WO2019208808A1 - Appearance inspecting device and appearance inspecting method - Google Patents

Appearance inspecting device and appearance inspecting method Download PDF

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Publication number
WO2019208808A1
WO2019208808A1 PCT/JP2019/018067 JP2019018067W WO2019208808A1 WO 2019208808 A1 WO2019208808 A1 WO 2019208808A1 JP 2019018067 W JP2019018067 W JP 2019018067W WO 2019208808 A1 WO2019208808 A1 WO 2019208808A1
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WO
WIPO (PCT)
Prior art keywords
main surface
defect
visual
large photomask
photomask
Prior art date
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PCT/JP2019/018067
Other languages
French (fr)
Japanese (ja)
Inventor
卓司 渡辺
慎一郎 村上
芳明 谷部
Original Assignee
大日本印刷株式会社
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Publication of WO2019208808A1 publication Critical patent/WO2019208808A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/956—Inspecting patterns on the surface of objects

Definitions

  • the present invention relates to an appearance inspection apparatus and an appearance inspection method used for appearance inspection of a large photomask.
  • photomasks are used for various pattern formations in, for example, a photolithography process at the time of manufacturing a flat panel display, a color filter or the like, more specifically, an exposure process.
  • a large-sized photomask may cause unevenness in the transfer pattern due to a slight shift in the line width and formation position of the transfer pattern from the design during the manufacturing process. Further, in the manufacturing process or the cleaning process, stains, dirt, foreign matters may adhere to the transfer pattern, and scratches may be formed. Such defects such as unevenness and stains may be easier to detect by using macro observation that is visually observed globally rather than by micro observation that observes the local area in detail with a microscope. For this reason, in inspection of these defects, for example, as described in Patent Document 1, macro observation is often performed using an appearance inspection apparatus.
  • an appearance inspection apparatus for performing macro observation an apparatus for inspecting a glass substrate for a liquid crystal display in addition to a large photomask is known.
  • Patent Documents 2 to 4 describe an appearance inspection apparatus for micro-observing defects detected by macro observation in this way.
  • the defect and its corrected part may be inspected again by macro observation.
  • the defect detected by micro observation and the corrected part thereof cannot be pointed out visually. For this reason, it is not easy to perform macro observation of the defect and the corrected part.
  • the main object of the present invention is to provide an appearance inspection apparatus and an appearance inspection method capable of obtaining a defect position with high accuracy in macro observation and pointing so that a defect detected by micro observation and a corrected portion thereof can be visually observed.
  • the present invention provides a visual designation means for indicating a visual designation position of a main surface of a large photomask designated based on visual observation, a visual designation information acquisition means for obtaining visual designation information, and Two-dimensional coordinate calculation means for calculating the two-dimensional coordinates of the main surface of the large photomask indicating the visually specified position from the visual specification information, and a microscope capable of moving each position of the main surface of the large photomask to an observable position A microscope driving means for moving the microscope to a position where the position of the main surface of the large photomask indicated by the two-dimensional coordinates can be observed, and two-dimensional coordinates indicating an arbitrary position of the main surface of the large photomask And a two-dimensional coordinate input means for inputting a visual inspection apparatus.
  • visual designation information calculation means for calculating the visual designation information from the two-dimensional coordinates input by the two-dimensional coordinate input means.
  • the visual designation information acquisition means acquires the visual designation information indicating an area having an area. This is because it is more effective to investigate the cause of unevenness, dirt, etc. caused by the line width of the transfer pattern by specifying the defect area and measuring the line width, reflectance, transmittance, and the like.
  • a rotation mechanism for rotating the large photomask around a rotation axis parallel to the main surface of the large photomask, and the main surface of the large photomask is parallel to the floor surface. It is preferable that the angle capable of rotating around the rotation axis from any direction is 90 ° or more. This is because visual observation of the surface of the large photomask is facilitated.
  • the rotatable angle is 270 ° or more. This is because visual observation of the back surface of the large photomask is facilitated.
  • an imaging device for imaging the main surface of the large photomask. This is because the state of the main surface of the large photomask can be made known.
  • the present invention also provides a visual designation information acquisition step for obtaining visual designation information of defects on the main surface of a large photomask pointed to based on visual observation, and the large photomask indicating a visual designation position from the visual designation information.
  • a two-dimensional coordinate calculation step for calculating the two-dimensional coordinates of the main surface of the first and second micro-observation steps for observing the position of the main surface of the large-sized photomask indicated by the two-dimensional coordinates with a microscope. Provide an appearance inspection method.
  • the visual designation information acquisition step is performed in a defect inspection step for inspecting the presence or absence of defects present on the main surface of the large photomask by observing the appearance
  • the defect inspection step is An irradiation area is provided on the main surface of the large photomask by irradiating the main surface of the large photomask with observation illumination at a fixed irradiation angle, and the large photomask is moved by moving the irradiation area up, down, left and right. It is preferable to perform a full-scale inspection for inspecting the entire main surface, and to perform the full-surface inspection at least twice by changing the irradiation angle of the observation illumination with respect to the main surface of the large-sized photomask.
  • the present invention provides a visual designation that calculates visual designation information from a defect correction step for correcting a defect on the main surface of the large photomask and a two-dimensional coordinate of the main surface of the large photomask that indicates the correction location of the defect.
  • an appearance inspection method comprising: an information calculation step; and a macro observation step of visually observing a corrected portion of the defect with the visual designation information. According to the present invention, it is easy to perform macro observation of a defect detected by micro observation and its corrected portion.
  • the present invention provides an irradiation area on the main surface of the large photomask by irradiating observation illumination at a predetermined irradiation angle on the main surface of the large photomask, and moves the irradiation area up, down, left and right.
  • the defect inspection method is characterized in that it is performed at least twice by changing the irradiation angle with respect to the main surface of the large-sized photomask.
  • the whole surface inspection is performed at a low irradiation angle full surface inspection in which the irradiation angle is within a range of 15 ° to 45 ° and an irradiation angle within the range of 45 ° to 75 °. It is desirable to include high-angle full-field inspection.
  • the entire surface inspection is performed while irradiating the observation illumination in a direction perpendicular to the one side from one side of the large photomask and moving in parallel with the one side.
  • the entire side of the large photomask is inspected by repeatedly performing the process of moving the irradiation region by a predetermined distance in a direction orthogonal to the one side after inspecting the length of the one side.
  • the moving speed of the irradiation region in the entire surface inspection is in a range of 5 cm / second to 9 cm / second.
  • the observation illumination alternately repeats the irradiation state and non-irradiation state of irradiation light on the main surface of the large photomask by the control unit.
  • the observation illumination is set to the non-irradiation state by the control unit, and a method of acquiring a visually designated position of a defect on the main surface of the large photomask with a laser pointer, or the irradiation state and the non-irradiation state are alternately switched at high speed.
  • FIG. 1st aspect It is a flowchart which shows an example of the external appearance inspection method of a 2nd aspect. It is explanatory drawing for demonstrating a defect inspection method. It is explanatory drawing which shows an example of the defect inspection method of this invention.
  • the appearance inspection apparatus includes a visual designation means for indicating a visual designation position of a main surface of a large photomask designated based on visual observation, and the large photomask indicating the visual designation position from visual designation information.
  • a two-dimensional coordinate calculating means for calculating two-dimensional coordinates of the main surface of the optical microscope, a microscope capable of moving each position of the main surface of the large photomask to an observable position, and the large photomask indicated by the two-dimensional coordinates
  • a microscope driving means for moving the microscope to a position where the position of the principal surface of the large-sized photomask can be observed
  • a two-dimensional coordinate input means for inputting a two-dimensional coordinate indicating an arbitrary position of the principal surface of the large photomask. It is characterized by.
  • the “main surface of a large photomask” means the front and back surfaces of the large photomask.
  • FIG. 1 is a schematic side view showing an example of an appearance inspection apparatus according to the present invention.
  • the X1 direction is a direction parallel to the floor surface 2
  • the Y1 direction is a direction parallel to the floor surface 2 and perpendicular to the X1 direction
  • the Z1 direction is a direction perpendicular to the floor surface 2. It is.
  • the appearance inspection apparatus 100 is installed on a base 5 installed on the floor 2, a gantry 10 movably installed on the base 5, and a gantry 10 via a rotary shaft 12.
  • the appearance inspection apparatus 100 includes a stage 16 installed on the floor 2, a laser pointer 20 and a microscope 50 attached to the stage 16, an operation unit 30, a computer 40, It has.
  • the computer 40 includes a display unit 40a, a control unit 40b, and a storage unit 40c.
  • the substrate support frame 14 has an opening 14 a that penetrates from the front surface to the back surface, and the front surface 70 a and the back surface 70 b of the large photomask 70 fixed to the substrate support frame 14 are opened from the front surface side and the back surface side of the substrate support frame 14. It can be observed through the part 14a.
  • the gantry 10 can be moved in the ⁇ Y1 direction with respect to the base 5 by giving a predetermined instruction to the control unit 40 b by a key operation of the operation unit 30.
  • the substrate support frame 14 can be moved in the ⁇ Z1 direction by driving by the gantry 10 by giving a predetermined instruction to the control unit 40b by a key operation of the operation unit 30, and around the rotation axis 12 parallel to the X1 direction.
  • the laser pointer 20 can be moved to each position in the ⁇ X1 direction and ⁇ Z1 direction on the front surface 16a of the stage 16, and can indicate each position on the front surface 70a and the back surface 70b of the large photomask 70.
  • the position of the laser pointer 20 on the surface 16a of the stage 16 and the direction of the laser pointer 20 to be described later can be controlled by giving predetermined instructions to the control unit 40b by key operation of the operation unit 30.
  • the microscope 50 is movable to each position in the ⁇ X1 direction and the ⁇ Z1 direction on the surface 16a of the stage 16. For this reason, the microscope 50 moves to a position for observing each position of the front surface 70a and the back surface 70b of the large-sized photomask 70 disposed at a position where it can be observed by the movement of the gantry 10 and the movement and rotation of the substrate support frame 14. be able to.
  • the operation of the appearance inspection apparatus 100 includes the first operation in the case where the observer 200 performs the appearance inspection of the large photomask 70 in the order of macro observation for visual observation and micro observation for detailed observation with a microscope. There are two types of second operations when the person 200 performs macro observation using information of defects obtained by micro observation.
  • FIG. 2 is a schematic diagram for explaining a first operation of the appearance inspection apparatus 100 shown in FIG. 2A schematically shows the laser pointer 20 and the large photomask 70 shown in FIG. 1, and FIG. 2B schematically shows the microscope 50 and the large photomask 70 shown in FIG. FIG.
  • the X2 direction is a direction parallel to one side of the surface 70a of the large photomask 70
  • the Y2 direction is a direction parallel to the surface 70a of the large photomask 70 and perpendicular to the X2 direction
  • Z2 The direction is a direction perpendicular to the surface 70 a of the large photomask 70.
  • the observer 200 When the first operation of the appearance inspection apparatus 100 shown in FIG. 1 is performed, first, the observer 200 performs macro observation that observes globally by visual observation, whereby the surface 70a of the large photomask 70 is observed. A defect 72 is detected.
  • the macro observation by visual observation may be performed using observation illumination fixed as in the observation illuminations 80a to 80c as shown in FIG. 1, but the observer 200 as shown in FIG. It is preferable to inspect the defect 72 by holding the observation illumination 80, irradiating the surface 70a of the large photomask 70 with the observation illumination 80 inclined at a predetermined angle, and observing while moving left and right.
  • the observer 200 gives a predetermined instruction to the control unit 40 b by operating the keys of the operation unit 30, so that a large photomask is used with the laser of the laser pointer 20.
  • the position of the defect 72 on the surface 70a of 70 is indicated.
  • the observer 200 gives a predetermined instruction to the control unit 40b by operating the key of the operation unit 30 in a state where the position of the defect 72 is pointed by the laser.
  • the appearance inspection apparatus 100 acquires the indication direction (P ⁇ x , P ⁇ y ) of the laser pointer 20 on the surface 16a of the stage 16 and the position of the large photomask 70 by the control unit 40b and stores them in the storage unit 40c.
  • the operation unit 30 is held by the observer 200, and when the defect 72 is found, the operation unit 30 is portable so that the operation can be performed on the spot.
  • a controller type is preferred.
  • the indication directions (P ⁇ x , P ⁇ y ) of the laser pointer 20 are, as shown in FIG. 2A, the angle of P ⁇ x in the X2 direction and the Y2 direction with respect to the reference direction in the Z2 direction. It means a direction inclined by an angle of P ⁇ y .
  • the reference direction is not necessarily set in the Z2 direction, and may be set in an arbitrary direction such as the Y1 direction in FIG.
  • the appearance inspection apparatus 100 causes the position of the laser pointer 20 on the surface 16a of the stage 16 and the direction of the laser pointer 20 to indicate. From the geometric relationship between (P ⁇ x , P ⁇ y ) and the position of the large photomask 70, the control unit 40 b determines the two-dimensional coordinates (Mx, My) of the surface 70 a of the large photomask 70 indicating the position of the defect 72. Calculate and store in the storage unit 40c.
  • the large-size photomask 70 is moved to the gantry 10.
  • the position of the surface 70a of the large-sized photomask 70 indicated by the two-dimensional coordinates (Mx, My) is observed from the reference position after the substrate support frame 14 is moved to a position where it can be observed by moving and rotating. Move to a possible position.
  • the observer 200 can perform micro observation of observing the defect 72 on the surface 70 a of the large photomask 70 with the microscope 50 after adjusting the focus of the microscope 50.
  • ⁇ x is set to 90 °
  • the large photomask 70 is rotated in the parallel direction of the stage 16, and the microscope 50 is moved in the two-dimensional direction (Mx, My) of the defect 72.
  • P ⁇ y ) and the position of the large photomask 70 are acquired, and then “the two-dimensional coordinates (Mx, My) of the surface 70a of the large photomask 70 can be calculated. It is possible to obtain the two-dimensional coordinates (Mx, My) of the surface 70a of the large photomask 70 indicating the position of
  • the indication direction (P ⁇ x , P ⁇ y ) of the laser pointer 20 After acquiring the position of the large photomask 70 determined from the position of the gantry 10 in the Y1 direction, the height H, and the rotation angle ⁇ x, the position information of the surface 70a of the large photomask 70 indicating the position of the defect 72 is obtained from these position information.
  • Two-dimensional coordinates (Mx, My) can be calculated. The method for calculating the two-dimensional coordinates (Mx, My) indicating the position of the defect 72 is not limited to this method.
  • FIG. 3 is a schematic diagram showing a second operation of the appearance inspection apparatus 100 shown in FIG.
  • FIG. 3A is a diagram showing the large photomask 70 shown in FIG. 1
  • FIG. 3B is a diagram showing the laser pointer 20 and the large photomask 70 shown in FIG. Note that the X2, Y2, and Z2 directions in FIG. 3 coincide with the X2, Y2, and Z2 directions in FIG.
  • the appearance inspection machine automatically performs micro observation automatically. After detecting the defect 74 on the surface 70a of the large photomask 70, the defect 74 is corrected. At this time, two-dimensional coordinates (Mx, My) of the surface 70a of the large photomask 70 indicating the position of the defect correction portion 74c or the defect 74 on the surface 70a of the large photomask 70 are converted into data along with the type of defect. .
  • the appearance inspection apparatus of the present invention not only obtains the two-dimensional coordinates of the main surface of the large photomask indicating the position of the defect detected by the macro observation, but also corrects the defect detected by the micro observation.
  • a means for inputting two-dimensional coordinates indicating the position of the defect is provided. Therefore, it is possible to easily inspect defects detected by both macro observation and micro observation.
  • the control unit 40b calculates the pointing direction (P ⁇ x , P ⁇ y ) of the laser pointer 20 pointing to the defect correction portion 74c, and the storage unit 40c.
  • the appearance inspection apparatus 100 is operated by the laser pointer 20.
  • the pointing direction (P ⁇ x , P ⁇ y ) of the laser pointer 20 is pointed by the laser of the laser pointer 20 so that the observer 200 can visually recognize the defect correction portion 74c. Thereby, the observer 200 can visually observe the defect correction portion 74c.
  • the large photomask 70 showing the defect correction portion 74c is corrected.
  • the indication direction (P ⁇ x , P ⁇ y ) of the laser pointer 20 pointing to the defect correction portion 74c is calculated as visual designation information for viewing the defect correction portion 74c. can do. For this reason, it is possible to point the defect correction portion 74c so that it can be visually checked by using the indication direction ( P ⁇ x , P ⁇ y ) of the laser pointer 20. Therefore, it is possible to perform macro observation of the defect correction portion 74c detected by micro observation.
  • the present invention it is possible to acquire the two-dimensional coordinates of the main surface of the large photomask indicating the position of the defect detected by the macro observation. Furthermore, the defect detected by micro observation and the corrected part can be pointed out so that it can be visually observed. Therefore, it is possible to easily inspect defects by appearance inspection including both macro observation and micro observation.
  • the visual designation information acquisition means is means for obtaining visual designation information of the visual designation position of the main surface of the large photomask pointed to based on visual observation.
  • the visual designation information acquisition means is not particularly limited.
  • the position of the defect 74 on the surface 70a of the large photomask 70 is indicated by the laser of the laser pointer 20.
  • the control unit 40b by giving a predetermined instruction to the control unit 40b, the position of the laser pointer 20 on the surface 16a of the stage 16, the indication direction (P ⁇ x , P ⁇ y ) of the laser pointer 20, and the position of the large photomask 70 are determined. Obtained by the control unit 40b.
  • FIG. 4 is a schematic view showing an example of the laser irradiation position of the laser pointer 20 on the surface 70a of the large photomask 70 viewed from the observer 200 shown in FIG.
  • the visual designation information acquisition means may be a means for designating a point indicated by the laser of the laser pointer 20 after capturing the position of the defect as a point, and the position of the defect may be a rectangular area, a circular area, or an elliptical area. It is possible to use a rectangle designation, a circle designation, or an ellipse designation pointed to by the laser of the laser pointer 20 after capturing it, or use a line designation pointed to by the laser of the laser pointer 20 after capturing the position of the defect as a straight line. It may be a means.
  • the observer 200 appropriately selects a defect position designation method according to the shape and distribution of the defect.
  • the control unit 40b is instructed that the position of the defect is a point, and the laser pointer instruction when the point position 411 is pointed as shown in FIG.
  • the direction (P ⁇ x , P ⁇ y ) is acquired.
  • the visual designation information acquisition means using the rectangular designation instructs the control unit 40b that the position of the defect is a rectangular area, and as shown in FIG. 4, diagonal positions 412 and 413 of the rectangular area.
  • the pointing directions (P ⁇ x , P ⁇ y ) of the laser pointer when pointing to are respectively acquired.
  • the controller 40b is instructed that the position of the defect is a circular area, and the center position 414 of the diameter of the circular area as shown in FIG.
  • the pointing directions (P ⁇ x , P ⁇ y ) of the laser pointer when pointing to the positions 415 and 416 at both ends are acquired. This means obtains the indication direction (P ⁇ x , P ⁇ y ) of the laser pointer when only the two points of the center position 414 and the both end positions 415 and 416 of the diameter of the circular region are indicated. It may be a thing.
  • the controller 40b is instructed that the position of the defect is an elliptical area, and as shown in FIG.
  • the pointing directions (P ⁇ x , P ⁇ y ) of the laser pointer when pointing to the positions 418 and 419 at both ends of the axis and the positions 420 and 421 at both ends of the short axis may be acquired. This means that only three points of the center position 417 of the elliptical region, the positions 418 and 419 at both ends of the long axis, and the positions 420 and 421 at both ends of the short axis are indicated.
  • the directions indicated by the laser pointers (P ⁇ x , P ⁇ y ) may be acquired.
  • the visual designation information acquisition means using the straight line designation instructs the control unit 40b that the position of the defect is a straight line and points to the positions 422 and 423 at both ends of the straight line as shown in FIG.
  • the laser pointer pointing directions (P ⁇ x , P ⁇ y ) may be acquired.
  • Table 1 shows the visual designation information. “Attribute” indicates a method for designating the region of the laser pointer 20. “Inclination” indicates the angle ⁇ x in FIG. 1, and “Pointing direction” indicates the pointing direction of the laser pointer 20.
  • the visual designation information acquisition means is not limited to the means using the method described above, and it is only necessary to designate an area including a defect on the main surface of the large photomask.
  • the method for designating the position of the defect is not limited to point designation, rectangle designation, circle designation, ellipse designation, and straight line designation, as long as the defect position can be designated optimally.
  • the visual designation information acquisition means may be means for obtaining visual designation information of points and straight lines on the main surface of the large photomask as the visual designation information, or a rectangular area on the main surface of the large photomask.
  • Means for acquiring visual designation information of an area having an area such as a circular area, an elliptical area, etc. may be used, but means for obtaining visual designation information of an area having the area is preferable.
  • Visual designation means The visual designation means in the present disclosure is a means for indicating the visual designation position of the main surface of the large-sized photomask designated based on the visual observation.
  • the visual designation means is not particularly limited, and examples thereof include a laser pointer and a pointer in a display image on a touch panel.
  • the laser pointer as shown in FIG. 1, it is preferable to arrange the laser pointer above the observer 200. This is because it does not hinder the observer 200 when observing the large photomask 70 visually.
  • Examples of the laser include red light and green light, and red light is preferable. This is because it is easy to visually recognize.
  • a high-intensity lamp whose diameter when irradiated on the surface of the large photomask can be about 5 mm, for example, may be used.
  • the laser pointer if a defect is found by performing visual observation while irradiating the illumination for observation, there is a possibility that the laser of the laser pointer indicating the above defective part cannot be confirmed because the brightness in the irradiation area of the illumination for observation is high There is.
  • the high-intensity lamp instead of the laser pointer, the high-intensity lamp is irradiated in the vicinity of the defect portion in the irradiation area of the observation illumination that captures the defect portion, and thereafter After the observation illumination is turned off, the defect portion is identified by the high-intensity lamp, and the position of the defect portion is irradiated to obtain the position information of the defect portion.
  • Such a high-intensity lamp may be capable of changing the area of the irradiation region on the surface of the large photomask. Since it is possible to acquire the position information of the defective portion by irradiating the high-intensity lamp on the irradiation portion of the observation illumination that captures the defective portion, and then narrowing the irradiation area of the high-intensity lamp. It is.
  • a high-intensity lamp for example, LSP68X240W-ST (trade name, light source: LED, color temperature: 6500K) manufactured by ITEC SYSTEM Co., Ltd., PS-NP1 (trade name, light source: Xenon HID Lamp, color) manufactured by POLARION Temperature: 4300K), 370TFI / R (trade name, light source: halogen lamp, color temperature: about 3000K) manufactured by Sener and Burns Co., Ltd., and the like.
  • the visual designation information acquisition means when the observation illumination illuminates the surface of the large photomask and finds a defective portion, a shadow is generated so as to indicate the defective portion, and the position of the shadow is determined. It may be a means for specifying.
  • a means for generating a shadow for example, a member having a tip portion such as a pointer is prepared, and this is inserted between the illumination for observation and the surface of the large photomask so that a shadow pointing to the defective portion is generated.
  • a filter that creates a shadow such as a cross, is detachably placed in the observation illumination, and the observation is performed without the filter, and when a defect is found, the filter is placed in the illumination area of the observation illumination.
