JP2011174817A - Foreign matter inspection system, exposure system, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foreign matter inspection system capable of detecting the surface, to which a foreign matter is adhered, of two surfaces of an inspection target. <P>SOLUTION: The foreign matter inspection system is equipped with a floodlight projection part for projecting inspection light on the inspection target, a light detection part including a detector for detecting the intensity of the scattered light emitted from the inspection target on which the inspection light is projected and a control part. The detector detects the intensity of the first scattered light emitted from the inspection target by projecting the inspection light wherein a polarization direction is a first direction and the intensity of the second scattered light emitted from the inspection target by projecting the inspection light wherein the polarization direction is a second direction. The control part determines whether the surface to which the foreign matter is adhered is the first or second surface of the inspection target on the basis of whether the ratio of the intensities of the first and second scattered lights detected by the detector is larger or smaller than a standard value. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a foreign matter inspection apparatus, an exposure apparatus, and a device manufacturing method used in manufacturing a semiconductor device and a liquid crystal display device. In particular, the present invention relates to a foreign substance inspection apparatus for detecting the presence or absence of foreign substances on both surfaces of a flat glass and a pellicle formed on the upper side of a mask in order to correct the pressure of the mask deflection.

  In recent years, there is a concern that the mask will be bent by its own weight due to an increase in the size of the mask used in the exposure apparatus and image performance will deteriorate. Therefore, many contrivances have been made so far to reduce the self-weight deflection of the mask. Patent Document 1 discloses an exposure in which the upper side of a mask is closed with a flat glass to form a sealed chamber, the deflection of the lower surface of the mask is detected, and the pressure of the sealed chamber is adjusted based on the detection result to correct the deflection of the mask. An apparatus is disclosed.

  If foreign matter adheres to the upper and lower surfaces of the flat glass constituting the sealed chamber, the image performance at the time of exposure may be deteriorated. Therefore, it is necessary to detect and remove the foreign matters adhering to the upper and lower surfaces of the flat glass. In the transfer process from the storage location to the mask stage, the mask and the flat glass are separated, and the foreign matter inspection of the upper and lower surfaces of the mask and the flat glass is performed while the mask or the flat glass is being transferred while being held by the transfer member. . FIG. 11 shows a conventional foreign object inspection, which includes a light projecting unit including a light source 16 and a projection lens 17, and a light receiving unit including a light receiving lens 18 and a detector 15. And in the state hold | maintained at the conveyance member 19, the upper and lower surfaces of the flat glass 3 (or mask) are used for the upper and lower surfaces of the flat glass 3 (or mask) by using two foreign substance inspection devices. Foreign matter inspection is performed.

JP-A-10-214780

  After the foreign matter inspection is performed on the upper and lower surfaces of the mask and the flat glass 3 while being held by the transport member 19, the mask and the flat glass 3 are combined to correct the deflection of the mask. A drive mechanism for transporting the transport member 19 exists near the mask and the flat glass 3. Therefore, dust generated by driving of the driving mechanism may adhere to the upper surface of the mask or the lower surface of the flat glass 3 after the foreign matter inspection is completed and before the mask and the flat glass 3 are combined. Further, when the inside of the sealed space formed by combining the mask and the flat glass 3 is depressurized, a fine metal piece or the like flies from the contact portion between the mask and the flat glass 3, and the metal piece is on the upper surface or the plane of the mask. It may adhere to the lower surface of the glass 3.

  However, in the conventional foreign matter inspection, the foreign matter on the upper surface of the mask or the lower surface of the flat glass 3 cannot be inspected after the mask and the flat glass 3 are combined to construct a mechanism for correcting the deflection of the mask. Further, the foreign matter attached to the mask side surface of the pellicle after the pellicle protecting the mask pattern surface is attached cannot be inspected by the conventional foreign matter inspection so that the foreign matter does not adhere to the mask pattern surface. Therefore, an object of the present invention is to provide a foreign matter inspection apparatus capable of detecting which of two surfaces of a test object is a surface to which foreign matter is attached.

