflected laser 9 ′ to the position sensitive detector 10 is almost 0. It becomes. That is, it can be determined that the irradiation position can be returned to the original position because Δh becomes zero.

  FIG. 6 shows a flowchart of the operation of this embodiment. Prior to the foreign object detection operation by the detector 13, the same position of the transparent substrate 7 can always be measured by the detector 13 by the measurement of the substrate height fluctuation amount by the position sensitive detector 10 and the operation of shaking the mirror 4. It is.

  First, when the measurement is started, the control unit 22 drives and controls the stage 18 to move the transparent substrate 7 to the initial position at the start of inspection (S601). Next, at this initial position, the laser 6 is emitted from the laser light source 1 to irradiate the transparent substrate 7, the reflected light from the surface 71 of the transparent substrate 7 is detected by the position sensitive detector 10, and the position sensitive detector 10. A positional deviation amount Δh from the reference position of the peak position of the signal is obtained from the output signal from each pixel (S602).

  Next, Δm is obtained using (Equation 4) or (Equation 7) using this Δh (S603), and the control unit 22 controls the angle variable mechanism 5 to change the angle of the mirror 4 by Δm (S604). . Next, of the scattered light from the surface 71 by the laser 6 ′ reflected by the mirror 4 whose angle has been changed and incident on the transparent substrate 7, the surface 7 I of the scattered light 11 incident on and transmitted through the objective lens 12. A signal from the detector 13 that has detected the image is captured in the signal processing unit 21 (S605), and the detected signal is compared with a preset threshold value to detect a signal equal to or higher than the threshold value as a defect. When the defect exists, it is stored as defect information in association with the position information of the stage 18 at this time.

  Next, it is checked whether the inspection has been performed up to the final position of the transparent substrate 7 (S607). If the inspection has been performed up to the final position of the transparent substrate 7 (YES in S607), the measurement is terminated.

  On the other hand, when the final position of the transparent substrate 7 has not been reached, the stage 18 is driven and controlled by the control unit 22 to move the next inspection area of the transparent substrate 7 to the inspection position of the inspection optical system 100 (S608). , The steps from S602 are repeated.

  In the flowchart shown in FIG. 6, the transparent substrate 7 is moved sequentially (moved intermittently). However, if a galvanometer or a piezo actuator is used for the angle variable mechanism 5 for swinging the mirror 4, Since a high-speed scan of kHz is possible, the series of operations from S602 to S605 shown in FIG. 6 is sufficiently followed even when the transparent substrate 7 is continuously moved instead of intermittently moving the substrate in S607. Is possible.

  FIG. 7 is a diagram for explaining the effect of this embodiment. 6 is an incident laser, 7 is a transparent substrate, 8 is a transmission laser, 9 is a reflection laser, 10 is a position sensitive detector, θin is an incident angle, θref is a refraction angle, w is a beam width, and s is an irradiation position between the front and back sides. Deviation, t is the substrate thickness, Δz is the amount of vertical movement of the substrate, and Δx is the laser irradiation position deviation.

The refraction angle θref is expressed by the following equation from Snell's law.
θref = sin ⁻¹ (sin θin / n) (Equation 8)
From this, the moving distance s of the illumination position between the substrate front and back is expressed by the following equation.
s = t · tan {sin ⁻¹ (sin θin / n)} (Equation 9)
If you do not shake the mirror 4,
Δz = Δx / tan θin
It is.

When the detection angle θdet is 0 degree, that is, when detecting from directly above, in order to prevent the signal of the backside foreign matter from entering the detector, Δx <s−w (Equation 10)
Must. Therefore,
Δz <(s−w) / tan θin (Equation 11)
It is. From (Equation 9) and (Equation 11),
Δz <[t · tan {sin−1 (sin θin / n)} − w] / tan θin.
That is,
Δz / t <cos θin / √ {n ^ 2-1 + (cosθin) ^ 2}
−w / tan θin / t (Equation 12)
It is.

In the ideal case where the beam width w is 0, if θin is greater than 0, the second term on the right side is 0. The first term on the right side has a maximum value of 1 / n when θin is 0 degrees. From this, the maximum allowable amount Δzmax of the vertical movement of the transparent substrate 7 is
Δzmax = t / n
It is.

  Thus, it can be seen that the substrate vertical movement amount Δz is limited by the substrate thickness t and the refractive index n. As the substrate thickness t decreases, the allowable amount of vertical movement becomes increasingly severe. As an example, if the transparent substrate 7 is glass, the thickness t is 0.2 mm, and the refractive index n is 1.45, Δzmax is t / n, that is, 0.14 mm. However, this is an ideal case where the beam width w is 0, and actually it becomes smaller than this value depending on the beam width w. For example, when the beam width w is 0.1 mm, the right side is the largest when θin is about 35 degrees, and the allowable maximum value of Δz is 0.094 mm.

