JP2020051759A - Foreign matter inspection device, exposure device, and article production method - Google Patents

Abstract

To provide a foreign matter inspection device which is robust to a decrease in flatness of an object to be inspected.SOLUTION: A foreign matter inspection device which inspects foreign matter on a surface to be inspected of an object comprises: a light projecting section which projects inspection light onto the surface to be inspected; and a light receiving section which receives scattered light from the foreign matter caused by the inspection light being projected by the light projecting section. The light projecting section and the light receiving section are disposed so that a point where an optical axis of the light projecting section and an optical axis of the light receiving section cross is positioned out of a range of a possible height of the surface to be inspected.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a foreign matter inspection device, an exposure device, and an article manufacturing method.

  In recent years, there is a concern that a mask used in an exposure apparatus may be bent by its own weight due to an increase in the size of the mask and deteriorate image performance. Therefore, an exposure apparatus that forms a closed chamber by closing the upper side of the mask with flat glass, detects the bending of the lower surface of the mask, and adjusts the pressure of the closed chamber based on the detection result to correct the bending of the mask is known. Have been.

  Further, there is known a foreign matter inspection apparatus for inspecting foreign matter on a surface to be inspected of an object (for example, Patent Document 1). When performing a foreign substance inspection on the exposure apparatus having the above-described configuration, not only the mask but also the flat glass described above can be inspected.

JP 2012-032252 A

  However, the flat glass is generally formed to be thinner than the mask, and it is assumed that the amount of deflection of the flat glass is larger than that of the mask. Such a large deflection of the inspection object affects the accuracy of the determination of the presence or absence of a foreign substance.

  An object of the present invention is to provide, for example, a foreign matter inspection device that is robust against a decrease in flatness of an inspection object.

  According to one aspect of the present invention, there is provided a foreign matter inspection device for inspecting foreign matter on a surface to be inspected of an object, wherein the light projection unit that emits inspection light onto the surface to be inspected, and the inspection is performed by the light projection unit. A light receiving unit that receives scattered light from the foreign matter generated by the light being projected, and the point where the optical axis of the light projecting unit and the optical axis of the light receiving unit intersect is the surface to be measured. A foreign matter inspection apparatus is provided, wherein the light projecting unit and the light receiving unit are arranged so as to be shifted from a height range.

  According to the present invention, for example, it is possible to provide a foreign matter inspection apparatus that is robust against a decrease in flatness of an inspection object.

FIG. 1 is a diagram illustrating a configuration example of an exposure apparatus according to an embodiment. FIG. 2 is a diagram illustrating a configuration example of a foreign substance inspection apparatus provided in the exposure apparatus. FIG. 2 is a diagram illustrating a configuration example of a foreign substance inspection apparatus provided outside the exposure apparatus. FIG. 4 is a diagram showing an operation example of the foreign matter inspection device of FIG. 3. FIG. 6 is a diagram illustrating an example of a foreign substance inspection when the surface to be inspected has no bending. FIG. 7 is a diagram illustrating a variation in signal intensity with respect to a foreign substance in a case where a test surface has no bending. FIG. 4 is a diagram illustrating a phenomenon in which an illumination area shifts when a surface to be inspected is bent. FIG. 4 is a diagram for explaining a variation in signal strength with respect to a foreign substance when a test surface is bent. FIG. 4 is a diagram illustrating an example of an arrangement of a light projecting unit and a light receiving unit in the embodiment. FIG. 11 is a diagram illustrating a variation in signal intensity with respect to foreign matter in the arrangement of the light projecting unit and the light receiving unit in FIG. 10. FIG. 4 is a diagram illustrating an example of adjusting a relative position between a light emitting unit and a light receiving unit. FIG. 4 is a diagram illustrating an example of adjusting a relative position between a light emitting unit and a light receiving unit. The figure explaining the example which adjusts a parallel plate glass. The figure which shows the example of arrangement | positioning of a light shielding member. The figure which shows the example of arrangement | positioning of a light shielding member. The figure which shows the example of arrangement | positioning of a light shielding member. The figure which shows the example of arrangement | positioning of a light shielding member.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following embodiments merely show specific examples of implementation of the present invention, and the present invention is not limited to the following embodiments. In addition, not all combinations of features described in the following embodiments are necessarily essential for solving the problem of the present invention.

