JP6669481B2 - Inspection device - Google Patents

Description

  The present invention relates to an inspection device.

  Patent Document 1 discloses a pattern inspection apparatus that supports a photomask in a vertical direction and inspects a pattern formed on the photomask.

JP 2010-181296 A

  In the invention described in Patent Document 1, since the photomask is supported in the vertical direction, the position of the center of gravity of the apparatus is higher than that of the apparatus that instructs the photomask in the horizontal direction. As a result, there is a problem that the device is not stable.

  Further, in the invention described in Patent Literature 1, since the stage is directly mounted on the installation surface (for example, floor), there is a problem that even if vibration occurs during driving of the apparatus, the vibration cannot be suppressed. . In some cases, an anti-vibration table is provided below the stage in order to suppress vibration of the apparatus. In this case, however, the position of the center of gravity of the apparatus is further increased.

  The present invention has been made in view of such circumstances, and in an inspection apparatus that supports a photomask in a vertical direction, it is possible to lower the center of gravity of the apparatus while providing a vibration isolation table below a surface plate. It is an object to provide an inspection device.

  In order to solve the above problem, an inspection apparatus according to the present invention is, for example, a mask inspection apparatus that inspects a mask of an inspection target supported in a vertical direction, a lower surface, and an upper surface parallel to the lower surface, A surface plate formed so that a distance between the lower surface and the upper surface is shorter than a short side of the upper surface, a column provided on the surface plate so as to protrude upward from the upper surface, An imaging unit provided on a pillar, a vibration isolation table mounted on an installation surface, and a substantially cubic concave portion is formed at each of the four corners on the lower surface, and the vibration isolation table includes the concave portion. And a bottom surface of each of the concave portions is supported by the anti-vibration table.

  ADVANTAGE OF THE INVENTION According to the test | inspection apparatus which concerns on this invention, a substantially cubic recess is formed in each of the four corners on the lower surface of a surface plate, The board is placed on the installation surface. Accordingly, in the inspection device that supports the photomask in the vertical direction, the position of the center of gravity of the device can be lowered while the vibration isolation table is provided below the surface plate.

  A mask supporting portion for supporting the mask in a vertical direction, a groove along a longitudinal direction of the surface plate is formed on the upper surface at a position not overlapping with the concave portion in plan view; The support may move inside the groove. Thus, the position of the center of gravity can be lowered while maintaining the strength of the surface plate.

  Here, the depth of the concave portion may be formed to be 0.3 to 0.5 times the distance between the lower surface and the upper surface. Thereby, the strength of the surface plate can be maintained.

  Here, the imaging unit is provided so as to be movable along the pillar, and the groove is provided at a lower end surface of an opening formed in the mask support unit when the imaging unit comes into contact with the surface plate. May be formed at a depth such that the height of the optical axis substantially coincides with the height of the optical axis of the imaging unit. Thereby, the position of the center of gravity can be minimized.

  Here, the recess has four first recesses provided at the four corners of the lower surface, and two second recesses respectively provided along long sides of the lower surface, and the second One of the concave portions may be formed at a position where a part thereof overlaps with a part of the pillar in plan view. Thus, the second concave portion can be provided at a position closer to the center of gravity, and as a result, the stone surface plate with less distortion can be supported with a small number of second concave portions.

  Here, the mask support portion has a guide member that moves inside the groove, the guide member has a bottom surface air pad that discharges air toward the bottom surface of the groove, and air guides toward the side surface of the groove. And a guide member main body provided with the bottom surface air pad and the side surface air pad. Thereby, an air layer is formed between the guide member and the groove (side surface and bottom surface). Therefore, the guide member can be easily moved.

  Here, the side air pad includes a first side air pad fixed to a first side surface of the guide member main body, and a second side air pad provided in a hole formed in a second side surface opposite to the first side surface. And a second side air pad movably provided with respect to the guide member main body, wherein the guide member main body has a through hole formed in the first side air pad, and a second side air pad formed in the second side air pad. A flow path for supplying air to the formed through hole and a space between the hole and the second side air pad is formed, and the second side air pad is provided between the hole and the second side air pad. The guide member body may be moved by air supplied to the space. This makes it possible to automatically adjust the distance between the first side surface of the groove and the front end surface of the first side surface air pad and the distance between the second side surface of the groove and the front end surface of the second side surface air pad.