  Next, a case where the mirror 4 is shaken by being driven by the variable angle mechanism 5 will be considered. When the resolution of Δh that can be detected by the position sensitive detector 10 is Δhmin and the maximum value is Δhmax, the resolution of the amount Δz of the vertical movement (Z direction) of the transparent substrate 7 that can be detected from (Equation 1) is Δhmin / 2. The maximum value is Δhmax / 2. Here, as the position sensitive detector 10, a readily available CCD type line sensor having a pixel size of 7 μm and 256 pixels is used, and Δhmin is considered to be equal to the size of one pixel. In this case, the detectable resolution of Δz is 0.007 / 2 = 0.3535 mm, and the maximum value is 0.007 × 256/2 = 0.896 mm. That is, according to the present embodiment, even if the transparent substrate 7 moves up and down to a maximum of 0.896 mm, by shaking the mirror 4, the vertical direction of the transparent substrate 7 (Z Direction) variation can be corrected. This 0.0035 mm is a value that can be regarded as almost 0 in (Equation 12). Further, the maximum value of Δz of 0.896 mm is about 5 times when θin is 0 degree and about 10 times when θin is 35 degrees, compared with the case where the mirror 4 is not shaken. On the other hand, there is a remarkable improvement effect.

  As described above, by detecting the fluctuation of the height (Z direction) of the transparent substrate 7 with the position sensitive detector 10 and controlling the tilt of the mirror 4 with the angle variable mechanism 5 based on the output, When the stage 18 is driven to move the transparent substrate 7 in the X direction at a constant speed, the irradiation region of the surface 71 of the transparent substrate 7 by the incident laser 6 is moved at a constant speed (scanned at a constant speed). It becomes possible. Thereby, the signal detected by the detector 13 with the image of the scattered light generated by the foreign matter 14 on the surface 71 formed by the objective lens 12 is processed by the signal processing unit 21 and compared with a preset threshold value. Thus, the foreign matter 14 on the front surface 71 of the transparent substrate 7 can be reliably detected without being affected by the foreign matter 16 on the back surface 72 side.

  At this time, even if the height of the transparent substrate 7 fluctuates by moving the transparent substrate 7 in the X direction at a constant speed, the surface 71 of the transparent substrate 7 is scanned at a constant speed by the incident laser 6. Therefore, the position of the detected defect can be accurately grasped using the position information of the stage 18.

  As described above, in this embodiment, in the inspection of the transparent substrate surface foreign matter, it is possible to dramatically reduce the influence of the back foreign matter regardless of the vertical movement of the substrate.

  In this embodiment, the laser light source 1 is used. However, this does not need to be a laser, and a general light source such as a light emitting diode can be used instead.

  According to the present embodiment, the foreign object defect attached to the surface of the glass substrate or the transparent film having a thickness of about 0.2 mm to 0.01 mm is detected separately from the foreign object defect attached to the back side. Is possible.

[Modification 1]
Modification 1 of Example 1 demonstrated above is demonstrated using FIG. In the configuration shown in FIG. 8, the same components as those described in FIG. 801 is a laser light source, 802 is a lens, 803 is a laser, 804 is a mirror, 806 is an incident laser, 807 is a transparent substrate, 809 is a reflection laser, 810 is a position sensitive detector, 812 is an objective lens, 813 is a detector, 821 is a stage. In the configuration of this modification shown in FIG. 8, the angle variable mechanism 5, the scattered light 11, the surface foreign matter 14, the signal processing unit 21, the control unit 22, and the input / output unit 23, which are described in the first example, are not illustrated. These are the same as in FIG.

  In this modification, the incident laser 806 is a line beam that is long in the Y direction, the detector 813 is a line sensor, and the signal of the detector 813 is monitored while scanning the transparent substrate 7 in the X direction in FIG. Thus, the two-dimensional distribution of the surface foreign matter 14 on the transparent substrate 7 can be inspected at high speed.

