Inspection device, inspection method, and inspection program

Abstract

The present invention comprises: a light irradiation unit 2 that irradiates a light-transmissive and film-like test object W with inspection light L1; a scattered light detection unit 3 for detecting scattered light L2 which is produced from the test object W; a diffracted light detection section 4 for detecting diffracted light L3 which is produced from the test object W; and a signal processing unit 5 that determines, on the basis of a scattered light intensity signal from the scattered light detection unit 3 and a diffracted light intensity signal from the diffracted light detection unit 4, the presence or absence of foreign matter S which has adhered to the test object W and the presence or absence of a pinhole P which has been formed in the test object W.

Description

Inspection device, inspection method, and inspection program

[0001] The present invention relates to an inspection device, an inspection method, and an inspection program.

[0002] For example, a foreign matter inspection device for inspecting foreign matters adhering to a film-like test object such as a pellicle is disclosed in Patent Document 1. This foreign matter inspection device projects light onto the surface of the test object and detects the intensity of the scattered light from the surface, thereby detecting foreign matters adhering to the surface of the test object.

[0003] On the other hand, film-like test objects such as pellicles may have holes (pinholes) that penetrate from the front surface to the back surface, and it is conceivable that these pinholes could also be inspected using the above-mentioned foreign matter inspection device.

[0004] However, in the method of detecting the intensity of scattered light from the test object, it is difficult to distinguish between foreign matter adhering to the test object and pinholes formed in the test object.

[0005] Therefore, in order to identify pinholes, in addition to the above foreign body inspection, microscopic observation is performed using microscopes placed on both the front and back surfaces of the test object. By this microscopic observation, both the front and back surfaces of the test object are observed, and if similar images are observed on both surfaces, it can be determined that there is a pinhole.

[0006] However, the method of performing microscopic observation separately from the foreign substance inspection has the problem that it takes a long time to inspect the test object for foreign substances and pinholes.

[0007] JP 2011-53036 A

[0008] Therefore, the present invention has been made in consideration of the above-mentioned problems, and its main objective is to simultaneously determine the presence or absence of foreign matter and pinholes in a film-like test object that is light-transmitting.

[0009] That is, the inspection device according to the present invention is characterized by comprising a light irradiation unit that irradiates inspection light onto one side of a film-like test object having optical transparency, a scattered light detection unit that is arranged on the same side of the test object as the light irradiation unit and that detects scattered light generated from the test object, a diffracted light detection unit that is arranged on the other side of the test object opposite the light irradiation unit and that detects diffracted light generated from the test object, and a signal processing unit that determines whether or not there is foreign matter attached to the test object and whether or not there is a pinhole formed in the test object based on the scattered light intensity signal of the scattered light detection unit and the diffracted light intensity signal of the diffracted light detection unit.

[0010] With this foreign matter inspection device, the presence or absence of foreign matter attached to the test object and the presence or absence of pinholes formed in the test object can be automatically determined simultaneously based on the scattered light intensity signal from the scattered light detection unit and the diffracted light intensity signal from the diffracted light detection unit. Specifically, if a foreign matter is attached to the test object, the inspection light is irradiated onto the foreign matter, generating scattered light. The presence or absence of the foreign matter can be determined by detecting the scattered light. Furthermore, if a pinhole is formed in the test object, the inspection light passes through the pinhole, generating diffracted light. The presence or absence of the pinhole can be determined by detecting the diffracted light. However, if the device is configured to detect transmitted light, the test object is optically translucent, making it difficult to distinguish between transmitted light that has passed through the pinhole and light that has passed through the test object, making it difficult to determine the presence or absence of a pinhole. As described above, the inspection device of the present invention can automatically perform both foreign matter inspection and pinhole inspection of the test object, thereby significantly reducing the time required for foreign matter inspection and pinhole inspection and improving throughput.

[0011] In order to determine whether a foreign substance attached to the test object is attached to the front or back surface of the test object, it is desirable that the light irradiation unit has a first light irradiation unit that irradiates inspection light onto one side of the test object and a second light irradiation unit that irradiates inspection light onto the other side of the test object, the scattered light detection unit has a first scattered light detection unit arranged on the one side of the test object and a second scattered light detection unit arranged on the other side of the test object, and the signal processing unit determines whether the foreign substance is attached to the front or back surface of the test object based on the first scattered light intensity signal of the first scattered light detection unit and the second scattered light intensity signal of the second scattered light detection unit.