  • a means for causing a shadow in the defective portion can be exemplified.
  • a light shielding object is arranged in front of the light source for the observation illumination, and the visual designation position is set by alternately repeating the irradiation state and the non-irradiation state of the irradiation light on the main surface of the large photomask. It may be one that can be pointed.
  • a mode in which a visually designated position of a defect on the main surface of a large photomask is acquired with a laser pointer as a non-irradiation state, or on the large photomask by alternately switching between an irradiation state and a non-irradiation state at high speed A mode in which the visually designated position of the defect on the main surface of the large photomask is acquired with a laser pointer in a state where the brightness of the irradiation light is reduced can be mentioned.
  • the “switching at high speed” is preferably 70 Hz or more, more preferably 100 Hz or more.
  • a rotatable shading object is arranged in front of the light source for the observation illumination, and when a defective part is found, the shading object is rotated at a low speed.
  • the shading object is rotated at a low speed.
  • the illumination light source is turned ON / OFF at a low speed, so that irradiation or non-irradiation is repeated on the surface of the large photomask, or the irradiation surface is turned ON / OFF at a high speed. It may be a device that reduces the illuminance and enables position confirmation with a laser pointer. In addition to this, the illumination intensity may be adjusted by repeatedly increasing and decreasing the intensity of the illumination at intervals of 0.5 seconds or more.
  • FIGS. 14 and 15 Examples of such an apparatus include the apparatuses shown in FIGS. 14 and 15.
  • the apparatus shown in FIG. 14A includes a lamp house 1 and a light guide 2 that guides light from the lamp house.
  • the lamp house 1 includes a lamp 3 and a concave mirror 4 that reflects light from the lamp 3, and includes a light shielding plate 5 that can block an optical path from the concave mirror 4, and a drive unit 6 that rotates the light shielding plate 5.
  • the drive unit 6 incorporates a control unit that adjusts the rotational speed of the light-shielding plate 5.
  • FIG. 14B shows an example of the form of the light shielding plate 5.
  • the light shielding plate 5 in this form has a light shielding region 7 of 270 ° and a light transmitting region 8 of 90 °.
  • FIG. 14C shows another embodiment of the light shielding plate 5 having a 180 ° light shielding region 7 and a 180 ° light transmitting region 8.
  • the apparatus shown in FIG. 14 can be used in two modes. First, in the case of a defect that can be grasped by high-intensity light, the light shielding plate 3 is first arranged at a position where the light path from the concave mirror 4 is not shielded, and the presence or absence of the defect is inspected by the light irradiated from the tip of the light guide 2 To do. When a defect is found, the light shielding plate 3 is rotated at a low speed by the driving unit 6 and irradiation and non-irradiation are repeated on the surface of the large photomask. When the light path is shielded, the position can be specified by pointing the defect with the laser pointer.
  • the defect is visible even if the brightness is lowered, if the defect is found with the light irradiated from the tip of the light guide 2 in the same manner as described above, the light shielding plate 3 is rotated at a high speed, and a large photomask is used. The brightness on the surface is lowered, and in this state, it is possible to point the defect with the laser pointer and specify the position.
  • a control unit 9 for controlling ON / OFF of the lamp 1 is arranged instead of the light shielding plate 5 and the drive unit 6 of the apparatus shown in FIG.
  • an LED is used as the lamp 1.
  • the light shielding unit 3 can be used in two modes as in the apparatus of FIG. That is, when the ON / OFF control is performed at a low speed, the light shielding unit 3 is rotated at a low speed, and when the ON / OFF control is performed at a high speed, the light shielding unit 3 is rotated at a high speed.
  • Two-dimensional coordinate calculation means is means for calculating two-dimensional coordinates of the main surface of the large photomask indicating the visual designation position from the visual designation information.
  • the two-dimensional coordinate calculation means is not particularly limited.
  • the position of the laser pointer 20 on the surface 16a of the stage 16 the indication direction (P ⁇ x , P ⁇ y ) of the laser pointer 20, and a large size
  • the position of the laser pointer 20 on the surface 16a of the stage 16 is given by giving a predetermined instruction to the control unit 40b, as shown in FIGS. 1 and 2A.
  • a means for calculating by the control unit 40b from the geometric relationship between the indication direction (P ⁇ x , P ⁇ y ) of the laser pointer 20 and the position of the large photomask 70 can be mentioned.
  • a large photomask may be imaged, and the two-dimensional coordinates of the defect indicated using the touch panel may be calculated from a mark such as an alignment mark on the main surface of the large photomask.
  • FIG. 11 shows a configuration diagram for acquiring two-dimensional coordinates by the touch panel.
  • the photomask is imaged by an imaging device, and the photo corresponding to the defect position (x, y) touched on the display by the observer from the coordinates of the mark such as the alignment mark on the photomask and the position of the alignment mark on the image data
  • the two-dimensional coordinates (Mx, My) on the mask are obtained.
  • the two-dimensional coordinate calculation means calculates the two-dimensional coordinate indicating the point. That's fine. Further, if the visual designation information indicates the position of a region having an area such as a rectangular region, a circular region, or an elliptical region on the main surface 70a of the large photomask 70 shown in FIG.
  • the two-dimensional coordinate calculation means includes a two-dimensional coordinate indicating the diagonal position of the rectangular area, a two-dimensional coordinate indicating the center position and both ends of the diameter of the circular area, the elliptical area center position, and the long axis. A plurality of two-dimensional coordinates such as two-dimensional coordinates indicating the positions of both ends and the positions of both ends of the short axis may be calculated.
  • Microscope The microscope can move each position of the main surface of the large photomask to an observable position.
  • the microscope is not particularly limited, but has one or more functions of a dimension measuring function for measuring dimensions, a transmittance measuring function for measuring transmittance, and a reflectance measuring function for measuring reflectance. Those are preferred.
  • the microscope driving means is means for moving the microscope to a position where the position of the main surface of the large photomask indicated by the two-dimensional coordinates can be observed.
  • the microscope driving means is not particularly limited.
  • Examples include a stage that moves the microscope 50 to a position where the position of the main surface of the large photomask 70 indicated by the two-dimensional coordinates can be observed by giving a predetermined instruction.
  • the microscope driving means the two-dimensional coordinates are shown by moving the relative positions of the microscope and the large photomask, such as the stage 16 and the gantry 10 and the substrate support frame 14 shown in FIG. Any means for moving the microscope to a position where the position of the main surface of the large photomask can be observed can be used. Therefore, the microscope driving means may include means for moving the large photomask to the microscope side.
  • the microscope driving means may be a means for moving the microscope to an observable position by giving an instruction to the control unit to move the microscope in a manually input moving direction and moving distance, and the observation is possible. It may be a means for automatically moving the microscope to the observable position by giving an instruction to automatically move the microscope to the correct position, but the microscope is automatically moved to the observable position.
  • the means for moving to is preferable.
  • Two-dimensional coordinate input means The two-dimensional coordinate input means is a means for inputting two-dimensional coordinates indicating an arbitrary position of the main surface of the large photomask.
  • the two-dimensional coordinate input means for example, as shown in FIG. 1 and FIG. 3A, a predetermined instruction is given to the control unit 40b, whereby the surface of the large photomask 70 showing the defect correction portion 74c.
  • Examples include means for inputting the two-dimensional coordinates (Mx, My) of 70a to the storage unit 40c by the control unit 40b.
  • Visual designation information calculation means The visual inspection apparatus calculates visual designation information used to indicate the arbitrary position so as to be visible from the two-dimensional coordinates input by the two-dimensional coordinate input means. What comprises a visual designation
  • the visual designation information calculation means is not particularly limited as long as it can calculate the visual designation information of the laser pointer 20.
  • the two-dimensional coordinates (Mx, My) of the surface 70a of the large photomask 70 indicating the position of the laser pointer 20 on the surface 16a of the stage 16 and the defect correction location 74c.
  • the control unit 40b calculates the pointing directions (P ⁇ x , P ⁇ y ) of the laser pointer 20 pointing so that the defect correction portion 74c can be seen.
  • FIG. 12 shows a process of calculating visual designation information from arbitrary two-dimensional coordinates (Mx, My) on the photomask.
  • Arbitrary two-dimensional coordinates Mx, My) are input to the storage unit 40c (step 1), and visual designation information (P ⁇ x , P ⁇ y ) of the laser pointer 20 is calculated from the two-dimensional coordinates (Mx, My) (step 2). ).
  • FIG. 13 shows processing for calculating visual designation information using a touch panel.
  • the large photomask has been imaged, and the defect displayed on the display is designated by the touch panel to obtain the defect position (x, y) (step 1).
  • Marks such as alignment marks of the imaged photomask are extracted (step 2).
  • a defect position (Mx, My) on the photomask is calculated from a mark such as an alignment mark, and visual designation information (P ⁇ x , P ⁇ y ) is obtained (step 3).
  • the above-described appearance inspection apparatus usually further includes illumination for observation used for visual observation.
  • observation illumination for example, a plurality of observation illuminations having different types of light sources such as the observation illuminations 80a to 80c shown in FIG. 1 are preferable. This is because by using such a plurality of observation illuminations, it is easy to detect various types of defects (unevenness, spots, dirt, scratches, foreign matters, etc.) in visual observation.
  • the type of light source include fluorescent lamps, high-intensity halogen projectors, high-intensity LEDs, HID (Polarion), and Na lamps. If a combination of a Na lamp and a short wavelength cut filter is used as the light source, a coating unevenness inspection can also be performed.
  • the observation illumination may be a fixed type or a type that can be freely moved by an observer.
  • the appearance inspection apparatus normally further includes a rotation mechanism that rotates the large photomask around a rotation axis parallel to the main surface of the large photomask.
  • An appearance inspection apparatus 100 shown in FIG. 1 has a rotating shaft 12 fixed to a gantry 10 installed on a floor 2, and is fixed to the gantry 10 via a rotating shaft 12, and can be rotated around the rotating shaft 12.
  • a rotation mechanism composed of the substrate support frame 14 the large photomask 70 installed on the substrate support frame 14 is rotated around the rotation axis 12 parallel to the surface 70 a of the large photomask 70. Can do.
  • the rotation mechanism preferably has an angle capable of rotating the main surface of the large photomask around the rotation axis from a direction parallel to the floor surface at 90 ° or more.
  • the angle ⁇ x for rotating the surface 70a of the large photomask 70 from the direction parallel to the floor surface 2 around the rotation axis 12 is 90 ° or more. This is because, since the observer 200 can perform visual observation of the surface 70a in a state where the surface 70a is inclined in a direction perpendicular to the floor surface 2, visual observation of the surface 70a is facilitated.
  • those having a rotatable angle of 270 ° or more are preferable. For example, when the above-described angle ⁇ x shown in FIG.
  • the observer 200 visually observes the back surface 70b while the back surface 70b of the large photomask 70 is inclined in a direction perpendicular to the floor surface 2. This is because observation can be performed, so that visual observation of the back surface 70b is facilitated.
  • Imaging device As said external appearance inspection apparatus, what has further the imaging device which images the main surface of the said large sized photomask is preferable.
  • the appearance inspection apparatus 100 shown in FIG. 1 has a digital camera 90 that images the front surface 70a or the back surface 70b of the large photomask 70.
  • an image captured by the digital camera 90 can be displayed on the display unit 40a by the control unit 40b even for a person other than the observer 200 who directly observes the front surface 70a or the back surface 70b of the large photomask 70. Therefore, the state of the main surface of the large photomask can be made known.
  • the display image of the touch panel can be used in the two-dimensional coordinate calculation means, the visual designation information calculation means, and the visual designation means.
  • the imaging device include a TV camera and the like in addition to a digital camera.
  • the imaging device is disposed above the observer 200 like the digital camera 90 shown in FIG. This is because it does not hinder the observer 200 when observing the large photomask 70 visually.
  • the appearance inspection apparatus normally has a control unit such as the control unit 40b shown in FIG. 1 that controls components such as means, devices, and mechanisms included in the appearance inspection apparatus.
  • the appearance inspection apparatus may include an operation unit such as an operation unit 40b shown in FIG. 1 that gives a predetermined instruction to the control unit from the outside in order to control the components.
  • the visual inspection apparatus usually has the visual designation information, two-dimensional coordinates of the main surface of the large photomask indicating the visual designation position, two-dimensional coordinates indicating an arbitrary position of the main surface of the large photomask, And storage means such as the storage unit 40c shown in FIG. 1 for storing any one type or two or more types of information such as the visual position information.
  • the appearance inspection apparatus usually has display means such as the display unit 40a shown in FIG.
  • Examples of the display means include a liquid crystal display and an organic EL display.
  • the display means may be used as a touch panel used in the visual designation information acquisition means described in the item “1. Visual designation information acquisition means”.
  • the appearance inspection apparatus further includes input means for inputting two-dimensional coordinates indicating an arbitrary position of the main surface of the large photomask from the outside, and the microscope driving means is input by the input means.
  • the microscope may be moved to a position where the position of the main surface of the large photomask indicated by the dimensional coordinates can be observed.
  • two-dimensional coordinates indicating the position of a defect on the main surface of a large photomask automatically acquired by a micro appearance inspection machine that automatically performs micro observation are input from the micro appearance inspection machine to the appearance inspection apparatus. Then, the defect can be observed in detail by moving the microscope to a position where the position of the main surface indicated by the two-dimensional coordinates can be observed.
  • the main surface indicated by the two-dimensional coordinates By moving the microscope to a position where the position can be observed, various marks can be observed in detail.
  • the appearance inspection method of the present invention is a first mode used when the appearance inspection of a large photomask is performed in the order of macro observation and micro observation, and the appearance inspection of the large photomask is performed in the order of micro observation and macro observation. And the second mode used in the case of performing the above.
  • the visual inspection method includes a visual designation information acquisition step of obtaining visual designation information of a defect on a main surface of a large photomask pointed to based on visual observation, and the defect from the visual designation information.
  • a two-dimensional coordinate calculation step for calculating the two-dimensional coordinates of the main surface of the large photomask indicating the position of the microphotograph, and a micro observation step for observing the position of the main surface of the large photomask indicated by the two-dimensional coordinates with a microscope It is characterized by providing.
  • FIG. 5 is a flowchart illustrating an example of the appearance inspection method according to the first aspect.
  • a visual designation information acquisition step S11 is performed as shown in FIG.
  • the observer 200 performs a macro observation that observes globally visually, thereby detecting a defect 72 on the surface 70 a of the large photomask 70.
  • the observer 200 gives a predetermined instruction to the control unit 40 b by operating the keys of the operation unit 30, so that a large photomask is used with the laser of the laser pointer 20.
  • the position of the defect 72 on the surface 70a of 70 is indicated.
  • the observer 200 gives a predetermined instruction to the control unit 40b by operating the key of the operation unit 30 in a state where the position of the defect 72 is pointed by the laser.
  • the appearance inspection apparatus 100 acquires the indication direction (P ⁇ x , P ⁇ y ) of the laser pointer 20 and the position of the large photomask 70 on the surface 16a of the stage 16 by the control unit 40b and stores them in the storage unit 40c. To do.
  • a two-dimensional coordinate calculation step S12 is performed as shown in FIG.
  • the appearance inspection apparatus 100 causes the surface 16 a of the stage 16 when the observer 200 gives a predetermined instruction to the control unit 40 b by operating the keys of the operation unit 30.
  • the pointing direction (P ⁇ x , P ⁇ y ) of the laser pointer 20 From the geometrical relationship between the position of the laser pointer 20, the pointing direction (P ⁇ x , P ⁇ y ) of the laser pointer 20, and the position of the large photomask 70, the surface 70 a of the large photomask 70 indicating the position of the defect 72 is shown.
  • Two-dimensional coordinates (Mx, My) are calculated by the control unit 40b and stored in the storage unit 40c.
  • a micro observation step S13 is performed as shown in FIG.
  • the observer 200 gives a predetermined instruction to the control unit 40 b by operating the keys of the operation unit 30, so that the large photomask 70 is moved and moved.
  • the position of the surface 70a of the large photomask 70 indicated by two-dimensional coordinates (Mx, My) from the reference position after the substrate support frame 14 is moved and rotated to a position where it can be observed by the microscope 50. Is moved to an observable position.
  • the observer 200 performs micro observation of observing the defect 72 on the surface 70 a of the large photomask 70 with the microscope 50.
  • the laser indicating the position of the defect 72 on the surface 16a of the stage 16 as the visual designation information of the defect 72 on the surface 70a of the large photomask 70 indicated based on the visual observation.
  • the surface 70 a of the large photomask 70 indicating the position of the defect 72 is obtained from such visual designation information of the defect 72.
  • the two-dimensional coordinates (Mx, My) can be calculated.
  • the defect detected by the macro observation is micro-observed. Is easy.
  • Visual designation information acquisition step In the visual designation information acquisition step, visual designation information of a defect on the main surface of the large photomask pointed to based on visual observation is acquired.
  • the method for acquiring the visual designation information is not particularly limited.
  • Visual designation information acquisition unit is used.
  • a method for acquiring designated information is used.
  • the visual designation information is not particularly limited, and examples thereof include the visual designation information described in the item “A. Appearance inspection apparatus 1. Visual designation information acquisition unit”.
  • Two-dimensional coordinate calculation step In the two-dimensional coordinate calculation step, two-dimensional coordinates of the main surface of the large photomask indicating the position of the defect are calculated from the visual designation information.
  • the method for calculating the two-dimensional coordinates is not particularly limited.
  • Two-dimensional coordinate calculation means is used.
  • a method for calculating a dimensional coordinate may be used.
  • Micro Observation Step the position of the main surface of the large photomask indicated by the two-dimensional coordinates is observed with a microscope.
  • the microscope is not particularly limited, and examples thereof include a microscope described in the item “A. Appearance inspection apparatus 3. Microscope” as shown in FIG.
  • Appearance Inspection Method The appearance inspection method of the first aspect is usually carried out using the appearance inspection device described in the item “A. Appearance inspection device”.
  • the appearance inspection method of the first aspect usually includes a defect inspection step of finding defects by observing the appearance before the visual designation information acquisition step.
  • the visual designation information acquisition step is performed on the defect found by the defect inspection step.
  • this defect inspection process is not particularly limited, usually, as shown in FIG. 7, the observer 200 has the observation illumination 80, and the observation illumination 80 is applied to the surface 70 a of the large photomask 70. Is carried out by inspecting the defect 72 by irradiating at a predetermined angle and observing it while moving it vertically and horizontally.
  • the defect inspection process in this aspect is not specifically limited, It is preferable that it is a process using "C. Defect inspection method" mentioned later.
  • the visual inspection method includes a defect correction step for correcting a defect on a main surface of a large photomask, and a two-dimensional coordinate of the main surface of the large photomask indicating a correction location of the defect.
  • a visual designation information calculation step for calculating the visual designation information of the correction location, a macro observation step for performing visual observation of the correction location of the defect by indicating the correction location of the defect using the visual designation information, and It is characterized by providing.
  • FIG. 6 is a flowchart illustrating an example of the appearance inspection method according to the second aspect.
  • a defect correction step S21 is performed as shown in FIG.
  • a defect 74 on the surface 70a of the large photomask 70 is automatically detected by an appearance inspection machine that automatically performs micro observation, and then the defect 74 is corrected.
  • two-dimensional coordinates (Mx, My) of the surface 70a of the large photomask 70 indicating the position of the defect correction portion 74c or the defect 74 on the surface 70a of the large photomask 70 are converted into data along with the type of defect. .
  • a visual designation information calculation step S22 is performed as shown in FIG.
  • the observer 200 gives a predetermined instruction to the control unit 40 b by key operation of the operation unit 30, whereby the defect correction location 74 c or the position of the defect 74 is detected.
  • the two-dimensional coordinates (Mx, My) of the surface 70a of the large-sized photomask 70 showing are input to the storage unit 40c.
  • the observer 200 gives a predetermined instruction to the control unit 40b by operating the keys of the operation unit 30, whereby the large-sized photomask 70 showing the position of the laser pointer 20 on the surface 16a of the stage 16 and the defect correction portion 74c.
  • the pointing direction (P ⁇ x , P ⁇ y ) of the laser pointer 20 pointing to the defect correction location 74c is controlled from the geometric relationship between the two-dimensional coordinates (Mx, My) of the surface 70a of the laser beam and the position of the large photomask 70. Calculated by the unit 40b and stored in the storage unit 40c.
  • a macro observation step S23 is performed as shown in FIG.
  • the appearance inspection device 100 is moved to the laser pointer 20.
  • the pointing direction (P ⁇ x , P ⁇ y ) is used to point the defect correction portion 74c with the laser of the laser pointer 20 so that the observer 200 can see the defect.
  • the observer 200 visually observes a defect correction portion 74c indicated by the laser.
  • the surface 70a of the large photomask 70 showing the defect correction portion 74c is corrected.
  • the pointing direction (P ⁇ x , P ⁇ y) of the laser pointer 20 pointing to the defect correction portion 74c is used as visual designation information used to point the defect correction portion 74c so as to be visible. ) Can be calculated. For this reason, it is possible to point the defect correction portion 74c so that it can be visually checked by using the indication direction ( P ⁇ x , P ⁇ y ) of the laser pointer 20. Therefore, it is possible to perform macro observation of the defect correction portion 74c detected by micro observation.
  • Defect Correction Process In the defect correction process, defects on the main surface of the large photomask are corrected.
  • the method for correcting the defect is not particularly limited, but when the defect is a black defect, for example, a method of etching the black defect by irradiating a charged beam while supplying an assist gas to the black defect. Etc. Further, when the defect is a white defect, for example, a method of depositing a correction film by irradiating a charged beam while supplying a deposition gas to the white defect is exemplified.
  • the black defect means an unnecessary surplus portion in the mask pattern of the large photomask.
  • a white defect is a defect in a mask pattern of a large photomask.
  • Visual designation information calculation step In the visual designation information calculation step, it is used to indicate the defect correction location so that the defect correction location can be viewed from the two-dimensional coordinates of the main surface of the large photomask indicating the defect correction location. Calculate visual designation information.
  • the method for calculating the visual designation information is not particularly limited.
  • Other (1) Visual designation information calculation means and visual designation means” is provided. Examples include a method of calculating the visual position information using an information calculation means.
  • the defect correction location is visually observed by indicating the defect correction location using the visual designation information.
  • a method for indicating the corrected portion of the defect using the visual designation information is not particularly limited.
  • Appearance Inspection Method The appearance inspection method of the second aspect is usually carried out using the appearance inspection device described in the item “A. Appearance inspection device”.
  • the micro-appearance is a two-dimensional coordinate indicating the position of a defect on the surface of a large photomask that is automatically acquired by a micro appearance inspection machine that automatically performs micro observation.
  • the external appearance is input to the visual inspection apparatus described in the item “A.
  • Visual inspection apparatus” from the inspection machine and the position of the main surface of the large-sized photomask indicated by the two-dimensional coordinates can be observed. For example, a method of observing the defect in detail by moving the microscope in the inspection apparatus.
  • the defect inspection method of the present invention provides an irradiation region on the main surface of the large photomask by irradiating observation illumination at a predetermined irradiation angle on the main surface of the large photomask. It is a defect inspection method for inspecting the entire surface of the main surface of the large photomask by moving up, down, left and right, and inspecting for the presence or absence of defects present on the main surface of the large photomask.