  In this modification, the position sensitive detector 810 is a two-dimensional sensor matched to the line beam, or a plurality of one-dimensional sensors in which a plurality of light receiving elements (pixels) are arranged in the Z direction are arranged in the Y direction. To do. This makes it possible to measure the vertical movement of the transparent substrate 7 at a plurality of locations on the line beam. Further, by monitoring the reflected lasers 809 at a plurality of locations, even if the reflected laser 809 exhibits some abnormal behavior at one location and cannot measure the vertical movement of the substrate, the reflected lasers 809 at other locations are used. It is possible to measure the vertical movement of the substrate. For example, even when wrinkles, protrusions, or extremely large foreign matters are present on the transparent substrate 7 and the reflected laser 809 behaves abnormally, the influence of the reflected laser 809 is eliminated and the vertical direction (Z Variation in the direction) can be detected. As a method of monitoring the reflection lasers 809 at a plurality of locations, for example, there is a method of removing a location showing an extreme value and averaging the signals at other locations.

  FIG. 9 shows the result of measuring the distribution of foreign matter on the transparent substrate 7 without shaking the mirror 804 in the configuration of this modification. The size of the point indicates the intensity of scattered light measured by the detector 813. In the figure, when the lower left corner is the origin of coordinates, many points with high scattered light intensity can be seen on the side of the larger x coordinate (right side of the figure). The right-hand part is detected erroneously due to ascent (displacement in the Z direction).

  In this modification, the transparent substrate detected by the position sensitive detector 810 by swinging the angle of the mirror 804 (corresponding to Δm in FIG. 5) based on the vertical movement amount of the transparent substrate 7 measured by the position sensitive detector 810 in FIG. 7 is a measurement result of the foreign substance distribution when the position of the reflected light from the surface 7 is controlled so as to be always constant. Compared with the result of FIG. 9, it can be seen that there is no large point on the large side of the x coordinate when the lower left corner is the origin of the coordinate. From this result, it was determined that the surface of the inspected substrate was relatively clean.

  As described above, also in this modification, in the inspection of the transparent substrate front surface foreign matter, it is possible to dramatically reduce the influence of the back surface foreign matter regardless of the vertical movement of the substrate.

[Modification 2]
The configuration of the second modification of the first embodiment is shown in FIG. In the configuration shown in FIG. 11, the same parts as those in the configuration described in FIG. 1 is a laser light source, 2 is a lens, 3 is a laser, 4 is a mirror, 5 is a variable angle mechanism, 6 is an incident laser, 7 is a transparent substrate, 8 is a transmission laser, 9 is a reflection laser, and 10 is a position sensitive detector. , 11 is scattered light, 12 is an objective lens, 13 and 113 are detectors, 14 is a foreign object on the front surface, 16 is a foreign object on the back surface, 122 is a translucent mirror, and 123 and 124 are imaging lenses.

  In this modification, a semitransparent mirror 122, imaging lenses 123 and 124, and a detector 113 are added to the configuration described in the first embodiment, and an image of the surface foreign matter 14 is formed on the detector 13 surface. The back foreign matter 16 is arranged so that an image of the backside foreign matter 16 is formed on the surface of the detector 113.

  By adopting the configuration as shown in this modification, not only the front surface foreign material 14 but also the back surface foreign material 16 can be inspected simultaneously. Also in this configuration, when the reflection laser 9 is detected by the position sensitive detector 10, the transparent substrate 7 is moved when the transparent substrate 7 is moved at a constant speed in the X direction by driving a stage (not shown). , And the mirror 4 is shaken based on the detected vertical movement, the irradiation position of the front surface 71 and the rear surface 72 of the transparent substrate 7 by the incident laser 6 can always be moved at a constant speed. Thereby, according to this modification, it is possible to reliably identify and simultaneously inspect the front surface foreign material 14 and the back surface foreign material 16.

[Modification 3]
The configuration of the third modification of the first embodiment is shown in FIG. In the configuration shown in FIG. 12, the same parts as those in the configuration described in FIG. 1 is a laser light source, 2 is a lens, 3 is a laser, 4 is a mirror, 6 is an incident laser, 7 is a transparent substrate, 8 is a transmission laser, 9 is a reflection laser, 10 is a position sensitive detector, 11 is scattered light, 12 is an objective lens, 13 is a detector, 14 is a surface foreign object, 15 is a surface foreign object image, and 31 is a moving mechanism.

  In this modification, instead of rotating the mirror 4 of the first embodiment, the laser light source 1 is moved left and right by the moving mechanism 31. By moving the laser light source 1 with respect to the lens 2 in the X direction, the tilts of the laser 3 and the incident laser 6 change, so that the irradiation location on the transparent substrate 7 moves. Further, since the movement of the laser light source 1 is performed based on the measurement result of the position sensitive detector 10, the stage (not shown) is driven and the transparent substrate 7 is moved at a constant speed in the X direction as in the first embodiment. In this case, even if the transparent substrate 7 moves up and down (displaced in the Z direction), the irradiated portion of the surface 71 of the transparent substrate 7 by the incident laser 6 can be moved at a constant speed. If a galvanometer or a piezo actuator is used as the moving mechanism 31, it is possible to control to sufficiently follow the vertical movement speed of the transparent substrate 7.