  The present invention is a foreign matter inspection apparatus for inspecting a foreign matter adhering to a light transmissive test object, wherein a light projecting unit that projects test light onto the test object, and the test light is projected. A light receiving unit including a detector for detecting the intensity of scattered light generated from the test object, and a control unit, and the detector projects the first inspection light whose polarization direction is the first direction. The intensity of the first scattered light generated from the test object by being irradiated and the second test light generated from the test object by projecting the second inspection light whose polarization direction is the second direction. The intensity of the scattered light is detected, and the ratio of the intensity of the first scattered light and the second scattered light caused by the foreign matter adhering to the first surface of the test object is larger than a reference value, and the test object The first scattered light and the second generated by the foreign matter adhering to the second surface opposite to the first surface The ratio of the intensity of the scattered light is smaller than the reference value, and the control unit is configured such that the ratio of the intensity of the first scattered light and the intensity of the second scattered light detected by the detector is greater than the reference value. It is characterized in that it is determined which of the first surface and the second surface the surface to which the foreign substance is attached depending on whether it is small, and the determined result is output.

  ADVANTAGE OF THE INVENTION According to this invention, the foreign material inspection apparatus which can detect which surface of the 2 surfaces of a to-be-tested object is the surface to which the foreign material adhered can be provided.

The figure which shows the foreign material inspection apparatus of Example 1. The figure explaining inspecting the foreign matter on both the upper and lower sides of the specimen The figure which shows a mode that S polarized light and P polarized light are permeate | transmitting the test object The figure which shows the relationship between the incident angle of inspection light, and the amount of transmitted light Diagram showing the relationship between scattered light intensity on the upper and lower surfaces of the specimen The figure which shows the foreign material inspection apparatus in Example 2. The figure which shows the foreign material inspection apparatus in Example 3. The figure which shows the relationship between the scattered-light intensity | strength in the case of using P polarized light and S polarized light, and a foreign material size The figure which shows the foreign material inspection apparatus in Example 4. Figure showing exposure equipment The figure which shows the conventional foreign material inspection apparatus.

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

[Exposure equipment]
FIG. 10 shows an exposure apparatus. The mask 5 is held by vacuum suction by the mask holder 6 with the pattern surface facing down. A light source 1 that emits exposure light is provided above the mask 5, and an illumination optical system 2 is provided between the light source 1 and the mask 5. On the side of the mask 5 through which the exposure light is transmitted, a substrate 12 to be exposed is disposed with the projection optical system 11 interposed therebetween. The exposure light emitted from the light source 1 is applied to the mask 5 by the illumination optical system 2. The pattern image formed on the mask 5 is projected onto the substrate 12 through the projection optical system 11 by exposure light. A detection system 21 that detects the deflection of the mask 5 is provided below the mask holder 6. The detection system 21 has the configuration and function of a grazing incidence type focus sensor. Detection light is projected obliquely from the light source 10 such as a light emitting diode to the pattern surface of the mask 5 via a projection lens (not shown). The reflected light is detected by a detector 9 such as a photodiode through a light receiving lens (not shown) to detect the deflection of the mask 5. The detection signal output side of the detector 9 is connected to the calculation unit 8. An atmospheric pressure control unit 7 is connected to the output side of the calculation unit 8, and the atmospheric pressure control unit 7 is connected to an airtight chamber 13 that corrects the deflection of the mask 5 through a pipe 4. The hermetic chamber 13 has a sealed box shape in which the lower surface side is covered with the mask 5 and the upper surface side is closed with the flat glass 3. Since the flat glass 3 constituting the hermetic chamber 13 is a flat plate, it does not affect the exposure light. A space between the flat glass 3 and the mask 5 is an airtight chamber 13, and the pressure of the airtight chamber is controlled by the atmospheric pressure control unit 7 to control the deflection of the mask 5. The atmospheric pressure control unit 7 controls the atmospheric pressure in the hermetic chamber 13 based on the atmospheric pressure control amount input from the calculation unit 8. In this way, the deflection of the mask 5 is detected by the detection system 21, the deflection amount and the atmospheric pressure control amount for correcting the deflection amount are calculated by the calculation unit 8, and the atmospheric pressure in the hermetic chamber 13 is controlled by the atmospheric pressure control unit 7. Is done. For this reason, the lateral displacement of the pattern and the curvature of the image plane caused by the deflection caused by the weight of the mask 5 are reduced, and the distortion and the curvature of field caused by the thermal deformation of the mask 5 are reduced. Projection can be performed.

