JPWO2009031605A1 - Workpiece defect inspection apparatus and optical member manufacturing method using the same - Google Patents

Abstract

In a work defect inspection apparatus applied to an optical member such as a glass lens, an invisible defect included in the optical member can be inspected. The workpiece defect inspection apparatus 1 includes a light source 5 having an arbitrary wavelength within a range of 120 to 380 nm as a measurement wavelength and a diffusion optical system 9 that diffuses light emitted from the light source 5. Further, a collimator 12 that converts the light diffused by the diffusion optical system 9 into a parallel light flux and a work holding device 20 that holds the work 19 on the optical axis of the light emitted from the light source 5 are provided. Further, the ultraviolet light imaging system 15 that guides ultraviolet light to the ultraviolet light CCD camera 16 out of the light transmitted through the work 19 held by the work holding device 20 and light other than ultraviolet light to the fluorescent CCD camera 18. And a fluorescence imaging system 17. Thereby, an invisible defect in the workpiece 19 can be detected.

Description

  The present invention relates to a workpiece defect inspection apparatus for inspecting the presence of an optical defect in a workpiece (an optical material before processing) for manufacturing an optical member such as a glass lens, and an optical member manufacturing method using the workpiece defect inspection apparatus.

In an optical material for manufacturing an optical member, impurities (foreign matter) such as copper, sodium, and chlorine are mixed or remain in the manufacturing process, and defects may be caused due to the impurities. In order to extend the lifetime of the optical member and improve the transmittance (ratio of the amount of emitted light to the amount of incident light), it is necessary to remove such defects. Conventionally, defects in such optical materials have been visually inspected (see, for example, Patent Document 1).
JP 2004-54285 A

  However, with visual inspection, visible defects can be inspected, but invisible defects cannot be inspected. Therefore, depending on the use of the optical member, there may be a case where a defect on the product becomes obvious due to such an invisible defect. For example, in an apparatus that irradiates an optical member with ultraviolet light, such as a semiconductor exposure apparatus, if there is a defect in the optical member, the ultraviolet light is locally absorbed by the defective portion, causing the optical member to malfunction. Uniform exposure may be impaired.

  In view of such circumstances, the present invention is capable of inspecting invisible defects contained in an optical member so that the function as an optical member can be fully exhibited even for applications irradiated with ultraviolet light. An object of the present invention is to provide a possible workpiece defect inspection apparatus and a method for manufacturing an optical member using the workpiece defect inspection apparatus.

  According to the first aspect of the present invention, the light source (5) that emits light having a wavelength in the range of 120 to 380 nm, the diffusion optical system (9) that diffuses the light emitted from the light source, and the diffusion A collimator (12) for converting the light diffused by the optical system into a parallel light beam, a work holder (20) for holding the work (19) on the optical axis (optical path) of the light emitted from the light source, and the work holding Workpiece provided with an ultraviolet light detector (16) for detecting ultraviolet light transmitted through the work held by the tool and an ultraviolet light imaging system (15) for guiding the ultraviolet light transmitted through the work to the ultraviolet light detector A defect inspection apparatus (1) is provided.

  According to the second aspect of the present invention, the light source (5) that emits ultraviolet light, the holder (20) that holds the workpiece movably with respect to the ultraviolet light, and the workpiece holder held by the workpiece. A detector (16) for detecting the ultraviolet light transmitted through the workpiece, and detecting defects in the workpiece while moving the workpiece with respect to the ultraviolet light by the holder (20). A defect inspection apparatus (1) for obtaining a three-dimensional distribution of defects is provided.

  According to a third aspect of the present invention, there is provided a method for manufacturing an optical member by processing a workpiece (19), the workpiece preparing step (S1) for preparing the workpiece, and cutting the workpiece into a desired shape. The workpiece cutting step (S2), the workpiece polishing step (S3) for polishing the workpiece to have a predetermined transmittance, and the workpiece defect inspection apparatus (1) according to the present invention are used to inspect defects of the workpiece. An optical member manufacturing method including a defect inspection step (S4) is provided.