  As described above, also in this modified example, in the inspection of the foreign substance on the surface of the transparent substrate, the influence of the foreign substance on the back surface can be dramatically reduced regardless of the vertical movement of the substrate.

[Modification 4]
FIG. 13 shows the configuration of a fourth modification of the first embodiment. In the configuration shown in FIG. 13, the same parts as those in the configuration described in FIG. 1 is a laser light source, 2 is a lens, 3 is a laser, 4 is a mirror, 6 is an incident laser, 7 is a transparent substrate, 8 is a transmission laser, 9 is a reflection laser, 10 is a position sensitive detector, 11 is scattered light, Reference numeral 12 denotes an objective lens, 13 denotes a detector, 14 denotes a surface foreign matter, 15 denotes a surface foreign matter image, 32 denotes a slit, 33 denotes a moving mechanism, and 112 denotes a relay lens.

  In this modified example, instead of controlling the irradiation position of the incident laser 6 or 806 in the first embodiment and the modified examples 1 to 3, the detection location on the transparent substrate 7 by the detector 13 is controlled. When the surface foreign matter 14 exists on the surface 71 of the transparent substrate 7, the scattered light 11 is generated, and this forms the surface foreign matter image 15 on the opening 321 of the slit 32 by the objective lens 12. If the slit 32 is placed at a position that allows the scattered light from the front surface foreign material 14 to pass therethrough and blocks the scattered light from the back surface foreign material 16, only the scattered light from the front surface foreign material 14 is detected by the relay lens 112. Reach on vessel 13.

  Here, when the transparent substrate 7 moves up and down, the irradiation position on the surface 71 of the substrate 7 by the incident laser 6 shifts left and right (X direction). In this case, the reflected light from the surface 71 of the substrate 7 is detected. If the moving mechanism 33 is controlled in accordance with the output of the position sensitive detector 10 to shift the position of the slit 32 in the direction of the arrow in the figure, scattering from the position irradiated with the incident laser 6 on the surface 71 of the substrate 7 is performed. Light can be captured by the detector 13. Since the movement of the slit 32 in the arrow direction by the moving mechanism 33 is performed based on the measurement result of the position sensitive detector 10, the stage (not shown) is driven to move the transparent substrate 7 in the X direction at a constant speed. Sometimes, even if the transparent substrate 7 moves up and down (displaced in the Z direction), the illumination spot on the surface 71 of the transparent substrate 7 by the incident laser 6 can be moved at a constant speed. If a galvanometer or a piezo actuator is used as the moving mechanism 33, it is possible to perform control that sufficiently follows the vertical movement speed of the transparent substrate 7.

  As described above, also in this embodiment, in the inspection of the foreign matter on the surface of the transparent substrate, the influence of the foreign matter on the back surface can be dramatically reduced regardless of the vertical movement of the substrate.

[Modification 5]
FIG. 14 shows a configuration of a fifth modification of the first embodiment. In the configuration shown in FIG. 14, the same parts as those in the configuration described in FIG. 1 is a laser light source, 2 is a lens, 3 is a laser, 4 is a mirror, 6 is an incident laser, 7 is a transparent substrate, 8 is a transmission laser, 9 is a reflection laser, 10 is a position sensitive detector, 11 is scattered light, 12 is an objective lens, 13 is a detector, 14 is a surface foreign object, 15 is a surface foreign object image, and 34 is a moving mechanism.

  This modified example is a method for controlling the detection position of the detector 13 as in the modified example 4, but instead of moving the slit 32 described in the modified example 4, the detector 13 is moved by the moving mechanism 34. It is a thing. The detector 13 is placed at a position where scattered light from the front surface foreign material 14 is incident but scattered light from the back surface foreign material 16 is not incident. Based on the result of detecting the vertical movement (displacement in the Z direction) of the transparent substrate 7 by the position sensitive detector 10, the moving mechanism 34 is driven to move the position of the detector 13. As a result, as in the case of Modification 4, when the transparent substrate 7 is moved at a constant speed in the X direction by driving a stage (not shown), the transparent substrate 7 moves up and down (displaced in the Z direction). Even so, the detection position on the surface 71 of the transparent substrate 7 can be moved at a constant speed. If a galvanometer or a piezo actuator is used as the moving mechanism 33, it is possible to perform control that sufficiently follows the speed of vertical movement (displacement in the Z direction) of the transparent substrate 7.