[Example 1]
As shown in FIG. 1, a mask 5 and a flat glass 3 that is a light-transmitting test object are mounted on a mask stage 14 for exposure. A foreign substance inspection device is disposed on the upper side. When the drive unit 22 configured in the mask stage 14 or the foreign substance inspection apparatus is driven, the foreign substance inspection apparatus has the first surface (lower surface) of the flat glass 3 and the opposite side of the first surface as shown in FIG. The foreign matter adhering to the second surface (upper surface) is inspected. An inspection light selection member that selects one of the P-polarized inspection light and the S-polarized inspection light emitted from the light source 16 in addition to the projection lens 17 in the light projecting unit 25 that projects the inspection light onto the flat glass 3. 24a is arranged. As the inspection light selection member 24a, a λ / 2 plate, a polarizing beam splitter, a polarizing plate, other optical crystals, or the like is used. The light source 16 itself may have a function of selecting one of P-polarized light and S-polarized light. The P-polarized inspection light constitutes first inspection light whose polarization direction is the first direction, and the S-polarized inspection light constitutes second inspection light whose polarization direction is the second direction. On the other hand, the light receiving unit 26 includes a light receiving lens 18 and a detector 15 that detects the intensity of scattered light generated from the flat glass 3 by projecting the inspection light and sends the detection result to the control unit C. The detector 15 detects the intensity of the first scattered light (P-polarized scattered light) in a state where the first inspection light (P-polarized light) is projected, and the second inspection light (S-polarized light) is projected. The intensity of the second scattered light (S-polarized scattered light) is detected in the illuminated state. As a result, the detector 15 detects the intensity of the first scattered light (P-polarized scattered light) and the intensity of the second scattered light (S-polarized scattered light) separately.

  As shown in FIG. 1, the inspection light selection member 24 a is disposed in the light projecting unit 25, and the inspection light selection member 24 a is adjusted so that S-polarized light is projected onto the flat glass 3 that is the test object. . If it does so, inspection light turns into light which has a polarization azimuth | direction in the direction orthogonal to this paper surface in the upper and lower surfaces of the plane glass 3 (FIG. 3A). Similarly, when the inspection light selection member 24a is adjusted so that P-polarized light is projected onto the flat glass 3, the inspection light becomes light having a polarization direction in the direction of the arrow on the upper and lower surfaces of the flat glass 3 (FIG. 3B). An angle (θ) formed by the optical axis of the light projecting unit 25 and the normal line of the upper surface of the flat glass 3 as the test object passes through the horizontal axis and passes through the inspection light selection member 24a (when adjusted to S-polarized light or P-polarized light). The light quantity of the inspection light immediately after is set to 1. At that time, when the amount of light (Ts, Tp) transmitted from the upper surface of the flat glass 3 to the lower surface is taken as the vertical axis, the inspection light is as shown in FIG. For example, when θ = 85 °, Tp / Ts≈3.5. That is, by changing the inspection light selected by the inspection light selection member 24a from S-polarized light to P-polarized light, the amount of light that illuminates the foreign matter attached to the lower surface of the flat glass 3 is changed by a factor of 3.5.

  In this way, by changing the polarization direction of the inspection light by the inspection light selection member 24a, the amount of illumination with respect to the foreign matter attached to the upper surface of the flat glass 3 is kept constant regardless of the polarization direction, and is attached to the lower surface of the flat glass 3. The illumination light quantity with respect to the foreign substance can be changed. As a result, the control unit C detects the intensity change of the scattered light from the foreign matter accompanying the change in the polarization direction, so that the foreign matter is either the first surface or the second surface of the flat glass 3 (that is, any of the upper and lower surfaces). ) Can be detected and determined.