[Exposure equipment]
FIG. 1 shows a configuration of an exposure apparatus according to the embodiment. The exposure apparatus is an apparatus that exposes a substrate by projecting a mask pattern onto the substrate. The mask 5 is held by the mask holder 6 with the pattern surface down by vacuum suction. A light source 1 for emitting 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. Exposure light emitted from the light source 1 is applied to the mask 5 by the illumination optical system 2. The image of the pattern formed on the mask 5 is projected onto the substrate 12 through the projection optical system 11 by exposure light. A detection system 21 for detecting the deflection of the mask 5 is provided below the mask holder 6.

  The detection system 21 has the configuration and function of an oblique incidence type focus sensor. Detection light is emitted obliquely to the pattern surface of the mask 5 from a light source 10 such as a light emitting diode via a projection lens (not shown). The deflection of the mask 5 is detected by detecting the reflected light with a detector 9 such as a photodiode via a light receiving lens (not shown).

  The detection signal output side of the detector 9 is connected to the calculation unit 8. The output side of the arithmetic unit 8 is connected to an air pressure control unit 7. The air pressure control unit 7 is connected via a pipe 4 to an airtight chamber 13 for correcting the deflection of the mask 5. The airtight chamber 13 has a closed box shape in which the lower surface is closed by the mask 5 and the upper surface is closed by the flat glass 3 (glass plate). The flat glass 3 is disposed on the mask 5 at a distance from the mask 5 and is used to define an airtight chamber 13 which is a space for correcting the deflection of the mask 5. Since the flat glass 3 is a flat plate, it does not affect the exposure light. The space between the flat glass 3 and the mask 5 is an airtight chamber 13, and the pressure in the airtight chamber is controlled by the air pressure control unit 7 to control the deflection of the mask 5. The air pressure control unit 7 controls the air pressure of the airtight chamber 13 based on the air pressure control amount input from the calculation unit 8. As described above, the deflection of the mask 5 is detected by the detection system 21, the amount of deflection and the atmospheric pressure control amount for correcting the amount of deflection are calculated by the calculation unit 8, and the air pressure of the airtight chamber 13 is controlled by the air pressure control unit 7. Is done. For this reason, the lateral displacement of the pattern and the curvature of the image surface due to the deflection caused by the weight of the mask 5 and the distortion and the curvature of the image surface due to the thermal deformation of the mask 5 are reduced, and the pattern of the mask 5 can be satisfactorily reduced. Projection can be performed.

[Foreign matter inspection device]
If foreign matter adheres to the upper and lower surfaces (particularly the upper surface) of the flat glass 3, the upper surface (non-pattern surface) of the mask 5, and the pellicle 27 that protects the pattern of the mask 5, image performance during exposure may be reduced. Therefore, it is necessary to detect a foreign substance from these places using a foreign substance inspection device, and to remove the foreign substance when it is detected.

  In the present embodiment, the foreign matter inspection device may be provided in the exposure device, or may be provided as an external device of the exposure device. For example, as shown in FIG. 2, the foreign substance inspection of the flat glass 3 can be performed by the foreign substance inspection device 50 in the exposure apparatus. The foreign matter inspection device 50 inspects foreign matter adhering to the surface of the light-transmitting plate-shaped member arranged in the exposure apparatus. The light-transmitting plate-shaped member is, for example, the flat glass 3. The foreign substance inspection on the flat glass 3 is performed in a state where the mask 5 and the flat glass 3 are arranged on the mask stage 14 for exposure as shown in FIG.