  • the observation illumination is performed at least twice by changing the irradiation angle with respect to the main surface of the large photomask.
  • the main surface of the large-sized photomask that is, the defects existing on the surface include so-called unevenness, areas showing reflections different from the surroundings, spots, dirt, foreign matters, and edges of patterns formed on the large-sized photomask. Defects can be mentioned. Since these defects are difficult to find by general visual inspection, conventionally, for example, an inspection method using observation illumination as shown in FIG. 7 has been performed. That is, as shown in FIG. 7, an observer 200 has an observation illumination 80, irradiates the observation illumination 80 at a predetermined angle on the surface 70a of the large photomask 70, and observes while moving left and right. Thus, a method of inspecting the defect 72 has been adopted.
  • the defect inspection method of the present invention will be described in detail.
  • Irradiation angle A feature of the present invention is that, at the time of defect inspection of a large-sized photomask, the observation illumination is performed at least twice while changing the irradiation angle of the main surface of the large-sized photomask.
  • the reason why the defect oversight is reduced by performing the irradiation angle at least twice in this manner is estimated as follows. That is, according to the studies by the inventors, there is a high possibility that a foreign object which is a kind of the defect or a defect of an edge of a pattern formed on a large photomask can be found when the irradiation angle is small.
  • the unevenness, spots, dirt, and the like are more likely to be detected by increasing the irradiation angle and increasing the illuminance of the irradiation area to some extent.
  • the angle at which unevenness can be found differs depending on the type, and it may be overlooked by inspection at one angle. From the above points, as described above, it is possible to reduce the oversight of defects by performing the entire surface inspection at least twice at different angles.
  • a low irradiation angle full surface inspection in which a full inspection is performed at a low irradiation angle A with a small irradiation angle of the observation illumination 80 with respect to the main surface of the large photomask 70, and a large photomask 70 A high irradiation angle full surface inspection is performed in which a full surface inspection is performed at a high irradiation angle B where the irradiation angle of the observation illumination 80 with respect to the main surface is large.
  • the irradiation angle A in the low irradiation angle full-surface inspection is preferably in the range of 15 ° to 45 ° centering on 30 °, and more preferably in the range of 20 ° to 40 °. It is preferably in the range of 25 ° to 35 °.
  • the irradiation angle B in the high irradiation angle full-surface inspection is preferably within a range of 45 ° to 75 ° centering on 60 °, and more preferably within a range of 50 ° to 70 °, particularly 55. It is preferably within the range of ° to 65 °.
  • the entire surface inspection may be performed at least twice by changing the angle of the entire surface inspection. Therefore, the entire surface inspection may be performed three times or more.
  • the irradiation angle in each full-surface inspection is preferably constant, and is preferably performed within a range of at least ⁇ 10 °, preferably ⁇ 5 °.
  • the full surface inspection in the present invention is not particularly limited as long as it is a method capable of inspecting the entire surface of the large photomask, but the full surface inspection is orthogonal to the one side from one side of the large photomask. Irradiating the observation illumination in the direction to be observed, inspecting while moving parallel to the one side, inspecting the length of the one side, and then irradiating the region in a direction perpendicular to the one side It is preferable to perform the entire side inspection for inspecting the entire surface of the large photomask by repeatedly performing the process of moving the lens by a predetermined distance.
  • the observation illumination 80 is irradiated from one side 71 side of the large photomask 70 in a direction perpendicular to the one side 71 to form an irradiation region 81.
  • the observation illumination 80 is moved in parallel with the one side 71 to inspect the irradiation region 81 while moving it in a direction P parallel to the one side 71.
  • the irradiation region 81 is moved a predetermined distance in a direction R orthogonal to the one side 71. By repeating this operation, the entire surface of the large photomask 70 can be inspected. Note that the entire surface inspection by this method is referred to as a side entire surface inspection.
  • the irradiation region When the irradiation region is moved in the direction r perpendicular to the one side 71, it is preferable that the irradiation regions are moved so as to overlap each other by about 20 mm from the viewpoint of preventing defects from being overlooked.
  • the entire side inspection is preferably performed on two orthogonal sides, and particularly on all four sides as shown in FIG. This is because, depending on the direction of the pattern drawn on the large photomask, a defect may be missed in the entire side inspection of only one side.
  • the entire surface inspection is performed twice at least at different angles as described above. Therefore, when the entire surface inspection is performed on all four sides, the entire surface inspection is performed at least eight times. It can be said that it is most preferable to perform the entire surface inspection at least eight times from the viewpoint of minimizing the oversight of defects.
  • Moving speed of irradiation region The moving speed of the irradiation region irradiated by the observation illumination is preferably 5 cm / second to 9 cm / second, more preferably 6 cm / second to 8 cm / second, and particularly 7 cm / second. It is preferable that If it is earlier than the above range, there is a high possibility that the defect will be overlooked. If it is later than the above range, the intensity change of the reflected light becomes gradual when the defect such as unevenness is found, and the unevenness. This is because it becomes difficult to judge that it is.
  • C. Defect inspection method such as the type of illumination for observation and the method for fixing a large photomask are described in “A. Appearance inspection apparatus” and “B. What has been described can be used.
  • D. Large photomask manufacturing method The large photomask manufacturing method of the present invention is characterized by having an inspection step using the above-mentioned “B. Appearance inspection method” or “C. Defect inspection method”.
  • the large-sized photomask in the present invention is used in, for example, a photolithography process at the time of manufacturing a flat panel display, a color filter or the like, more specifically, an exposure process.
  • the manufacturing method of a large-sized photomask of the present invention is characterized by having an inspection process using the above-described appearance inspection method and defect inspection method in the appearance inspection process and the like, and other processes are conventionally performed. Since it is the same as the process which exists, description here is abbreviate
  • the present invention is not limited to the above embodiment.
  • the above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

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Abstract

The present disclosure provides an appearance inspecting device characterized by being provided with: a visual observation designating means for indicating a visual observation designation position on a main surface of a large photomask; the visual observation designating means; a visual observation designation information acquiring means for acquiring visual observation designation information; a two-dimensional coordinate calculating means for calculating two-dimensional coordinates on the main surface indicating the visual observation designation position, from the visual observation designation information; a microscope capable of moving to positions at which each position on the main surface can be observed; a microscope driving means for moving the microscope to a position at which the position on the main surface indicated by the two-dimensional coordinates can be observed; and a two-dimensional coordinate input means for inputting two-dimensional coordinates indicating an arbitrarily defined position on the main surface of the large photomask.

Description

外観検査装置および外観検査方法Appearance inspection apparatus and appearance inspection method
　本発明は、大型フォトマスクの外観検査に用いられる外観検査装置および外観検査方法に関する。 The present invention relates to an appearance inspection apparatus and an appearance inspection method used for appearance inspection of a large photomask.
　大型フォトマスクは、例えばフラットパネルディスプレイやカラーフィルタ等の製造時のフォトリソグラフィプロセス、より具体的には露光プロセス等において各種のパターン形成に用いられている。 Large photomasks are used for various pattern formations in, for example, a photolithography process at the time of manufacturing a flat panel display, a color filter or the like, more specifically, an exposure process.
　大型フォトマスクは、製造過程において、転写パターンの線幅や形成位置が設計から僅かにずれることにより、転写パターンにムラが生じることがある。また、製造過程または洗浄過程においては、転写パターンに、シミ、汚れ、異物が付着したり、キズが形成されることがある。これらのムラやシミ等の欠陥は、顕微鏡で局所を詳細に観察するミクロ観察ではなく、目視で大局的に観察するマクロ観察を用いた方が検出が容易である場合がある。このため、これらの欠陥の検査においては、例えば、特許文献１に記載されているように、外観検査装置を用いてマクロ観察を行うことが多い。 A large-sized photomask may cause unevenness in the transfer pattern due to a slight shift in the line width and formation position of the transfer pattern from the design during the manufacturing process. Further, in the manufacturing process or the cleaning process, stains, dirt, foreign matters may adhere to the transfer pattern, and scratches may be formed. Such defects such as unevenness and stains may be easier to detect by using macro observation that is visually observed globally rather than by micro observation that observes the local area in detail with a microscope. For this reason, in inspection of these defects, for example, as described in Patent Document 1, macro observation is often performed using an appearance inspection apparatus.
　マクロ観察を行う外観検査装置としては、大型フォトマスクの他にも液晶ディスプレイ用ガラス基板等の検査を行う装置が知られている。このような外観検査装置には、マクロ観察により被検査試料の主面の欠陥を検出した後に、該欠陥をミクロ観察することにより詳細に解析するものがある。 As an appearance inspection apparatus for performing macro observation, an apparatus for inspecting a glass substrate for a liquid crystal display in addition to a large photomask is known. Among such appearance inspection apparatuses, there is an apparatus that analyzes a defect in detail by micro-observing the defect after detecting a defect on the main surface of the sample to be inspected by macro observation.
　例えば、特許文献２～４には、このようにマクロ観察により検出された欠陥をミクロ観察する外観検査装置が記載されている。 For example, Patent Documents 2 to 4 describe an appearance inspection apparatus for micro-observing defects detected by macro observation in this way.
特開２０１３－４５７９７号公報JP 2013-45797 A 特開２００８－１７５５４８号公報JP 2008-175548 A 特開平４－１５１５４７号公報JP-A-4-151547 特開２００５－１６４６１０号公報JP 2005-164610 A
　マクロ観察においては精度よく欠陥位置を取得する必要がある。さらに、ミクロ観察により大型フォトマスクの主面の欠陥を検出した後に、改めて該欠陥やその修正箇所をマクロ観察で検査することがある。しかしながら、上述したような外観検査装置およびそれを用いた外観検査方法では、ミクロ観察により検出された該欠陥やその修正箇所を目視で観察できるように指し示せなかった。このため、該欠陥やその修正箇所をマクロ観察することが容易ではなかった。 In the macro observation, it is necessary to acquire the defect position with high accuracy. Furthermore, after detecting a defect on the main surface of a large photomask by micro observation, the defect and its corrected part may be inspected again by macro observation. However, in the appearance inspection apparatus and the appearance inspection method using the same as described above, the defect detected by micro observation and the corrected part thereof cannot be pointed out visually. For this reason, it is not easy to perform macro observation of the defect and the corrected part.
　本発明は、マクロ観察においては精度よく欠陥位置を取得でき、ミクロ観察により検出された欠陥やその修正箇所を目視できるように指し示すことができる外観検査装置および外観検査方法を提供することを主目的とする。 The main object of the present invention is to provide an appearance inspection apparatus and an appearance inspection method capable of obtaining a defect position with high accuracy in macro observation and pointing so that a defect detected by micro observation and a corrected portion thereof can be visually observed. And
　上記課題を解決するために、本発明は、目視観察に基づいて指し示される大型フォトマスク主面の目視指定位置を指し示す目視指定手段と、目視指定情報を取得する目視指定情報取得手段と、上記目視指定情報から目視指定位置を示す上記大型フォトマスクの主面の二次元座標を算出する二次元座標算出手段と、上記大型フォトマスクの主面の各位置を観察可能な位置に移動可能な顕微鏡と、上記二次元座標で示される上記大型フォトマスクの主面の位置を観察可能な位置に上記顕微鏡を移動させる顕微鏡駆動手段と、上記大型フォトマスクの主面の任意の位置を示す二次元座標を入力する二次元座標入力手段と、を備えることを特徴とする外観検査装置を提供する。 In order to solve the above-mentioned problems, the present invention provides a visual designation means for indicating a visual designation position of a main surface of a large photomask designated based on visual observation, a visual designation information acquisition means for obtaining visual designation information, and Two-dimensional coordinate calculation means for calculating the two-dimensional coordinates of the main surface of the large photomask indicating the visually specified position from the visual specification information, and a microscope capable of moving each position of the main surface of the large photomask to an observable position A microscope driving means for moving the microscope to a position where the position of the main surface of the large photomask indicated by the two-dimensional coordinates can be observed, and two-dimensional coordinates indicating an arbitrary position of the main surface of the large photomask And a two-dimensional coordinate input means for inputting a visual inspection apparatus.
　本発明によれば、マクロ観察およびミクロ観察の両方からなる外観検査による欠陥の検査を容易に行うことができる。 According to the present invention, it is possible to easily inspect defects by visual inspection consisting of both macro observation and micro observation.
　上記発明においては、上記二次元座標入力手段により入力された二次元座標から、上記目視指定情報を算出する目視指定情報算出手段を備えることが好ましい。 In the above invention, it is preferable to include visual designation information calculation means for calculating the visual designation information from the two-dimensional coordinates input by the two-dimensional coordinate input means.
　上記発明においては、上記目視指定情報取得手段は、面積を有する領域を示す上記目視指定情報を取得することが好ましい。転写パターンの線幅によって生じるムラ、汚れ等は欠陥の領域を指定して線幅、反射率、透過率等を測定して原因を調査するほうが効果的であるからである。 In the above invention, it is preferable that the visual designation information acquisition means acquires the visual designation information indicating an area having an area. This is because it is more effective to investigate the cause of unevenness, dirt, etc. caused by the line width of the transfer pattern by specifying the defect area and measuring the line width, reflectance, transmittance, and the like.
　上記発明においては、光源の種類が互いに異なる複数の観察用照明をさらに有することが好ましい。目視観察において、多様な種類の欠陥を検出することが容易になるからである。 In the above invention, it is preferable to further have a plurality of illuminations for observation with different types of light sources. This is because it becomes easy to detect various types of defects in visual observation.
　また、上記発明においては、上記大型フォトマスクの主面に平行な回動軸まわりに上記大型フォトマスクを回動させる回動機構をさらに有し、上記大型フォトマスクの主面を床面と平行な方向から回動軸まわりに回転可能な角度が９０°以上であることが好ましい。上記大型フォトマスクの表面の目視観察が容易になるからである。 Further, in the above invention, there is further provided a rotation mechanism for rotating the large photomask around a rotation axis parallel to the main surface of the large photomask, and the main surface of the large photomask is parallel to the floor surface. It is preferable that the angle capable of rotating around the rotation axis from any direction is 90 ° or more. This is because visual observation of the surface of the large photomask is facilitated.
　また、上記発明においては、上記回転可能な角度が２７０°以上であることが好ましい。上記大型フォトマスクの裏面の目視観察が容易になるからである。 Further, in the above invention, it is preferable that the rotatable angle is 270 ° or more. This is because visual observation of the back surface of the large photomask is facilitated.
　また、上記発明においては、上記大型フォトマスクの主面を撮像する撮像装置をさらに有することが好ましい。上記大型フォトマスクの主面の状態を周知させることができるからである。 In the above invention, it is preferable to further include an imaging device for imaging the main surface of the large photomask. This is because the state of the main surface of the large photomask can be made known.
　また、本発明は、目視観察に基づいて指し示される大型フォトマスクの主面の欠陥の目視指定情報を取得する目視指定情報取得工程と、上記目視指定情報から目視指定位置を示す上記大型フォトマスクの主面の二次元座標を算出する二次元座標算出工程と、上記二次元座標で示される上記大型フォトマスクの主面の位置を顕微鏡により観察するミクロ観察工程と、を備えることを特徴とする外観検査方法を提供する。 The present invention also provides a visual designation information acquisition step for obtaining visual designation information of defects on the main surface of a large photomask pointed to based on visual observation, and the large photomask indicating a visual designation position from the visual designation information. A two-dimensional coordinate calculation step for calculating the two-dimensional coordinates of the main surface of the first and second micro-observation steps for observing the position of the main surface of the large-sized photomask indicated by the two-dimensional coordinates with a microscope. Provide an appearance inspection method.
　本発明によれば、マクロ観察により検出された欠陥をミクロ観察することが容易である。 According to the present invention, it is easy to micro-observe defects detected by macro observation.
　さらに、上記外観検査方法では、上記目視指定情報取得工程は、外観の観察により上記大型フォトマスクの主面に存在する欠陥の有無を検査する欠陥検査工程内で行われ、上記欠陥検査工程が、上記大型フォトマスクの主面に対して観察用照明を一定の照射角度で照射することにより上記大型フォトマスクの主面に照射領域を設け、上記照射領域を上下左右に動かすことにより上記大型フォトマスクの主面の全面を検査する全面検査を行い、上記全面検査は、上記観察用照明の上記大型フォトマスクの主面に対する照射角度を変えて少なくとも２回行うものであることが好ましい。 Further, in the appearance inspection method, the visual designation information acquisition step is performed in a defect inspection step for inspecting the presence or absence of defects present on the main surface of the large photomask by observing the appearance, and the defect inspection step is An irradiation area is provided on the main surface of the large photomask by irradiating the main surface of the large photomask with observation illumination at a fixed irradiation angle, and the large photomask is moved by moving the irradiation area up, down, left and right. It is preferable to perform a full-scale inspection for inspecting the entire main surface, and to perform the full-surface inspection at least twice by changing the irradiation angle of the observation illumination with respect to the main surface of the large-sized photomask.
　さらに、本発明は、大型フォトマスクの主面の欠陥を修正する欠陥修正工程と、上記欠陥の修正箇所を示す上記大型フォトマスクの主面の二次元座標から、目視指定情報を算出する目視指定情報算出工程と、上記欠陥の修正箇所を上記目視指定情報により目視観察を行うマクロ観察工程と、を備えることを特徴とする外観検査方法を提供する。
　本発明によれば、ミクロ観察により検出された欠陥やその修正箇所をマクロ観察することが容易である。 Furthermore, the present invention provides a visual designation that calculates visual designation information from a defect correction step for correcting a defect on the main surface of the large photomask and a two-dimensional coordinate of the main surface of the large photomask that indicates the correction location of the defect. There is provided an appearance inspection method comprising: an information calculation step; and a macro observation step of visually observing a corrected portion of the defect with the visual designation information.
According to the present invention, it is easy to perform macro observation of a defect detected by micro observation and its corrected portion.
　また、本発明は、大型フォトマスクの主面に対して観察用照明を一定の照射角度で照射することにより上記大型フォトマスクの主面に照射領域を設け、上記照射領域を上下左右に動かすことにより上記大型フォトマスクの主面の全面を検査する全面検査を行い、上記大型フォトマスクの主面に存在する欠陥の有無を検査する欠陥検査方法であって、上記全面検査は、上記観察用照明の上記大型フォトマスクの主面に対する照射角度を変えて少なくとも２回行うことを特徴とする欠陥検査方法を提供する。 Further, the present invention provides an irradiation area on the main surface of the large photomask by irradiating observation illumination at a predetermined irradiation angle on the main surface of the large photomask, and moves the irradiation area up, down, left and right. A defect inspection method for inspecting the entire main surface of the large-sized photomask by inspecting the presence or absence of defects present on the main surface of the large-sized photomask, wherein the entire surface inspection includes the observation illumination The defect inspection method is characterized in that it is performed at least twice by changing the irradiation angle with respect to the main surface of the large-sized photomask.
　上記欠陥検査方法において、上記全面検査は、上記照射角度を１５°～４５°の範囲内の角度で行う低照射角全面検査と、上記照射角度が４５°～７５°の範囲内の角度で行う高照射角全面検査とを含むことがこのましい。 In the defect inspection method, the whole surface inspection is performed at a low irradiation angle full surface inspection in which the irradiation angle is within a range of 15 ° to 45 ° and an irradiation angle within the range of 45 ° to 75 °. It is desirable to include high-angle full-field inspection.
　さらに、上記全面検査が、上記大型フォトマスクの一つの辺側から上記一つの辺に対し直交する方向に上記観察用照明を照射し、かつ上記一つの辺に対して平行に移動しながら検査し、上記一つの辺の長さ分検査した後、上記一つの辺に直交する方向に照射領域を所定の距離で移動させる工程を繰り返し行うことにより、大型フォトマスク全面を検査する辺全面検査であることがこのましく、特に、上記辺全面検査を、上記大型フォトマスクの４つの辺に対して行うことが好ましい。 Further, the entire surface inspection is performed while irradiating the observation illumination in a direction perpendicular to the one side from one side of the large photomask and moving in parallel with the one side. In this case, the entire side of the large photomask is inspected by repeatedly performing the process of moving the irradiation region by a predetermined distance in a direction orthogonal to the one side after inspecting the length of the one side. In particular, it is particularly preferable to perform the entire side inspection on the four sides of the large photomask.
　上記欠陥検査方法では、上記全面検査における上記照射領域の移動速度が、５ｃｍ／秒～９ｃｍ／秒の範囲内であることが好ましい。
　上記目視指定情報取得工程において、上記観察用照明が、制御部により上記大型フォトマスクの主面に対する照射光の照射状態および非照射状態を交互に繰り返すことが好ましい。中でも、上記観察用照明を制御部により上記非照射状態として、レーザーポインターで大型フォトマスクの主面の欠陥の目視指定位置を取得する方法や、上記照射状態および非照射状態を交互に高速で切り替えることにより上記大型フォトマスク上の照射光の輝度を低減させた状態で、レーザーポインターで大型フォトマスクの主面の欠陥の目視指定位置を取得する方法が好ましい。 In the defect inspection method, it is preferable that the moving speed of the irradiation region in the entire surface inspection is in a range of 5 cm / second to 9 cm / second.
In the visual designation information acquisition step, it is preferable that the observation illumination alternately repeats the irradiation state and non-irradiation state of irradiation light on the main surface of the large photomask by the control unit. Above all, the observation illumination is set to the non-irradiation state by the control unit, and a method of acquiring a visually designated position of a defect on the main surface of the large photomask with a laser pointer, or the irradiation state and the non-irradiation state are alternately switched at high speed. Thus, it is preferable to obtain a visually designated position of a defect on the main surface of the large photomask with a laser pointer in a state where the brightness of the irradiation light on the large photomask is reduced.
　本発明においては、マクロ観察およびミクロ観察の両方からなる外観検査による欠陥の検査を容易に行うことができるという効果を奏する。 In the present invention, there is an effect that it is possible to easily inspect defects by appearance inspection including both macro observation and micro observation.
本発明の外観検査装置の一例を示す概略側面図である。It is a schematic side view which shows an example of the external appearance inspection apparatus of this invention. 図１に示される外観検査装置の第１の動作を説明する模式図である。It is a schematic diagram explaining the 1st operation | movement of the external appearance inspection apparatus shown by FIG. 図１に示される外観検査装置の第２の動作を示す模式図である。It is a schematic diagram which shows the 2nd operation | movement of the external appearance inspection apparatus shown by FIG. 図１に示される観察者から目視される大型フォトマスクを示した概略図である。It is the schematic which showed the large sized photomask visually recognized by the observer shown by FIG. 第１態様の外観検査方法の一例を示すフローチャートである。It is a flowchart which shows an example of the external appearance inspection method of a 1st aspect. 第２態様の外観検査方法の一例を示すフローチャートである。It is a flowchart which shows an example of the external appearance inspection method of a 2nd aspect. 欠陥検査方法を説明するための説明図である。It is explanatory drawing for demonstrating a defect inspection method. 本発明の欠陥検査方法の一例を示す説明図である。It is explanatory drawing which shows an example of the defect inspection method of this invention. 本発明の欠陥検査方法の一例を示す説明図である。It is explanatory drawing which shows an example of the defect inspection method of this invention. 本発明の欠陥検査方法の一例を示す説明図である。It is explanatory drawing which shows an example of the defect inspection method of this invention. 本発明の外観検査装置の一例を説明するための説明図である。It is explanatory drawing for demonstrating an example of the external appearance inspection apparatus of this invention. 本発明の外観検査装置の一例を示すフローチャートである。It is a flowchart which shows an example of the external appearance inspection apparatus of this invention. 本発明の外観検査装置の一例を示すフローチャートである。It is a flowchart which shows an example of the external appearance inspection apparatus of this invention. 本発明の外観検査装置における欠陥を発見するための光源の一例を示す説明図である。It is explanatory drawing which shows an example of the light source for discovering the defect in the external appearance inspection apparatus of this invention. 本発明の外観検査装置における欠陥を発見するための光源の他の例を示す説明図である。It is explanatory drawing which shows the other example of the light source for discovering the defect in the external appearance inspection apparatus of this invention.