  Prior to the inspection, the intensity of scattered light from a foreign substance with a known particle size attached to the upper surface of the flat glass 3 is detected and recorded in each polarization direction (S, P polarization) (FIG. 5A). Similarly, the intensity of scattered light from a foreign substance having a known particle diameter attached to the lower surface of the flat glass 3 is detected and recorded for each polarized light (S, P polarized light) (FIG. 5B). At the time of inspection, the recording results in FIGS. 5A and 5B are used as criteria for determining the size of the foreign matter. For example, if 100 μm foreign matter is attached to the upper and lower surfaces of the flat glass 3, the intensity of scattered light from the foreign matter on the top surface is 1 (both S and P polarized light), and the intensity of scattered light from the foreign matter of 50 μm is S polarized. 6.3, P polarization is 8.4. Similarly, the intensity of scattered light from the foreign matter on the lower surface is 0.45 for S-polarized light and 2.16 for P-polarized light. Thus, the intensity of the scattered light from the foreign matter adhering to the upper surface is such that the adjustment state of the inspection light selection member 24a, the stability of the light amount of the inspection light, and the flat surface even when the inspection light is illuminated with the same optical path and the same amount of light. Due to variations in the optical characteristics of the glass 3, S polarization = P polarization is not always satisfied. Therefore, as shown in FIG. 5C, the ratio of the intensity of the P-polarized scattered light and the intensity of the S-polarized scattered light of the foreign matter attached to the upper surface = 8.4 / 6.3 = 1.33, and the foreign matter also attached to the lower surface. Note that the ratio of the intensity of the P-polarized scattered light and the intensity of the S-polarized scattered light = 2.16 / 0.45 = 4.8. The ratio of the intensity of the first scattered light (P-polarized scattered light) and the intensity of the second scattered light (S-polarized scattered light) attached to the lower surface (first surface) is a reference value regardless of the size of the foreign matter. Greater than (eg 2.5). On the other hand, the ratio of the intensity of the first scattered light (P-polarized scattered light) attached to the upper surface (second surface) and the intensity of the second scattered light (S-polarized scattered light) is independent of the size of the foreign matter. It is smaller than a reference value (for example, 2.5). Therefore, the control unit C determines whether the foreign matter depends on whether the ratio of the intensity of the first scattered light (P-polarized scattered light) and the intensity of the second scattered light (S-polarized scattered light) is larger or smaller than the reference value. It is determined whether it is attached to the upper surface or the lower surface. In setting the reference value, the size of the foreign matter, the position of the foreign matter, the adjustment accuracy of the inspection light selection member 24a, the stability of the amount of inspection light, the intensity of the scattered light due to the optical characteristics of the flat glass 3 serving as the test object, etc. It is desirable to set in consideration of variations in the ratio (P-polarized light / S-polarized light).

  Next, a flow for inspecting the size of the foreign matter attached to the flat glass 3, the attachment position, and the top and bottom surfaces will be described. In step 1, a foreign substance having a known size is placed on the upper and lower surfaces of a test object having optical transparency to the foreign substance inspection apparatus. Then, the inspection light selecting member 24a selects inspection light as one of S-polarized light and P-polarized light, and inspects a necessary inspection region. As a result, an appropriate light amount of the light source is determined, and sensitivity curves as shown in FIGS. 5A and 5B are created and recorded, and then used as criteria for determining the size of the foreign matter. In step 2, the ratio of the intensity of the P-polarized scattered light and the S-polarized scattered light shown in FIG. 5C is obtained from the sensitivity curve, and a reference value (threshold value) for determining which of the upper and lower surfaces has foreign matter is set. . In step 3, the inspection light selection member 24 a configured in the foreign substance inspection apparatus is adjusted so that the inspection light becomes S-polarized light, and the drive unit 22 or the mask stage configured in the foreign substance inspection apparatus with the light amount obtained in step 1 The required inspection area of the test object is inspected while driving 14. If foreign matter is detected in step 3, in step 4, the inspection light selection member 24a configured in the foreign matter inspection apparatus is adjusted so that the inspection light becomes P-polarized light. The foreign matter inspection apparatus inspects a necessary inspection region of the test object while driving the drive unit 22 or the mask stage 14 configured in the foreign matter inspection apparatus with the light amount obtained in step 1. The drive direction of the drive unit 22 or the mask stage 14 in step 3 is the reverse direction of the drive direction of the drive unit 22 or the mask stage 14 in step 4. Alternatively, the inspection light may be P-polarized light at step 3 and the inspection light may be S-polarized light at step 4.

  In step 5, the control unit C determines whether the foreign matter has adhered to the upper surface or the lower surface of the test object based on the results obtained in steps 3 and 4 and the reference value set in step 2. In step 6, the control unit C determines the position of the foreign matter in the inspection area from the result obtained in step 5 and the driving amount of the driving unit. In step 7, the control unit C determines the size of the detected foreign matter based on the sensitivity curve on the upper surface and the sensitivity curve on the lower surface of the test object obtained in step 1. In step 8, the control unit C outputs the result determined in steps 5-7. By taking the above steps with the configuration of the present embodiment, the foreign matter inspection apparatus can detect foreign matter present on the upper and lower surfaces of the flat glass 3 that is the test object.