  As described above, also in this embodiment, in the inspection of the foreign matter on the surface of the transparent substrate, the influence of the foreign matter on the back surface can be dramatically reduced regardless of the vertical movement of the substrate.

[Modification 6]
FIG. 15 shows the configuration of a sixth modification of the first embodiment. In the configuration shown in FIG. 15, the same parts as those in the configuration described in FIG. 1 is a laser light source, 2 is a lens, 3 is a laser, 4 is a mirror, 5 is an angle variable mechanism, 6 is an incident laser, 7 is a transparent substrate, 8 is a transmitted laser, 11 is scattered light, 12 is an objective lens, 13 is A detector, 14 is a surface foreign matter, 15 is a surface foreign matter image, and 35 is a focus detector.

  In this modification, a focus detector 35 is used instead of the position sensitive detector 10 described in the first embodiment to detect the vertical movement (displacement in the Z direction) of the transparent substrate 7. The focus detector 35 is generally used in an automatic focusing mechanism such as a microscope, and is disposed in the vicinity of a portion where the incident laser 6 is incident on the transparent substrate 7. Based on the information from the focus detector 35, the vertical movement of the transparent substrate 7 is detected and the angle variable mechanism 5 is controlled to drive a stage (not shown) as described in the first embodiment. When the transparent substrate 7 is moved in the X direction at a constant speed, even if the transparent substrate 7 moves up and down (displaces in the Z direction), the detection position on the surface 71 of the transparent substrate 7 is fixed at a constant speed. It is possible to move with.

  As described above, also in the present embodiment, in the inspection of the foreign substance on the surface of the transparent substrate, the influence of the foreign substance on the back surface can be dramatically reduced regardless of the vertical movement of the substrate.

  In Example 1, although the example which isolate | separates and detects the foreign material defect adhering to the surface side of the transparent substrate 7 from the defect adhering to the back surface side was demonstrated in Example 2, it adheres to the surface side of the transparent substrate 7 An example of detecting defects such as wrinkles, chips and dents on the front side in addition to the foreign substance defects separated from the defects on the back side, such as defects, flaws, chips and dents, will be described with reference to the drawings.

  FIG. 16 illustrates a schematic configuration of the detection optical system 200 of the transparent substrate defect inspection apparatus according to the second embodiment. The present embodiment is different from the configuration of the first embodiment described in FIG. 1 in that two detection systems are provided. In the configuration shown in FIG. 16, the same parts as those in the configuration of the first embodiment described with reference to FIG.

  The second embodiment differs from the configuration of FIG. 1 described in the first practical example in that a first detection system in which the objective lens 211 and the detector 213 are combined, and a first detection system in which the objective lens 221 and the detector 223 are combined. 2, processing the output signal from the detector 213 and the output signal from the detector 223 to detect defects on the surface of the transparent substrate 7 and classify the types of the detected defects Are output from the control unit 232 and the control unit 232 that control the angle variable mechanism in response to the output from the signal / position sensitive detector 10 processed by the signal processing unit 231. The input / output unit 233 is provided for displaying the inspection result and inputting the inspection condition.

  In the detection optical system 200 according to the second embodiment shown in FIG. 16, the laser 3 emitted from the laser light source 1 is reflected by the mirror 4 to be incident on the surface 71 of the transparent substrate 7. When the foreign substance defect 14 exists on the surface 71 of the transparent substrate 7, scattered light is generated from the foreign substance defect 14 irradiated with the incident laser 6. Of the generated scattered light, the light that is scattered in the direction of the angle θdet1 (the high angle direction) and enters the objective lens 212 is transmitted through the objective lens 212 and forms an image of the foreign substance defect 14 on the imaging surface 215. Reference numeral 213 denotes a detector whose position is adjusted so that the detection surface is positioned on the image plane 215. As a result, an image of scattered light from the foreign substance defect 14 scattered in the direction of the angle θdet1 is detected by the detector 213.

  On the other hand, of the scattered light generated by the foreign object defect 14, the light that is scattered in the direction of the angle θdet 2 (low angle direction) and enters the objective lens 222 is transmitted through the objective lens 222 and is incident on the imaging surface 225. Form an image. Reference numeral 223 denotes a detector whose position is adjusted so that the detection surface is positioned on the imaging plane 225. As a result, the image of the scattered light from the foreign substance defect 14 scattered in the direction of the angle θdet2 is detected by the detector 223.