  The foreign matter inspection device 50 receives a light projecting unit 25 that emits inspection light (illumination light) on a surface to be inspected of an object, and receives scattered light from a foreign matter generated by projecting the inspection light by the light projecting unit. And a light receiving unit 26. The light projecting unit 25 changes a light source 16 such as a light emitting diode (LED), an illumination lens 17 through which emitted light emitted from the light source 16 passes, and an optical path of emitted light that reaches the surface to be measured via the illumination lens 17. And a parallel plate glass 24 that is an optical path changing member. The light source 16 can be, for example, an LED that emits light of the same wavelength as the light of the light source 1 (FIG. 1) of the exposure apparatus. In recent years, the size of the mask has been increased, and in order to cope with this, in the light source 16, even in the foreign substance inspection, LEDs are arranged in multiple rows in a direction (X direction) orthogonal to the inspection driving direction (Y direction in FIG. 2). Line LED may be used. Further, the light projecting unit 25 may include an adjusting unit 51 which is a mechanism for adjusting the position of the light projecting unit 25 in the Y direction.

  The light receiving unit 26 can include the light receiving lens 18 and the sensor unit 19 that converts light passing through the light receiving lens 18 into an electric signal. When a line LED is used as the light source 16 of the light projecting unit 25, the light receiving lens 18 may be an array lens extending in the X direction accordingly. Further, the light receiving unit 26 may include an adjusting unit 52 that is a mechanism for adjusting the position of the light receiving unit 26 in the Y direction.

  The light projecting unit 25 emits inspection light obliquely onto the flat glass 3 which is the surface to be inspected of the object. The light receiving unit 26 receives scattered light from a foreign substance generated by the emission of the inspection light. In the embodiment, the incident angle of the inspection light from the light source 16 is set obliquely with respect to the normal to the surface to be inspected. Further, the optical axis of the light receiving unit 26 (the surface to be measured → the light receiving lens 18 → the sensor unit 19) is set obliquely with respect to the normal line of the surface to be measured.

  As described above, the foreign matter inspection device 50 is arranged above the flat glass 3 and inspects foreign matter on the upper surface of the flat glass 3. As described above, since the closed space is formed by the mask 5 and the flat glass 3 and the probability that foreign matter adheres to the lower surface of the flat glass 3 is low, the lower surface of the flat glass 3 can be excluded from the inspection target. The foreign substance inspection device 50 performs the foreign substance inspection on all the target areas of the flat glass 3 to be inspected, so that the inspection can be performed while the mask stage 14 is driven in the Y direction.

  FIG. 3 is a diagram illustrating a configuration example of a foreign substance inspection apparatus 501 provided outside the exposure apparatus. In the example of FIG. 3, the mask 5 is held by a mask holder 28 (inspection stage), and the flat glass 3 on the mask 5 is set as a surface to be inspected. The first inspection unit 70 has a configuration similar to that of the foreign substance inspection device 50 of FIG. The first inspection unit 70 may include an adjustment unit 53 that is a mechanism for adjusting the position of the first inspection unit 70 in the Z direction. When the surface of the mask 5 is used as the surface to be inspected instead of the flat glass 3, the flat glass 3 (and other members forming the closed space) is retracted from above the mask 5, and the first inspection unit is adjusted by the adjustment unit 53. By adjusting the position of 70 in the Z direction, the inspection can be performed.

  Further, the foreign substance inspection device 501 has a second inspection unit 80 for performing a foreign substance inspection on the pellicle 27 as a light-transmitting plate-shaped member. The second inspection unit 80 includes a light emitting unit 56 and a light receiving unit 57. The light projecting unit 56 and the light receiving unit 57 may have the same configuration as the light projecting unit 25 and the light receiving unit 26 in the foreign matter inspection device 50 shown in FIG. 2, respectively. The light projecting unit 56 includes an adjusting unit 58 that adjusts the position of the light projecting unit 56 in the Y direction. The light receiving unit 57 is an adjusting unit that adjusts the position of the light receiving unit 57 in the Y direction. 59. Further, the second inspection unit 80 may include an adjustment unit 60 that is a mechanism for adjusting the position of the second inspection unit 80 in the Z direction. The control unit C controls the respective adjustment units provided in the first inspection unit 70 and the second inspection unit 80. Further, the control unit C has, for example, a processor including a CPU and a memory, and also functions as a processing unit that processes the light reception results of the light receiving units 26 and 57 to determine the presence or absence of a foreign substance (see FIG. 2). Also has such a control unit, but illustration thereof is omitted in FIG. 2).