  According to a fourth aspect of the present invention, there is provided a method for manufacturing an optical member by processing a workpiece (19), the workpiece preparing step (S1) for preparing the workpiece, and cutting the workpiece into a desired shape. A workpiece cutting step (S2), a workpiece polishing step (S3) for polishing the workpiece to have a predetermined transmittance, and a workpiece defect inspection apparatus (1) according to the present invention to inspect defects in the workpiece. And a defect inspection step (S4) for measuring a three-dimensional distribution.

  According to a fifth aspect of the present invention, there is provided a method for manufacturing an optical member by processing a workpiece (19), wherein a workpiece preparing step (S1) for preparing a workpiece cut in a plate shape in advance, and the workpiece An optical member comprising: a workpiece polishing step (S3) for polishing the workpiece so as to have a predetermined transmittance; and a defect inspection step (S4) for inspecting a defect of the workpiece using the workpiece defect inspection apparatus (1) according to the present invention. A manufacturing method is provided.

  According to a fifth aspect of the present invention, there is provided a method for manufacturing an optical member by processing a workpiece (19), wherein a workpiece preparing step (S1) for preparing a workpiece cut in a plate shape in advance, and the workpiece A workpiece polishing step (S3) for polishing the workpiece so as to have a predetermined transmittance, and a defect inspection step for measuring a three-dimensional distribution by inspecting a defect of the workpiece using the workpiece defect inspection apparatus (1) according to the present invention ( A method for manufacturing an optical member including S4) is provided.

  In the above description, in order to explain the present invention in an easy-to-understand manner, the description has been made in association with the reference numerals of the drawings representing the embodiments. However, the present invention is not limited to the embodiments.

  According to the present invention, since an invisible defect in a workpiece can be detected, the function as an optical member can be fully exhibited even for applications where ultraviolet light is irradiated. In particular, since the position of an invisible defect in a workpiece can be accurately identified three-dimensionally, high-quality optics used in an application in which such a defect is reliably removed and ultraviolet light is irradiated. A member can be provided.

It is a horizontal sectional view which shows the workpiece | work defect inspection apparatus which concerns on Embodiment 1 of this invention. It is a perspective view of the workpiece | work which concerns on the same Embodiment 1. 2A and 2B are schematic diagrams illustrating an imaging state of a workpiece according to the first embodiment, where FIG. 3A is a diagram in the case where the surface of the workpiece is focused, and FIG. FIG. It is a perspective view which shows an example of the workpiece holding apparatus of the workpiece | work defect inspection apparatus of this invention. It is a flowchart explaining the manufacturing method of the optical member using the workpiece | work defect inspection apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Work defect inspection apparatus, 2 ... Airframe, 3 ... Lamp box, 4 ... Aperture, 5 ... Light source, 6 ... Reflector, 7 ... Housing, 9 ... Diffuse optical system, 9a ... ... concave lens, 10 ... light guide, 12 ... collimator, 13 ... spectroscopic mirror, 15 ... ultraviolet light imaging system, 15a ... reflection mirror, 15b ... reflection mirror, 16 ... CCD camera for ultraviolet light ( Ultraviolet light detector), 17 …… Fluorescence imaging system, 17a …… Reflection mirror, 17b, 17c …… Reflection mirror, 18 …… CCD camera for fluorescence (fluorescence detector), 19 …… Work, 19a, 19b… ... surface, 19c ... inside, 20 ... work holding device (work holder), 31 ... grip arm, 37 ... X stage, 35 ... Y stage, 33 ... Z stage, F1, F2, F3 ... Defects, M1, M2, M3, N1, N2, N3 ...... defect image of the thickness of T1 ...... workpiece

Embodiments of the present invention will be described below.
Embodiment 1 of the Invention