  With respect to the fluctuation in the height of the surface 71 of the transparent substrate 7 in this embodiment (displacement in the Z direction), the incident laser 6 detected by the position sensitive detector 10 is the same as described in the first embodiment. Based on the detection signal of the reflected light from the surface 71 of the transparent substrate 7, the control unit 232 controls the angle variable mechanism 5 to adjust the angle of the mirror 4.

  Defects to be inspected in the second embodiment include a defect 241, a chip defect 242, a concave defect 243 and the like generated on the surface 71 side of the transparent substrate 7 in addition to the foreign substance defect 14 as shown in FIG.

  When these defects are present on the surface 71 side of the transparent substrate 7, it is known that when each incident is irradiated with the incident laser 6 from the angle direction of θin, the method of generating scattered light differs depending on each defect. Yes.

  That is, the foreign matter defect 14 generates scattered light having substantially the same intensity in the direction of θdet1 and the direction of θdet2. In contrast, the concave defect 243 generates relatively strong scattered light in the direction of θdet2 as compared to the direction of θdet1. Further, from the defect 241, scattered light is generated from a continuous region having a relatively narrow width in the direction of θdet1 and the direction of θdet2. Further, from the chip defect 242, scattered light is generated in a relatively large area in the direction of θdet <b> 1 and the direction of θdet <b> 2 with a wider area than in the case of the foreign substance defect 14. Therefore, it is possible to specify the type of detected defect by performing image processing on the detected defect and extracting an image feature amount such as the area and shape of the defect.

  The procedure of the inspection in this embodiment is basically the same as the procedure described with reference to FIG. 6 in the first embodiment, but in the case of the first embodiment, only the presence / absence of a defect is determined in S606. On the other hand, in the second embodiment, as shown in FIG. 18, the defect presence / absence determination process is performed in S606, the presence / absence of a defect is checked (S6061), and if there is no defect, the flow of FIG. Similarly, it is checked whether it is the final position of the transparent substrate 7 (S607). On the other hand, when a defect is detected in the check of S6061, a defect classification step (S6062) for classifying the detected defect is executed as a sub-step of S606.

  Details of the defect classification step (S6062) are shown in FIG. In the defect classification step (S6062), first, the detected defect data is input (S1901), and the continuity of the defect is checked from the defect coordinate data to determine whether it is an isolated defect (S1902). When it is determined that the defect is an isolated defect (in the case of YES), the output of the detector 213 in the high angle direction (θdet1) is compared with the output of the detector 223 in the low angle direction (θdet2) (S1903), If both detectors output a defect signal (YES), it is determined as a foreign object defect (S1904). When only one detector outputs a defect signal (NO in S1903), it is checked whether a defect signal is output from the detector 223 in the low angle direction (θdet2) (S1905). If a defect signal is output from the detector 223 in the direction (θdet2) (in the case of YES), it is determined that the defect is a concave defect (S1906). On the other hand, when the defect signal is not output from the detector 223 in the low angle direction (θdet2) and the defect signal is detected from the detector 213 in the high angle direction (θdet1) (NO in S1905). The other defect is determined (S1907).

  If it is determined in S1902 that the detected defect is not an isolated defect (in the case of NO), it is determined whether or not the defect is a linear defect (S1908). If it is determined that the defect is a linear defect, the defect is determined to be a flaw defect (S1909). On the other hand, when it is determined that the defect is not on the line but has a spread (NO in S1908), the defect is determined to be a defective defect (S1910).

  In this way, the types of detected defects are classified, and the results are displayed on the input / output unit 233 on the screen and output.

  According to this embodiment, the surface defects can be reliably detected without being affected by the defects existing on the back surface of the transparent substrate, and the defects on the surface are detected and classified for each defect type, and output. Therefore, it becomes easy to specify the cause of the defect occurrence, and it becomes possible to take measures against the defect occurrence at an early stage.

  The configurations described in the first to sixth modifications of the first embodiment can also be applied to this embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Laser light source 2 ... Lens 3 ... Laser 4 ... Mirror 5 ... Angle variable mechanism 6 ... Incident laser 7 ... Transparent substrate 8 ... Transmission laser 9 ... Reflected laser 10 ... Position sensitive detector 11 ... Scattered light 12, 212, 222 ... Objective lens 13, 113, 213, 223 ... Detector 14 ... Surface foreign matter 15 ... Surface Foreign object image 16 ... Backside foreign object 21 ... Stage 22 ... Translucent mirror 23, 24 ... Image forming lens 31, 33, 34 ... Movement mechanism 32 ... Slit 35 ... Focus detection 112 ... Relay lens θin ... Incident angle θdet ... Detection angle.

