JP2007163137A - Foreign matter inspection device and foreign matter inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine whether or not foreign matter exists in an object under inspection and at what position foreign matter exists, if any. <P>SOLUTION: A first inspection beam FL1 from a first light source 11 is caused to enter a surface 82S of a shading film 82 obliquely from above the object 80 under inspection with the shading film 82 formed on a front surface 81S of a transparent substrate 81, and its reflected light is received by a first photo-detector 21. Further, a second inspection beam FL2 from a second light source 12 is caused to enter a rear surface 82R of the shading film 82 obliquely from below the object 80, and its reflected light is received by a second photo-detector 22. Based on a combination of cases where scattered light is received or not by the first photo-detector 21 and/or the second photo-detector 22, it is determined whether or not foreign matter FS is deposited on the object 80, and at what position foreign matter is deposited, if any. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a foreign matter inspection apparatus and a foreign matter inspection method for inspecting foreign matter attached to an inspection object having a light shielding film formed on a substrate surface.

  The liquid crystal display is configured by sealing liquid crystal between a color filter substrate which is a glass substrate on which a color filter is formed and a TFT array substrate which is a glass substrate on which a TFT (Thin Film Transistor) array is formed. In order to form a TFT array on a glass substrate, a metal film for an electrode is formed on the glass substrate, and a resist film as a photosensitive agent is applied on the metal film. Then, a mask substrate having a predetermined pattern (circuit pattern) is opposed to the resist film with a minute interval, and light such as ultraviolet rays is irradiated from above the mask substrate to transfer the circuit pattern to the resist film. Then, after removing the resist film in the portion where the pattern is not transferred and performing etching, the photosensitive agent is removed, whereby a TFT array substrate on which a circuit pattern is formed can be obtained.

  By the way, the above-described mask substrate is obtained by forming a circuit pattern which is a light-shielding thin film on a transparent glass substrate, and the circuit pattern is transferred to a resist film to obtain a TFT array substrate. Therefore, the circuit pattern needs to be formed on the mask substrate with high accuracy. In other words, since a large number of TFT array substrates are generated using the same mask substrate, if the mask substrate itself is defective, the TFT array substrate to which the circuit pattern is transferred will also be defective. A defective TFT array substrate will be produced in large quantities. For this reason, it is necessary to inspect whether the mask substrate has a defect in advance.

Then, patent document 1 is disclosed as an example of what inspects the defect of a glass substrate. In patent document 1, it is inspected whether the surface or back surface of the glass substrate has a defect. The glass substrate is irradiated with a laser beam and scattered light is received to detect the surface or back surface of the glass substrate. Identifying defects.
JP-A-9-258197

  By the way, the method disclosed in Patent Document 1 identifies whether or not a defect has occurred in a glass substrate. However, in a part such as a mask substrate formed by forming a light shielding film on a glass substrate, the light shielding film is used. It is necessary to inspect whether foreign matter is adhered to the surface of the substrate or whether foreign matter is adhered between the substrate and the light shielding film. That is, if a foreign substance adheres between the glass substrate and the light shielding film as the mask pattern, it cannot be removed by washing or the like, resulting in a defective product. On the other hand, when a foreign substance adheres to the surface of the light shielding film, the foreign substance can be removed by washing or the like. Therefore, the foreign substance can be used as a non-defective product by removing the foreign substance. Therefore, when inspecting whether or not foreign matter has adhered to the mask substrate, it is extremely important to inspect not only whether or not foreign matter has adhered, but also where the foreign matter has adhered. That is.

  In particular, if foreign matter adheres between the glass substrate and the light shielding film, a problem occurs in the transfer accuracy of the mask pattern. If the foreign matter is peeled off, the light shielding film formed on the foreign matter is also integrated. Therefore, light is transmitted through the peeled portion, and an incorrect circuit pattern is transferred to the resist film. As a result, there is a problem that proper operation as a TFT array substrate of a liquid crystal display cannot be performed.

  In view of the above, an object of the present invention is to determine whether or not the above-mentioned foreign matter is attached and to which position the foreign matter is attached.