  According to the foreign matter inspection apparatus 501 provided outside such an exposure apparatus, foreign matter inspection can be performed on any of the flat glass 3, the upper surface (non-pattern surface) of the mask 5, and the pellicle 27. In FIG. 4, the upper left diagram illustrates a scene where the first inspection unit 70 performs the foreign substance inspection on the upper surface of the mask 5. The upper right figure shows a scene where the first inspection unit 70 performs the foreign substance inspection on the upper surface of the flat glass 3. As described above, the control unit C controls the adjustment unit 53 of the first inspection unit 70 to adjust the position of the first inspection unit 70 in the Z direction by an amount indicated by ΔZ, and correct the scattered light from the foreign matter. Make it detectable. The mask holder 28 is configured to be movable in the Y direction by a drive mechanism (not shown). Therefore, the foreign substance inspection apparatus 501 can perform the inspection while driving the mask holder 28 in the Y direction in order to perform the foreign substance inspection in all the regions to be inspected.

[Arrangement of light-emitting part and light-receiving part]
Hereinafter, the relationship between the light projecting unit 25 and the light receiving unit 26 of FIG. 2 or 3 will be described. Similar discussion can be made regarding the relationship between the light projecting unit 56 and the light receiving unit 57 in FIG.

  As described above, in the embodiment, the incident angle of the inspection light from the light source 16 is set to be oblique with respect to the normal to the surface to be inspected. Further, the optical axis of the light receiving unit 26 (the surface to be measured → the light receiving lens 18 → the sensor unit 19) is set obliquely with respect to the normal line of the surface to be measured. Regarding the arrangement of the light projecting unit 25 and the light receiving unit, (1) specular reflection light of inspection light from the surface to be inspected does not enter the sensor unit 19; (2) stray light such as flare does not enter the sensor unit 19; (3) Determined in accordance with inspection specifications such as satisfying the detection accuracy of foreign matter.

  However, the light emitted from the LED has no directivity and has a light distribution angle distribution. Therefore, even if the collimator lens is appropriately arranged between the LED light emitting surface and the surface to be inspected, the illumination area is widened on the surface to be inspected, and the intensity distribution within that region (the direction in which the LED light emitting elements are arranged in multiple rows) And an intensity distribution in the direction perpendicular to the direction. For example, as shown in FIG. 5, the intensity distribution I of the inspection light obliquely incident on the surface to be inspected from the light source has a maximum on the incident optical axis and tends to decrease in an off-axis direction.

  This is because the relative position relationship between the optical axis of the light receiving section on the test surface and the illumination region having the intensity distribution changes within the test region due to the difference in the shape of the test surface, resulting in the same size. Means that the inspection result of the foreign matter varies. Hereinafter, a configuration for suppressing such a variation in the inspection result will be proposed.

  Usually, the thickness of the flat glass 3 is smaller than that of the mask. The reason is to reduce utility and cost related to weight at all. In addition, an adverse effect on the exposure performance due to an increase in deflection due to a decrease in thickness is smaller than that of a mask. An example of the bending of the mask 5 is shown at the lower left of FIG. 4, and an example of the bending of the flat glass 3 is shown at the lower right. Deflection is indicated by dashed lines. As described above, since the deflection of the mask is smaller than that of the flat glass 3, when the object to be inspected is a mask, it is less susceptible to a change in the intensity of the inspection light. In the example of FIG. 5, the height of the surface to be inspected (the position in the Z direction) is substantially the same at the positions A, B, and C in the Y direction. In this case, at positions A, B, and C in the Y direction, the optical axis of the light receiving unit 26 is near the peak position of the light intensity distribution on the surface to be measured, and as shown in FIG. , B, and C, the change in light intensity is small. Therefore, as shown in FIG. 6B, the variation in the intensity of the optical signal received with respect to a foreign substance having the same size is small. Therefore, the light projecting unit and the light receiving unit may be arranged such that the optical axis of the light projecting unit and the optical axis of the light receiving unit intersect on the surface to be inspected. As a result, the signal output on the sensor can be kept high.