[0012] As a specific embodiment of the diffracted light detection unit, the diffracted light detection unit may be provided with a focusing optical system arranged to avoid the optical axis of the inspection light and for focusing the diffracted light, and a diffracted light detector for detecting the diffracted light focused by the focusing optical system. With this configuration, the focusing optical system is arranged to avoid the optical axis of the inspection light that has passed through the test object, thereby preventing erroneous determination due to detection of the inspection light that has passed through the test object (transmitted light).

[0013] A specific embodiment of the focusing optical system may include a reflecting mirror for changing the optical path of the diffracted light focused by the focusing mirror, and a light guide for focusing the diffracted light reflected by the reflecting mirror onto the light detection area of ​​the diffracted light detector. Changing the optical path of the focused diffracted light with the reflecting mirror allows for flexibility in the optical arrangement of the focusing optical system. As a result, physical interference with peripheral devices can be reduced, enabling the inspection device to be made more compact. Furthermore, the light guide allows the diffracted light focused in a line shape to be smoothly guided to the diffracted light detector.

[0014] As a specific embodiment of the focusing optical system, it is desirable that the focusing optical system is one for focusing diffracted light of first or higher orders, i.e., the focusing optical system is disposed at a position where it can focus diffracted light of first or higher orders.

[0015] In a specific embodiment of the light irradiation unit and the focusing optical system, the light irradiation unit preferably includes a scanning optical system that scans the inspection light in a predetermined direction relative to the test object, and the focusing optical system preferably includes a focusing mirror having a uniform cross-sectional shape along an axis parallel to the scanning direction of the inspection light. In this configuration, the relative positions of the scanning optical system and the focusing mirror are fixed, and it is possible to move the scanning optical system, the focusing mirror, and the test object relative to each other in a direction intersecting the scanning direction. In addition, the diffracted light focused by the focusing mirror having a uniform cross-sectional shape is linear.

[0016] In order to improve the efficiency of collecting diffracted light by the collecting mirror, it is desirable that the collecting mirror be an elliptical cylindrical concave mirror.

[0017] In order to reduce the influence of transmitted light through the test object, it is desirable that the light irradiation unit irradiates the test object with inspection light of a wavelength that provides a transmittance of 40% or less through the test object. The wavelength of the inspection light preferably provides a transmittance of 20% or less through the test object, more preferably 10% or less.

[0018] There is a risk that the inspection light will be scattered by the edge of the pinhole or the like and detected by the scattered light detection unit. For this reason, it is desirable that the scattered light detection unit include a polarizing filter that transmits the light scattered from the foreign object while cutting the light scattered from the pinhole, and a scattered light detector that detects the scattered light that has transmitted through the polarizing filter.

[0019] As a specific embodiment of the determination by the signal processing unit, it is desirable that the signal processing unit determines that the pinhole is present when the scattered light intensity signal is less than a predetermined value and the diffracted light intensity signal is equal to or greater than a predetermined value, and determines that the foreign matter is present when the scattered light intensity signal is equal to or greater than a predetermined value and the diffracted light intensity signal is less than the predetermined value.

[0020] The object to be inspected is preferably a pellicle, such as an EUV pellicle. Extreme ultraviolet (EUV) light sources are being used in semiconductor manufacturing exposure devices in response to the miniaturization of semiconductor integrated circuits. Extreme ultraviolet (EUV) light is easily absorbed by pellicles, so it is desirable for the pellicle to have a small film thickness (e.g., about 50 nm). Therefore, pinholes of about 1 μm, for example, are likely to form in EUV pellicles, making the inspection device of the present invention suitable for use.

[0021] Furthermore, the inspection method according to the present invention is characterized in that it irradiates an inspection light onto a film-like test object having optical transparency, detects scattered light generated from the test object, detects diffracted light generated from the test object, and determines whether or not there is any foreign matter attached to the test object and whether or not there is any pinhole formed in the test object based on the intensity signals of the scattered light and the diffracted light.