  The foreign matter inspection apparatus of the present invention includes a first light source that irradiates light from the surface side of the light shielding film of the object to be inspected having a light shielding film formed on the surface of the transparent substrate toward the surface of the light shielding film, A first scattered light detecting means provided at a position where the scattered light reflected by the light shielding film can be received; a second light source for irradiating light from the back surface side of the substrate toward the back surface of the light shielding film; Second scattered light detection means provided at a position where the scattered light reflected by the back surface of the film can be received, and the first scattered light detection means receive the scattered light, and the second scattered light detection means is the scattered light. Is not received, it is determined that foreign matter is attached to the surface of the light shielding film, and when the first scattered light detection means and the second scattered light detection means receive scattered light, A determination device for determining that foreign matter is adhered between the substrate and the light shielding film; Characterized in that it has a.

  Another foreign matter inspection apparatus of the present invention is a first light source that irradiates light from the surface side of the light shielding film of the object to be inspected having a light shielding film formed on the surface of a transparent substrate toward the surface of the light shielding film. A first scattered light detecting means provided at a position where the scattered light reflected by the surface of the light shielding film can be received, and a second light source for irradiating light from the back surface side of the substrate toward the back surface of the light shielding film And second scattered light detection means provided at a position where the scattered light reflected by the back surface of the light shielding film can be received, and whether or not the light incident on the first scattered light detection means contains scattered light. , Whether or not foreign matter adheres to the light-shielding film, depending on whether or not scattered light is included in the light incident on the second scattered light detection means, and when the foreign matter is attached The foreign matter is attached to the surface of the light shielding film, or And having a a determination device whether the foreign substance is adhered to the back surface of or the substrate the foreign substance is adhered to between the shielding film and the plate.

  In the foreign matter inspection method of the present invention, the first inspection light is irradiated from the surface side of the light-shielding film to the surface of the light-shielding film of the object to be inspected having the light-shielding film formed on the surface of the transparent substrate, The second inspection light is irradiated from the back surface side of the substrate toward the back surface of the light shielding film, the scattered light is included in the first inspection light reflected by the surface of the light shielding film, and on the back surface of the light shielding film. When the reflected second inspection light does not contain scattered light, it is determined that a foreign substance is attached to the surface of the light shielding film, and the first inspection light reflected on the surface of the light shielding film and In the case where scattered light is included in the second inspection light reflected by the back surface of the light shielding film, it is determined that a foreign substance is attached between the substrate and the substrate.

  In another foreign matter inspection method of the present invention, the first inspection light is irradiated from the surface side of the light shielding film of the object to be inspected having the light shielding film formed on the surface of the transparent substrate toward the surface of the light shielding film. Irradiating the second inspection light from the back surface side of the substrate toward the back surface of the light shielding film, and whether or not the first inspection light reflected by the surface of the light shielding film contains scattered light, Whether or not foreign matter is attached to the light shielding film by the combination of whether or not scattered light is included in the second inspection light reflected by the back surface of the light shielding film, and when the foreign matter is attached Determines whether the foreign matter is attached to the surface of the light shielding film, whether the foreign matter is attached between the substrate and the light shielding film, or whether the foreign matter is attached to the back surface of the substrate. It is characterized by doing.

  In the present invention, it is possible to determine whether or not foreign matter is attached to the object to be inspected, and if it is attached, to which position it is attached.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, the foreign matter inspection apparatus 1 of the present invention includes a first light source 11, a second light source 12, a first photodetector 21, a second photodetector 22, a third photodetector 23, and a first detector. 1 focusing lens 41, first imaging lens 42, second focusing lens 51, second imaging lens 52, third imaging lens 53, and determination device 30.

  The object 80 to be inspected by the foreign substance inspection apparatus 1 has a light shielding film 82 formed on the surface of a transparent substrate 81. Since the light shielding film 82 is a thin film that does not transmit light, light incident from above the object 80 is reflected by the front surface 82S, and light incident from below is reflected by the rear surface 82R. Note that the light shielding film 82 may completely block light, but may have a small amount of transmitted light. The inspection object 80 includes a mask substrate and a TFT array substrate used for manufacturing a liquid crystal display. As the mask substrate, a light-shielding thin film as a circuit pattern is formed on a transparent glass substrate. The TFT array substrate has a circuit pattern metal film formed on a glass substrate. Therefore, the light shielding film 82 in the present embodiment is a light shielding thin film of the mask substrate and a metal film of the TFT array substrate.