  On the other hand, in the case of the flat glass 3, since the bending is relatively large, the flat glass 3 is easily affected by the change in the intensity of the inspection light. As shown in FIG. 7, at the position A, when the height of the surface to be inspected (the position in the Z direction) changes by Z1 with respect to the position B, the illumination area is shifted by a in parallel with the surface to be inspected. Similarly, at the position C, when the height (position in the Z direction) of the test surface changes by Z2 with respect to the position B, the illumination area shifts by b in parallel with the test surface.

  If the inspection target is the flat glass 3 and the arrangement is adjusted so that the optical axis of the light projecting portion and the optical axis of the light receiving portion intersect on the surface to be inspected, the variation in signal intensity for foreign matters having the same size increases. . This is because the intensity change in the vicinity of the optical axis of the light projecting portion is large, and is therefore sensitive to a change in the height of the surface to be measured. As shown in FIG. 8A, the illumination area is shifted in the direction (a, b) parallel to the surface to be inspected in accordance with the deflection (Z1, Z2) on the surface to be inspected. Between A, B, and C, the illumination intensity on the optical axis of the light receiving portion on the surface to be detected changes sensitively. Therefore, as shown in FIG. 8B, the variation in signal strength for foreign substances having the same size becomes large.

  Therefore, in the embodiment, the light projecting unit 25 and the light receiving unit 26 are positioned such that the point where the optical axis of the light projecting unit 25 intersects with the optical axis of the light receiving unit 26 is shifted from the height range of the surface to be measured. 26 are arranged. For example, as shown in FIG. 9, in a region off the optical axis of the light projecting unit 25 on the test surface, a region where the light intensity changes gradually in a direction parallel to the test surface (Y direction). The light projecting unit 25 and the light receiving unit 26 are arranged such that the optical axis of the light receiving unit 26 is located. Then, as shown in FIG. 10A, even if the illumination area is shifted in a direction parallel to the test surface (a, b) in accordance with the deflection (Z1, Z2) on the test surface, the Y direction. The light intensity on the optical axis of the light receiving portion on the surface to be inspected between the positions A, B, and C changes insensitively (slowly). Therefore, as shown in FIG. 10B, variation in signal intensity with respect to foreign matters having the same size is small. At this time, the intensity of the illumination light and the light from the foreign matter are also reduced, and the signal output on the sensor is reduced. A change in the amount of light from the foreign matter detected by the sensor unit, which occurs when adjusting the relative position of the light receiving unit with respect to the illumination area, can adjust the output of the light source.

  In the case of the mask 5, if the optical axis of the light receiving unit is adjusted to be in the illumination area as in the case of the flat glass 3, the diffracted light generated when illuminating the pattern on the lower surface of the mask is erroneously detected by the light receiving unit. Could be done. The measures for this will be described later.

  Adjustment of the relative position between the light projecting unit 25 and the light receiving unit 26 can be performed using the adjusting unit 51 of the light projecting unit 25, the adjusting unit 52 of the light receiving unit 26, or both. FIG. 11 shows an example in which the light projecting unit 25 is adjusted in the inspection driving direction (Y direction) by using the adjusting unit 51 of the light projecting unit 25. The control unit C can control the adjustment unit 51 so that the point where the optical axis of the light projecting unit 25 and the optical axis of the light receiving unit 26 intersect is shifted from the height range of the surface to be measured. . FIG. 12 shows an example in which the light receiving unit 26 is adjusted in the inspection driving direction (Y direction) by using the adjusting unit 52 of the light receiving unit 26. The control unit C can control the adjustment unit 52 so that the point where the optical axis of the light projecting unit 25 and the optical axis of the light receiving unit 26 intersect is a position shifted from the height range that the surface to be measured can take. . FIG. 13 shows an example in which the position of the optical axis of the light projecting unit 25 is adjusted using the parallel flat glass 24 of the light projecting unit 25. Here, as shown in FIG. 13, the light projecting unit 25 adjusts the amount of change in the optical path of the outgoing light reaching the surface to be measured by adjusting the rotation angle of the parallel flat glass 24 that is the optical path changing member. An adjusting unit 24a is included. The control unit C can control the adjustment unit 24a such that the point where the optical axis of the light projecting unit 25 and the optical axis of the light receiving unit 26 intersect is shifted from the height range that the surface to be measured can take. .