[Example 2]
In the first embodiment, the light projecting unit 25 selectively projects one of the P-polarized inspection light and the S-polarized inspection light, and the detector 15 projects the P-polarized light while the P-polarized inspection light is projected. The intensity of the scattered light was detected, and the intensity of the S-polarized scattered light was detected in a state where the S-polarized inspection light was projected. Then, the inspection light selecting member 24a is arranged in the light projecting unit 25 so that the light projecting unit 25 selectively projects one of the P-polarized inspection light and the S-polarized inspection light. In the second embodiment, the light projecting unit 25 projects both P-polarized inspection light and S-polarized inspection light. Then, as shown in FIG. 6, instead of providing the inspection light selection member 24a in the light projecting unit 25, the selection member 24b that selectively transmits one of the P-polarized scattered light and the S-polarized scattered light is tested. It arrange | positions between the plane glass 3 which is a thing, and the detector 15. FIG. As a result, in the foreign matter inspection apparatus according to the second embodiment, the detector 15 detects the intensity of the P-polarized scattered light in a state where the selection member 24b selectively transmits the P-polarized scattered light, and the selection member 24b detects S. The intensity of the S-polarized scattered light is detected in a state of selectively transmitting the polarized scattered light. As the selection member 24b, a λ / 2 plate, a polarizing beam splitter, a polarizing plate, and other optical crystals are used. Also in the second embodiment, the foreign matter present on the upper and lower surfaces of the flat glass 3 as the test object is obtained by performing the foreign matter inspection twice by changing the polarization direction of the scattered light transmitted to the detector 15 by the selection member 24b. Can be detected.

[Example 3]
In Examples 1 and 2, the foreign matter existing on the upper and lower surfaces of the flat glass 3 was inspected by changing the polarization direction of the inspection light or scattered light and performing the foreign matter inspection twice. In the third embodiment, as in the second embodiment, the light projecting unit 25 projects both P-polarized inspection light and S-polarized inspection light. In the second embodiment, the selection member 24 b that selectively transmits one of the P-polarized scattered light and the S-polarized scattered light is disposed in the light receiving unit 26. In the third embodiment, instead of the selection member 24b, as shown in FIG. 7, a polarization beam splitter that separates P-polarized scattered light and S-polarized scattered light generated by foreign matter on the upper and lower surfaces of the flat glass 3 ( A beam splitter 24c is disposed. In the third embodiment, there are two detectors 15, that is, a first detector 15 a that detects the intensity of the P-polarized scattered light and a second detector 15 b that detects the intensity of the P-polarized scattered light. The controller C obtains the ratio of the intensity of the P-polarized scattered light and the S-polarized scattered light from the detection results of the first and second detectors 15 a and 15 b, and the foreign matter adheres to either the upper or lower surface of the flat glass 3. Judgment is made. Further, in the third embodiment, since it is not necessary to switch the polarization direction of the inspection light or scattered light as in the first and second embodiments, it is not necessary to perform the foreign substance inspection twice, and the inspection time can be reduced to half.

  An inspection flow when the foreign matter inspection apparatus according to the third embodiment is used will be described. In step 1, a foreign substance whose size is known is arranged on the upper and lower surfaces of the flat glass 3 having light permeability with respect to the foreign substance inspection apparatus. Then, a necessary inspection area is inspected using a foreign substance inspection apparatus. As a result, an appropriate light amount of the light source is determined, and sensitivity curves are created and recorded for each of the first detector 15a and the second detector 15b as shown in FIGS. 8A and 8B. This is a standard for judging size. In step 2, the ratio of the intensity of the P-polarized scattered light and the S-polarized scattered light is obtained from the sensitivity curves of the detectors 15a and 15b, and a reference value for determining which of the upper and lower surfaces has foreign matter (in FIG. Threshold). In step 3, the foreign matter inspection apparatus inspects a necessary inspection region while driving the drive unit 22 or the mask stage 14 configured in the foreign matter inspection apparatus with the light amount obtained in step 1. Thereby, the first detector 15a acquires the intensity of the P-polarized scattered light generated by the foreign matter, and the second detector 15b acquires the intensity of the S-polarized scattered light.

  In step 4, the control unit C determines whether the surface to which the foreign matter has adhered is the upper surface or the lower surface of the flat glass 3 based on the result obtained in step 3 and the reference value set in step 2. In step 5, the control unit C determines the position of the foreign matter in the inspection area from the result obtained in step 4 and the driving amount of the driving unit. In Step 6, the control unit C determines the size of the detected foreign matter based on the sensitivity curve of the first detector 15a and the sensitivity curve of the second detector 15b created and recorded in Step 1. In Example 3, the foreign substance which exists in the upper and lower surfaces of the flat glass 3 which is a test object is detectable only by test | inspecting the test | inspection area | region of the flat glass 3 once.