　以下、本発明の外観検査装置および外観検査方法について詳細に説明する。 Hereinafter, the appearance inspection apparatus and the appearance inspection method of the present invention will be described in detail.
Ａ．外観検査装置
　本発明の外観検査装置は、目視観察に基づいて指し示される大型フォトマスク主面の目視指定位置を指し示す目視指定手段と、目視指定情報から、上記目視指定位置を示す上記大型フォトマスクの主面の二次元座標を算出する二次元座標算出手段と、上記大型フォトマスクの主面の各位置を観察可能な位置に移動可能な顕微鏡と、上記二次元座標で示される上記大型フォトマスクの主面の位置を観察可能な位置に上記顕微鏡を移動させる顕微鏡駆動手段と、上記大型フォトマスクの主面の任意の位置を示す二次元座標を入力する二次元座標入力手段と、を備えることを特徴とする。ここで、本発明において、「大型フォトマスクの主面」とは、大型フォトマスクの表面および裏面を意味する。 A. Appearance inspection apparatus The appearance inspection apparatus according to the present invention includes a visual designation means for indicating a visual designation position of a main surface of a large photomask designated based on visual observation, and the large photomask indicating the visual designation position from visual designation information. A two-dimensional coordinate calculating means for calculating two-dimensional coordinates of the main surface of the optical microscope, a microscope capable of moving each position of the main surface of the large photomask to an observable position, and the large photomask indicated by the two-dimensional coordinates A microscope driving means for moving the microscope to a position where the position of the principal surface of the large-sized photomask can be observed, and a two-dimensional coordinate input means for inputting a two-dimensional coordinate indicating an arbitrary position of the principal surface of the large photomask. It is characterized by. Here, in the present invention, the “main surface of a large photomask” means the front and back surfaces of the large photomask.
　本発明の外観検査装置の一例の構成および動作について図面を参照しながら説明する。図１は、本発明の外観検査装置の一例を示す概略側面図である。なお、図１において、Ｘ１方向とは床面２と平行な方向であり、Ｙ１方向とは床面２と平行かつＸ１方向と垂直な方向であり、Ｚ１方向とは床面２と垂直な方向である。 The configuration and operation of an example of the appearance inspection apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a schematic side view showing an example of an appearance inspection apparatus according to the present invention. In FIG. 1, the X1 direction is a direction parallel to the floor surface 2, the Y1 direction is a direction parallel to the floor surface 2 and perpendicular to the X1 direction, and the Z1 direction is a direction perpendicular to the floor surface 2. It is.
　最初に、図１に示される外観検査装置１００の構成について説明する。
　外観検査装置１００は、図１に示されるように、床面２に設置された基部５と、基部５に移動可能に設置された架台１０と、架台１０に回転軸１２を介して設置された基板支持枠１４と、を備える。また、外観検査装置１００は、図１に示されるように、床面２に設置されたステージ１６と、ステージ１６に取り付けられたレーザーポインター２０および顕微鏡５０と、操作部３０と、コンピュータ４０と、を備えている。コンピュータ４０は、表示部４０ａ、制御部４０ｂ、および記憶部４０ｃを有している。 First, the configuration of the appearance inspection apparatus 100 shown in FIG. 1 will be described.
As shown in FIG. 1, the appearance inspection apparatus 100 is installed on a base 5 installed on the floor 2, a gantry 10 movably installed on the base 5, and a gantry 10 via a rotary shaft 12. A substrate support frame 14. As shown in FIG. 1, the appearance inspection apparatus 100 includes a stage 16 installed on the floor 2, a laser pointer 20 and a microscope 50 attached to the stage 16, an operation unit 30, a computer 40, It has. The computer 40 includes a display unit 40a, a control unit 40b, and a storage unit 40c.
　基板支持枠１４は表面から裏面まで貫通する開口部１４ａを有し、基板支持枠１４に固定された大型フォトマスク７０の表面７０ａおよび裏面７０ｂは、基板支持枠１４の表面側および裏面側から開口部１４ａを介して観察可能である。架台１０は、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、基部５に対して±Ｙ１方向に移動可能である。基板支持枠１４は、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、架台１０による駆動で±Ｚ１方向に移動可能であり、かつＸ１方向に平行な回転軸１２まわりに回動可能である。レーザーポインター２０は、ステージ１６の表面１６ａにおいて±Ｘ１方向および±Ｚ１方向の各位置に移動可能であり、大型フォトマスク７０の表面７０ａおよび裏面７０ｂの各位置を指し示すことができる。ステージ１６の表面１６ａにおけるレーザーポインター２０の位置およびレーザーポインター２０の後述する指示方向は、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより制御可能である。 The substrate support frame 14 has an opening 14 a that penetrates from the front surface to the back surface, and the front surface 70 a and the back surface 70 b of the large photomask 70 fixed to the substrate support frame 14 are opened from the front surface side and the back surface side of the substrate support frame 14. It can be observed through the part 14a. The gantry 10 can be moved in the ± Y1 direction with respect to the base 5 by giving a predetermined instruction to the control unit 40 b by a key operation of the operation unit 30. The substrate support frame 14 can be moved in the ± Z1 direction by driving by the gantry 10 by giving a predetermined instruction to the control unit 40b by a key operation of the operation unit 30, and around the rotation axis 12 parallel to the X1 direction. It can be rotated. The laser pointer 20 can be moved to each position in the ± X1 direction and ± Z1 direction on the front surface 16a of the stage 16, and can indicate each position on the front surface 70a and the back surface 70b of the large photomask 70. The position of the laser pointer 20 on the surface 16a of the stage 16 and the direction of the laser pointer 20 to be described later can be controlled by giving predetermined instructions to the control unit 40b by key operation of the operation unit 30.
　顕微鏡５０は、ステージ１６の表面１６ａにおいて±Ｘ１方向および±Ｚ１方向の各位置に移動可能である。このため、顕微鏡５０は、架台１０の移動ならびに基板支持枠１４の移動および回動により観察可能な位置に配置された大型フォトマスク７０の表面７０ａおよび裏面７０ｂの各位置を観察する位置に移動することができる。 The microscope 50 is movable to each position in the ± X1 direction and the ± Z1 direction on the surface 16a of the stage 16. For this reason, the microscope 50 moves to a position for observing each position of the front surface 70a and the back surface 70b of the large-sized photomask 70 disposed at a position where it can be observed by the movement of the gantry 10 and the movement and rotation of the substrate support frame 14. be able to.
　続いて、図１に示される外観検査装置１００の動作について説明する。
　外観検査装置１００の動作には、観察者２００が、大型フォトマスク７０の外観検査を目視により観察するマクロ観察および顕微鏡で詳細に観察するミクロ観察の順番に行う場合の第１の動作と、観察者２００が、ミクロ観察で得られた欠陥の情報を用いてマクロ観察を行う場合の第２の動作の二通りがある。 Next, the operation of the appearance inspection apparatus 100 shown in FIG. 1 will be described.
The operation of the appearance inspection apparatus 100 includes the first operation in the case where the observer 200 performs the appearance inspection of the large photomask 70 in the order of macro observation for visual observation and micro observation for detailed observation with a microscope. There are two types of second operations when the person 200 performs macro observation using information of defects obtained by micro observation.
　図２は、図１に示される外観検査装置１００の第１の動作を説明する模式図である。図２（ａ）は、図１に示されるレーザーポインター２０および大型フォトマスク７０を模式的に示す図であり、図２（ｂ）は、図１に示される顕微鏡５０および大型フォトマスク７０を模式的に示す図である。なお、図２において、Ｘ２方向とは大型フォトマスク７０の表面７０ａの一辺と平行な方向であり、Ｙ２方向とは大型フォトマスク７０の表面７０ａと平行かつＸ２方向と垂直な方向であり、Ｚ２方向とは大型フォトマスク７０の表面７０ａと垂直な方向である。図１において、大型フォトマスク７０の表面７０ａおよび裏面７０ｂを床面２と平行な方向から回動軸１２まわりに回転させる角度θｘが０°である場合には、図２におけるＸ２方向、Ｙ２方向、およびＺ２方向は、図１におけるＸ１方向、Ｙ１方向、およびＺ１方向と一致する。 FIG. 2 is a schematic diagram for explaining a first operation of the appearance inspection apparatus 100 shown in FIG. 2A schematically shows the laser pointer 20 and the large photomask 70 shown in FIG. 1, and FIG. 2B schematically shows the microscope 50 and the large photomask 70 shown in FIG. FIG. In FIG. 2, the X2 direction is a direction parallel to one side of the surface 70a of the large photomask 70, the Y2 direction is a direction parallel to the surface 70a of the large photomask 70 and perpendicular to the X2 direction, Z2 The direction is a direction perpendicular to the surface 70 a of the large photomask 70. In FIG. 1, when the angle θx for rotating the front surface 70a and the back surface 70b of the large photomask 70 around the rotation axis 12 from the direction parallel to the floor surface 2 is 0 °, the X2 direction and the Y2 direction in FIG. , And the Z2 direction coincide with the X1, Y1, and Z1 directions in FIG.
　図１に示される外観検査装置１００の第１の動作が行われる場合には、まず、観察者２００が、目視により大局的に観察するマクロ観察を行うことにより、大型フォトマスク７０の表面７０ａの欠陥７２を検出する。
　この際の目視によるマクロ観察は、図１に示されるように観察用照明８０ａ～８０ｃのように固定した観察用照明を用いて観察してもよいが、図７に示すように観察者２００が、観察用照明８０を持ち、大型フォトマスク７０の表面７０ａに対し、上記観察用照明８０を所定の角度で傾けて照射し、左右に動かしながら観察して、欠陥７２を検査することが好ましい。 When the first operation of the appearance inspection apparatus 100 shown in FIG. 1 is performed, first, the observer 200 performs macro observation that observes globally by visual observation, whereby the surface 70a of the large photomask 70 is observed. A defect 72 is detected.
In this case, the macro observation by visual observation may be performed using observation illumination fixed as in the observation illuminations 80a to 80c as shown in FIG. 1, but the observer 200 as shown in FIG. It is preferable to inspect the defect 72 by holding the observation illumination 80, irradiating the surface 70a of the large photomask 70 with the observation illumination 80 inclined at a predetermined angle, and observing while moving left and right.
　次に、図１および図２（ａ）に示されるように、観察者２００が、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、レーザーポインター２０のレーザーで大型フォトマスク７０の表面７０ａの欠陥７２の位置を指し示す。 Next, as shown in FIG. 1 and FIG. 2A, the observer 200 gives a predetermined instruction to the control unit 40 b by operating the keys of the operation unit 30, so that a large photomask is used with the laser of the laser pointer 20. The position of the defect 72 on the surface 70a of 70 is indicated.
　次に、図１および図２（ａ）に示されるように、観察者２００が、欠陥７２の位置をレーザーで指し示した状態において、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、外観検査装置１００は、ステージ１６の表面１６ａにおけるレーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）、および大型フォトマスク７０の位置を制御部４０ｂにより取得し、記憶部４０ｃに記憶する。
　ここで、図７に示すようなマクロ観察が行われている場合は、上記操作部３０は観察者２００が保持し、欠陥７２を発見した場合、その場で上記操作ができるような携帯可能なコントローラータイプのものが好ましい。 Next, as shown in FIGS. 1 and 2A, the observer 200 gives a predetermined instruction to the control unit 40b by operating the key of the operation unit 30 in a state where the position of the defect 72 is pointed by the laser. Thus, the appearance inspection apparatus 100 acquires the indication direction (P θx , P θy ) of the laser pointer 20 on the surface 16a of the stage 16 and the position of the large photomask 70 by the control unit 40b and stores them in the storage unit 40c. .
Here, when the macro observation as shown in FIG. 7 is performed, the operation unit 30 is held by the observer 200, and when the defect 72 is found, the operation unit 30 is portable so that the operation can be performed on the spot. A controller type is preferred.
　ここで、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）とは、図２（ａ）に示されるように、Ｚ２方向の基準方向に対して、Ｘ２方向にＰθｘの角度、Ｙ２方向にＰθｙの角度傾いた方向を意味する。なお、基準方向は必ずしもＺ２方向に設定する必要はなく、例えば、図１におけるＹ１方向のような任意の方向に設定してもよい。 Here, the indication directions (P θx , P θy ) of the laser pointer 20 are, as shown in FIG. 2A, the angle of P θx in the X2 direction and the Y2 direction with respect to the reference direction in the Z2 direction. It means a direction inclined by an angle of P θy . The reference direction is not necessarily set in the Z2 direction, and may be set in an arbitrary direction such as the Y1 direction in FIG.
　次に、観察者２００が操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、外観検査装置１００は、ステージ１６の表面１６ａにおけるレーザーポインター２０の位置、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）、および大型フォトマスク７０の位置の幾何学的な関係から、欠陥７２の位置を示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）を制御部４０ｂにより算出し、記憶部４０ｃに記憶する。 Next, when the observer 200 gives a predetermined instruction to the control unit 40b by the key operation of the operation unit 30, the appearance inspection apparatus 100 causes the position of the laser pointer 20 on the surface 16a of the stage 16 and the direction of the laser pointer 20 to indicate. From the geometric relationship between (P θx , P θy ) and the position of the large photomask 70, the control unit 40 b determines the two-dimensional coordinates (Mx, My) of the surface 70 a of the large photomask 70 indicating the position of the defect 72. Calculate and store in the storage unit 40c.
　次に、図１および図２（ｂ）に示されるように、観察者２００が操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、大型フォトマスク７０を、架台１０の移動ならびに基板支持枠１４の移動および回動により観察可能な位置に移動させた上で、顕微鏡５０を基準位置から二次元座標（Ｍｘ，Ｍｙ）で示される大型フォトマスク７０の表面７０ａの位置を観察可能な位置に移動させる。これにより、観察者２００は顕微鏡５０の焦点を調整した後に、大型フォトマスク７０の表面７０ａの欠陥７２を顕微鏡５０で観察するミクロ観察を行うことができる。具体的には、図１においてθｘを９０°に設定し、大型フォトマスク７０をステージ１６の平行方向に回動し、顕微鏡５０を欠陥７２の二次元方向（Ｍｘ，Ｍｙ）に移動させる。 Next, as shown in FIG. 1 and FIG. 2B, when the observer 200 gives a predetermined instruction to the control unit 40 b by operating the keys of the operation unit 30, the large-size photomask 70 is moved to the gantry 10. In addition, the position of the surface 70a of the large-sized photomask 70 indicated by the two-dimensional coordinates (Mx, My) is observed from the reference position after the substrate support frame 14 is moved to a position where it can be observed by moving and rotating. Move to a possible position. Thereby, the observer 200 can perform micro observation of observing the defect 72 on the surface 70 a of the large photomask 70 with the microscope 50 after adjusting the focus of the microscope 50. Specifically, in FIG. 1, θx is set to 90 °, the large photomask 70 is rotated in the parallel direction of the stage 16, and the microscope 50 is moved in the two-dimensional direction (Mx, My) of the defect 72.
　以上の通り、外観検査装置１００の第１の動作においては、目視観察に基づいて指し示される大型フォトマスク７０の表面７０ａの欠陥７２の目視指定情報として、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）、および大型フォトマスク７０の位置を取得した上で、「大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）を算出することができる。よって、マクロ観察により検出された欠陥の位置を示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）を取得することができる。 As described above, in the first operation of the appearance inspection apparatus 100, the indication direction (P θx , P θx ,) of the indication direction of the laser pointer 20 as the visual designation information of the defect 72 on the surface 70a of the large photomask 70 pointed based on the visual observation. P θy ) and the position of the large photomask 70 are acquired, and then “the two-dimensional coordinates (Mx, My) of the surface 70a of the large photomask 70 can be calculated. It is possible to obtain the two-dimensional coordinates (Mx, My) of the surface 70a of the large photomask 70 indicating the position of
　なお、例えば、ステージ１６の表面１６ａにおけるレーザーポインター２０の位置を固定する場合は、図１および図２（ａ）に示されるように、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）、ならびに架台１０のＹ１方向の位置、高さＨ、および回転角θｘから決まる大型フォトマスク７０の位置を取得した上で、これらの位置情報から、欠陥７２の位置を示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）を算出することができる。なお、欠陥７２の位置を示す二次元座標（Ｍｘ，Ｍｙ）の算出方法は、この方法に限定されない。 For example, when the position of the laser pointer 20 on the surface 16a of the stage 16 is fixed, as shown in FIGS. 1 and 2A, the indication direction (P θx , P θy ) of the laser pointer 20, and After acquiring the position of the large photomask 70 determined from the position of the gantry 10 in the Y1 direction, the height H, and the rotation angle θx, the position information of the surface 70a of the large photomask 70 indicating the position of the defect 72 is obtained from these position information. Two-dimensional coordinates (Mx, My) can be calculated. The method for calculating the two-dimensional coordinates (Mx, My) indicating the position of the defect 72 is not limited to this method.
　図３は、図１に示される外観検査装置１００の第２の動作を示す模式図である。図３（ａ）は、図１に示される大型フォトマスク７０を示す図であり、図３（ｂ）は、図１に示されるレーザーポインター２０および大型フォトマスク７０を示す図である。なお、図３におけるＸ２方向、Ｙ２方向、およびＺ２方向は、図２におけるＸ２方向、Ｙ２方向、およびＺ２方向と一致する。 FIG. 3 is a schematic diagram showing a second operation of the appearance inspection apparatus 100 shown in FIG. FIG. 3A is a diagram showing the large photomask 70 shown in FIG. 1, and FIG. 3B is a diagram showing the laser pointer 20 and the large photomask 70 shown in FIG. Note that the X2, Y2, and Z2 directions in FIG. 3 coincide with the X2, Y2, and Z2 directions in FIG.
　図１に示される外観検査装置１００の第２の動作が行われる場合には、まず、図１および図３（ａ）に示されるように、ミクロ観察を自動的に行う外観検査機により自動的に大型フォトマスク７０の表面７０ａの欠陥７４を検出した後に、欠陥７４を修正する。この際には、大型フォトマスク７０の表面７０ａの欠陥の修正箇所７４ｃあるいは欠陥７４の位置を示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）を欠陥の種類等と共にデータ化する。次に、観察者２００が、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、欠陥の修正箇所７４ｃあるいは欠陥７４の位置を示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）を記憶部４０ｃに入力する。 When the second operation of the appearance inspection apparatus 100 shown in FIG. 1 is performed, first, as shown in FIGS. 1 and 3 (a), the appearance inspection machine automatically performs micro observation automatically. After detecting the defect 74 on the surface 70a of the large photomask 70, the defect 74 is corrected. At this time, two-dimensional coordinates (Mx, My) of the surface 70a of the large photomask 70 indicating the position of the defect correction portion 74c or the defect 74 on the surface 70a of the large photomask 70 are converted into data along with the type of defect. . Next, when the observer 200 gives a predetermined instruction to the control unit 40b by operating the keys of the operation unit 30, the two-dimensional coordinates of the surface 70a of the large photomask 70 indicating the position of the defect correction location 74c or the defect 74 are shown. (Mx, My) is input to the storage unit 40c.
　このように、本発明の外観検査装置は、マクロ観察により検出された欠陥の位置を示す大型フォトマスクの主面の二次元座標を取得するだけではなく、ミクロ観察により検出された欠陥の修正箇所あるいは欠陥の位置を示す二次元座標を入力する手段を備えている。よって、マクロ観察およびミクロ観察の両方で検出した欠陥の検査を容易に行うことができる。 As described above, the appearance inspection apparatus of the present invention not only obtains the two-dimensional coordinates of the main surface of the large photomask indicating the position of the defect detected by the macro observation, but also corrects the defect detected by the micro observation. Alternatively, a means for inputting two-dimensional coordinates indicating the position of the defect is provided. Therefore, it is possible to easily inspect defects detected by both macro observation and micro observation.
　次に、図１および図３（ａ）に示されるように、ステージ１６の表面１６ａにおけるレーザーポインター２０の設置位置、欠陥の修正箇所７４ｃを示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）、および大型フォトマスク７０の位置の幾何学的な関係から、欠陥の修正箇所７４ｃを指し示すレーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）を制御部４０ｂにより算出し、記憶部４０ｃに記憶する。 Next, as shown in FIGS. 1 and 3A, the two-dimensional coordinates (Mx) of the surface 70a of the large photomask 70 showing the installation position of the laser pointer 20 on the surface 16a of the stage 16 and the defect correction location 74c. , My), and the geometric relationship between the positions of the large photomask 70, the control unit 40b calculates the pointing direction (P θx , P θy ) of the laser pointer 20 pointing to the defect correction portion 74c, and the storage unit 40c. To remember.
　次に、図１および図３（ｂ）に示されるように、観察者２００が、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、外観検査装置１００が、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）を使用して、欠陥の修正箇所７４ｃを観察者２００が目視できるようにレーザーポインター２０のレーザーで指し示す。これにより、観察者２００は、欠陥の修正箇所７４ｃを目視により観察することができる。 Next, as shown in FIG. 1 and FIG. 3B, when the observer 200 gives a predetermined instruction to the control unit 40 b by operating the keys of the operation unit 30, the appearance inspection apparatus 100 is operated by the laser pointer 20. The pointing direction (P θx , P θy ) of the laser pointer 20 is pointed by the laser of the laser pointer 20 so that the observer 200 can visually recognize the defect correction portion 74c. Thereby, the observer 200 can visually observe the defect correction portion 74c.
　以上の通り、外観検査装置１００の第２の動作においては、ミクロ観察により検出された大型フォトマスク７０の表面７０ａの欠陥７４を修正した上で、欠陥の修正箇所７４ｃを示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）から、欠陥の修正箇所７４ｃを目視するための目視指定情報として、欠陥の修正箇所７４ｃを指し示すレーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）を算出することができる。このため、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）を使用して、欠陥の修正箇所７４ｃを目視できるように指し示すことができる。よって、ミクロ観察により検出された欠陥の修正箇所７４ｃをマクロ観察することができる。 As described above, in the second operation of the appearance inspection apparatus 100, after correcting the defect 74 on the surface 70a of the large photomask 70 detected by micro observation, the large photomask 70 showing the defect correction portion 74c is corrected. From the two-dimensional coordinates (Mx, My) of the surface 70a, the indication direction (P θx , P θy ) of the laser pointer 20 pointing to the defect correction portion 74c is calculated as visual designation information for viewing the defect correction portion 74c. can do. For this reason, it is possible to point the defect correction portion 74c so that it can be visually checked by using the indication direction ( Pθx , Pθy ) of the laser pointer 20. Therefore, it is possible to perform macro observation of the defect correction portion 74c detected by micro observation.