[0022] Furthermore, the inspection program of the present invention is an inspection program used in an inspection device having a light irradiation unit that irradiates inspection light onto a film-like test object having optical transparency, a scattered light detection unit that is arranged on the same side of the test object as the light irradiation unit and that detects scattered light generated from the test object, and a diffracted light detection unit that is arranged on the opposite side of the test object from the light irradiation unit and that detects diffracted light generated from the test object, and is characterized in that it provides a computer with the function of determining whether or not there is foreign matter attached to the test object and whether or not there is a pinhole formed in the test object based on the scattered light intensity signal of the scattered light detection unit and the diffracted light intensity signal of the diffracted light detection unit.

[0023] According to the present invention configured as described above, it is possible to simultaneously determine the presence or absence of foreign matter and pinholes in a film-like test object having optical transparency.

[0024] It is a schematic diagram showing an inspection device according to an embodiment of the present invention. It is a perspective view showing a diffracted light detection unit of the same embodiment. It is a schematic diagram showing a method of determining whether a foreign substance and a pinhole are present on the front surface or the back surface of the same embodiment.

[0025] <One embodiment of the present invention> Hereinafter, one embodiment of an inspection device according to the present invention will be described with reference to the drawings. Note that in all of the drawings shown below, parts are appropriately omitted or exaggerated for ease of understanding. Identical components are assigned the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0026] The inspection device 100 of this embodiment inspects foreign matter S adhering to a film-like test object W having optical transparency and pinholes P formed in the test object W.

[0027] Here, the film-like specimen W having optical transparency is a protective film (pellicle) that prevents foreign matter from adhering to a photomask during an exposure process, specifically, a protective film (EUV pellicle) that prevents foreign matter from adhering to a photomask during an exposure process using an extreme ultraviolet (EUV) light source. Note that the protective film is not limited to an EUV pellicle, and other pellicles may also be used. In the following, the back surface of the specimen W refers to the surface on the photomask side, that is, the surface facing the pattern. On the other hand, the front surface of the specimen W refers to the surface facing away from the photomask, that is, the outer surface.

[0028] As shown in FIG. 1, the inspection device 100 of this embodiment includes a light irradiation unit 2 that irradiates the test object W with inspection light L1, a scattered light detection unit 3 that detects scattered light L2 generated by the irradiation of the inspection light L1, a diffracted light detection unit 4 that detects diffracted light L3 generated by the irradiation of the inspection light L1, and a signal processing unit 5 that determines whether or not a foreign substance S is attached to the test object W and whether or not a pinhole P is formed in the test object W based on the scattered light intensity signal of the scattered light detection unit 3 and the diffracted light intensity signal of the diffracted light detection unit 4.

[0029] In this embodiment, the light irradiation unit 2, scattered light detection unit 3, and diffracted light detection unit 4 are fixed to an inspection pedestal (not shown). An EUV pellicle, which is the specimen W, is fixed to a holding frame 11, which can be moved linearly in one direction (the X direction in FIG. 1 ) relative to the inspection pedestal by a transport mechanism (transport stage) not shown. Therefore, a space is formed in the inspection pedestal through which the specimen W passes by the transport mechanism (transport stage).

[0030] The light irradiation unit 2 includes a first light irradiation unit 2 that irradiates one surface (here, the back surface) of an EUV pellicle, which is the test object W, with the inspection light L1, and a second light irradiation unit 2' that irradiates the other surface (here, the front surface) of the test object W with the inspection light L1. The first light irradiation unit 2 and the second light irradiation unit 2' have the same configuration, and the difference between them is whether the inspection light L1 is irradiated onto one surface of the test object W or the other surface.

[0031] The following description will be given representatively of the first light irradiating unit 2. Specifically, the first light irradiating unit 2 has a laser light source 21 that emits laser light, which is the inspection light L1, and a scanning optical system 22 that scans the laser light L1 from the laser light source 21 in a predetermined direction relative to the test object W. Here, the predetermined direction is a direction (Y direction) perpendicular to the transport direction (X direction) of the test object W in a horizontal plane. Note that the first light irradiating unit 2 is provided on the inspection stand below a space through which the test object W passes by the transport mechanism.

[0032] The laser light source 21 emits laser light L1 having a wavelength that provides a transmittance of 40% or less through the test object W. Here, the wavelength of the laser light L1 preferably provides a transmittance of 20% or less through the test object W, more preferably 10% or less.