  A first embodiment of the workpiece defect inspection apparatus 1 of the present invention shown in FIGS. 1 to 3 will be described. As shown in FIG. 1, the workpiece defect inspection apparatus 1 includes a machine body 2 including a lamp box 3 that houses a light source 5 and a housing 7 that houses an optical system and a detector. A lamp box 3 is installed on the airframe 2, and heat radiation openings 4 are formed in the lamp box 3 at two locations. A light source 5 is placed in the lamp box 3, and a reflector (reflecting plate) 6 is installed behind the light source 5. Here, as the wavelength of the light emitted from the light source 5, any wavelength belonging to the range of 120 to 220 nm can be selected according to the absorption band of the defect to be detected. As a specific example of the light source 5, an Xe excimer lamp, an ArF excimer laser, a mercury lamp, or a D2 lamp having a center wavelength of 172 nm can be used. When a light source that generates light having a continuous wavelength, such as a mercury lamp or a D2 lamp, is used, the wavelength necessary for the inspection may be selected appropriately using a filter. Or the lamp box 3 which accommodates the light source which produces the light of a different wavelength may be prepared, and the lamp box 3 may be replaced according to the optical member to test | inspect. A cylindrical light guide 10 is attached to the light source 5 in such a manner as to extend horizontally between the lamp box 3 and the housing 7.

  As shown in FIG. 1, a housing 7 is installed on the body 2, and in the housing 7, as shown in FIG. 1, a diffusion optical system 9, a collimator 12, a spectroscopic mirror 13, an ultraviolet light are provided. An imaging system 15, an ultraviolet light CCD (charge coupled device) camera (ultraviolet light detector) 16, a fluorescent imaging system 17, a fluorescent CCD camera (fluorescence detector) 18, and a work holding device 20 are mounted. .

  The diffusing optical system 9 includes a concave lens 9 a fitted to the housing 7, and diffuses the ultraviolet light 50 that has passed through the light guide 10. The ultraviolet light imaging system 15 includes a spectroscopic mirror 13, a concave lens-like reflection mirror 15 a, and a plate-like reflection mirror 15 b, and causes the CCD camera 16 to form an image of the ultraviolet light transmitted through the work 19. The fluorescence imaging system 17 includes a concave lens-shaped reflection mirror 17 a and two flat reflection mirrors 17 b and 17 c, and causes the CCD camera 18 to image the fluorescence generated from the work 19. The spectroscopic mirror 13 reflects light having a wavelength of 165 to 185 nm (deep ultraviolet light) by 90% or more and has a wavelength separation characteristic of transmitting 95 to 99% of light in other wavelength regions (less than 165 nm or more than 185 nm). is doing.

  Further, as shown in FIG. 1, a work holding device (work holding tool) 20 is provided at a predetermined position between the collimator 12 and the spectroscopic mirror 13. Here, the predetermined position is a position where a position conjugate with the light receiving surface of the ultraviolet CCD camera 16 is within the work 19 in a state where the work 19 is held by the work holding device 20. As shown in FIG. 2, the work holding device 20 can detachably hold a rectangular parallelepiped work 19 having a thickness T1 (for example, T1 = 150 mm). As shown in FIG. 4, the work holding device 20 is engaged with a U-shaped arm 31 that holds both sides of the work 19 and an engaging portion (not shown) provided on the arm 31 and extends in the X direction. An X stage 37 formed with an existing guide groove 37a, and a Z stage formed with a guide groove 33a that engages with an engaging portion (not shown) provided on the back of the X stage 37 and extends in the Z direction. 33 and a pair of Y stages 35 each formed with a guide groove 35a that engages with an engaging portion (not shown) provided at the bottom of the Z stage 33 and extends in the Y direction. The guide grooves 33a, 35a, and 37a accommodate ball screws (not shown) that are engaged with screw holes (not shown) of engaging portions provided in the X stage 37, the Z stage 33, and the arm 31, respectively. ing. By driving these ball screws by a driving device (not shown), the gripping arm 31 is moved on the X stage 37, the Y stage 35, and the Z stage 33, whereby the workpiece 19 is moved with respect to the ultraviolet light 50. Can be moved in the X, Y and Z directions. A linear motor can be used in place of the ball screw. The Z stage 33 can move the work 19 in the optical axis (optical path of ultraviolet light) direction (Z direction) by a first stroke (for example, 200 mm). The X stage 37 and the Y stage 33 light the work 19 Each can move by a second stroke (for example, 250 mm) in a direction (X direction and Y direction) orthogonal to the axis. The first stroke is a stroke including a range in which the position conjugate with the light receiving surface of the ultraviolet CCD camera 16 extends from one surface 19a of the work 19 to the other surface 19b through the interior 19c. On the other hand, the second stroke refers to the movement of the work 19 in the X direction and the Y direction when the cross section of the light that has been converted into a parallel light beam by the collimator 12 is smaller than the cross section of the work 19 in the defect inspection process described later This stroke is necessary to irradiate the entire surface of the work 19 with this light.