  In the embodiment, the control unit C controls these adjustment units according to the flatness (including deflection and unevenness) of the test surface. For example, the relationship between the flatness of the test surface calculated from the physical property values of the object to be inspected, the light intensity distribution on the test surface, and the necessary adjustment amount is recorded in advance, and based on the relationship, , The adjustment amount may be determined. Here, the flatness of the test surface may be a value indicating a height range that the test surface can take. Further, before the foreign substance inspection, the adjustment amount may be determined based on the flatness of the test surface calculated or measured in advance and the change in the signal intensity detected for the sample foreign substance. As described above, the control unit C can determine the adjustment amount based on the previously obtained relationship between the flatness of the surface to be inspected and the adjustment amount by the adjustment unit.

  In the adjustment as described above, in the inspection area on the inspection surface, in the height range (including the bending and the shape) that the inspection surface can take, the output change of the foreign matter of the same size in the inspection area is changed. The inspection is performed so that the detection reproducibility level of the foreign substance inspection is achieved. That is, the control unit C determines the adjustment amount by the adjustment unit such that the predetermined accuracy of the determination of the presence or absence of a foreign substance is ensured even if the surface to be inspected is deformed according to the assumed flatness.

  Next, measures for erroneous detection of diffracted light from the mask pattern will be described.

  A process pattern to be exposed is formed on a mask for an exposure apparatus. Therefore, when the object to be inspected by the foreign substance inspection device is a mask, the inspection light is emitted by the light emitting unit, so that diffracted light is generated in the pattern part of the mask. Such diffracted light may adversely affect the determination of the presence or absence of foreign matter. Since the type of pattern is arbitrary, it is necessary to block inspection light incident on the pattern in order to prevent erroneous detection by the light receiving unit.

  Therefore, in the embodiment, as shown in FIG. 14, a light blocking member 35 that blocks a part of the inspection light is arranged near the surface to be inspected. When the upper surface of the mask 5 is inspected by the first inspection unit 70, as shown in FIG. 15, inspection light is incident on the upper surface of the mask 5, incident on the pattern unit P via refraction, and diffracted therefrom. Light may enter the light receiving unit 26. Therefore, in the embodiment, the light shielding member 35 is arranged so that the inspection light does not reach (incident) the position of the pattern.

  When inspecting the pellicle 27 by the second inspection unit 80, as shown in FIG. 16, inspection light enters the pellicle surface, enters the pattern unit P via refraction, and receives diffracted light therefrom. The light may enter the portion 56. Therefore, in the embodiment, the light shielding member 35 is arranged so that the inspection light does not reach (incident) the position of the pattern.

  When the first inspection unit 70 inspects the upper surface of the flat glass 3, as shown in FIG. 17, the inspection light enters the upper surface of the flat glass 3, exits through refraction, and exits through the upper surface of the mask 5. And enters the pattern portion P via refraction. Therefore, diffracted light from the pattern part P can enter the light receiving part 26. Therefore, in the embodiment, the light shielding member 35 is arranged so that the inspection light does not reach (incident) the position of the pattern.

  In the examples shown in FIGS. 15 to 17 described above, the foreign matter inspection apparatus has a light-shielding adjustment unit 35 a that adjusts the position of the light-shielding member 35. The control unit C can control the light shielding adjustment unit 35a so that the inspection light does not reach the position of the pattern unit P. At this time, even if a change (flatness, posture, shape, deflection, thickness) of the test surface occurs, the control unit C blocks the inspection light for the foreign matter on the test surface, The light-shielding adjusting unit 35a is controlled so that the inspection light does not reach the first position. Further, the control unit C performs the adjustment by the light-shielding adjustment unit 35a in response to the adjustment of the relative position between the light emitting unit and the light receiving unit by the adjustment unit. Thereby, each time the relative position between the light projecting unit and the light receiving unit is adjusted, the light blocking member 35 is arranged at an appropriate position.