[0033] The scanning optical system 22 has a scanning mirror (galvanometer mirror or polygon mirror) 221 that scans the laser light L1 from the laser light source 21 in the Y direction, and if necessary, a guide mirror 222 may be provided between the laser light source 21 and the scanning mirror 221, or a guide mirror 223 may be provided on the light emission side (the test object W side) of the scanning mirror 221. The scanning optical system 22 causes the laser light L1 to be incident on the back surface of the test object W.

[0034] The scattered light detection unit 3 is intended to detect scattered light L2 generated by irradiation with inspection light L1, and has a first scattered light detection unit 31 arranged on the back side of the test object W, and a second scattered light detection unit 32 arranged on the front side of the test object W.

[0035] The first scattered light detection unit 31 is disposed on the same side as the first light irradiator 2 with respect to the test object W. Specifically, the first scattered light detection unit 31 includes a first polarizing filter 311 for transmitting scattered light L2 from the foreign substance S while cutting out scattered light from the pinhole P, and a first scattered light detector 312 for detecting scattered light L2 transmitted through the polarizing filter 311. In this embodiment, a photomultiplier tube (PMT) is used as the first scattered light detector 312, but a photodiode, a CCD camera, a CMOS image sensor, or the like can also be used. The first scattered light detection unit 31 is disposed on the inspection stand below a space through which the test object W passes by the transport mechanism.

[0036] The second scattered light detection unit 32 is disposed on the other side of the test object W, opposite to the first light irradiation unit 2. Specifically, the second scattered light detection unit 32 includes a second polarizing filter 321 for transmitting scattered light L2 from the foreign substance S while cutting out scattered light from the pinhole P, and a second scattered light detector 322 for detecting scattered light L2 transmitted through the polarizing filter 321. In this embodiment, a photomultiplier tube (PMT) is used as the second scattered light detector 322, but a photodiode, a CCD camera, a CMOS image sensor, or the like can also be used. The second scattered light detection unit 32 is disposed on the inspection stand above a space through which the test object W passes by the transport mechanism.

[0037] The diffracted light detection unit 4 detects first-order or higher diffracted light L3, and in this embodiment, it detects second-order and third-order diffracted light. As shown in FIGS. 1 and 2 , the diffracted light detection unit 4 is disposed on the opposite side of the light irradiation unit 2 with respect to the test object W. Specifically, the diffracted light detection unit 4 is disposed to avoid the optical axis of the inspection light L1 (specifically, the optical path of the transmitted light L4 transmitted through the test object W) and includes a focusing optical system 41 for focusing the diffracted light L3 and a diffracted light detector 42 for detecting the diffracted light L3 focused by the focusing optical system 41. In this embodiment, a photomultiplier tube (PMT) is used as the diffracted light detector 42, but a photodiode, a CCD camera, a CMOS image sensor, or the like may also be used. The diffracted light detection unit 4 is disposed on the inspection stand above the space through which the test object W passes by the transport mechanism.

[0038] The focusing optical system 41 focuses the first-order or higher (second- and third-order in this embodiment) diffracted light L3 and includes a focusing mirror 411 having a uniform cross-sectional shape along an axis parallel to the scanning direction (Y direction) of the inspection light L1. The focusing mirror 411 is positioned to avoid the optical path of the transmitted light L4. The focusing mirror 411 in this embodiment is an elliptical cylindrical concave mirror, and its cross section perpendicular to the Y direction has a partial elliptical shape, and the cross-sectional shape is uniform along the Y direction. Here, it is desirable to position the elliptical cylindrical concave mirror so that one focus of the ellipse of the elliptical cylindrical concave surface is the irradiation position of the laser light L1 on the test object W. The focusing mirror 411 focuses the diffracted light L3 on a straight line to form a line-shaped light.

[0039] In addition, the focusing optical system 41 of this embodiment has a reflecting mirror 412 for changing the optical path of the diffracted light L3 focused by the focusing mirror 411, and a light guide 413 for focusing the diffracted light L3 reflected by the reflecting mirror 412 onto the optical detection area of ​​the diffracted light detector 42.

[0040] Here, the reflecting mirror 412 is disposed so as to reflect upward (here, vertically upward) the diffracted light L3 collected by the collecting mirror 411. The reflecting mirror 412 is also disposed at or near the other focal point of the ellipse of the collecting mirror 411.