  The casing 7 is sealed, and the inside thereof is in a state where the oxygen concentration is extremely low by nitrogen purge in order to prevent foreign matters generated by ultraviolet light from adhering to the workpiece.

The operation of inspecting the defect of the workpiece 19 using the workpiece defect inspection apparatus 1 having the above-described configuration and the procedure of manufacturing an optical member made of synthetic quartz glass (SiO ₂ ) using the operation will be described with reference to FIG. However, it will be described below.

  First, in a work preparation step (S1), a quartz glass ingot is synthesized by a known method. For example, a gas containing a silicon compound raw material gas such as silicon tetrachloride or an organosilicon compound, a combustion-supporting gas such as oxygen, or a combustion gas such as hydrogen is ejected from a multi-tube burner, and the reaction is performed in a flame. And deposit and melt glass particles on the rotating target. Then, a cylindrical quartz glass ingot is obtained as the ingot. In addition, it is also possible to employ the synthesis method disclosed in JP-A-10-279319 and JP-A-11-292551.

  Next, the process proceeds to a workpiece cutting step, and this quartz glass is cut into a desired shape (for example, a rectangular parallelepiped shape, a cylindrical shape, etc.) and size using a band saw or a blade (S2).

  Thereafter, the process proceeds to a workpiece polishing step, and the surface of the quartz glass is polished. At this time, the surface roughness is set such that the quartz glass has a predetermined transmittance (for example, 50% or more) (S3).

  Next, the process proceeds to a defect inspection process, and a defect in the quartz glass is inspected using the workpiece defect inspection apparatus 1 as described below (S4). This quartz glass is attached to the grip arm 31 of the work holding device 20 as a work 19, and deep ultraviolet light (DUV) having a center wavelength of 172 nm is emitted from the light source 5. As shown in FIG. 1, this deep ultraviolet light reaches the housing 7 from the lamp box 3 through the light guide 10, diffuses without impairing the illuminance uniformity by the concave lens 9 a of the diffusion optical system 9, and is predetermined by the collimator 12. Then, the light beam passes through the work 19 and reaches the spectroscopic mirror 13. Then, most of the deep ultraviolet light is reflected by the spectroscopic mirror 13, reflected by the reflecting mirror 15a of the ultraviolet light imaging system 15, converged, reflected by the reflecting mirror 15b, and then the CCD camera 16 for ultraviolet light. To form an image. By driving the X stage 37 and the Y stage 35 of the work holding device 20, for example, a two-dimensional image in a range of 100 mm × 100 mm can be acquired. Therefore, as shown in FIG. 2, when there are defects F1, F2, and F3 on the surfaces 19a and 19b and the interior 19c of the workpiece 19, the portions corresponding to the defects F1, F2, and F3 in the image of the CCD camera 16 for ultraviolet light. Appears as a dark shadow. As a result, for the defects F1, F2, and F3, the position of the workpiece 19 in the XY coordinates is found, and the two-dimensional distribution of the defects can be measured.