<Embodiment of Article Manufacturing Method>
The article manufacturing method according to the embodiment of the present invention is suitable for manufacturing an article such as a microdevice such as a semiconductor device, an element having a fine structure, and a flat display. In the article manufacturing method according to the present embodiment, a step of forming a latent image pattern on the photosensitive agent applied to the substrate using the above-described exposure apparatus (a step of exposing the substrate), and a step of forming the latent image pattern in the step. Developing the substrate. Further, the manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist peeling, dicing, bonding, packaging, and the like). The article manufacturing method of the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

3: flat glass, 5: mask, 25: light emitting part, 26: light receiving part, 27: pellicle, 50: foreign matter inspection device

Claims (12)

A foreign matter inspection device for inspecting foreign matter on a surface to be inspected of an object,
A light emitting unit that emits inspection light onto the surface to be inspected,
A light receiving unit that receives scattered light from the foreign matter caused by the inspection light being emitted by the light emitting unit,
Has,
The light projecting unit and the light receiving unit are arranged such that a point at which the optical axis of the light projecting unit and the optical axis of the light receiving unit intersect is shifted from a height range that the test surface can take. A foreign matter inspection device characterized by the above-mentioned. An adjusting unit that adjusts a relative position between the light emitting unit and the light receiving unit,
A control unit that controls the adjustment unit so that a point at which the optical axis of the light emitting unit and the optical axis of the light receiving unit intersect is shifted from the height range.
The foreign matter inspection device according to claim 1, comprising: The light projecting unit includes a light source, a lens through which emitted light emitted from the light source passes, and an optical path changing member that changes an optical path of the emitted light that reaches the test surface via the lens.
An adjusting unit that adjusts a change amount of the optical path by adjusting a rotation angle of the optical path changing member;
A control unit that controls the adjustment unit so that a point at which the optical axis of the light emitting unit and the optical axis of the light receiving unit intersect is shifted from the height range.
The foreign matter inspection device according to claim 1, comprising:   The foreign matter inspection device according to claim 2, wherein the control unit controls the adjustment unit according to flatness of the surface to be inspected. Further comprising a processing unit for processing the light receiving result of the light receiving unit to determine the presence or absence of the foreign matter,
5. The control unit according to claim 4, wherein the control unit determines an adjustment amount by the adjustment unit such that a predetermined accuracy of the determination is ensured even if the test surface has a deformation according to the flatness. 6. Foreign matter inspection device.   The foreign matter according to claim 5, wherein the control unit determines the adjustment amount based on a relationship obtained in advance between the flatness of the surface to be inspected and the adjustment amount by the adjustment unit. Inspection equipment. The object is a mask for an exposure apparatus on which a pattern is formed,
A light blocking member that blocks a part of the inspection light,
A light-shielding adjustment unit that adjusts the position of the light-shielding member,
Further having
The foreign matter inspection apparatus according to claim 2, wherein the control unit further controls the light blocking adjustment unit so that the inspection light does not reach the position of the pattern.   The foreign matter inspection device according to claim 7, wherein the control unit controls the light blocking adjustment unit in response to controlling the adjustment unit. An exposure apparatus that exposes the substrate by projecting a mask pattern onto the substrate,
An exposure apparatus, comprising: the foreign matter inspection apparatus according to any one of claims 1 to 8, which inspects foreign matter attached to a surface of a light-transmitting plate-shaped member disposed in the exposure apparatus.   The exposure apparatus according to claim 9, wherein the plate-shaped member includes a glass plate disposed on the mask and spaced apart from the mask, and for correcting a deflection of the mask.   The exposure apparatus according to claim 9, wherein the plate member includes a pellicle for protecting the pattern of the mask. A step of exposing a substrate using the exposure apparatus according to any one of claims 9 to 11,
Developing the exposed substrate in the step,
And manufacturing an article from the developed substrate.

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