[0041] 2, the light introduction ends of the optical fibers are arranged in a straight line on the light introduction side (the reflection mirror 412 side), and the light extraction ends of the optical fibers are arranged in a roughly circular bundle on the light extraction side (the diffracted light detector 42 side). The light guide 413 extends vertically upward, and guides the diffracted light L3 to the diffracted light detector 42 provided above the reflection mirror 412.

[0042] In this way, by using the reflecting mirror 412 and the light guide 413 to guide the diffracted light L3 focused by the focusing mirror 411 upward, it is possible to secure space on the inspection stand to install other equipment such as the second scattered light detection unit 32.

[0043] The signal processing unit 5 receives light intensity signals from the first scattered light detector 312, the second scattered light detector 322, and the diffracted light detector 42, and based on these light intensity signals, determines whether or not there is a foreign matter S attached to the test object W and whether or not there is a pinhole P formed in the test object W, and determines whether the foreign matter S is attached to the front or back surface of the test object W.

[0044] This signal processing unit 5 is a computer having a CPU, memory, input / output interface, AD converter, etc., and performs the function of inspecting foreign matter and pinholes by the CPU and peripheral devices working together based on an inspection program stored in the memory.

[0045] <Determining Whether a Foreign Substance S or a Pinhole P (See FIG. 3)> When the inspection light L1 is irradiated from the back side, the signal processing unit 5 determines that a pinhole P is present if the scattered light intensity signal (here, the larger of the first scattered light intensity signal and the second scattered light intensity signal) is less than a predetermined value and the diffracted light intensity signal is equal to or greater than a predetermined value. On the other hand, when the inspection light L1 is irradiated from the back side, the signal processing unit 5 determines that a foreign substance S is present if the scattered light intensity signal (here, at least one of the first scattered light intensity signal and the second scattered light intensity signal) is equal to or greater than a predetermined value and the diffracted light intensity signal is less than a predetermined value. Note that the predetermined value of the scattered light intensity signal and the predetermined value of the diffracted light intensity signal may be different from each other. In this way, the signal processing unit 5 determines whether a foreign substance S is attached to the test object W or whether a pinhole P has been formed in the test object W based on the scattered light intensity signal and the diffracted light intensity signal. If both the scattered light intensity signal and the diffracted light intensity signal are less than a predetermined value, it is determined that no foreign matter or pinhole is present, and if both the scattered light signal intensity and the diffracted light signal intensity are equal to or greater than a predetermined value, it is determined that a foreign matter is present.

[0046] <Determining Whether a Foreign Particle S is Located on the Front or Back Side (See FIG. 4)> When the light irradiator 2 irradiates the inspection light L1 from the back side, the signal processor 5 determines that a foreign particle S is located on the back side if the first scattered light intensity signal is equal to or greater than a predetermined value and the second scattered light intensity is less than a predetermined value. On the other hand, when the light irradiator 2′ (similar in configuration to the light irradiator 2) irradiates the inspection light L1 from the front side, the signal processor 5 determines that a foreign particle S is located on the front side if the first scattered light intensity signal is less than a predetermined value and the second scattered light intensity is equal to or greater than a predetermined value. Note that the predetermined values ​​of the first scattered light intensity signal and the second scattered light intensity signal may be different from each other. Note that when both the first scattered light intensity signal and the second scattered light intensity signal are less than the predetermined value, it is determined that no foreign particle is present. When both the first scattered light intensity signal and the second scattered light intensity signal are equal to or greater than a predetermined value, it is determined that a foreign particle is present in the larger of the two signals. Furthermore, when both the first scattered light intensity signal and the second scattered light intensity signal are saturated (saturation occurs), integration processing is performed and it is determined that a foreign substance is present in the signal with the larger signal (signal with the larger area).

[0047] Furthermore, the signal processing unit 5 can obtain position information (X coordinate, Y coordinate) of the determined foreign matter and position information (X coordinate, Y coordinate) of the determined pinhole from position information (X coordinate) obtained from the transport mechanism (transport stage) and position information (Y coordinate) obtained from the scanning optical system (scanning mirror).The signal processing unit 5 can then display the position information (X coordinate, Y coordinate) of the foreign matter and the position information (X coordinate, Y coordinate) of the pinhole on a display or other display unit 6.Possible modes for displaying on the display unit 6 include selectively mapping the foreign matter S, selectively mapping the pinhole P, or mapping both the foreign matter S and the pinhole P and displaying them in a distinguishable manner.