  The foreign matter inspection apparatus 1 is a device for determining whether or not foreign matter (dust, organic stains, etc.) is attached to the inspected object 80 and to which position it is attached. In the foreign matter inspection apparatus 1, laser light that is diverging light is oscillated from the first light source 11, and is incident on the surface 82 </ b> S of the light shielding film 82 as convergent light by the first focusing lens 41. The light reflected by the light shielding film 82 enters the first imaging lens 42 and forms an image on the first photodetector 21. The first light source 11 causes laser light to enter the surface 82S of the light shielding film 82 from obliquely above, and the first photodetector 21 is disposed at a position where the laser light reflected by the surface 82S of the light shielding film 82 can be received. The first photodetector 21 receives the laser light reflected by the surface 82S of the light shielding film 82. However, if scattered light is generated when the first inspection light FL1 is reflected, the scattered light is always generated. (That is, the first photodetector 21 is, in other words, the first scattered light detector). The first photodetector 21 will be described using a CCD (Charge Coupled Device). However, any detector that can detect light may be used. Light enters the first photodetector 21 in a predetermined region by the first imaging lens 42. The CCD constituting the first photodetector 21 photoelectrically converts incident light into an electric signal and outputs it to the determination device 30.

  Similarly to the first light source 11, the second light source 12 is also for oscillating laser light. The laser light emitted from the second light source 12 is shielded from the object 80 by the first focusing lens 51. The light is reflected by the back surface 82 </ b> R of the film 82, and is imaged on the second photodetector 22 by the second imaging lens 52. Similarly to the first photodetector 21, the second light source 22 causes the second light source 12 to make laser light incident on the back surface 82 </ b> R of the light shielding film 82 from obliquely below, and the back surface 82 </ b> R of the light shielding film 82. It is assumed that the reflected laser beam is disposed at a position where it can be received and a CCD is applied as the light receiving means. The second light detection means 22 is also configured to always receive the scattered light when scattered light is generated when the second inspection light FL2 is reflected (that is, the second light detection). In other words, the device 22 is a second scattered light detector). Then, the electrical signal photoelectrically converted by the second photodetector 22 is output to the determination device 30. Here, the spot position of the back surface 82R of the light shielding film 82 of the laser light emitted from the second light source 12 and the spot position of the surface 82S of the light shielding film 82 of the laser light emitted from the first light source 11 are: The 1st light source 11 and the 2nd light source 12 are arrange | positioned so that it may become the same position in the front and back of the light shielding film 82. FIG. In addition, although what demonstrated the laser beam from the 1st light source 11 and the 2nd light source 12 was demonstrated, it is not limited to this, For example, you may apply the light from a light emitting diode, a lamp light source, etc.

  And the 3rd photodetector 23 is arrange | positioned diagonally below the to-be-inspected object 80 (on the opposite side to the 1st light source 11). A CCD is also applied to the third photodetector 23. Here, the third photodetector 23 is arranged at a position where the laser beam from the first light source 11 can be received. As will be described later, it is used to detect whether or not a missing portion (pinhole) has occurred in the light shielding film 82 of the object 80. The light incident on the third photodetector 23 is photoelectrically converted and output to the determination device 30 as an electrical signal.

  Since the foreign object inspection apparatus 1 shown in FIG. 1 inspects the entire object to be inspected 80, the optical system of the foreign object inspection apparatus 1 (part of the foreign object inspection apparatus 1 in FIG. 1 excluding the determination device 30), or The inspection object 80 is moved in the X direction (arrow direction in FIG. 1) and the Y direction (FIG. 1 depth direction), and the first inspection light FL1 and the second inspection light FL2 are applied to all portions of the inspection object 80. To detect scattered light. For this reason, for example, a stage (not shown) that operates in the XY directions is provided on the inspection object 80.