　したがって、本発明によれば、マクロ観察により検出された欠陥の位置を示す大型フォトマスクの主面の二次元座標を取得することができる。さらに、ミクロ観察により検出された欠陥やその修正箇所を目視できるように指し示すことができる。よって、マクロ観察およびミクロ観察の両方からなる外観検査による欠陥の検査を容易に行うことができる。 Therefore, according to the present invention, it is possible to acquire the two-dimensional coordinates of the main surface of the large photomask indicating the position of the defect detected by the macro observation. Furthermore, the defect detected by micro observation and the corrected part can be pointed out so that it can be visually observed. Therefore, it is possible to easily inspect defects by appearance inspection including both macro observation and micro observation.
１．目視指定情報取得手段
　上記目視指定情報取得手段は、目視観察に基づいて指し示される大型フォトマスクの主面の目視指定位置の目視指定情報を取得する手段である。 1. Visual designation information acquisition means The visual designation information acquisition means is means for obtaining visual designation information of the visual designation position of the main surface of the large photomask pointed to based on visual observation.
　上記目視指定情報取得手段としては、特に限定されないが、例えば、図１および図２（ａ）に示されるように、大型フォトマスク７０の表面７０ａの欠陥７４の位置をレーザーポインター２０のレーザーで指し示した状態において、制御部４０ｂに所定の指示を与えることにより、ステージ１６の表面１６ａにおけるレーザーポインター２０の位置、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）、および大型フォトマスク７０の位置を制御部４０ｂにより取得する。 The visual designation information acquisition means is not particularly limited. For example, as shown in FIGS. 1 and 2A, the position of the defect 74 on the surface 70a of the large photomask 70 is indicated by the laser of the laser pointer 20. In this state, by giving a predetermined instruction to the control unit 40b, the position of the laser pointer 20 on the surface 16a of the stage 16, the indication direction (P θx , P θy ) of the laser pointer 20, and the position of the large photomask 70 are determined. Obtained by the control unit 40b.
　ここで、図４は、図１に示される観察者２００から目視される大型フォトマスク７０の表面７０ａにおけるレーザーポインター２０のレーザーの照射位置の例を示した概略図である。上記目視指定情報取得手段としては、欠陥の位置を点と捉えた上で、レーザーポインター２０のレーザーで指し示す点を指定する手段でもよいし、欠陥の位置を矩形領域、円形領域、楕円形領域と捉えた上で、レーザーポインター２０のレーザーで指し示す矩形指定、円指定、楕円指定を用いる手段でもよいし、さらに欠陥の位置を直線と捉えた上で、レーザーポインター２０のレーザーで指し示す直線指定を用いる手段でもよい。 Here, FIG. 4 is a schematic view showing an example of the laser irradiation position of the laser pointer 20 on the surface 70a of the large photomask 70 viewed from the observer 200 shown in FIG. The visual designation information acquisition means may be a means for designating a point indicated by the laser of the laser pointer 20 after capturing the position of the defect as a point, and the position of the defect may be a rectangular area, a circular area, or an elliptical area. It is possible to use a rectangle designation, a circle designation, or an ellipse designation pointed to by the laser of the laser pointer 20 after capturing it, or use a line designation pointed to by the laser of the laser pointer 20 after capturing the position of the defect as a straight line. It may be a means.
　観察者２００は、欠陥の形状、分布によって、欠陥の位置の指定方法を適宜選択する。上記点指定を用いる上記目視指定情報取得手段では、制御部４０ｂに欠陥の位置が点であることを指示して、図４に示されるように点の位置４１１を指し示した時のレーザーポインターの指示方向（Ｐθｘ，Ｐθｙ）を取得する。また、上記矩形指定を用いる上記目視指定情報取得手段では、制御部４０ｂに欠陥の位置が矩形領域であることを指示して、図４に示されるように矩形領域の対角の位置４１２、４１３を指し示した時のレーザーポインターの指示方向（Ｐθｘ，Ｐθｙ）をそれぞれ取得する。また、上記円指定を用いる上記目視指定情報取得手段では、制御部４０ｂに欠陥の位置が円形領域であることを指示して、図４に示されるように円形領域の直径の中心の位置４１４および両端の位置４１５、４１６を指し示した時のレーザーポインターの指示方向（Ｐθｘ，Ｐθｙ）をそれぞれ取得する。なお、この手段は、円形領域の直径の中心の位置４１４および両端の位置４１５、４１６のどちらかの２点のみを指し示した時のレーザーポインターの指示方向（Ｐθｘ，Ｐθｙ）をそれぞれ取得するものでもよい。また、楕円指定を用いる上記目視指定情報取得手段では、制御部４０ｂに欠陥の位置が楕円形領域であることを指示して、図４に示されるように楕円形領域の中心の位置４１７、長軸の両端の位置４１８、４１９、および短軸の両端の位置４２０、４２１を指し示した時のレーザーポインターの指示方向（Ｐθｘ，Ｐθｙ）をそれぞれ取得すればよい。なお、この手段は、楕円形領域の中心の位置４１７、長軸の両端の位置４１８、４１９のどちらか、および短軸の両端の位置４２０、４２１のどちらかの３点のみを指し示した時のレーザーポインターの指示方向（Ｐθｘ，Ｐθｙ）をそれぞれ取得するものでもよい。さらに、直線指定を用いる上記目視指定情報取得手段では、制御部４０ｂに欠陥の位置が直線であることを指示して、図４に示されるように直線の両端の位置４２２、４２３を指し示した時のレーザーポインターの指示方向（Ｐθｘ，Ｐθｙ）をそれぞれ取得すればよい。 The observer 200 appropriately selects a defect position designation method according to the shape and distribution of the defect. In the visual designation information acquisition means using the point designation, the control unit 40b is instructed that the position of the defect is a point, and the laser pointer instruction when the point position 411 is pointed as shown in FIG. The direction (P θx , P θy ) is acquired. Further, the visual designation information acquisition means using the rectangular designation instructs the control unit 40b that the position of the defect is a rectangular area, and as shown in FIG. 4, diagonal positions 412 and 413 of the rectangular area. The pointing directions (P θx , P θy ) of the laser pointer when pointing to are respectively acquired. Further, in the visual designation information acquisition means using the circle designation, the controller 40b is instructed that the position of the defect is a circular area, and the center position 414 of the diameter of the circular area as shown in FIG. The pointing directions (P θx , P θy ) of the laser pointer when pointing to the positions 415 and 416 at both ends are acquired. This means obtains the indication direction (P θx , P θy ) of the laser pointer when only the two points of the center position 414 and the both end positions 415 and 416 of the diameter of the circular region are indicated. It may be a thing. Further, in the visual designation information acquisition means using the ellipse designation, the controller 40b is instructed that the position of the defect is an elliptical area, and as shown in FIG. The pointing directions (P θx , P θy ) of the laser pointer when pointing to the positions 418 and 419 at both ends of the axis and the positions 420 and 421 at both ends of the short axis may be acquired. This means that only three points of the center position 417 of the elliptical region, the positions 418 and 419 at both ends of the long axis, and the positions 420 and 421 at both ends of the short axis are indicated. The directions indicated by the laser pointers (P θx , P θy ) may be acquired. Furthermore, when the visual designation information acquisition means using the straight line designation instructs the control unit 40b that the position of the defect is a straight line and points to the positions 422 and 423 at both ends of the straight line as shown in FIG. The laser pointer pointing directions (P θx , P θy ) may be acquired.
　表１は目視指定情報を示している。「属性」はレーザーポインター２０の領域指定方法を示している。「傾き」は図１の角度θｘ、「指示方向」はレーザーポインター２０の指示方向を示している。 Table 1 shows the visual designation information. “Attribute” indicates a method for designating the region of the laser pointer 20. “Inclination” indicates the angle θx in FIG. 1, and “Pointing direction” indicates the pointing direction of the laser pointer 20.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　上記目視指定情報取得手段としては、上記の方法を用いた手段に限定されるものではなく、上記大型フォトマスクの主面における欠陥を含む領域を指定できればよい。上記欠陥の位置の指定方法としては、点指定、矩形指定、円指定、楕円指定、直線指定に限定されるものではなく、欠陥の位置を最適に指定できればよい。なお、上記目視指定情報取得手段としては、上記目視指定情報として、上記大型フォトマスクの主面における点や直線の目視指定情報を取得する手段でもよいし、上記大型フォトマスクの主面における矩形領域、円形領域、楕円形領域等のような面積を有する領域の目視指定情報を取得する手段でもよいが、該面積を有する領域の目視指定情報を取得する手段が好ましい。 The visual designation information acquisition means is not limited to the means using the method described above, and it is only necessary to designate an area including a defect on the main surface of the large photomask. The method for designating the position of the defect is not limited to point designation, rectangle designation, circle designation, ellipse designation, and straight line designation, as long as the defect position can be designated optimally. The visual designation information acquisition means may be means for obtaining visual designation information of points and straight lines on the main surface of the large photomask as the visual designation information, or a rectangular area on the main surface of the large photomask. Means for acquiring visual designation information of an area having an area such as a circular area, an elliptical area, etc. may be used, but means for obtaining visual designation information of an area having the area is preferable.
２．目視指定手段
　本開示における目視指定手段は、目視観察に基づいて指し示される大型フォトマスク主面の目視指定位置を指し示す手段である。 2. Visual designation means The visual designation means in the present disclosure is a means for indicating the visual designation position of the main surface of the large-sized photomask designated based on the visual observation.
　上記目視指定手段としては、特に限定されないが、例えば、レーザーポインター、タッチパネルの表示画像内におけるポインター等が挙げられる。
　上記レーザーポインターとしては、図１に示されるように、観察者２００の頭上に配置されたものが好ましい。観察者２００が大型フォトマスク７０を目視により観察する際に妨げとならないからである。 The visual designation means is not particularly limited, and examples thereof include a laser pointer and a pointer in a display image on a touch panel.
As the laser pointer, as shown in FIG. 1, it is preferable to arrange the laser pointer above the observer 200. This is because it does not hinder the observer 200 when observing the large photomask 70 visually.
　また、上記レーザーとしては、例えば、赤色光や緑色光等が挙げられるが、赤色光が好ましい。目視で視認し易いからである。
　上記レーザーポインターに替えて、上記大型フォトマスク表面上に照射された際の径が、例えば５ｍｍ程度にできる高輝度ランプを用いてもよい。上記レーザーポインターでは、観察用照明を照射しつつ目視観察を行い、欠陥を発見した場合、観察用照明の照射領域内の輝度が高いため、上記欠陥部分を示すレーザーポインターのレーザーが確認できない可能性がある。このような場合は、上記レーザーポインターに替えて上記高輝度ランプを用いることにより、欠陥部分を捉えた上記観察用照明の照射領域内に上記高輝度ランプを欠陥部分近傍に重ねて照射し、その後観察用照明を消した後、上記高輝度ランプで上記欠陥部分を特定し、その位置を照射させることにより、欠陥部分の位置情報を取得させることが可能となる。 Examples of the laser include red light and green light, and red light is preferable. This is because it is easy to visually recognize.
Instead of the laser pointer, a high-intensity lamp whose diameter when irradiated on the surface of the large photomask can be about 5 mm, for example, may be used. In the above laser pointer, if a defect is found by performing visual observation while irradiating the illumination for observation, there is a possibility that the laser of the laser pointer indicating the above defective part cannot be confirmed because the brightness in the irradiation area of the illumination for observation is high There is. In such a case, by using the high-intensity lamp instead of the laser pointer, the high-intensity lamp is irradiated in the vicinity of the defect portion in the irradiation area of the observation illumination that captures the defect portion, and thereafter After the observation illumination is turned off, the defect portion is identified by the high-intensity lamp, and the position of the defect portion is irradiated to obtain the position information of the defect portion.
　このような高輝度ランプは、大型フォトマスク表面での照射領域の面積を変化されることが可能なものであってもよい。欠陥部分を捉えた上記観察用照明の照射部分に重ねて上記高輝度ランプを照射し、その後、高輝度ランプの照射領域を狭めることにより、欠陥部分の位置情報を取得させることが可能となるからである。 Such a high-intensity lamp may be capable of changing the area of the irradiation region on the surface of the large photomask. Since it is possible to acquire the position information of the defective portion by irradiating the high-intensity lamp on the irradiation portion of the observation illumination that captures the defective portion, and then narrowing the irradiation area of the high-intensity lamp. It is.
　このような高輝度ランプとしては、例えば、株式会社アイテックシステム製ＬＳＰ６８Ｘ２４０Ｗ－ＳＴ（商品名、光源：ＬＥＤ、色温度：６５００Ｋ）、ＰＯＬＡＲＩＯＮ社製ＰＳ－ＮＰ１（商品名、光源：Ｘｅｎｏｎ　ＨＩＤ　Ｌａｍｐ、色温度：４３００Ｋ）、セナーアンドバーンズ株式会社製３７０ＴＦＩ／Ｒ（商品名、光源：ハロゲンランプ、色温度：約３０００Ｋ）等を挙げることができる。
　また、上記目視指定情報取得手段としては、上記観察用照明が、上記大型フォトマスク表面を照射し、欠陥部分を発見した際に、欠陥部分を示すように影を生じさせ、その影の位置を特定する手段であってもよい。 As such a high-intensity lamp, for example, LSP68X240W-ST (trade name, light source: LED, color temperature: 6500K) manufactured by ITEC SYSTEM Co., Ltd., PS-NP1 (trade name, light source: Xenon HID Lamp, color) manufactured by POLARION Temperature: 4300K), 370TFI / R (trade name, light source: halogen lamp, color temperature: about 3000K) manufactured by Sener and Burns Co., Ltd., and the like.
In addition, as the visual designation information acquisition means, when the observation illumination illuminates the surface of the large photomask and finds a defective portion, a shadow is generated so as to indicate the defective portion, and the position of the shadow is determined. It may be a means for specifying.
　影を生じさせる手段としては、例えば、指し棒等の先端部分を有する部材を準備し、これを上記観察用照明と上記大型フォトマスク表面との間に挿入することにより、欠陥部分を指し示す影を生じさせる手段や、観察用照明に例えば十字等の影を生じさせるフィルターを脱着可能に配置し、フィルター無しの状態で観察を行い、欠陥を発見した際にフィルターを観察用照明の照射部に配置し、欠陥部分に影を生じさせる手段等を挙げることができる。
　このような影を生じさせた際の位置の特定は、影の位置を上記レーザーポインターのレーザーで指し示し、上述した方法により位置を特定する方法や、後述する撮像装置により影の部分を撮像し、この映像を解析して位置を特定する方法等を挙げることができる。 As a means for generating a shadow, for example, a member having a tip portion such as a pointer is prepared, and this is inserted between the illumination for observation and the surface of the large photomask so that a shadow pointing to the defective portion is generated. For example, a filter that creates a shadow, such as a cross, is detachably placed in the observation illumination, and the observation is performed without the filter, and when a defect is found, the filter is placed in the illumination area of the observation illumination. In addition, a means for causing a shadow in the defective portion can be exemplified.
Specification of the position when such a shadow is generated is indicated by pointing the position of the shadow with the laser of the laser pointer, specifying the position by the method described above, or imaging the shadow part by an imaging device described later, A method of analyzing the video and specifying the position can be cited.
　さらに、例えば上記観察用照明の光源の前に遮光物等を配置し、これを用いて上記大型フォトマスクの主面に対する照射光の照射状態および非照射状態を交互に繰り返すことにより目視指定位置を指し示すことができるようにしたものであってもよい。
　具体的には、非照射状態としてレーザーポインターで大型フォトマスクの主面の欠陥の目視指定位置を取得する態様や、照射状態および非照射状態を交互に高速で切り替えることにより上記大型フォトマスク上の照射光の輝度を低減させた状態で、レーザーポインターで大型フォトマスクの主面の欠陥の目視指定位置を取得する態様を挙げることができる。
　なお、上記「高速で切り替える」とは、７０Ｈｚ以上、より好ましくは１００Ｈｚ以上であることが好ましい。 Furthermore, for example, a light shielding object is arranged in front of the light source for the observation illumination, and the visual designation position is set by alternately repeating the irradiation state and the non-irradiation state of the irradiation light on the main surface of the large photomask. It may be one that can be pointed.
Specifically, a mode in which a visually designated position of a defect on the main surface of a large photomask is acquired with a laser pointer as a non-irradiation state, or on the large photomask by alternately switching between an irradiation state and a non-irradiation state at high speed A mode in which the visually designated position of the defect on the main surface of the large photomask is acquired with a laser pointer in a state where the brightness of the irradiation light is reduced can be mentioned.
The “switching at high speed” is preferably 70 Hz or more, more preferably 100 Hz or more.
　上述した方法を具現化する装置としては、上記観察用照明の光源の前に、回転可能な遮光物を配置し、欠陥部分を発見した際に、この遮光物を低速で回転させること、具体的には１Ｈｚ以下で回転させることにより観察用照明の大型フォトマスク表面での照射、非照射を繰り返すことにより、欠陥の検出とレーザーポインターの認識がしやすいようにしたり、あるいは、高速に回転させて照射面の照度を低下させ、上記レーザーポインターのレーザーの位置を確認できるようにしたりする装置を挙げることができる。
　また、欠陥部分を発見した際に、観察用照明の光源を低速でＯＮ／ＯＦＦさせることにより、大型フォトマスク表面での照射、非照射を繰り返したり、高速でＯＮ／ＯＦＦさせることにより照射面の照度を低下させ、同様にレーザーポインターでの位置確認ができるようにする装置であってもよい。この他にも照明の強度を０．５秒以上の間隔で繰り返し強弱をつけて照射面の照度を調整してもよい。 As an apparatus that embodies the above-described method, a rotatable shading object is arranged in front of the light source for the observation illumination, and when a defective part is found, the shading object is rotated at a low speed. In order to make it easier to detect defects and to recognize laser pointers by rotating irradiation at the surface of a large photomask for observation illumination repeatedly by rotating at 1 Hz or less, or rotating at high speed. An apparatus that reduces the illuminance on the irradiated surface and makes it possible to confirm the position of the laser of the laser pointer can be given.
In addition, when a defective part is discovered, the illumination light source is turned ON / OFF at a low speed, so that irradiation or non-irradiation is repeated on the surface of the large photomask, or the irradiation surface is turned ON / OFF at a high speed. It may be a device that reduces the illuminance and enables position confirmation with a laser pointer. In addition to this, the illumination intensity may be adjusted by repeatedly increasing and decreasing the intensity of the illumination at intervals of 0.5 seconds or more.
　このような装置としては、例えば、図１４および図１５に示す装置を挙げることができる。
　図１４（ａ）に示す装置は、ランプハウス１とランプハウスからの光を導光するライトガイド２とを有するものである。ランプハウス１は、ランプ３とランプ３からの光を反射する凹面鏡４とを有し、凹面鏡４からの光路を遮ることが可能な遮光板５、およびこの遮光板５を回転させる駆動部６を有する。駆動部６には遮光版５の回転数を調整する制御部が組み込まれている。図１４（ｂ）は、上記遮光板５の形態の一例を示すものであり、この形態の遮光板５は、２７０°の遮光領域７と９０°の透光領域８とを有する。一方、図１４（ｃ）には、１８０°の遮光領域７と１８０°の透光領域８とを有する遮光板５の他の形態を示す。 Examples of such an apparatus include the apparatuses shown in FIGS. 14 and 15.
The apparatus shown in FIG. 14A includes a lamp house 1 and a light guide 2 that guides light from the lamp house. The lamp house 1 includes a lamp 3 and a concave mirror 4 that reflects light from the lamp 3, and includes a light shielding plate 5 that can block an optical path from the concave mirror 4, and a drive unit 6 that rotates the light shielding plate 5. Have. The drive unit 6 incorporates a control unit that adjusts the rotational speed of the light-shielding plate 5. FIG. 14B shows an example of the form of the light shielding plate 5. The light shielding plate 5 in this form has a light shielding region 7 of 270 ° and a light transmitting region 8 of 90 °. On the other hand, FIG. 14C shows another embodiment of the light shielding plate 5 having a 180 ° light shielding region 7 and a 180 ° light transmitting region 8.
　図１４に示す装置は、二つの態様で用いることができる。まず、高輝度の光で把握できる欠陥の場合は、まず上記遮光板３を上記凹面鏡４からの光路を遮光しない位置に配置し、ライトガイド２の先端から照射される光で欠陥の有無を検査する。欠陥を発見した場合は、上記駆動部６により遮光板３を低速で回転させ、大型フォトマスク表面への照射、非照射を繰り返し、非照射状態の際、すなわち遮光板３で上記凹面鏡４からの光路を遮光したときに、上記レーザーポインターで欠陥を指し示し、位置を特定することが可能となる。 The apparatus shown in FIG. 14 can be used in two modes. First, in the case of a defect that can be grasped by high-intensity light, the light shielding plate 3 is first arranged at a position where the light path from the concave mirror 4 is not shielded, and the presence or absence of the defect is inspected by the light irradiated from the tip of the light guide 2 To do. When a defect is found, the light shielding plate 3 is rotated at a low speed by the driving unit 6 and irradiation and non-irradiation are repeated on the surface of the large photomask. When the light path is shielded, the position can be specified by pointing the defect with the laser pointer.
　一方、輝度を下げても欠陥が目視できる場合は、上記と同様にしてライトガイド２の先端から照射される光で欠陥を発見した場合は、上記遮光板３を高速で回転させ、大型フォトマスク表面での輝度を低下させ、この状態で上記レーザーポインターにより欠陥を指し示し、位置を特定することが可能となる。 On the other hand, if the defect is visible even if the brightness is lowered, if the defect is found with the light irradiated from the tip of the light guide 2 in the same manner as described above, the light shielding plate 3 is rotated at a high speed, and a large photomask is used. The brightness on the surface is lowered, and in this state, it is possible to point the defect with the laser pointer and specify the position.
　図１５に示す装置は、上記図１４に示す装置の遮光板５および駆動部６の替わりに、ランプ１のＯＮ／ＯＦＦを制御する制御部９が配置されている。図１５に示す装置の場合、ランプ１をしてはＬＥＤが用いられている。 In the apparatus shown in FIG. 15, a control unit 9 for controlling ON / OFF of the lamp 1 is arranged instead of the light shielding plate 5 and the drive unit 6 of the apparatus shown in FIG. In the case of the apparatus shown in FIG. 15, an LED is used as the lamp 1.
　図１５に示す装置においても、図１４の装置と同様に二つの態様で用いることが可能となる。すなわち、ＯＮ／ＯＦＦの制御を低速で行う場合が、上記遮光部３を低速で回転させる態様となり、ＯＮ／ＯＦＦの制御を高速行う場合が、上記遮光部３を高速で回転させる態様となる。 15 can be used in two modes as in the apparatus of FIG. That is, when the ON / OFF control is performed at a low speed, the light shielding unit 3 is rotated at a low speed, and when the ON / OFF control is performed at a high speed, the light shielding unit 3 is rotated at a high speed.
３．二次元座標算出手段
　上記二次元座標算出手段は、上記目視指定情報から、上記目視指定位置を示す上記大型フォトマスクの主面の二次元座標を算出する手段である。 3. Two-dimensional coordinate calculation means The two-dimensional coordinate calculation means is means for calculating two-dimensional coordinates of the main surface of the large photomask indicating the visual designation position from the visual designation information.