  However, in this case, even though the two-dimensional distribution in the XY coordinates of the defects F1, F2, and F3 can be measured, the depths (positions in the Z direction) of the defects F1, F2, and F3 are unknown, so the defects F1, F2, The three-dimensional distribution of F3 cannot be measured. Therefore, the workpiece 19 is scanned in the optical axis direction (Z direction) by the Z stage 33, and as shown in FIG. 3, the contrasts for the images M1, M2, M3, N1, N2, and N3 of the defects F1, F2, and F3 are obtained. By checking the change in quality, it is possible to determine the depth of the defects F1, F2, and F3 and measure the three-dimensional distribution.

  That is, in order to determine the depths of the defects F1, F2, and F3, the work 19 is moved to the first position in the optical axis direction (Z direction) by the work holding device 20. When the surface 19a of the work 19 is in focus, as shown in FIG. 3A, the contrast of the images M1 and M2 of the two defects F1 and F2 on the surface 19a of the work 19 is improved, and the work 19 As for the image M3 of the defect F3 in the inside 19c, the contrast is deteriorated. When the work holding device 20 moves the work 19 from the first position in the optical axis direction (Z direction) to the second position, when the inside 19c of the work 19 is in focus, as shown in FIG. The contrasts of the images N1 and N2 of the two defects F1 and F2 on the surface 19a of the work 19 are deteriorated, and the contrast of the image N3 of the defect F3 in the interior 19c of the work 19 is improved. Therefore, the depths of the defects F1, F2, and F3 are determined based on the change in the quality of the contrast, and the defects F1 and F2 on the surface 19a of the work 19 and the defect F3 on the inside 19c of the work 19 are distinguished. be able to. As a result, the three-dimensional distribution of the defects F1, F2, and F3 can be measured together with the positions of the defects F1, F2, and F3 in the XY coordinates.

  In addition, since the workpiece | work 19 has predetermined | prescribed transmittance | permeability, the defect inspection of the workpiece | work 19 can be performed smoothly. In addition, since the inside of the housing 7 is in a state where the oxygen concentration is extremely low as described above, the absorption of deep ultraviolet light by oxygen is greatly suppressed, and the deep ultraviolet light is efficiently irradiated inside the housing 7. can do.

  Further, the defects in the work 19 include not only those that absorb only the deep ultraviolet light but do not emit fluorescence when the work 19 is irradiated with deep ultraviolet light (non-fluorescent defects). One that absorbs ultraviolet light and emits fluorescence at the same time (fluorescent defect) is assumed. With regard to the fluorescent defect, after the fluorescence passes through the spectroscopic mirror 13, it is reflected by the reflection mirror 17a of the fluorescence imaging system 17. The light is reflected and converged, sequentially reflected by the two reflecting mirrors 17b and 17c, and then reaches the fluorescent CCD camera 18 to form an image. Therefore, as shown in FIG. 2, when there are defects F1, F2, and F3 on the surfaces 19a and 19b and the interior 19c of the work 19, the image corresponding to the defects F1, F2, and F3 is present in the image of the fluorescent CCD camera 18. Shines brightly. As a result, it is possible to estimate the causal component of the defect in the work 19 also from the image taken by the fluorescent CCD camera 18. Therefore, it is possible to comprehensively analyze and judge defects in the work 19 by combining with reference to an image taken by the fluorescent CCD camera 18 in addition to an image taken by the ultraviolet CCD camera 16. Becomes easy.