  The determination device 30 is a device for determining whether or not a foreign substance is attached to the inspection object 80 and in which position the foreign substance is attached when it is attached. That is, the determination device 30 has foreign matters attached based on the photoelectrically converted electrical signals output from the first photodetector 21, the second photodetector 22, and the third photodetector 23. If it is attached or not, it is determined at which position it is attached, and the result is output. As an example of the output means for outputting the result, there is a display device such as a printer as a printing means for printing the determination result and a monitor as a display means for displaying the determination result. By connecting such an output means to the determination device 30, it is possible to output whether or not foreign matter is attached to the inspection object 80, and where it is attached, if it is attached.

  Next, processing performed by the foreign matter inspection apparatus 1 will be described. In FIG. 1, if no foreign matter FS is attached to the surface 82S of the light shielding film 82 of the inspection object 80, the laser light emitted from the first light source 11 (referred to as the first inspection light FL1) is first focused. The light is reflected by the surface 82S of the planar light-shielding film 82 through the lens 41. Accordingly, since the reflecting surface is a plane, the first inspection light FL1 reflected by the surface 82S of the light shielding film 82 is caused to pass through a predetermined region (imaging region) of the first photodetector 21 by the first imaging lens 42. ). On the other hand, the laser light emitted from the second light source 12 (referred to as the second inspection light FL2) passes through the second focusing lens 51 and is reflected by the back surface 82R of the planar light shielding film 82, so that the second result is obtained. The light is received by a predetermined region (imaging region) of the second photodetector 22 by the image lens 52.

  FIG. 2 shows the surface 82S of the light shielding film 82 of the object 80 to be inspected with a foreign substance FS attached thereto. The cause of foreign matter adhering to the surface 82S of the light shielding film 82 is that some foreign matter adheres after the process of forming the light shielding film 82 on the substrate 81 and before the process proceeds to the step of inspecting by the foreign matter inspection apparatus 1. It may be possible to do so. If foreign matter adheres to the surface 82S of the light shielding film 82, the foreign object can be removed by cleaning the inspected object 80. If the foreign object is removed, the inspected object 80 can be used as a non-defective product. it can.

  When the foreign matter FS adheres to the surface 82S of the light shielding film 82, the first inspection light FL1 emitted from the first light source 11 and passing through the first focusing lens 41 is reflected by the surface 82S of the light shielding film 82. The first inspection light FL1 enters the foreign material FS. Since the part of the foreign material FS has a non-planar reflecting surface, scattered light SL is generated. Therefore, the first photodetector 21 receives the scattered light SL. On the other hand, the second inspection light FL2 emitted from the second light source 12 does not reach the foreign material FS adhering to the surface 82S of the light shielding film 82, and is reflected by the back surface 82R of the light shielding film 82. Accordingly, since the reflecting surfaces are all flat, the second inspection light FL2 reflected by the back surface 82R of the light shielding film 82 is not light containing scattered light, and the second photodetector 2 detects scattered light. Not.

  FIG. 3 shows a case where the foreign substance FS adheres between the substrate 81 and the light shielding film 82 (the back surface 82R of the light shielding film 82). As a cause of the foreign material FS adhering to the back surface 82R of the light shielding film 82, the foreign material FS may adhere to the front surface 81S of the substrate 81 before the light shielding film 82 is formed on the substrate 81. When the foreign matter FS adheres to the back surface 82R of the light shielding film 82, as shown in FIG. 3, the light shielding film 82 slightly protrudes due to the foreign matter FS in the portion where the foreign matter FS adheres. When the first inspection light FL1 from the first light source 11 is incident on the raised light shielding film 82, the reflection surface at the raised portion is not a flat surface, and thus scattered light SL is generated. Therefore, if the foreign matter FS is attached to the back surface 82 </ b> R of the light shielding film 82, the scattered light SL is detected by the first photodetector 21.