　上記二次元座標算出手段としては、特に限定されないが、例えば、上記目視指定情報として、ステージ１６の表面１６ａにおけるレーザーポインター２０の位置、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）、および大型フォトマスク７０の位置を取得した場合には、図１および図２（ａ）に示されるように、制御部４０ｂに所定の指示を与えることにより、ステージ１６の表面１６ａにおけるレーザーポインター２０の位置、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）、および大型フォトマスク７０の位置の幾何学的な関係から制御部４０ｂにより算出する手段が挙げられる。また、例えば、大型フォトマスクを撮像し、タッチパネルを利用して指示した欠陥の二次元座標を大型フォトマスクの主面のアライメントマーク等のようなマークから算出してもよい。 The two-dimensional coordinate calculation means is not particularly limited. For example, as the visual designation information, the position of the laser pointer 20 on the surface 16a of the stage 16, the indication direction (P θx , P θy ) of the laser pointer 20, and a large size When the position of the photomask 70 is acquired, the position of the laser pointer 20 on the surface 16a of the stage 16 is given by giving a predetermined instruction to the control unit 40b, as shown in FIGS. 1 and 2A. A means for calculating by the control unit 40b from the geometric relationship between the indication direction (P θx , P θy ) of the laser pointer 20 and the position of the large photomask 70 can be mentioned. Further, for example, a large photomask may be imaged, and the two-dimensional coordinates of the defect indicated using the touch panel may be calculated from a mark such as an alignment mark on the main surface of the large photomask.
　図１１はタッチパネルによる二次元座標を取得する構成図を示す。撮像装置によりフォトマスクを撮像し、フォトマスク上のアライメントマーク等のマークの座標と画像データ上のアライメントマークの位置から、観察者がディスプレイ上でタッチした欠陥位置（ｘ，ｙ）に対応するフォトマスク上の二次元座標（Ｍｘ，Ｍｙ）を求める。 FIG. 11 shows a configuration diagram for acquiring two-dimensional coordinates by the touch panel. The photomask is imaged by an imaging device, and the photo corresponding to the defect position (x, y) touched on the display by the observer from the coordinates of the mark such as the alignment mark on the photomask and the position of the alignment mark on the image data The two-dimensional coordinates (Mx, My) on the mask are obtained.
　また、上記目視指定情報が、図４に示される大型フォトマスク７０の主面７０ａにおける点の位置を指し示すものであれば、上記二次元座標算出手段は、該点を示す二次元座標を算出すればよい。また、上記目視指定情報が、図４に示される大型フォトマスク７０の主面７０ａにおける矩形領域、円形領域、または楕円形領域等のような面積を有する領域の位置を指し示すものであれば、上記二次元座標算出手段は、矩形領域の対角の位置をそれぞれ示す二次元座標、円形領域の直径の中心の位置および両端の位置をそれぞれ示す二次元座標、楕円形領域の中心の位置、長軸の両端の位置、および短軸の両端の位置をそれぞれ示す二次元座標等のような複数の二次元座標を算出すればよい。 If the visual designation information indicates the position of a point on the main surface 70a of the large photomask 70 shown in FIG. 4, the two-dimensional coordinate calculation means calculates the two-dimensional coordinate indicating the point. That's fine. Further, if the visual designation information indicates the position of a region having an area such as a rectangular region, a circular region, or an elliptical region on the main surface 70a of the large photomask 70 shown in FIG. The two-dimensional coordinate calculation means includes a two-dimensional coordinate indicating the diagonal position of the rectangular area, a two-dimensional coordinate indicating the center position and both ends of the diameter of the circular area, the elliptical area center position, and the long axis. A plurality of two-dimensional coordinates such as two-dimensional coordinates indicating the positions of both ends and the positions of both ends of the short axis may be calculated.
４．顕微鏡
　上記顕微鏡は、上記大型フォトマスクの主面の各位置を観察可能な位置に移動可能なものである。 4). Microscope The microscope can move each position of the main surface of the large photomask to an observable position.
　上記顕微鏡としては、特に限定されないが、寸法を測定する寸法測定機能、透過率を測定する透過率測定機能、および反射率を測定する反射率測定機能のいずれか一種または二種以上の機能を有するものが好ましい。 The microscope is not particularly limited, but has one or more functions of a dimension measuring function for measuring dimensions, a transmittance measuring function for measuring transmittance, and a reflectance measuring function for measuring reflectance. Those are preferred.
５．顕微鏡駆動手段
　上記顕微鏡駆動手段は、上記二次元座標で示される上記大型フォトマスクの主面の位置を観察可能な位置に上記顕微鏡を移動させる手段である。 5. Microscope driving means The microscope driving means is means for moving the microscope to a position where the position of the main surface of the large photomask indicated by the two-dimensional coordinates can be observed.
　上記顕微鏡駆動手段としては、特に限定されないが、例えば、図１に示されるステージ１６ように、上記外観検査装置に駆動可能に配置され、上記顕微鏡を保持可能なステージであって、制御部４０ｂに所定の指示を与えることによって、上記二次元座標で示される上記大型フォトマスク７０の主面の位置を観察可能な位置に上記顕微鏡５０を移動させるステージ等が挙げられる。また、上記顕微鏡駆動手段としては、図１に示されるステージ１６ならびに架台１０および基板支持枠１４のように、上記顕微鏡および上記大型フォトマスクの相対位置を移動させることにより、上記二次元座標で示される上記大型フォトマスクの主面の位置を観察可能な位置に上記顕微鏡を移動させる手段であればよい。このため、上記顕微鏡駆動手段は、上記大型フォトマスクを上記顕微鏡側に移動させる手段を含むものでもよい。 The microscope driving means is not particularly limited. For example, a stage that can be driven by the appearance inspection apparatus and can hold the microscope as in the stage 16 shown in FIG. Examples include a stage that moves the microscope 50 to a position where the position of the main surface of the large photomask 70 indicated by the two-dimensional coordinates can be observed by giving a predetermined instruction. Further, as the microscope driving means, the two-dimensional coordinates are shown by moving the relative positions of the microscope and the large photomask, such as the stage 16 and the gantry 10 and the substrate support frame 14 shown in FIG. Any means for moving the microscope to a position where the position of the main surface of the large photomask can be observed can be used. Therefore, the microscope driving means may include means for moving the large photomask to the microscope side.
　上記顕微鏡駆動手段としては、手動で入力した移動方向および移動距離で上記顕微鏡を移動させる指示を制御部に与えることによって、上記観察可能な位置に上記顕微鏡を移動させる手段でもよいし、上記観察可能な位置に上記顕微鏡を自動的に移動させる指示を制御部に与えることによって、上記観察可能な位置に上記顕微鏡を自動的に移動させる手段でもよいが、上記観察可能な位置に上記顕微鏡を自動的に移動させる手段が好ましい。 The microscope driving means may be a means for moving the microscope to an observable position by giving an instruction to the control unit to move the microscope in a manually input moving direction and moving distance, and the observation is possible. It may be a means for automatically moving the microscope to the observable position by giving an instruction to automatically move the microscope to the correct position, but the microscope is automatically moved to the observable position. The means for moving to is preferable.
６．二次元座標入力手段
　上記二次元座標入力手段は、上記大型フォトマスクの主面の任意の位置を示す二次元座標を入力する手段である。 6). Two-dimensional coordinate input means The two-dimensional coordinate input means is a means for inputting two-dimensional coordinates indicating an arbitrary position of the main surface of the large photomask.
　上記二次元座標入力手段としては、例えば、図１および図３（ａ）に示されるように、制御部４０ｂに所定の指示を与えることにより、欠陥の修正箇所７４ｃを示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）を制御部４０ｂにより記憶部４０ｃに入力する手段等が挙げられる。 As the two-dimensional coordinate input means, for example, as shown in FIG. 1 and FIG. 3A, a predetermined instruction is given to the control unit 40b, whereby the surface of the large photomask 70 showing the defect correction portion 74c. Examples include means for inputting the two-dimensional coordinates (Mx, My) of 70a to the storage unit 40c by the control unit 40b.
７．その他
　本発明の外観検査装置のその他の特徴について詳細に説明する。 7). Others Other features of the appearance inspection apparatus of the present invention will be described in detail.
（１）目視指定情報算出手段
　上記外観検査装置は、上記二次元座標入力手段により入力された二次元座標から、上記任意の位置を目視できるように指し示すために使用される目視指定情報を算出する目視指定情報算出手段を備えるものが好ましい。 (1) Visual designation information calculation means The visual inspection apparatus calculates visual designation information used to indicate the arbitrary position so as to be visible from the two-dimensional coordinates input by the two-dimensional coordinate input means. What comprises a visual designation | designated information calculation means is preferable.
　上記目視指定情報算出手段としては、特に限定されないが、レーザーポインター２０の目視指定情報を算出するものであればよい。例えば、図１および図３（ａ）に示されるように、ステージ１６の表面１６ａにおけるレーザーポインター２０の位置、欠陥の修正箇所７４ｃを示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）、および大型フォトマスク７０の位置の幾何学的な関係から、欠陥の修正箇所７４ｃを目視できるように指し示すレーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）を制御部４０ｂにより算出する。 The visual designation information calculation means is not particularly limited as long as it can calculate the visual designation information of the laser pointer 20. For example, as shown in FIGS. 1 and 3A, the two-dimensional coordinates (Mx, My) of the surface 70a of the large photomask 70 indicating the position of the laser pointer 20 on the surface 16a of the stage 16 and the defect correction location 74c. ) And the geometrical relationship between the positions of the large photomask 70, the control unit 40b calculates the pointing directions (P θx , P θy ) of the laser pointer 20 pointing so that the defect correction portion 74c can be seen.
　図１２はフォトマスク上の任意の二次元座標（Ｍｘ,Ｍｙ）から目視指定情報を算出する処理を示している。任意の二次元座標Ｍｘ，Ｍｙ）を記憶部４０ｃに入力し（ステップ１）、二次元座標（Ｍｘ、Ｍｙ）からレーザーポインター２０の目視指定情報（Ｐθｘ，Ｐθｙ）を算出する（ステップ２）。 FIG. 12 shows a process of calculating visual designation information from arbitrary two-dimensional coordinates (Mx, My) on the photomask. Arbitrary two-dimensional coordinates Mx, My) are input to the storage unit 40c (step 1), and visual designation information (P θx , P θy ) of the laser pointer 20 is calculated from the two-dimensional coordinates (Mx, My) (step 2). ).
　図１３はタッチパネルを使用して目視指定情報を算出する処理を示している。大型フォトマスクは撮像されており、ディスプレイに表示された欠陥をタッチパネルにより指定して、欠陥位置（ｘ，ｙ）を取得する（ステップ１）。撮像されたフォトマスクのアライメントマーク等のマークを抽出する（ステップ２）。アライメントマーク等のマークからフォトマスク上の欠陥位置（Ｍｘ、Ｍｙ）を算出し、目視指定情報（Ｐθｘ，Ｐθｙ）を求める（ステップ３）。 FIG. 13 shows processing for calculating visual designation information using a touch panel. The large photomask has been imaged, and the defect displayed on the display is designated by the touch panel to obtain the defect position (x, y) (step 1). Marks such as alignment marks of the imaged photomask are extracted (step 2). A defect position (Mx, My) on the photomask is calculated from a mark such as an alignment mark, and visual designation information (P θx , P θy ) is obtained (step 3).
（２）観察用照明
　上記外観検査装置は、通常は、目視観察に用いられる観察用照明をさらに有する。 (2) Illumination for observation The above-described appearance inspection apparatus usually further includes illumination for observation used for visual observation.
　上記観察用照明としては、例えば、図１に示される観察用照明８０ａ～８０ｃのような光源の種類が互いに異なる複数の観察用照明が好ましい。このような複数の観察用照明を用いることにより、目視観察において、多様な種類の欠陥（ムラ、シミ、汚れ、キズ、異物等）を検出することが容易になるからである。上記光源の種類としては、例えば、蛍光灯、高輝度ハロゲン投光機、高輝度ＬＥＤ、ＨＩＤ（ポラリオン）、Ｎａランプ等が挙げられる。なお、光源としてＮａランプに短波長カットフィルターを組み合わせたものを用いれば、塗布ムラ検査も実施可能である。また、上記観察用照明としては、固定されたタイプでもよいし、観察者が手に持ち自由に動かすことができるタイプでもよい。 As the observation illumination, for example, a plurality of observation illuminations having different types of light sources such as the observation illuminations 80a to 80c shown in FIG. 1 are preferable. This is because by using such a plurality of observation illuminations, it is easy to detect various types of defects (unevenness, spots, dirt, scratches, foreign matters, etc.) in visual observation. Examples of the type of light source include fluorescent lamps, high-intensity halogen projectors, high-intensity LEDs, HID (Polarion), and Na lamps. If a combination of a Na lamp and a short wavelength cut filter is used as the light source, a coating unevenness inspection can also be performed. In addition, the observation illumination may be a fixed type or a type that can be freely moved by an observer.
（３）回動機構
　上記外観検査装置は、通常は、上記大型フォトマスクの主面に平行な回動軸まわりに上記大型フォトマスクを回動させる回動機構をさらに有する。 (3) Rotation mechanism The appearance inspection apparatus normally further includes a rotation mechanism that rotates the large photomask around a rotation axis parallel to the main surface of the large photomask.
　図１に示される外観検査装置１００は、床面２に設置された架台１０に固定された回転軸１２と、架台１０に回転軸１２を介して固定され、回転軸１２まわりに回動可能な基板支持枠１４から構成される回動機構を有することより、基板支持枠１４に設置された大型フォトマスク７０を、大型フォトマスク７０の表面７０ａに平行な回動軸１２まわりに回動させることができる。 An appearance inspection apparatus 100 shown in FIG. 1 has a rotating shaft 12 fixed to a gantry 10 installed on a floor 2, and is fixed to the gantry 10 via a rotating shaft 12, and can be rotated around the rotating shaft 12. By having a rotation mechanism composed of the substrate support frame 14, the large photomask 70 installed on the substrate support frame 14 is rotated around the rotation axis 12 parallel to the surface 70 a of the large photomask 70. Can do.
　上記回動機構としては、上記大型フォトマスクの主面を床面と平行な方向から回動軸まわりに回転可能な角度が９０°以上であるものが好ましい。例えば、図１に示されるように、大型フォトマスク７０の表面７０ａを床面２と平行な方向から回動軸１２まわりに回転させる角度θｘが９０°以上であることにより、大型フォトマスク７０の表面７０ａを床面２と垂直な方向に傾斜させた状態で、観察者２００が表面７０ａの目視観察を行うことができるので、表面７０ａの目視観察が容易になるからである。中でも、上記回転可能な角度が２７０°以上であるものが好ましい。例えば、図１に示される上述した角度θｘが２７０°以上であることにより、大型フォトマスク７０の裏面７０ｂを床面２と垂直な方向に傾斜させた状態で、観察者２００が裏面７０ｂの目視観察を行うことができるので、裏面７０ｂの目視観察が容易になるからである。 The rotation mechanism preferably has an angle capable of rotating the main surface of the large photomask around the rotation axis from a direction parallel to the floor surface at 90 ° or more. For example, as shown in FIG. 1, the angle θx for rotating the surface 70a of the large photomask 70 from the direction parallel to the floor surface 2 around the rotation axis 12 is 90 ° or more. This is because, since the observer 200 can perform visual observation of the surface 70a in a state where the surface 70a is inclined in a direction perpendicular to the floor surface 2, visual observation of the surface 70a is facilitated. Among these, those having a rotatable angle of 270 ° or more are preferable. For example, when the above-described angle θx shown in FIG. 1 is 270 ° or more, the observer 200 visually observes the back surface 70b while the back surface 70b of the large photomask 70 is inclined in a direction perpendicular to the floor surface 2. This is because observation can be performed, so that visual observation of the back surface 70b is facilitated.
（４）撮像装置
　上記外観検査装置としては、上記大型フォトマスクの主面を撮像する撮像装置をさらに有するものが好ましい。 (4) Imaging device As said external appearance inspection apparatus, what has further the imaging device which images the main surface of the said large sized photomask is preferable.
　例えば、図１に示される外観検査装置１００は、大型フォトマスク７０の表面７０ａまたは裏面７０ｂを撮像するデジタルカメラ９０を有している。これにより、大型フォトマスク７０の表面７０ａまたは裏面７０ｂを直接観察している観察者２００以外の人にも、デジタルカメラ９０により撮像した画像を制御部４０ｂにより表示部４０ａに表示させることができる。よって、上記大型フォトマスクの主面の状態を周知させることができるからである。また、撮像した画像をタッチパネルに表示させることにより、上記二次元座標算出手段、上記目視指定情報算出手段、および上記目視指定手段において、タッチパネルの表示画像を用いることができる。なお、上記撮像装置としては、例えば、デジタルカメラの他にもＴＶカメラ等が挙げられる。 For example, the appearance inspection apparatus 100 shown in FIG. 1 has a digital camera 90 that images the front surface 70a or the back surface 70b of the large photomask 70. As a result, an image captured by the digital camera 90 can be displayed on the display unit 40a by the control unit 40b even for a person other than the observer 200 who directly observes the front surface 70a or the back surface 70b of the large photomask 70. Therefore, the state of the main surface of the large photomask can be made known. Moreover, by displaying the captured image on the touch panel, the display image of the touch panel can be used in the two-dimensional coordinate calculation means, the visual designation information calculation means, and the visual designation means. Note that examples of the imaging device include a TV camera and the like in addition to a digital camera.
　また、上記撮像装置としては、図１に示されるデジタルカメラ９０のように、観察者２００の頭上に配置されたものが好ましい。観察者２００が大型フォトマスク７０を目視により観察する際に妨げとならないからである。 Further, as the above-described imaging device, it is preferable that the imaging device is disposed above the observer 200 like the digital camera 90 shown in FIG. This is because it does not hinder the observer 200 when observing the large photomask 70 visually.
（５）その他
　上記外観検査装置は、通常、上記外観検査装置が備える手段、装置、機構等の構成要素を制御する図１に示される制御部４０ｂのような制御手段を有する。また、上記外観検査装置は、上記構成要素を制御するために上記制御手段に所定の指示を外部から与える図１に示される操作部４０ｂのような操作手段を有していてもよい。 (5) Others The appearance inspection apparatus normally has a control unit such as the control unit 40b shown in FIG. 1 that controls components such as means, devices, and mechanisms included in the appearance inspection apparatus. In addition, the appearance inspection apparatus may include an operation unit such as an operation unit 40b shown in FIG. 1 that gives a predetermined instruction to the control unit from the outside in order to control the components.
　また、上記外観検査装置は、通常、上記目視指定情報、上記目視指定位置を示す上記大型フォトマスクの主面の二次元座標、上記大型フォトマスクの主面の任意の位置を示す二次元座標、および上記目視用位置情報等のいずれか一種または二種以上の情報を記憶する図１に示される記憶部４０ｃのような記憶手段を有する。 In addition, the visual inspection apparatus usually has the visual designation information, two-dimensional coordinates of the main surface of the large photomask indicating the visual designation position, two-dimensional coordinates indicating an arbitrary position of the main surface of the large photomask, And storage means such as the storage unit 40c shown in FIG. 1 for storing any one type or two or more types of information such as the visual position information.
　また、上記外観検査装置は、通常、図１に示される表示部４０ａのような表示手段を有する。上記表示手段としては、例えば、液晶ディスプレイ、有機ＥＬディスプレイ等が挙げられる。また、上記表示手段は、上記「１．目視指定情報取得手段」の項目に記載された目視指定情報取得手段で用いられるタッチパネルとして用いてもよい。 Further, the appearance inspection apparatus usually has display means such as the display unit 40a shown in FIG. Examples of the display means include a liquid crystal display and an organic EL display. The display means may be used as a touch panel used in the visual designation information acquisition means described in the item “1. Visual designation information acquisition means”.
　さらに、上記外観検査装置は、上記大型フォトマスクの主面の任意の位置を示す二次元座標を外部から入力する入力手段をさらに有し、上記顕微鏡駆動手段が、上記入力手段により入力される二次元座標で示される上記大型フォトマスクの主面の位置を観察可能な位置に上記顕微鏡を移動させることができるものでもよい。これにより、例えば、ミクロ観察を自動的に行うミクロ外観検査機により自動的に取得される大型フォトマスクの主面の欠陥の位置を示す二次元座標をミクロ外観検査機から上記外観検査装置に入力した上で、該二次元座標で示される上記主面の位置を観察可能な位置に上記顕微鏡を移動させて、該欠陥を詳細に観察することができる。また、大型フォトマスクの主面に記載されたアライメントマークや品名等の各種マークの位置を示す二次元座標を外部から上記外観検査装置に入力した上で、該二次元座標で示される上記主面の位置を観察可能な位置に顕微鏡を移動させて、各種マークを詳細に観察することができる。 Further, the appearance inspection apparatus further includes input means for inputting two-dimensional coordinates indicating an arbitrary position of the main surface of the large photomask from the outside, and the microscope driving means is input by the input means. The microscope may be moved to a position where the position of the main surface of the large photomask indicated by the dimensional coordinates can be observed. As a result, for example, two-dimensional coordinates indicating the position of a defect on the main surface of a large photomask automatically acquired by a micro appearance inspection machine that automatically performs micro observation are input from the micro appearance inspection machine to the appearance inspection apparatus. Then, the defect can be observed in detail by moving the microscope to a position where the position of the main surface indicated by the two-dimensional coordinates can be observed. Further, after inputting two-dimensional coordinates indicating the positions of various marks such as alignment marks and product names described on the main surface of the large photomask from the outside to the appearance inspection apparatus, the main surface indicated by the two-dimensional coordinates By moving the microscope to a position where the position can be observed, various marks can be observed in detail.
Ｂ．外観検査方法
　本発明の外観検査方法は、大型フォトマスクの外観検査をマクロ観察およびミクロ観察の順番に行う場合に用いられる第１態様と、大型フォトマスクの外観検査をミクロ観察およびマクロ観察の順番に行う場合に用いられる第２態様と、に大別される。 B. Appearance Inspection Method The appearance inspection method of the present invention is a first mode used when the appearance inspection of a large photomask is performed in the order of macro observation and micro observation, and the appearance inspection of the large photomask is performed in the order of micro observation and macro observation. And the second mode used in the case of performing the above.
Ｉ．第１態様
　第１態様の外観検査方法は、目視観察に基づいて指し示される大型フォトマスクの主面の欠陥の目視指定情報を取得する目視指定情報取得工程と、上記目視指定情報から、上記欠陥の位置を示す上記大型フォトマスクの主面の二次元座標を算出する二次元座標算出工程と、上記二次元座標で示される上記大型フォトマスクの主面の位置を顕微鏡により観察するミクロ観察工程と、を備えることを特徴とする。 I. First aspect The visual inspection method according to the first aspect includes a visual designation information acquisition step of obtaining visual designation information of a defect on a main surface of a large photomask pointed to based on visual observation, and the defect from the visual designation information. A two-dimensional coordinate calculation step for calculating the two-dimensional coordinates of the main surface of the large photomask indicating the position of the microphotograph, and a micro observation step for observing the position of the main surface of the large photomask indicated by the two-dimensional coordinates with a microscope It is characterized by providing.
　第１態様の外観検査方法の一例について図面を参照しながら説明する。図５は、第１態様の外観検査方法の一例を示すフローチャートである。 An example of the appearance inspection method according to the first aspect will be described with reference to the drawings. FIG. 5 is a flowchart illustrating an example of the appearance inspection method according to the first aspect.