  When defects F1, F2, and F3 are found in the workpiece 19 in the defect inspection process, the process proceeds to a defect removal process, and the defects F1, F2, and F3 are appropriately removed to complete the optical member (S5). That is, as shown in FIG. 2, when there are defects F1 and F2 on the surface 19a of the work 19, the defects F1 and F2 are removed by polishing the surfaces 19a and 19b of the work 19, for example. Further, when there is a defect F3 in the inside 19c of the work 19, for example, the defect F3 is removed by excising a part including the defect F3 from the work 19. Then, a high-quality optical member that does not include the defects F1, F2, and F3 is obtained. Here, the production of the optical member made of synthetic quartz glass is completed.

  As described above, according to the first embodiment, invisible defects F1, F2, and F3 included in the optical member can be inspected and removed. The optical member from which defects have been removed in this manner can fully exhibit its function even in an apparatus (such as a semiconductor exposure apparatus) that irradiates the optical member with ultraviolet light.

  In addition, since the work holding device 20 can move the work 19 by a predetermined second stroke in a direction orthogonal to the optical axis, the entire surface of the work 19 can be inspected.

  In the first embodiment described above, the case where the optical member is manufactured is shifted from the defect inspection process to the defect removal process. However, in the case where the workpiece 19 is used as an optical member such as a photomask, after the defect inspection process (before or after the defect removal process) in order to further improve the flatness of the surfaces 19a and 19b of the workpiece 19. Then, the process proceeds to a grinding / polishing process, and the surfaces 19a and 19b of the workpiece 19 are ground and polished. As the grinding / polishing method, a known method (for example, a processing method using a polishing apparatus disclosed in Japanese Patent Application Laid-Open No. 2007-98542 or Japanese Patent Application Laid-Open No. 2007-98543) can be used.

[Embodiment 2 of the Invention]
Below, the manufacture example of the photomax for liquid crystal pattern formation is demonstrated. First, a quartz glass substrate (optical member) having an optical surface polished to a predetermined flatness is prepared. After washing the quartz glass substrate with pure water, the quartz glass substrate is held by the work holding device 20 of the work defect inspection apparatus 1 described in the first embodiment, and defects are inspected in the same manner as in the first embodiment. Next, if a defect exists in the quartz glass substrate, it is removed by the method described in the first embodiment. Next, after the quartz glass substrate is washed, a chromium (Cr) film is formed on one surface of the quartz glass substrate by sputtering. Although there is a portion that is shielded by the member that holds the quartz glass substrate and the chromium film is not formed, a chromium film may be formed at portions other than the shielded portion.

  A resist (liquid) is applied to the surface on which the chromium film is formed. As the resist, for example, a novolac resin (AZ 1500, AZP 1500 from AZ) or the like can be used as a positive resist. According to the pattern to be formed, the resist is partially irradiated while scanning the laser beam. After the laser light irradiation, an alkaline solution is brought into contact with the resist on the substrate to remove the resist and the chromium film and form a pattern. In the case of a positive resist, the portion exposed to laser light is etched away with an alkaline solution. As the wavelength of the laser beam to be irradiated, a 413 nm laser or the like can be used. This resist coating and etching are repeated according to the pattern to be formed, and a predetermined pattern of chromium is formed on one surface of the quartz glass substrate. After the pattern formation, the substrate may be washed with pure water to inspect the formed pattern. When a defect is detected in the pattern by inspection, laser repair is performed to remove an unnecessary portion of the pattern or add a light shielding member, thereby completing the pattern and completing the photomask.

  In the photomask manufacturing example, an antioxidant film such as chromium oxide (CrO) or an antireflection film may be further provided on the chromium film. Moreover, although the photomask for liquid crystals was manufactured in the said manufacture example, you may manufacture the photomask for semiconductors using this invention. In this case, after forming a chromium film, a pattern may be formed using an electron beam instead of laser irradiation. For example, when forming a halftone pattern, it is possible to use MoSi as the light shielding film.