Claims (15)

A stage unit that is movable in a plane by placing an optically transparent substrate;
An illumination optical system that irradiates light from an oblique direction on the surface of the optically transparent substrate placed on the stage unit;
A scattered light detection optical system having a detector that detects an image of light scattered by the optically transparent substrate irradiated with light by the illumination optical system;
A height detection system for detecting the height of the surface of the optically transparent substrate irradiated with light by the illumination optical system;
A signal processing unit that detects a defect on the surface of the substrate by processing a detection signal of light scattered by the optically transparent substrate detected by the scattered light detection optical system;
A control unit that controls the stage unit, the illumination optical system unit, the scattered light detection optical system unit, the height detection system, and the signal processing unit;
The control unit controls the illumination optical system based on the height information of the surface of the optically transparent substrate detected by the height detection system, and is oblique to the surface of the optically transparent substrate. A defect inspection apparatus for a transparent substrate, wherein an image of the surface of the optically transparent substrate is projected onto a detector of the scattered light detection optical system by adjusting an incident angle of light emitted from the optical system.   The illumination optical system includes a light source that emits illumination light, a lens that collimates the illumination light emitted from the light source, a mirror that converts an optical path of light transmitted through the lens, and an inclination angle of the mirror. An angle variable mechanism, and the control unit controls the angle variable mechanism of the illumination optical system based on height information of the surface of the optically transparent substrate detected by the height detection system, and 2. The defect inspection apparatus for a transparent substrate according to claim 1, wherein an incident angle of light applied to the surface of the optically transparent substrate from an oblique direction is adjusted.   The illumination optical system converts a light source that emits illumination light, a moving mechanism that moves the position of the light source, a lens that collimates illumination light emitted from the light source, and an optical path of light transmitted through the lens. The control unit controls a moving mechanism of the illumination optical system based on height information of the surface of the optically transparent substrate detected by the height detection system, and controls the position of the light source. 2. The defect inspection apparatus for a transparent substrate according to claim 1, wherein an incident angle of light irradiated from an oblique direction to the surface of the optically transparent substrate is adjusted by changing the angle of the transparent substrate. 3. A stage unit that is movable in a plane by placing an optically transparent substrate;
An illumination optical system that irradiates light from an oblique direction on the surface of the optically transparent substrate placed on the stage unit;
A scattered light detection optical system having a detector that detects an image of light scattered by the optically transparent substrate irradiated with light by the illumination optical system;
A height detection system for detecting the height of the surface of the optically transparent substrate irradiated with light by the illumination optical system;
A signal processing unit that detects a defect on the surface of the substrate by processing a detection signal of light scattered by the optically transparent substrate detected by the scattered light detection optical system;
A control unit that controls the stage unit, the illumination optical system unit, the scattered light detection optical system unit, the height detection system, and the signal processing unit;
The control unit controls the scattered light detection optical system based on height information of the surface of the optically transparent substrate detected by the height detection system, and controls the surface of the optically transparent substrate. A defect inspection apparatus for a transparent substrate, wherein an image forming position of the scattered light image corresponding to a change in height is matched with a position of a detector of the scattered light detection optical system.   The scattered light detection optical system further includes an objective lens, a slit portion formed with a slit through which light passes, a moving mechanism portion that moves the slit portion in a direction perpendicular to the optical axis of the objective lens, and an imaging lens. The control unit controls the moving mechanism unit of the scattered light detection optical system based on height information of the surface of the optically transparent substrate detected by the height detection system, and 5. The slit formed in the slit portion is moved to an imaging position of a scattered light image from the surface of the substrate that changes according to a change in the height of the surface of the transparent substrate. Inspection equipment for transparent substrates.   The scattered light detection optical system further includes an objective lens and a moving mechanism that moves the detector in a direction perpendicular to the optical axis of the objective lens, and the control unit detects the height detected by the height detection system. The moving mechanism of the scattered light detection optical system is controlled based on the height information of the surface of the optically transparent substrate, and changes according to the change in the height of the surface of the optically transparent substrate. The defect inspection apparatus for a transparent substrate according to claim 4, wherein the position of the detector is moved to an imaging position of a scattered light image from the surface of the substrate.   The illumination optical system irradiates the surface of the optically transparent substrate with a linear illumination light that is long in one direction from an oblique direction, and the scattered light detection optical system is a linear light that is long in the one direction. 5. The transparent substrate according to claim 1, wherein the transparent substrate includes an array sensor in which a plurality of pixels that detect an image of scattered light from the substrate irradiated with the illumination light is arranged one-dimensionally or two-dimensionally. Defect inspection equipment.   The height detection system has a detection surface configured by arranging a plurality of pixels in a one-dimensional or two-dimensional manner, and is reflected by the surface of the optically transparent substrate irradiated with light by the illumination optical system. 5. The transparent substrate defect inspection apparatus according to claim 1, wherein the height of the surface of the optically transparent substrate is detected by detecting light on the detection surface. Place an optically transparent substrate on a stage that can move in a plane and move it in one direction.