　本例の外観検査方法においては、まず、図５に示すように目視指定情報取得工程Ｓ１１を行う。例えば、まず、図１に示されるように、観察者２００が、目視により大局的に観察するマクロ観察を行うことにより、大型フォトマスク７０の表面７０ａの欠陥７２を検出する。次に、図１および図２（ａ）に示されるように、観察者２００が、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、レーザーポインター２０のレーザーで大型フォトマスク７０の表面７０ａの欠陥７２の位置を指し示す。次に、図１および図２（ａ）に示されるように、観察者２００が、欠陥７２の位置をレーザーで指し示した状態において、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、外観検査装置１００は、ステージ１６の表面１６ａにおける、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）、および大型フォトマスク７０の位置を制御部４０ｂにより取得し、記憶部４０ｃに記憶する。 In the appearance inspection method of this example, first, a visual designation information acquisition step S11 is performed as shown in FIG. For example, as shown in FIG. 1, first, the observer 200 performs a macro observation that observes globally visually, thereby detecting a defect 72 on the surface 70 a of the large photomask 70. Next, as shown in FIG. 1 and FIG. 2A, the observer 200 gives a predetermined instruction to the control unit 40 b by operating the keys of the operation unit 30, so that a large photomask is used with the laser of the laser pointer 20. The position of the defect 72 on the surface 70a of 70 is indicated. Next, as shown in FIGS. 1 and 2A, the observer 200 gives a predetermined instruction to the control unit 40b by operating the key of the operation unit 30 in a state where the position of the defect 72 is pointed by the laser. Thus, the appearance inspection apparatus 100 acquires the indication direction (P θx , P θy ) of the laser pointer 20 and the position of the large photomask 70 on the surface 16a of the stage 16 by the control unit 40b and stores them in the storage unit 40c. To do.
　次に、図５に示すように二次元座標算出工程Ｓ１２を行う。例えば、図１および図２（ａ）に示されるように、観察者２００が操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、外観検査装置１００は、ステージ１６の表面１６ａにおけるレーザーポインター２０の位置、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）、および大型フォトマスク７０の位置の幾何学的な関係から、欠陥７２の位置を示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）を制御部４０ｂにより算出し、記憶部４０ｃに記憶する。 Next, a two-dimensional coordinate calculation step S12 is performed as shown in FIG. For example, as shown in FIG. 1 and FIG. 2A, the appearance inspection apparatus 100 causes the surface 16 a of the stage 16 when the observer 200 gives a predetermined instruction to the control unit 40 b by operating the keys of the operation unit 30. From the geometrical relationship between the position of the laser pointer 20, the pointing direction (P θx , P θy ) of the laser pointer 20, and the position of the large photomask 70, the surface 70 a of the large photomask 70 indicating the position of the defect 72 is shown. Two-dimensional coordinates (Mx, My) are calculated by the control unit 40b and stored in the storage unit 40c.
　次に、図５に示すようにミクロ観察工程Ｓ１３を行う。例えば、図１および図２（ｂ）に示されるように、観察者２００が操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、大型フォトマスク７０を、架台１０の移動ならびに基板支持枠１４の移動および回動により顕微鏡５０により観察可能な位置に移動させた上で、顕微鏡５０を基準位置から二次元座標（Ｍｘ，Ｍｙ）で示される大型フォトマスク７０の表面７０ａの位置を観察可能な位置に移動させる。次に、観察者２００は顕微鏡５０の焦点を調整した後に、大型フォトマスク７０の表面７０ａの欠陥７２を顕微鏡５０で観察するミクロ観察を行う。 Next, a micro observation step S13 is performed as shown in FIG. For example, as shown in FIG. 1 and FIG. 2 (b), the observer 200 gives a predetermined instruction to the control unit 40 b by operating the keys of the operation unit 30, so that the large photomask 70 is moved and moved. The position of the surface 70a of the large photomask 70 indicated by two-dimensional coordinates (Mx, My) from the reference position after the substrate support frame 14 is moved and rotated to a position where it can be observed by the microscope 50. Is moved to an observable position. Next, after adjusting the focus of the microscope 50, the observer 200 performs micro observation of observing the defect 72 on the surface 70 a of the large photomask 70 with the microscope 50.
　以上の通り、本例の外観検査方法においては、目視観察に基づいて指し示される大型フォトマスク７０の表面７０ａの欠陥７２の目視指定情報として、ステージ１６の表面１６ａにおける欠陥７２の位置を指し示すレーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）、および大型フォトマスク７０の位置を取得した上で、このような欠陥７２の目視指定情報から、欠陥７２の位置を示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）を算出することができる。 As described above, in the appearance inspection method of this example, the laser indicating the position of the defect 72 on the surface 16a of the stage 16 as the visual designation information of the defect 72 on the surface 70a of the large photomask 70 indicated based on the visual observation. After obtaining the indication direction (P θx , P θy ) of the pointer 20 and the position of the large photomask 70, the surface 70 a of the large photomask 70 indicating the position of the defect 72 is obtained from such visual designation information of the defect 72. The two-dimensional coordinates (Mx, My) can be calculated.
　したがって、第１態様によれば、マクロ観察により検出された欠陥の位置を示す大型フォトマスクの主面の二次元座標を取得することができるために、マクロ観察により検出された欠陥をミクロ観察することが容易である。 Therefore, according to the first aspect, since the two-dimensional coordinates of the main surface of the large photomask indicating the position of the defect detected by the macro observation can be acquired, the defect detected by the macro observation is micro-observed. Is easy.
１．目視指定情報取得工程
　上記目視指定情報取得工程においては、目視観察に基づいて指し示される大型フォトマスクの主面の欠陥の目視指定情報を取得する。 1. Visual designation information acquisition step In the visual designation information acquisition step, visual designation information of a defect on the main surface of the large photomask pointed to based on visual observation is acquired.
　上記目視指定情報を取得する方法としては、特に限定されないが、例えば、上記「Ａ．外観検査装置　１．目視指定情報取得手段」の項目に記載された目視指定情報取得手段を用いて、上記目視指定情報を取得する方法等が挙げられる。また、上記目視指定情報としては、特に限定されないが、例えば、上記「Ａ．外観検査装置　１．目視指定情報取得手段」の項目に記載された目視指定情報等が挙げられる。 The method for acquiring the visual designation information is not particularly limited. For example, the visual designation information acquisition unit described in the item of “A. Appearance inspection apparatus 1. Visual designation information acquisition unit” is used. For example, a method for acquiring designated information. The visual designation information is not particularly limited, and examples thereof include the visual designation information described in the item “A. Appearance inspection apparatus 1. Visual designation information acquisition unit”.
２．二次元座標算出工程
　上記二次元座標算出工程においては、上記目視指定情報から、上記欠陥の位置を示す上記大型フォトマスクの主面の二次元座標を算出する。 2. Two-dimensional coordinate calculation step In the two-dimensional coordinate calculation step, two-dimensional coordinates of the main surface of the large photomask indicating the position of the defect are calculated from the visual designation information.
　上記二次元座標を算出する方法としては、特に限定されないが、例えば、上記「Ａ．外観検査装置　２．二次元座標算出手段」の項目に記載された二次元座標算出手段を用いて、上記二次元座標を算出する方法等が挙げられる。 The method for calculating the two-dimensional coordinates is not particularly limited. For example, the two-dimensional coordinate calculation means described in the item “A. Appearance inspection apparatus 2. Two-dimensional coordinate calculation means” is used. For example, a method for calculating a dimensional coordinate may be used.
３．ミクロ観察工程
　上記ミクロ観察工程においては、上記二次元座標で示される上記大型フォトマスクの主面の位置を顕微鏡により観察する。 3. Micro Observation Step In the micro observation step, the position of the main surface of the large photomask indicated by the two-dimensional coordinates is observed with a microscope.
　上記顕微鏡としては、特に限定されないが、例えば、図１に示されるように、上記「Ａ．外観検査装置　３．顕微鏡」の項目に記載された顕微鏡等が挙げられる。 The microscope is not particularly limited, and examples thereof include a microscope described in the item “A. Appearance inspection apparatus 3. Microscope” as shown in FIG.
４．外観検査方法
　第１態様の外観検査方法は、通常、上記「Ａ．外観検査装置」の項目に記載された外観検査装置を用いて実施する。 4). Appearance Inspection Method The appearance inspection method of the first aspect is usually carried out using the appearance inspection device described in the item “A. Appearance inspection device”.
５．その他
　第１態様の外観検査方法においては、通常、上記目視指定情報取得工程の前に外観の観察により欠陥を発見する欠陥検査工程を有する。上記欠陥検査工程により発見された欠陥に対し、上記目視指定情報取得工程が行われるのである。
　この欠陥検査工程は、特に限定されるものではないが、通常、図７に示す通り、観察者２００が、観察用照明８０を持ち、大型フォトマスク７０の表面７０ａに対し、上記観察用照明８０を所定の角度で傾けて照射し、上下左右に動かしながら観察して、欠陥７２を検査することにより行われる。
　本態様における欠陥検査工程は、特に限定するものではないが、後述する「Ｃ．欠陥検査方法」を用いる工程であることが好ましい。 5. Others The appearance inspection method of the first aspect usually includes a defect inspection step of finding defects by observing the appearance before the visual designation information acquisition step. The visual designation information acquisition step is performed on the defect found by the defect inspection step.
Although this defect inspection process is not particularly limited, usually, as shown in FIG. 7, the observer 200 has the observation illumination 80, and the observation illumination 80 is applied to the surface 70 a of the large photomask 70. Is carried out by inspecting the defect 72 by irradiating at a predetermined angle and observing it while moving it vertically and horizontally.
Although the defect inspection process in this aspect is not specifically limited, It is preferable that it is a process using "C. Defect inspection method" mentioned later.
ＩＩ．第２態様
　第２態様の外観検査方法は、大型フォトマスクの主面の欠陥を修正する欠陥修正工程と、上記欠陥の修正箇所を示す上記大型フォトマスクの主面の二次元座標から、上記欠陥の修正箇所の目視指定情報を算出する目視指定情報算出工程と、上記欠陥の修正箇所を上記目視指定情報を使用して指し示すことにより、上記欠陥の修正箇所の目視観察を行うマクロ観察工程と、を備えることを特徴とする。 II. Second aspect The visual inspection method according to the second aspect includes a defect correction step for correcting a defect on a main surface of a large photomask, and a two-dimensional coordinate of the main surface of the large photomask indicating a correction location of the defect. A visual designation information calculation step for calculating the visual designation information of the correction location, a macro observation step for performing visual observation of the correction location of the defect by indicating the correction location of the defect using the visual designation information, and It is characterized by providing.
　第２態様の外観検査方法の一例について図面を参照しながら説明する。図６は、第２態様の外観検査方法の一例を示すフローチャートである。 An example of the appearance inspection method of the second aspect will be described with reference to the drawings. FIG. 6 is a flowchart illustrating an example of the appearance inspection method according to the second aspect.
　本例の外観検査方法においては、まず、図６に示すように欠陥修正工程Ｓ２１を行う。例えば、まず、図１に示されるように、ミクロ観察を自動的に行う外観検査機により自動的に大型フォトマスク７０の表面７０ａの欠陥７４を検出した後に、欠陥７４を修正する。この際には、大型フォトマスク７０の表面７０ａの欠陥の修正箇所７４ｃあるいは欠陥７４の位置を示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）を欠陥の種類等と共にデータ化する。 In the appearance inspection method of this example, first, a defect correction step S21 is performed as shown in FIG. For example, as shown in FIG. 1, first, a defect 74 on the surface 70a of the large photomask 70 is automatically detected by an appearance inspection machine that automatically performs micro observation, and then the defect 74 is corrected. At this time, two-dimensional coordinates (Mx, My) of the surface 70a of the large photomask 70 indicating the position of the defect correction portion 74c or the defect 74 on the surface 70a of the large photomask 70 are converted into data along with the type of defect. .
　次に、図６に示すように目視指定情報算出工程Ｓ２２を行う。例えば、図１および図３（ａ）に示されるように、観察者２００が、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、欠陥の修正箇所７４ｃあるいは欠陥７４の位置を示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）を記憶部４０ｃに入力する。続いて、観察者２００が、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、ステージ１６の表面１６ａにおけるレーザーポインター２０の位置、欠陥の修正箇所７４ｃを示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）、および大型フォトマスク７０の位置の幾何学的な関係から、欠陥の修正箇所７４ｃを指し示すレーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）を制御部４０ｂにより算出し記憶部４０ｃに記憶する。 Next, a visual designation information calculation step S22 is performed as shown in FIG. For example, as shown in FIG. 1 and FIG. 3A, the observer 200 gives a predetermined instruction to the control unit 40 b by key operation of the operation unit 30, whereby the defect correction location 74 c or the position of the defect 74 is detected. The two-dimensional coordinates (Mx, My) of the surface 70a of the large-sized photomask 70 showing are input to the storage unit 40c. Subsequently, the observer 200 gives a predetermined instruction to the control unit 40b by operating the keys of the operation unit 30, whereby the large-sized photomask 70 showing the position of the laser pointer 20 on the surface 16a of the stage 16 and the defect correction portion 74c. The pointing direction (P θx , P θy ) of the laser pointer 20 pointing to the defect correction location 74c is controlled from the geometric relationship between the two-dimensional coordinates (Mx, My) of the surface 70a of the laser beam and the position of the large photomask 70. Calculated by the unit 40b and stored in the storage unit 40c.
　次に、図６に示すようにマクロ観察工程Ｓ２３を行う。例えば、図１および図３（ｂ）に示されるように、観察者２００が、操作部３０のキー操作で制御部４０ｂに所定の指示を与えることにより、外観検査装置１００が、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）を使用して、欠陥の修正箇所７４ｃを観察者２００が目視できるようにレーザーポインター２０のレーザーで指し示す。次に、観察者２００は、レーザーで指し示される欠陥の修正箇所７４ｃを目視により観察する。 Next, a macro observation step S23 is performed as shown in FIG. For example, as shown in FIG. 1 and FIG. 3B, when the observer 200 gives a predetermined instruction to the control unit 40 b by a key operation of the operation unit 30, the appearance inspection device 100 is moved to the laser pointer 20. The pointing direction (P θx , P θy ) is used to point the defect correction portion 74c with the laser of the laser pointer 20 so that the observer 200 can see the defect. Next, the observer 200 visually observes a defect correction portion 74c indicated by the laser.
　以上の通り、本例の外観検査方法においては、ミクロ観察により検出された大型フォトマスク７０の表面７０ａの欠陥７４を修正した上で、欠陥の修正箇所７４ｃを示す大型フォトマスク７０の表面７０ａの二次元座標（Ｍｘ，Ｍｙ）から、欠陥の修正箇所７４ｃを目視できるように指し示すために使用される目視指定情報として、欠陥の修正箇所７４ｃを指し示すレーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）を算出することができる。このため、レーザーポインター２０の指示方向（Ｐθｘ，Ｐθｙ）を使用して、欠陥の修正箇所７４ｃを目視できるように指し示すことができる。よって、ミクロ観察により検出された欠陥の修正箇所７４ｃをマクロ観察することができる。 As described above, in the appearance inspection method of this example, after correcting the defect 74 on the surface 70a of the large photomask 70 detected by micro observation, the surface 70a of the large photomask 70 showing the defect correction portion 74c is corrected. From the two-dimensional coordinates (Mx, My), the pointing direction (P θx , P θy) of the laser pointer 20 pointing to the defect correction portion 74c is used as visual designation information used to point the defect correction portion 74c so as to be visible. ) Can be calculated. For this reason, it is possible to point the defect correction portion 74c so that it can be visually checked by using the indication direction ( Pθx , Pθy ) of the laser pointer 20. Therefore, it is possible to perform macro observation of the defect correction portion 74c detected by micro observation.
　したがって、第２態様によれば、ミクロ観察により検出された欠陥やその修正箇所を目視できるように指し示すことができるために、該欠陥やその修正箇所をマクロ観察することが容易である。 Therefore, according to the second aspect, since it is possible to indicate the defect detected by micro observation and its corrected portion so as to be visible, it is easy to perform macro observation of the defect and its corrected portion.
１．欠陥修正工程
　上記欠陥修正工程においては、大型フォトマスクの主面の欠陥を修正する。 1. Defect Correction Process In the defect correction process, defects on the main surface of the large photomask are corrected.
　上記欠陥を修正する方法としては、特に限定されないが、上記欠陥が黒欠陥である場合には、例えば、上記黒欠陥にアシストガスを供給しながら荷電ビームを照射し、上記黒欠陥をエッチングする方法等が挙げられる。また、上記欠陥が白欠陥である場合には、例えば、上記白欠陥にデポジション用ガスを供給しながら荷電ビームを照射し、修正膜を堆積する方法が挙げられる。 The method for correcting the defect is not particularly limited, but when the defect is a black defect, for example, a method of etching the black defect by irradiating a charged beam while supplying an assist gas to the black defect. Etc. Further, when the defect is a white defect, for example, a method of depositing a correction film by irradiating a charged beam while supplying a deposition gas to the white defect is exemplified.
　なお、本発明において、黒欠陥とは、大型フォトマスクのマスクパターンにおける不要な余剰部分をいう。また、白欠陥とは、大型フォトマスクのマスクパターンにおける欠損をいう。 In the present invention, the black defect means an unnecessary surplus portion in the mask pattern of the large photomask. A white defect is a defect in a mask pattern of a large photomask.
２．目視指定情報算出工程
　上記目視指定情報算出工程においては、上記欠陥の修正箇所を示す上記大型フォトマスクの主面の二次元座標から、上記欠陥の修正箇所を目視できるように指し示すために使用される目視指定情報を算出する。 2. Visual designation information calculation step In the visual designation information calculation step, it is used to indicate the defect correction location so that the defect correction location can be viewed from the two-dimensional coordinates of the main surface of the large photomask indicating the defect correction location. Calculate visual designation information.
　上記目視指定情報を算出する方法としては、特に限定されないが、例えば、上記「Ａ．外観検査装置　６．その他　（１）目視指定情報算出手段および目視指定手段」の項目に記載された目視用位置情報算出手段を用いて、上記目視用位置情報を算出する方法等が挙げられる。 The method for calculating the visual designation information is not particularly limited. For example, the visual position described in the item “A. Appearance inspection apparatus 6. Other (1) Visual designation information calculation means and visual designation means” is provided. Examples include a method of calculating the visual position information using an information calculation means.
３．マクロ観察工程
　上記マクロ観察工程においては、上記欠陥の修正箇所を上記目視指定情報を使用して指し示すことにより、上記欠陥の修正箇所の目視観察を行う。 3. Macro observation step In the macro observation step, the defect correction location is visually observed by indicating the defect correction location using the visual designation information.
　上記欠陥の修正箇所を上記目視指定情報を使用して指し示す方法としては、特に限定されないが、例えば、上記「Ａ．外観検査装置　６．その他　（１）目視指定情報算出手段および目視指定手段」の項目に記載された目視指定手段を用いて、上記欠陥の修正箇所を指し示す方法等が挙げられる。 A method for indicating the corrected portion of the defect using the visual designation information is not particularly limited. For example, the above-mentioned “A. Appearance inspection apparatus 6. Other (1) Visual designation information calculation means and visual designation means” Examples include a method of pointing a correction location of the defect using the visual designation means described in the item.
４．外観検査方法
　第２態様の外観検査方法は、通常、上記「Ａ．外観検査装置」の項目に記載された外観検査装置を用いて実施する。 4). Appearance Inspection Method The appearance inspection method of the second aspect is usually carried out using the appearance inspection device described in the item “A. Appearance inspection device”.
ＩＩＩ．その他の態様
　本発明の外観検査方法のその他の態様として、ミクロ観察を自動的に行うミクロ外観検査機により自動的に取得される大型フォトマスクの表面の欠陥の位置を示す二次元座標をミクロ外観検査機から上記「Ａ．外観検査装置」の項目に記載された外観検査装置に入力した上で、該二次元座標で示される上記大型フォトマスクの主面の位置を観察可能な位置に上記外観検査装置における顕微鏡を移動させて、該欠陥を詳細に観察する方法等が挙げられる。 III. Other Embodiments As another embodiment of the appearance inspection method of the present invention, the micro-appearance is a two-dimensional coordinate indicating the position of a defect on the surface of a large photomask that is automatically acquired by a micro appearance inspection machine that automatically performs micro observation. The external appearance is input to the visual inspection apparatus described in the item “A. Visual inspection apparatus” from the inspection machine and the position of the main surface of the large-sized photomask indicated by the two-dimensional coordinates can be observed. For example, a method of observing the defect in detail by moving the microscope in the inspection apparatus.
Ｃ．欠陥検査方法
　本発明の欠陥検査方法は、大型フォトマスクの主面に対して観察用照明を一定の照射角度で照射することにより上記大型フォトマスクの主面に照射領域を設け、上記照射領域を上下左右に動かすことにより上記大型フォトマスクの主面の全面を検査する全面検査を行い、上記大型フォトマスクの主面に存在する欠陥の有無を検査する欠陥検査方法であって、上記全面検査は、上記観察用照明の上記大型フォトマスクの主面に対する照射角度を変えて少なくとも２回行うことを特徴とするものである。 C. Defect Inspection Method The defect inspection method of the present invention provides an irradiation region on the main surface of the large photomask by irradiating observation illumination at a predetermined irradiation angle on the main surface of the large photomask. It is a defect inspection method for inspecting the entire surface of the main surface of the large photomask by moving up, down, left and right, and inspecting for the presence or absence of defects present on the main surface of the large photomask. The observation illumination is performed at least twice by changing the irradiation angle with respect to the main surface of the large photomask.
　上記大型フォトマスクの主面、すなわち表面に存在する欠陥としては、いわゆるムラと称される周囲と異なる反射を示す領域、シミや汚れ、異物、さらには大型フォトマスクに形成されたパターンのエッジの不具合等を挙げることができる。これらの欠陥は、一般的な目視による検査では発見することが難しいことから、従来より、例えば図７に示すような観察用照明を用いた検査方法が行われていた。
　すなわち、図７に示すように観察者２００が、観察用照明８０を持ち、大型フォトマスク７０の表面７０ａに対し、上記観察用照明８０を所定の角度で傾けて照射し、左右に動かしながら観察して、欠陥７２を検査するといった方法が採用されてきた。 The main surface of the large-sized photomask, that is, the defects existing on the surface include so-called unevenness, areas showing reflections different from the surroundings, spots, dirt, foreign matters, and edges of patterns formed on the large-sized photomask. Defects can be mentioned. Since these defects are difficult to find by general visual inspection, conventionally, for example, an inspection method using observation illumination as shown in FIG. 7 has been performed.
That is, as shown in FIG. 7, an observer 200 has an observation illumination 80, irradiates the observation illumination 80 at a predetermined angle on the surface 70a of the large photomask 70, and observes while moving left and right. Thus, a method of inspecting the defect 72 has been adopted.