  On the other hand, the second inspection light FL2 emitted from the second light source 12 is reflected by the back surface 82R of the light shielding film 82. However, if the foreign matter FS is attached to the back surface 82R of the light shielding film 82, the second inspection light FL2 is transmitted through the substrate 81. Then, the light is reflected by the foreign matter FS adhering to the back surface 82R of the light shielding film 82. Therefore, the reflecting surface is not flat and scattered light SL is generated. Accordingly, the scattered light SL is detected by the second photodetector 22. That is, when the foreign substance FS is attached to the back surface 82R of the light shielding film 82, scattered light is detected by both the first photodetector 21 and the second photodetector 22.

  FIG. 4 shows a case where the foreign substance FS is attached to the back surface 81 </ b> R of the substrate 81. Even if the foreign matter FS adheres to the back surface 81R of the substrate 81, the first inspection light FL1 emitted from the first light source 11 is reflected by the surface 82S of the light shielding film 82. Therefore, since the reflecting surface has a planar shape, the first photodetector 21 does not receive scattered light. On the other hand, the laser light emitted from the second light source 12 is reflected by the back surface 82R of the planar light shielding film 82 and is received by the second photodetector 22, but the second light emitted from the second light source 12 is reflected. Part of the second inspection light FL2 is reflected by the foreign matter FS adhering to the back surface 81R of the substrate 81. Accordingly, the scattered light SL is generated by the foreign matter FS, and the scattered light SL is detected by the second photodetector 22.

  FIG. 5 shows a case where a missing portion (pinhole) DF is generated in a part of the light shielding film 82. A possible cause of the occurrence of the missing portion DF in the light shielding film 82 is that the light shielding film 82 is cracked or peeled off. When the missing portion DF is generated in the light shielding film 82, part or all of the first inspection light FL1 emitted from the first light source 11 is not reflected by the surface 82S of the light shielding film 82, and the missing portion DF is removed. To Penetrate. The transmitted light passes through the third imaging lens 53 as transmitted light TL, and the transmitted light TL is detected by the third photodetector 23. When all of the first inspection light FL1 is transmitted through the missing portion DF, the light is not reflected by the surface 82S of the light shielding film 82, and therefore the light is not detected by the first photodetector 21. On the other hand, when a part of the first inspection light FL1 is transmitted through the missing portion DF, a part of the light is reflected by the surface 82S of the light shielding film 82, so that the reflected light is reflected on the first photodetector 21. Is detected.

  On the other hand, when the missing portion DF is generated in the light shielding film 82, a part or all of the second inspection light FL2 emitted from the second light source 12 is not reflected by the surface 82S of the light shielding film 82, and the missing portion DF. Transparent. When all of the second inspection light FL2 from the second light source 12 passes through the missing portion DF, no light is detected by the second photodetector 22. On the other hand, when a part of the second inspection light FL2 from the second light source 12 is transmitted through the missing portion DF, a part of the second inspection light FL2 is reflected, so that the reflected light is transmitted to the second photodetector 22. Detected. As shown in FIG. 1, the second light detector 22 and the third light detector 23 are arranged on the back surface side of the substrate 81, and each receives light. The first light source 11 and the second light source 12 are arranged so that the laser light is incident on the inspection object 80 at an angle different from the irradiation angle of the laser light from the second light source 12.

  The determination device 30 is connected to the first light detector 21, the second light detector 22, and the third light detector 23 described above, and the electric signal photoelectrically converted in each light detector is determined by the determination device 30. Is output. As each photodetector, a CCD is applied. In the case of a CCD, one in which a plurality of light receiving elements are arranged in the X direction (horizontal direction) and the Y direction (vertical direction) is applied. By applying a plurality of light receiving elements arranged in the X direction and the Y direction, light can be received in a region having a certain area. The light received by the light receiving element is photoelectrically converted into an electrical signal and output to the determination device 30. Therefore, as information on the electrical signal output from each photodetector to the determination device 30, the addresses (addresses assigned to the X direction and the Y direction) and the light intensity of the light receiving elements constituting each photodetector, respectively. There is information.

  The determination device 30 determines whether or not the scattered light SL is received based on the information output from each photodetector. When determining whether or not the scattered light SL is received, the determination is performed based on the light amount distribution. FIG. 6A shows a light receiving area of each photodetector when the scattered light SL is not received. If the scattered light SL is not generated, the light received by each photodetector is imaged in a predetermined imaging area FA. At this time, the light quantity distribution on the central axis C shown in FIG. 4A is as shown in FIG. That is, the light amount distribution is high in the imaging area FA, but the light quantity is “0” outside the imaging area.