  In the first and second embodiments described above, the case where the ultraviolet CCD camera 16 is used as the ultraviolet detector has been described. However, an ultraviolet detector other than the ultraviolet CCD camera 16 (for example, a line sensor or other image). Sensor) can be substituted.

  In the first and second embodiments described above, the diffusing optical system 9 including the concave lens 9a has been described. However, a diffraction grating, an optical fiber, a diffusing film, a diffusing plate, or the like may be used instead of the concave lens 9a.

  Further, in the first and second embodiments described above, when moving the focal point of the deep ultraviolet light to clarify the defect depth (position in the optical axis direction) of the work 19, the work 19 is moved in the optical axis direction. However, it is also possible to substitute a method in which the ultraviolet light CCD camera 16 is advanced and retracted while the work 19 is fixed. Moreover, although the workpiece | work holding | maintenance apparatus 20 was illustrated in FIG. 4, the mechanism which hold | maintains and moves the workpiece | work 19 is not limited to those illustrations, Arbitrary mechanisms can be employ | adopted. Since the work holding device 20 can move the work 19 in a direction orthogonal to the optical axis by the X stage 33 and the Y stage 35, the entire surface of the work 19 can be scanned with ultraviolet light. Further, a parallel light beam having a predetermined spread (for example, parallel light from a surface light source) may be incident on the workpiece. By doing so, the same function as that of the apparatus shown in FIG. 1 can be achieved without using the diffusion optical system 9 and the collimator 12.

Moreover, in Embodiment 1 and 2 mentioned above, the case where the synthetic quartz glass-made optical member was manufactured was demonstrated. However, the material of the optical member is not limited to synthetic quartz glass, but may be fused quartz glass (oxyhydrogen flame fused quartz glass, electrofused quartz glass). Further, it may be a crystal such as rubidium aluminum garnet (LuAG) or fluoride (for example, CaF ₂ (calcium fluoride, fluorite), BaLiF ₃ ) used in lithography of 200 nm or less.

  Moreover, although Embodiment 1 and 2 mentioned above demonstrated the case where the light source 5 which makes the arbitrary wavelength which belongs in the range of 120-220 nm the measurement wavelength was used, the measurement wavelength of the light source 5 was extended to the long wavelength side. The light source 5 having an arbitrary wavelength within the range of 120 to 380 nm as a measurement wavelength can be substituted.

  In the first embodiment described above, the manufacturing method starting from the synthesis of the quartz glass ingot has been described. However, the synthetic quartz glass ingot is previously cut into a plate shape (that is, the surface to be inspected is planar). It is also possible to start from the process of preparing the workpiece 19.

  In the first and second embodiments described above, the manufacturing method has been described in which the defect removal process is performed when defects F1, F2, and F3 are found in the workpiece 19 in the defect inspection process. However, the defect removal process is omitted. Is also possible.

  The present invention is extremely useful for inspecting defects in optical members irradiated with ultraviolet light such as an ArF excimer laser having an oscillation wavelength of 193 nm.

Claims (20)