[0048] Effect of the Present Embodiment The inspection apparatus 100 of the present embodiment configured as described above can automatically determine the presence or absence of a foreign substance S attached to the test object W and the presence or absence of a pinhole P formed in the test object W, all at once, based on the scattered light intensity signals from the scattered light detectors 31 and 32 and the diffracted light intensity signal from the diffracted light detector 4. Specifically, if a foreign substance S is attached to the test object W, the inspection light L1 is irradiated onto the foreign substance S, generating scattered light L2. The presence or absence of the foreign substance S can be determined by detecting the scattered light L2. Furthermore, if a pinhole P is formed in the test object W, the inspection light L1 passes through the pinhole P, generating diffracted light L3. The presence or absence of the pinhole P can be determined by detecting the diffracted light L3. As described above, the inspection apparatus 100 of the present embodiment can automatically perform both foreign substance inspection and pinhole inspection of the test object W, thereby significantly reducing the time required for foreign substance inspection and pinhole inspection, and improving throughput.

[0049] <Other Embodiments> For example, the scattered light detection unit 3 may be configured to include only either the first scattered light detection unit 31 or the second scattered light detection unit 32. In this case, the signal processing unit 5 may not determine whether the foreign matter S is on the front surface or the back surface.

[0050] In the above embodiment, since the configuration includes the first light irradiation unit 2 and the second light irradiation unit 2′, the diffracted light detector 4 may be provided on one side (back side) of the test object W, in addition to the other side (front side) of the test object W. Furthermore, in the foreign matter inspection device 100, the front and back of the pellicle may be reversed.

[0051] Furthermore, the scattered light detector 3 may be configured without a polarizing filter.

[0052] Furthermore, the collecting mirror 411 of the collecting optical system 41 is an elliptical cylindrical concave mirror, but a collecting mirror having another shape may be used, or a collecting lens may be used instead of the collecting mirror 411.

[0053] Furthermore, although the light collecting optical system 41 has a configuration including the reflecting mirror 412 and the light guide 413, it may have a configuration without at least one of the reflecting mirror 412 and the light guide 413. Furthermore, the light guide 413 is not limited to a configuration using an optical fiber, and may use a light guiding member such as a rod lens.

[0054] Although each scattered light detection unit in the above embodiment has one scattered light detector, it may have a configuration in which each scattered light detector has multiple scattered light detectors. By providing multiple scattered light detectors in this way, if a signal is detected by any one of them, it can be determined to be a foreign object, which is expected to improve detection sensitivity.

[0055] Although the above embodiment distinguishes between foreign matter and pinholes, the pinhole inspection device may be configured to detect only pinholes by the following configuration: That is, the pinhole inspection device includes a light irradiation unit that irradiates an optically transparent film-like object to be inspected with inspection light, a diffracted light detection unit that is disposed on the opposite side of the object to the light irradiation unit and that detects diffracted light generated from the object, and a signal processing unit that determines the presence or absence of pinholes formed in the object based on a diffracted light intensity signal from the diffracted light detection unit.

[0056] In addition, various modifications and combinations of the embodiments may be made as long as they do not go against the spirit of the present invention.

[0057] According to the present invention, it is possible to simultaneously determine the presence or absence of foreign matter and pinholes in a film-like test object having optical transparency.

[0058] 100: Foreign substance inspection device W: Test object S: Foreign substance P: Pinhole 2: Light irradiation unit 21: Scanning optical system L1: Inspection light 3: Scattered light detection unit L2: Scattered light 31: First scattered light detection unit 32: Second scattered light detection unit 311, 321: Polarization filters 312, 322: Scattered light detector 4: Diffracted light detection unit L3: Diffracted light L4: Transmitted light 41: Light-collecting optical system 411: Collecting mirror 412: Reflecting mirror 413: Light guide 42: Diffracted light detector 5: Signal processing unit

Claims

1. A light irradiation unit that irradiates inspection light onto one surface of a film-like object to be inspected having light transmissivity; A scattered light detection unit that is disposed on the same surface side as the light irradiation unit with respect to the object to be inspected and detects scattered light generated from the object to be inspected; A diffracted light detection unit that is disposed on the other surface side opposite to the light irradiation unit with respect to the object to be inspected and detects diffracted light generated from the object to be inspected; An inspection apparatus comprising: a signal processing unit that determines the presence or absence of foreign matter attached to the object to be inspected and the presence or absence of pinholes formed in the object to be inspected based on the scattered light intensity signal of the scattered light detection unit and the diffracted light intensity signal of the diffracted light detection unit.