  On the other hand, FIG. 7A shows a light receiving area of each detection light when the scattered light SL is generated. When each detector receives the scattered light SL, in addition to the imaging area FA, for example, as shown in FIG. Accordingly, the light quantity distribution on the central axis C detects scattered light SA1 and SA2 even outside the imaging area FA, as shown in FIG. Although it may be determined that the scattered light SL is detected when there is light other than the image formation area FA and the light amount is not “0”, light having an intensity equal to or greater than a certain threshold is received in consideration of errors and the like. May be detected as scattered light.

  As described above, the determination device 30 can determine whether or not each detector receives the scattered light SL. Here, as described above, when the foreign matter FS adheres to the surface 82S of the light shielding film 82, the scattered light SL is detected by the first photodetector 21, but the second photodetector 22 detects. Scattered light SL is not detected. Further, when the foreign substance FS is attached between the substrate 81 and the light shielding film 82 (the back surface 82R of the light shielding film 82), scattered light is emitted to both the first photodetector 21 and the second photodetector 22. SL is detected. Further, when the foreign substance FS is attached to the back surface 81R of the substrate 81, the scattered light SL is not detected by the first photodetector 21, but the scattered light SL is detected by the second photodetector 22. The And when the foreign material FS has not adhered to the to-be-inspected object 80, the scattered light SL is not detected by both the 1st photodetector 21 and the 2nd photodetector 22. FIG.

  On the other hand, regardless of whether or not light is received by the first photodetector 21 and the second photodetector 22, if the light-shielding film 82 has the missing portion DF, the third photodetector 23 is When the light is received and there is no missing portion DF, the third photodetector 23 does not receive the light.

  FIG. 8 (in the figure, “−” shown at the bottom of the first photodetector 21 and the second photodetector 22 is true or false). Show good). The determination device 30 determines whether or not the scattered light is received based on the electrical signals output from the first photodetector 21, the second photodetector 22, and the third photodetector 23. Determine according to the distribution. At this time, whether or not the scattered light was detected by each photodetector depending on whether or not it was detected that the light amount was not “0” outside the imaging region, or whether or not a light amount equal to or greater than a preset threshold was detected. Determine whether or not. Then, by comparing the presence / absence of detection of scattered light in each photodetector with the table of FIG. 8, whether or not the foreign matter FS is attached to the inspected object 80, and if the foreign matter FS is attached, It is determined whether it is attached to the front surface 82S of the light shielding film 82, the rear surface 82R of the light shielding film 82, or the rear surface 81R of the substrate 81. Then, it is determined whether or not the missing portion DF is generated in the light shielding film 82 depending on whether or not the light is received by the third photodetector 23. Based on the determination result, the determination device 30 outputs to the output means (not shown) whether the foreign matter FS is attached to the inspection object 80 and where it is attached.

  As described above, the present invention includes a first light source that irradiates a first inspection light from a surface side of a light shielding film of a test object having a light shielding film formed on a transparent substrate toward the surface of the light shielding film. A second light source that emits second inspection light from the back surface side of the substrate toward the back surface of the light shielding film, and the first light at a position where the first inspection light reflected by the surface of the light shielding film can be received. The detector is provided with a second photodetector at a position where the second inspection light reflected by the back surface of the light shielding film can be received, and the first photodetector and the second photodetector detect the scattered light. It can be determined whether or not a foreign object is attached to the object to be inspected, and if it is attached, which position is attached. Further, whether or not a missing portion is generated in the light shielding film can be determined by the presence or absence of light reception by the third photodetector.