A light source that emits light having a wavelength in the range of 120 to 380 nm;
A diffusion optical system for diffusing the light emitted from the light source;
A collimator that collimates the light diffused by the diffusion optical system;
A workpiece holder for holding a workpiece for an optical member on the optical axis of the light emitted from the light source;
An ultraviolet light detector for detecting ultraviolet light transmitted through the workpiece held by the workpiece holder;
A work defect inspection apparatus comprising: an ultraviolet light imaging system that guides ultraviolet light transmitted through the work to an ultraviolet light detector.   The workpiece according to claim 1, wherein the workpiece holder is provided so as to be movable in an optical axis direction so that a position conjugate with the ultraviolet light detector is within the workpiece held by the workpiece holder. Defect inspection equipment.   The workpiece defect inspection apparatus according to claim 1, wherein the ultraviolet light detector measures a two-dimensional distribution of defects in the workpiece.   The workpiece according to any one of 1 to 3, further comprising a fluorescence detector and a fluorescence imaging system that guides a part of the light transmitted through the workpiece held by the workpiece holder to the fluorescence detector. Defect inspection equipment.   The said light source is a workpiece | work defect inspection apparatus as described in any one of Claims 1-4 which radiate | emits the light within the range of 120-220 nm.   The work defect inspection apparatus according to claim 1, wherein the work holder is provided so as to be movable in a direction intersecting the optical axis. A light source that emits ultraviolet light;
A workpiece holder for holding the workpiece movably with respect to the ultraviolet light;
A detector for detecting the ultraviolet light transmitted through the workpiece held by the workpiece holder, and detecting defects present in the workpiece while moving the workpiece with respect to the ultraviolet light by the workpiece holder. A defect inspection apparatus for obtaining a three-dimensional distribution of defects in a workpiece.   Furthermore, the defect inspection apparatus of Claim 7 provided with the fluorescence detector which detects the fluorescence which generate | occur | produced when ultraviolet light passes a workpiece | work.   The defect inspection apparatus according to claim 7, wherein the depth of the defect in the workpiece is obtained by observing the contrast of the defect image while moving the workpiece along the optical path of the ultraviolet light with respect to the ultraviolet light.   The defect inspection apparatus according to claim 7, wherein a two-dimensional distribution of defects in the workpiece is obtained by observing an image of the defect while moving the workpiece perpendicularly to an optical path of ultraviolet light with respect to ultraviolet light. A method of manufacturing an optical member by processing a workpiece,
A workpiece preparation step of preparing the workpiece;
A workpiece cutting step of cutting the workpiece into a desired shape;
A workpiece polishing step of polishing the workpiece to have a predetermined transmittance;
The manufacturing method of an optical member including the defect inspection process of inspecting the defect of the said workpiece | work using the workpiece | work defect inspection apparatus as described in any one of Claims 1-10. A method of manufacturing an optical member by processing a workpiece,
A workpiece preparation step of preparing the workpiece;
A workpiece cutting step of cutting the workpiece into a desired shape;
A workpiece polishing step of polishing the workpiece to have a predetermined transmittance;
A method for manufacturing an optical member, comprising: a defect inspection step of measuring a three-dimensional distribution by inspecting a defect of the workpiece using the workpiece defect inspection apparatus according to claim 6. A method of manufacturing an optical member by processing a workpiece,
A workpiece preparation step of preparing a workpiece cut in advance in a plate shape;
A workpiece polishing step of polishing the workpiece to have a predetermined transmittance;
The manufacturing method of an optical member including the defect inspection process of inspecting the defect of the said workpiece | work using the workpiece | work defect inspection apparatus as described in any one of Claims 1-10. A method of manufacturing an optical member by processing a workpiece,
A workpiece preparation step of preparing a workpiece cut in advance in a plate shape;
A workpiece polishing step of polishing the workpiece to have a predetermined transmittance;
A method for manufacturing an optical member, comprising: a defect inspection step of measuring a three-dimensional distribution by inspecting a defect of the workpiece using the workpiece defect inspection apparatus according to claim 6.   Furthermore, the manufacturing method of the optical member as described in any one of Claims 11-14 including the defect removal process of removing the said defect, when a defect is found in the said workpiece | work.   The optical member is a photomask, and further includes a step of providing a metal film on one surface of the work and a step of forming a metal film pattern by removing a part of the metal film. A method for producing an optical member according to claim 1.   The said transmittance | permeability is 50% or more, The manufacturing method of the optical member as described in any one of Claims 11-16.   The method of manufacturing an optical member according to any one of claims 11 to 17, wherein a material of the optical member is synthetic quartz glass.   The method for producing an optical member according to claim 11, wherein a material of the optical member is calcium fluoride.   The method of manufacturing an optical member according to any one of claims 11 to 17, wherein a material of the optical member is a fluoride crystal that can transmit deep ultraviolet light.

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