Irradiate light from an oblique direction to the surface of an optically transparent substrate moved in one direction by the stage part,
A detector detects an image of light scattered by the optically transparent substrate irradiated with the light,
Detecting the height of the surface of the optically transparent substrate irradiated with the light;
A transparent substrate defect inspection method for processing a detection signal of an image of light scattered on the detected optically transparent substrate to detect defects on the surface of the optically transparent substrate,
Adjusting the incident angle of the light irradiated from an oblique direction to the surface of the optically transparent substrate based on the detected information on the height of the surface of the substrate, or of the surface of the optically transparent substrate By aligning the image formation position of the scattered light image corresponding to a change in height and the position of the detector, the detector detects the image of the scattered light of the defect on the surface of the optically transparent substrate. A method for inspecting a defect in a transparent substrate.   Irradiating light from the oblique direction to the surface of the optically transparent substrate, converting the optical path of the light emitted from the light source with a mirror, and irradiating the surface of the optically transparent substrate from the oblique direction Adjusting the incident angle of the light applied to the optically transparent substrate surface from an oblique direction based on the detected height information on the surface of the substrate. The transparent substrate defect inspection method according to claim 9, wherein the inspection is performed by adjusting an angle of a mirror that converts the optical path based on height information.   To irradiate light on the surface of the optically transparent substrate from an oblique direction, the light emitted from the light source is collimated by a lens, the optical path of the collimated light is converted by a mirror, and the optically transparent This is done by irradiating light on the surface of the substrate from an oblique direction, and adjusting the incident angle of the light irradiated on the surface of the optically transparent substrate from the oblique direction based on the detected information on the height of the surface of the substrate. This is done by adjusting the incident angle of the light that irradiates the surface of the optically transparent substrate from an oblique direction by changing the position of the light source with respect to the direction perpendicular to the optical axis of the lens. The defect inspection method for a transparent substrate according to claim 9.   Detecting an image of light scattered by the substrate with a detector, condensing the light scattered by the substrate with an objective lens, and at the imaging position of the light scattered by the substrate collected by the objective lens Transmitting through the arranged slit, and imaging the light transmitted through the slit on the detection surface of the detector with an imaging lens, according to the change in the height of the surface of the optically transparent substrate Scattering of the scattered light image from the surface of the substrate by the objective lens that changes in accordance with a change in the height of the surface of the optically transparent substrate is matched with the position of the detector. The transparent substrate defect inspection method according to claim 9, wherein the method is performed by moving the slit to a light imaging position.   Detecting an image of light scattered by the substrate with a detector, condensing the light scattered by the substrate with an objective lens, and at the imaging position of the light scattered by the substrate collected by the objective lens Transmitting through the arranged slit, and imaging the light transmitted through the slit on the detection surface of the detector with an imaging lens, according to the change in the height of the surface of the optically transparent substrate Matching the imaging position of the scattered light image with the position of the detector means that the scattered light image from the surface of the substrate changes according to the change in the height of the surface of the optically transparent substrate. The transparent substrate defect inspection method according to claim 9, wherein the detection is performed by moving the position of the detector to an image position.   Irradiating light from the oblique direction to the surface of the optically transparent substrate is performed by irradiating the surface of the optically transparent substrate from an oblique direction with linear illumination light that is long in one direction, The detection of an image of light scattered by an optically transparent substrate using a detector is a linear illumination that is long in one direction with a detector composed of an array sensor in which a plurality of pixels are arranged one-dimensionally or two-dimensionally. The transparent substrate defect inspection method according to claim 9, wherein the inspection is performed by detecting an image of scattered light from the substrate irradiated with light.   Detecting the height of the surface of the optically transparent substrate irradiated with the light, one-dimensionally reflecting a plurality of pixels from the surface of the optically transparent substrate irradiated with the light. Alternatively, the height of the surface of the substrate is detected by detecting with a detector having a detection surface configured in a two-dimensional arrangement and processing a signal detected by the detector. The transparent substrate defect inspection method according to claim.

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