It is a schematic block diagram of the foreign material inspection apparatus of this invention. It is explanatory drawing when the foreign material has adhered to the surface of the light shielding film. It is explanatory drawing when the foreign material has adhered to the back surface of the light shielding film. It is explanatory drawing when the foreign material has adhered to the back surface of a board | substrate. It is explanatory drawing when the missing part has arisen in the light shielding film. It is explanatory drawing which shows typically the light reception area | region and light quantity distribution when scattered light is not contained. It is explanatory drawing which shows typically a light reception area | region and scattered light distribution when scattered light is contained. It is a figure which shows the table based on the result of having detected the presence or absence of scattered light.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Foreign substance inspection apparatus 11 1st light source 12 2nd light source 21 1st photodetector 22 2nd photodetector 23 3rd photodetector 30 Determination apparatus 81 Substrate 82 Light shielding film DF Missing part FL1 Inspection light FL2 Inspection light FS Foreign matter

Claims (6)

A first light source for irradiating light from the surface side of the light shielding film to the surface of the light shielding film of a test object having a light shielding film formed on the surface of the transparent substrate, and scattered light reflected by the light shielding film First scattered light detection means provided at a position where the light can be received, a second light source that emits light from the back surface side of the substrate toward the back surface of the light shielding film, and scattered light reflected by the back surface of the light shielding film Second scattered light detection means provided at a position where the light can be received;
When the first scattered light detection means receives scattered light and the second scattered light detection means does not receive scattered light, it is determined that foreign matter is attached to the surface of the light shielding film; A determination device that determines that a foreign substance is attached between the substrate and the light shielding film when the first scattered light detection unit and the second scattered light detection unit receive the scattered light. Foreign matter inspection apparatus characterized by A first light source that irradiates light from the surface side of the light shielding film to the surface of the light shielding film of the object to be inspected having a light shielding film formed on the surface of the transparent substrate, and the light reflected from the surface of the light shielding film First scattered light detection means provided at a position where scattered light can be received, a second light source for irradiating light from the back side of the substrate toward the back side of the light shielding film, and reflected by the back side of the light shielding film Second scattered light detection means provided at a position where the scattered light can be received;
The combination of whether or not the light incident on the first scattered light detecting means includes scattered light and whether or not the light incident on the second scattered light detecting means includes scattered light, Whether or not foreign matter has adhered to the light shielding film, and if the foreign matter has adhered, the foreign matter has adhered to the surface of the light shielding film or the foreign matter between the substrate and the light shielding film. A foreign substance inspection apparatus comprising: a determination device that determines whether or not the foreign substance is attached to the back surface of the substrate. The opposite side of the surface of the substrate on which the light shielding film is formed, and when the light from the first light source passes through the object to be inspected, the light transmitted through the object to be inspected can be received A third light detecting means is provided at a position,
The determination apparatus determines that the light-shielding film has a defective portion by detecting that the third light detection unit has received light transmitted through the object to be inspected that has passed through the light-shielding film. The foreign matter inspection apparatus according to claim 2.   4. The foreign matter inspection apparatus according to claim 2, wherein the first inspection light and the second inspection light are laser beams. A first inspection light is irradiated from the surface side of the light shielding film of the object to be inspected having a light shielding film formed on the surface of the transparent substrate toward the surface of the light shielding film, and the light shielding film is formed from the back surface side of the substrate. Irradiate the second inspection light toward the back of the
When the first inspection light reflected on the surface of the light shielding film includes scattered light and the second inspection light reflected on the back surface of the light shielding film does not include scattered light, the light shielding film Scattered light is included in the first inspection light reflected on the surface of the light shielding film and the second inspection light reflected on the back surface of the light shielding film. In this case, it is determined that a foreign substance is adhered between the substrate and the substrate. A first inspection light is irradiated from the surface side of the light shielding film of the object to be inspected having a light shielding film formed on the surface of the transparent substrate toward the surface of the light shielding film, and the light shielding film is formed from the back surface side of the substrate. Irradiate the second inspection light toward the back of the
Whether scattered light is included in the first inspection light reflected on the surface of the light shielding film, and whether scattered light is included in the second inspection light reflected on the back surface of the light shielding film. Depending on the combination, whether or not foreign matter has adhered to the light shielding film, and if the foreign matter has adhered, whether the foreign matter has adhered to the surface of the light shielding film, or between the substrate and the light shielding film A foreign matter inspection method, wherein it is determined whether or not the foreign matter is attached between them or the foreign matter is attached to the back surface of the substrate.

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