　しかしながら、上述した方法で検査を行った場合でも、欠陥の見落としが生じる可能性があり、検査の信頼性として、十分に満足し得るものではないのが現状であった。
　本発明者等は、上記問題点を解決すべく鋭意検討した結果、観察用照明の大型フォトマスクの主面に対する角度により、発見できる欠陥が異なる場合があることを見出し、上述した欠陥検査方法を発見するに至ったものであり、上述した欠陥検査方法を用いることにより大型フォトマスクの欠陥の検査における見落としを大幅に低減できるといった効果を奏するものである。
　以下、本発明の欠陥検査方法について、詳細に説明する。 However, even when the inspection is performed by the above-described method, the defect may be overlooked, and the present situation is that the reliability of the inspection is not satisfactory.
As a result of intensive studies to solve the above problems, the present inventors have found that the defects that can be found may differ depending on the angle of the illumination for observation with respect to the main surface of the large photomask, and the defect inspection method described above. As a result, the use of the defect inspection method described above has the effect of significantly reducing oversight in the inspection of defects in large photomasks.
Hereinafter, the defect inspection method of the present invention will be described in detail.
１．照射角度
　本発明の特徴は、大型フォトマスクの欠陥検査に際し、上記観察用照明の上記大型フォトマスクの主面に対する照射角度を変えて少なくとも２回行う点である。このように照射角度を変えて少なくとも２回行うことにより、欠陥の見落としが減少する理由は以下のように推定される。
　すなわち、発明者等の検討によれば、上記欠陥の一種である異物や大型フォトマスクに形成されたパターンのエッジの不具合等は、上記照射角度が小さい方が発見できる可能性が高い。一方、上記ムラ、シミ、および汚れ等は、上記照射角度を大きくし、照射領域の照度をある程度高くした方が発見できる可能性が高い。さらに、ムラは種類によって、発見できる角度が異なり、一つの角度での検査では見落とす可能性がある。以上の点から、上述した通り、全面検査を角度を変えて少なくとも２回以上行うことにより、欠陥の見落としを減少さえることが可能となるのである。 1. Irradiation angle A feature of the present invention is that, at the time of defect inspection of a large-sized photomask, the observation illumination is performed at least twice while changing the irradiation angle of the main surface of the large-sized photomask. The reason why the defect oversight is reduced by performing the irradiation angle at least twice in this manner is estimated as follows.
That is, according to the studies by the inventors, there is a high possibility that a foreign object which is a kind of the defect or a defect of an edge of a pattern formed on a large photomask can be found when the irradiation angle is small. On the other hand, the unevenness, spots, dirt, and the like are more likely to be detected by increasing the irradiation angle and increasing the illuminance of the irradiation area to some extent. In addition, the angle at which unevenness can be found differs depending on the type, and it may be overlooked by inspection at one angle. From the above points, as described above, it is possible to reduce the oversight of defects by performing the entire surface inspection at least twice at different angles.
　具体的には、図８に示すように、大型フォトマスク７０の主面に対する観察用照明８０の照射角度が小さい低照射角Ａで全面検査を行う低照射角全面検査と、大型フォトマスク７０の主面に対する観察用照明８０の照射角度が大きい高照射角Ｂで全面検査を行う高照射角全面検査を行うものである。
　ここで、低照射角全面検査における照射角度Ａは、３０°を中心に、１５°～４５°の範囲内であることが好ましく、中でも２０°～４０°の範囲内であることが好ましく、特に２５°～３５°の範囲内であることが好ましい。 Specifically, as shown in FIG. 8, a low irradiation angle full surface inspection in which a full inspection is performed at a low irradiation angle A with a small irradiation angle of the observation illumination 80 with respect to the main surface of the large photomask 70, and a large photomask 70 A high irradiation angle full surface inspection is performed in which a full surface inspection is performed at a high irradiation angle B where the irradiation angle of the observation illumination 80 with respect to the main surface is large.
Here, the irradiation angle A in the low irradiation angle full-surface inspection is preferably in the range of 15 ° to 45 ° centering on 30 °, and more preferably in the range of 20 ° to 40 °. It is preferably in the range of 25 ° to 35 °.
　一方、高照射角全面検査における照射角度Ｂは、６０°を中心に、４５°～７５°の範囲内であることが好ましく、中でも５０°～７０°の範囲内であることが好ましく、特に５５°～６５°の範囲内であることが好ましい。
　本発明においては、上述した通り、全面検査の角度を変えて少なくとも２回の全面検査を行えばよく、したがって、３回以上全面検査を行ってもよい。 On the other hand, the irradiation angle B in the high irradiation angle full-surface inspection is preferably within a range of 45 ° to 75 ° centering on 60 °, and more preferably within a range of 50 ° to 70 °, particularly 55. It is preferably within the range of ° to 65 °.
In the present invention, as described above, the entire surface inspection may be performed at least twice by changing the angle of the entire surface inspection. Therefore, the entire surface inspection may be performed three times or more.
　また、各全面検査における照射角度は一定であることが好ましく、少なくとも±１０°、好ましくは±５°の範囲内で行われることが好ましい。 Further, the irradiation angle in each full-surface inspection is preferably constant, and is preferably performed within a range of at least ± 10 °, preferably ± 5 °.
２．全面検査
　本発明における全面検査は、上記大型フォトマスクの全面が検査できる方法でれば、特に限定されないが、上記全面検査が、上記大型フォトマスクの一つの辺側から上記一つの辺に対し直交する方向に上記観察用照明を照射し、かつ上記一つの辺に対して平行に移動しながら検査し、上記一つの辺の長さ分検査した後、上記一つの辺に直交する方向に照射領域を所定の距離で移動させる工程を繰り返し行うことにより、大型フォトマスク全面を検査する辺全面検査であることが好ましい。 2. Full surface inspection The full surface inspection in the present invention is not particularly limited as long as it is a method capable of inspecting the entire surface of the large photomask, but the full surface inspection is orthogonal to the one side from one side of the large photomask. Irradiating the observation illumination in the direction to be observed, inspecting while moving parallel to the one side, inspecting the length of the one side, and then irradiating the region in a direction perpendicular to the one side It is preferable to perform the entire side inspection for inspecting the entire surface of the large photomask by repeatedly performing the process of moving the lens by a predetermined distance.
　すなわち、図９に示すように大型フォトマスク７０の一つの辺７１側から、上記一つの辺７１に直交する方向に上記観察用照明８０を照射し、照射領域８１を形成する。次いで、上記観察用照明８０を上記一つの辺７１に対して平行に動かすことにより上記照射領域８１を上記一つの辺７１に平行な方向Ｐに動かしながら検査する。上記一つの辺７１の長さ分検査した後、上記一つの辺７１に直交する方向Ｒに照射領域８１を所定の距離を移動させる。この操作を繰り返すことにより、大型フォトマスク７０の全面を検査することが可能となる。なお、この方法による全面検査を辺全面検査とする。 That is, as shown in FIG. 9, the observation illumination 80 is irradiated from one side 71 side of the large photomask 70 in a direction perpendicular to the one side 71 to form an irradiation region 81. Next, the observation illumination 80 is moved in parallel with the one side 71 to inspect the irradiation region 81 while moving it in a direction P parallel to the one side 71. After inspecting the length of the one side 71, the irradiation region 81 is moved a predetermined distance in a direction R orthogonal to the one side 71. By repeating this operation, the entire surface of the large photomask 70 can be inspected. Note that the entire surface inspection by this method is referred to as a side entire surface inspection.
　上記一つの辺７１に直交する方向ｒに照射領域を移動させる場合は、照射領域が２０ｍｍ程度重なるように移動することが欠陥の見落としを防止する点で好ましい。
　本発明においては、上記辺全面検査を直交する二つの辺において行うことが好ましく、特に図１０に示しますように、４辺全てで行うことが好ましい。
　大型フォトマスクに描かれているパターンの方向によっては、上記一つの辺のみの辺全面検査では、欠陥を見落とす可能性があるからである。 When the irradiation region is moved in the direction r perpendicular to the one side 71, it is preferable that the irradiation regions are moved so as to overlap each other by about 20 mm from the viewpoint of preventing defects from being overlooked.
In the present invention, the entire side inspection is preferably performed on two orthogonal sides, and particularly on all four sides as shown in FIG.
This is because, depending on the direction of the pattern drawn on the large photomask, a defect may be missed in the entire side inspection of only one side.
　上記各辺全面検査では、上述した通り少なくとも角度を変えて２回全面検査を行うものであるので、４辺全てで辺全面検査を行った場合は、少なくとも８回の全面検査を行うことになり、この少なくとも８回の全面検査を行うことが、欠陥の見落としを最小限とするとの観点から最も好ましいといえる。 As described above, the entire surface inspection is performed twice at least at different angles as described above. Therefore, when the entire surface inspection is performed on all four sides, the entire surface inspection is performed at least eight times. It can be said that it is most preferable to perform the entire surface inspection at least eight times from the viewpoint of minimizing the oversight of defects.
３．照射領域の移動速度
　上記観察用照明が照射する照射領域の移動速度は、５ｃｍ／秒～９ｃｍ／秒であることが好ましく、中でも６ｃｍ／秒～８ｃｍ／秒であることが好ましく、特に７ｃｍ／秒であることが好ましい。上記範囲より早い場合は、欠陥の見落としが生じる可能性が高くなるからであり、上記範囲より遅い場合は、ムラ等の欠陥の発見に際して、反射光の強度の変化が緩やかとなってしまい、ムラであるとの判断が難しくなってしまうからである。 3. Moving speed of irradiation region The moving speed of the irradiation region irradiated by the observation illumination is preferably 5 cm / second to 9 cm / second, more preferably 6 cm / second to 8 cm / second, and particularly 7 cm / second. It is preferable that If it is earlier than the above range, there is a high possibility that the defect will be overlooked. If it is later than the above range, the intensity change of the reflected light becomes gradual when the defect such as unevenness is found, and the unevenness. This is because it becomes difficult to judge that it is.
４．その他
　上記観察用照明の種類や、大型フォトマスクの固定方法等の、「Ｃ．欠陥検査方法」での記載の無い事項は、上記「Ａ．外観検査装置」および「Ｂ．外観検査方法」において説明したものを用いることが可能である。
Ｄ．大型フォトマスクの製造方法
　本発明の大型フォトマスクの製造方法は、上記「Ｂ．外観検査方法」もしくは「Ｃ．欠陥検査方法」を用いた検査工程を有することを特徴とするものである。
　本発明における大型フォトマスクは、例えばフラットパネルディスプレイやカラーフィルタ等の製造時のフォトリソグラフィプロセス、より具体的には露光プロセス等において用いられるものである。 4). Other Matters not described in “C. Defect inspection method” such as the type of illumination for observation and the method for fixing a large photomask are described in “A. Appearance inspection apparatus” and “B. What has been described can be used.
D. Large photomask manufacturing method The large photomask manufacturing method of the present invention is characterized by having an inspection step using the above-mentioned "B. Appearance inspection method" or "C. Defect inspection method".
The large-sized photomask in the present invention is used in, for example, a photolithography process at the time of manufacturing a flat panel display, a color filter or the like, more specifically, an exposure process.
　本発明の大型フォトマスクの製造方法は、外観検査工程等において、上述した外観検査方法や欠陥検査方法を用いた検査工程を有することを特徴とするものであり、その他の工程は従来行われている工程と同様であるので、ここでの説明は、省略する。 The manufacturing method of a large-sized photomask of the present invention is characterized by having an inspection process using the above-described appearance inspection method and defect inspection method in the appearance inspection process and the like, and other processes are conventionally performed. Since it is the same as the process which exists, description here is abbreviate | omitted.
　なお、本発明は、上記実施形態に限定されるものではない。上記実施形態は、例示であり、本発明の特許請求の範囲に記載された技術的思想と実質的に同一な構成を有し、同様な作用効果を奏するものは、いかなるものであっても本発明の技術的範囲に包含される。 The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.
　１００…外観検査装置
　１０…架台
　１２…回転軸
　１４…基板支持枠
　１６…ステージ
　２０…レーザーポインター
　３０…操作部
　４０…コンピュータ
　４１１、４１２、４１３、４１４、４１５、４１６、４１７、４１８、４１９、４２０、４２１…レーザーポインター照射位置
　５０…顕微鏡
　９０…デジタルカメラ DESCRIPTION OF SYMBOLS 100 ... Appearance inspection apparatus 10 ... Stand 12 ... Rotating shaft 14 ... Substrate support frame 16 ... Stage 20 ... Laser pointer 30 ... Operation part 40 ... Computer 411, 412, 413, 414, 415, 416, 417, 418, 419, 420 , 421 ... Laser pointer irradiation position 50 ... Microscope 90 ... Digital camera

Claims (19)

  1. 　目視観察に基づいて指し示される大型フォトマスク主面の目視指定位置を指し示す目視指定手段と、
    　目視指定情報を取得する目視指定情報取得手段と、
    　前記目視指定情報から目視指定位置を示す前記大型フォトマスクの主面の二次元座標を算出する二次元座標算出手段と、
    　前記大型フォトマスクの主面の各位置を観察可能な位置に移動可能な顕微鏡と、
    　前記二次元座標で示される前記大型フォトマスクの主面の位置を観察可能な位置に前記顕微鏡を移動させる顕微鏡駆動手段と、
    　前記大型フォトマスクの主面の任意の位置を示す二次元座標を入力する二次元座標入力手段と、
    　を備えることを特徴とする外観検査装置。     Visual designation means for indicating the visual designation position of the main surface of the large photomask pointed to based on visual observation;
    Visual designation information acquisition means for acquiring visual designation information;
    Two-dimensional coordinate calculation means for calculating the two-dimensional coordinates of the main surface of the large photomask indicating the visual designation position from the visual designation information;
    A microscope capable of moving each position of the main surface of the large photomask to an observable position;
    Microscope driving means for moving the microscope to a position where the position of the main surface of the large photomask indicated by the two-dimensional coordinates can be observed;
    Two-dimensional coordinate input means for inputting two-dimensional coordinates indicating an arbitrary position of the main surface of the large photomask;
    An appearance inspection apparatus comprising:
  2. 　前記二次元座標入力手段により入力された二次元座標から、前記目視指定情報を算出する目視情報算出手段を備えることを特徴とする請求項１に記載の外観検査装置。 The visual inspection apparatus according to claim 1, further comprising visual information calculation means for calculating the visual designation information from the two-dimensional coordinates input by the two-dimensional coordinate input means.
  3. 　前記目視指定情報取得手段は、面積を有する領域を示す前記目視指定情報を取得すること特徴とする請求項１または請求項２に記載の外観検査装置。 3. The visual inspection apparatus according to claim 1, wherein the visual designation information acquisition unit acquires the visual designation information indicating a region having an area.
  4. 　光源の種類が互いに異なる複数の観察用照明をさらに有することを特徴とする請求項１から請求項３までのいずれかに記載の外観検査装置。 4. The visual inspection apparatus according to claim 1, further comprising a plurality of observation illuminations having different types of light sources.
  5. 　前記大型フォトマスクの主面に平行な回動軸まわりに前記大型フォトマスクを回動させる回動機構をさらに有し、前記大型フォトマスクの主面を床面と平行な方向から回動軸まわりに回転可能な角度が９０°以上であることを特徴とする請求項１から請求項４までのいずれかに記載の外観検査装置。 A rotation mechanism for rotating the large photomask around a rotation axis parallel to the main surface of the large photomask, and the main surface of the large photomask from the direction parallel to the floor surface around the rotation axis; The visual inspection apparatus according to any one of claims 1 to 4, wherein an angle of rotation is 90 ° or more.
  6. 　前記回転可能な角度が２７０°以上であることを特徴とする請求項５に記載の外観検査装置。 The visual inspection apparatus according to claim 5, wherein the rotatable angle is 270 ° or more.
  7. 　前記大型フォトマスクの主面を撮像する撮像装置をさらに有することを特徴とする請求項１から請求項６までのいずれかに記載の外観検査装置。 The visual inspection apparatus according to any one of claims 1 to 6, further comprising an image pickup device for picking up an image of a main surface of the large photomask.
  8. 　目視観察に基づいて指し示される大型フォトマスクの主面の欠陥の目視指定情報を取得する目視指定情報取得工程と、
    　前記目視指定情報から前記欠陥の位置を示す前記大型フォトマスクの主面の二次元座標を算出する二次元座標算出工程と、
    　前記二次元座標で示される前記大型フォトマスクの主面の位置を顕微鏡により観察するミクロ観察工程と、
    　を備えることを特徴とする外観検査方法。     A visual designation information acquisition step for obtaining visual designation information of defects on the main surface of the large photomask pointed to based on visual observation;
    A two-dimensional coordinate calculation step for calculating a two-dimensional coordinate of the main surface of the large photomask indicating the position of the defect from the visual designation information;
    A micro observation step of observing with a microscope the position of the main surface of the large photomask indicated by the two-dimensional coordinates;
    An appearance inspection method comprising:
  9. 　前記目視指定情報取得工程は、外観の観察により前記大型フォトマスクの主面に存在する欠陥の有無を検査する欠陥検査工程内で行われ、
    　前記欠陥検査工程が、
    　前記大型フォトマスクの主面に対して観察用照明を一定の照射角度で照射することにより前記大型フォトマスクの主面に照射領域を設け、前記照射領域を上下左右に動かすことにより前記大型フォトマスクの主面の全面を検査する全面検査を行い、
    　前記全面検査は、前記観察用照明の前記大型フォトマスクの主面に対する照射角度を変えて少なくとも２回行うものであることを特徴とする請求項８に記載の外観検査方法。     The visual designation information acquisition step is performed in a defect inspection step for inspecting the presence or absence of defects present on the main surface of the large photomask by observing the appearance,
    The defect inspection step
    An irradiation area is provided on the main surface of the large photomask by irradiating observation illumination at a predetermined irradiation angle on the main surface of the large photomask, and the large photomask is moved by moving the irradiation area up, down, left and right. Perform a full inspection to inspect the entire main surface of
    The appearance inspection method according to claim 8, wherein the entire surface inspection is performed at least twice by changing an irradiation angle of the observation illumination with respect to a main surface of the large-sized photomask.
  10. 　大型フォトマスクの主面の欠陥を修正する欠陥修正工程と、
    　前記欠陥の修正箇所を示す前記大型フォトマスクの主面の二次元座標から、目視指定情報を算出する目視指定情報算出工程と、
    　前記欠陥の修正箇所を前記目視指定情報により目視観察を行うマクロ観察工程と、
    　を備えることを特徴とする外観検査方法。     A defect correction process for correcting defects on the main surface of the large photomask;
    From the two-dimensional coordinates of the main surface of the large photomask indicating the defect correction location, a visual designation information calculation step for calculating visual designation information,
    A macro observation step of visually observing the defect correction location according to the visual designation information;
    An appearance inspection method comprising:
  11. 　大型フォトマスクの主面に対して観察用照明を一定の照射角度で照射することにより前記大型フォトマスクの主面に照射領域を設け、前記照射領域を上下左右に動かすことにより前記大型フォトマスクの主面の全面を検査する全面検査を行い、前記大型フォトマスクの主面に存在する欠陥の有無を検査する欠陥検査方法であって、
    　前記全面検査は、前記観察用照明の前記大型フォトマスクの主面に対する照射角度を変えて少なくとも２回行うことを特徴とする欠陥検査方法。     An irradiation area is provided on the main surface of the large photomask by irradiating observation illumination at a predetermined irradiation angle on the main surface of the large photomask, and the large photomask is moved by moving the irradiation area up, down, left, and right. A defect inspection method for performing a full inspection to inspect the entire main surface and inspecting for the presence or absence of defects present on the main surface of the large photomask,
    The defect inspection method, wherein the entire surface inspection is performed at least twice by changing an irradiation angle of the observation illumination with respect to a main surface of the large photomask.
  12. 　前記全面検査は、前記照射角度を１５°～４５°の範囲内の角度で行う低照射角全面検査と、前記照射角度が４５°～７５°の範囲内の角度で行う高照射角全面検査とを含むことを特徴とする請求項１１に記載の欠陥検査方法。 The full inspection includes a low irradiation angle full inspection performed at an irradiation angle of 15 ° to 45 °, and a high irradiation angle full inspection performed at an irradiation angle of 45 ° to 75 °. The defect inspection method according to claim 11, comprising:
  13. 　前記全面検査が、前記大型フォトマスクの一つの辺側から前記一つの辺に対し直交する方向に前記観察用照明を照射し、かつ前記一つの辺に対して平行に移動しながら検査し、前記一つの辺の長さ分検査した後、前記一つの辺に直交する方向に照射領域を所定の距離で移動させる工程を繰り返し行うことにより、大型フォトマスク全面を検査する辺全面検査であることを特徴とする請求項１１または１２に記載の欠陥検査方法。 The whole surface inspection is performed while irradiating the observation illumination in a direction orthogonal to the one side from one side of the large photomask and moving in parallel with the one side, After inspecting the length of one side, it is an entire side inspection that inspects the entire surface of a large photomask by repeatedly performing a process of moving the irradiation region by a predetermined distance in a direction orthogonal to the one side. The defect inspection method according to claim 11, wherein the defect inspection method is a defect inspection method.
  14. 　前記辺全面検査を、前記大型フォトマスクの４つの辺に対して行うことを特徴とする請求項１３に記載の欠陥検査方法。 14. The defect inspection method according to claim 13, wherein the entire side inspection is performed on four sides of the large photomask.
  15. 　前記全面検査における前記照射領域の移動速度が、５ｃｍ／秒～９ｃｍ／秒の範囲内であることを特徴とする請求項１１～請求項１４のいずれかの請求項に記載の欠陥検査方法。 The defect inspection method according to any one of claims 11 to 14, wherein a moving speed of the irradiation region in the entire surface inspection is in a range of 5 cm / second to 9 cm / second.
  16. 　前記目視指定情報取得工程において、前記観察用照明が、制御部により、前記大型フォトマスクの主面に対する照射光の照射状態および非照射状態を交互に繰り返すことを特徴とする請求項９に記載の外観検査方法。 The said illumination for observation repeats the irradiation state and non-irradiation state of irradiation light with respect to the main surface of the said large sized photomask alternately by the control part in the said visual designation | designated information acquisition process. Appearance inspection method.
  17. 　前記観察用照明を、制御部により前記非照射状態として、レーザーポインターで大型フォトマスクの主面の欠陥の目視指定位置を取得することを特徴とする請求項１６に記載の外観検査方法。 The visual inspection method according to claim 16, wherein the observation illumination is set to the non-irradiation state by a control unit, and a visually designated position of a defect on a main surface of a large photomask is obtained with a laser pointer.
  18. 　前記照射状態および非照射状態を交互に高速で切り替えることにより前記大型フォトマスク上の照射光の輝度を低減させた状態で、レーザーポインターで大型フォトマスクの主面の欠陥の目視指定位置を取得することを特徴とする請求項１６に記載の外観検査方法。 A visually designated position of a defect on the main surface of the large photomask is acquired with a laser pointer in a state where the brightness of the irradiation light on the large photomask is reduced by alternately switching between the irradiation state and the non-irradiation state The visual inspection method according to claim 16.
  19. 　請求項８～請求項１０、および請求項１６～１８のいずれかの請求項に記載の外観検査方法、または請求項１０～請求項１５のいずれかの請求項に記載の欠陥検査方法を用いた検査工程を有することを特徴とする大型フォトマスクの製造方法。 The appearance inspection method according to any one of claims 8 to 10 and 16 to 18, or the defect inspection method according to any one of claims 10 to 15 is used. A method for producing a large-sized photomask, comprising an inspection step.
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