[Example 4]
In Examples 1 to 3, the test object of the foreign substance inspection apparatus was the flat glass 3. In the fourth embodiment, as shown in FIG. 9, the foreign matter inspection apparatus is used to protect the pattern surface of the mask 5 by being attached to the surface (lower surface) on the side where the substrate 12 is disposed, of the two surfaces of the mask 5. Foreign matter on the upper and lower surfaces of the pellicle 27 can also be inspected. The size of the foreign matter in Examples 1 to 4 may be determined from the number of pixels of the detector 15 of the foreign matter inspection apparatus.

[Device manufacturing method]
Next, device manufacturing methods such as semiconductor integrated circuit elements and liquid crystal display elements using the above-described exposure apparatus will be described as an example. The device undergoes an exposure process for exposing the substrate using the above-described exposure apparatus, a development process for developing the substrate exposed in the exposure process, and another known process for processing the substrate developed in the development process. Manufactured by. Other known processes are etching, resist stripping, dicing, bonding, packaging processes, and the like. As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

Claims (8)

A foreign matter inspection apparatus for inspecting foreign matter attached to a light-transmitting test object,
A light projecting unit that projects inspection light onto the test object;
A light receiving unit including a detector that detects the intensity of scattered light generated from the test object by projecting the inspection light;
A control unit;
With
The detector has the intensity of the first scattered light generated from the test object when the first inspection light whose polarization direction is the first direction is projected, and the polarization direction is the second direction. Detecting the intensity of the second scattered light generated from the test object by projecting the second inspection light;
The ratio of the intensity of the first scattered light and the second scattered light generated by the foreign matter adhering to the first surface of the test object is greater than a reference value, and is on the opposite side of the first surface of the test object. The ratio of the intensity of the first scattered light and the second scattered light generated by the foreign matter attached to the second surface is smaller than the reference value,
The controller is
Depending on whether the ratio of the intensity of the first scattered light and the intensity of the second scattered light detected by the detector is larger or smaller than the reference value, the surface on which foreign matter has adhered is the first surface and the second surface. Determine which of the faces
Output the judgment result,
Foreign matter inspection apparatus characterized by the above. The light projecting unit selectively projects one of the first inspection light and the second inspection light,
The detector detects the intensity of the first scattered light in a state where the first inspection light is projected, and the detector detects the intensity of the second scattered light in a state where the second inspection light is projected. The foreign matter inspection apparatus according to claim 1, wherein intensity is detected. The light projecting unit projects both the first inspection light and the second inspection light,
The light receiving unit includes a selection member that is disposed between the test object and the detector and selectively transmits one of the first scattered light and the second scattered light,
The detector detects the intensity of the first scattered light in a state where the selection member selectively transmits the first scattered light, and the selection member selectively transmits the second scattered light. 2. The foreign matter inspection apparatus according to claim 1, wherein the intensity of the second scattered light is detected in a state where the second scattered light is detected. The light projecting unit projects both the first inspection light and the second inspection light,
The light receiving unit includes a beam splitter that is disposed between the test object and the detector and separates the first scattered light and the second scattered light,
The detector includes a first detector that detects the intensity of the first scattered light separated by the beam splitter, and a second detector that detects the intensity of the second scattered light,
The said control part acquires the ratio of the intensity | strength of a said 1st scattered light and a said 2nd scattered light from the detection result of a said 1st detector, and the detection result of a said 2nd detector, It is characterized by the above-mentioned. Item 1. A foreign matter inspection apparatus according to Item 1.   The first inspection light and the first scattered light are P-polarized light, and the second inspection light and the second scattered light are S-polarized light. The foreign matter inspection apparatus according to claim 1. An exposure apparatus that exposes a substrate through a mask pattern,
A space sandwiched between the two surfaces of the mask opposite to the surface on which the substrate is disposed and the flat glass is an airtight chamber, and the deflection of the mask is controlled by adjusting the pressure in the airtight chamber. Configured to be
6. The foreign matter inspection apparatus according to claim 1, wherein the exposure apparatus inspects foreign matter attached to a first surface of the flat glass and a second surface opposite to the first surface. 7. An exposure apparatus comprising: An exposure apparatus that exposes a substrate through a mask pattern,
A pellicle is attached to the surface on which the substrate is disposed, of the two surfaces of the mask,
6. The foreign matter inspection apparatus according to claim 1, wherein the exposure apparatus inspects foreign matter attached to a first surface of the pellicle and a second surface opposite to the first surface. An exposure apparatus comprising the exposure apparatus. Exposing the substrate using the exposure apparatus according to claim 6 or 7,
Developing the substrate exposed in the step;
A device manufacturing method including:

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