2. The light irradiation unit includes: A first light irradiation unit that irradiates inspection light onto one surface of the object to be inspected; A second light irradiation unit that irradiates inspection light onto the other surface of the object to be inspected, The scattered light detection unit includes: A first scattered light detection unit disposed on one surface side of the object to be inspected; A second scattered light detection unit disposed on the other surface side of the object to be inspected, The signal processing unit determines whether the foreign matter is attached to the front surface or the back surface of the object to be inspected based on the first scattered light intensity signal of the first scattered light detection unit and the second scattered light intensity signal of the second scattered light detection unit. The inspection apparatus according to claim 1.

3. The diffracted light detection unit includes: A condensing optical system that is disposed avoiding the optical axis of the inspection light and condenses the diffracted light; A diffracted light detector that detects the diffracted light condensed by the condensing optical system. The inspection apparatus according to claim 1 or 2.

4. The condensing optical system includes: A reflection mirror for changing the optical path of the diffracted light condensed by the condensing mirror; A light guide for focusing the diffracted light reflected by the reflection mirror onto the light detection region of the diffracted light detector. The inspection apparatus according to claim 3.

5. The light irradiation unit has a scanning optical system that scans the inspection light in a predetermined direction with respect to the object to be inspected; The condensing optical system has a condensing mirror having an equal cross-sectional shape along an axis parallel to the scanning direction of the inspection light. The inspection apparatus according to claim 3.

6. The condensing mirror is an elliptical cylinder concave mirror. The inspection apparatus according to claim 5.

7. The condensing optical system is for condensing diffracted light of the first order or higher. The inspection apparatus according to claim 3.

8. The light irradiation unit irradiates inspection light having a wavelength at which the transmittance with respect to the object to be inspected is 40% or less. The inspection apparatus according to claim 1 or 2.

9. The scattered light detection unit includes a polarization filter for cutting the scattered light from the pinhole while transmitting the scattered light from the foreign matter, and a scattered light detector for detecting the scattered light transmitted through the polarization filter. The inspection apparatus according to claim 1 or 2.

10. The signal processing unit determines that the pinhole exists when the scattered light intensity signal is less than a predetermined value and the diffracted light intensity signal is equal to or greater than the predetermined value, and determines that the foreign matter exists when the scattered light intensity signal is equal to or greater than the predetermined value and the diffracted light intensity signal is less than the predetermined value. The inspection apparatus according to claim 1 or 2.

11. The object to be inspected is a pellicle. The inspection apparatus according to claim 1 or 2.

12. Irradiate an inspection light on a film-shaped object to be inspected having light transmissivity, detect the scattered light generated from the object to be inspected, detect the diffracted light generated from the object to be inspected, and based on the intensity signal of the scattered light and the intensity signal of the diffracted light, determine the presence or absence of foreign matter attached to the object to be inspected and the presence or absence of pinholes formed in the object to be inspected. An inspection method.

13. An inspection program used for an inspection apparatus having a light irradiation unit that irradiates an inspection light on one surface of a film-shaped object to be inspected having light transmissivity, a scattered light detection unit that is disposed on the same one surface side as the light irradiation unit with respect to the object to be inspected and detects the scattered light generated from the object to be inspected, and a diffracted light detection unit that is disposed on the other surface side opposite to the light irradiation unit with respect to the object to be inspected and detects the diffracted light generated from the object to be inspected, the computer is caused to have a function of determining the presence or absence of foreign matter attached to the object to be inspected and the presence or absence of pinholes formed in the object to be inspected based on the scattered light intensity signal of the scattered light detection unit and the diffracted light intensity signal of the diffracted light detection unit. An inspection program.