  Here, the mask support portion includes a frame that holds the mask, and an adjusting mechanism provided below the frame, the adjusting mechanism adjusting the height of the frame. The member main body is provided with a pin that penetrates in a vertical direction and whose upper end surface is substantially hemispherical. The lower end of the pin is provided on the bottom air pad, and the upper end of the pin contacts the bottom surface of the adjustment mechanism. You may touch. Thus, the heavy mask supporting portion can be supported by the highly rigid groove, and an unfavorable bias load on the air pad can be avoided.

  ADVANTAGE OF THE INVENTION According to this invention, in the test | inspection apparatus which supports a photomask in a perpendicular direction, the gravity center position of an apparatus can be made low, providing a vibration isolation table under a surface plate.

It is a front view showing the outline of inspection device 1 concerning a 1st embodiment. FIG. 2 is a plan view schematically showing the inspection device 1. It is a perspective view showing the outline of inspection device 1. It is the schematic for demonstrating the guide member 33, and is the top view which expanded the inspection device 1 partially. FIG. 5 is a schematic view for explaining a guide member 33, and is a cross-sectional view taken along line AA of FIG.

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

<First embodiment>
FIG. 1 is a front view schematically showing an inspection apparatus 1 according to the first embodiment. FIG. 2 is a plan view schematically showing the inspection apparatus 1. FIG. 3 is a perspective view schematically showing the inspection device 1. In this specification, a direction perpendicular to the paper surface in FIG. 1 is defined as an x direction, a vertical direction in the paper surface is defined as a y direction (vertical direction), and a direction orthogonal to the x direction and the y direction is defined as a z direction. 2 and 3, illustration of a part of the configuration is omitted.

  The inspection device 1 is, for example, an inspection device that supports a photomask M to be inspected in a substantially vertical direction and moves a camera or the like in the vertical direction to inspect a pattern or the like formed on the photomask M.

  The photomask M to be inspected in the present embodiment is, for example, an exposure mask used for manufacturing a substrate for a display device of a liquid crystal display device. The photomask M is one in which one or a plurality of image device transfer patterns are formed on a large, substantially rectangular substrate having a side of, for example, more than 1 m.

  The inspection apparatus 1 mainly includes a surface plate 10, an imaging unit 20, a mask support unit 30, and a vibration isolation table 50 (including vibration isolation tables 51 and 52; see FIG. 3).

  The surface plate 10 is configured as a stage, and is supported on vibration isolation tables 51 and 52 installed at a plurality of locations (six locations) on the installation surface F.

  The platen 10 is a substantially rectangular parallelepiped (thick plate) stone member having a width W of about 1200 mm and a thickness T of about 400 mm. In other words, the surface plate 10 has a lower surface 10a and an upper surface 10e parallel to the lower surface 10a, and a distance between the lower surface 10a and the upper surface 10e is shorter than a short side of the upper surface 10e.

  On the lower surface 10a of the surface plate 10, recesses 10b and 10c having a substantially cubic shape are formed. The recess 10b is formed at each of four corners of the lower surface 10a. The recess 10c is formed at two locations, one location each along the long side of the lower surface 10a. Thus, the concave portions 10b and 10c are formed at a total of six places. By providing the concave portion 10c in addition to the concave portion 10b, distortion of the stone surface plate 10 can be reduced.

  Of the two concave portions 10c, the concave portion 10c formed on the + z side is formed at a position overlapping a part of the pillar 21 (described in detail later) in plan view (when viewed from above (+ y direction)). . Accordingly, the concave portion 10c is provided at a position closer to the center of gravity, and the distortion of the stone surface plate 10 can be further reduced. Further, the two concave portions 10c are formed at positions that are point-symmetric with respect to the center of gravity position G of the inspection device 1 in plan view (see FIG. 2). The concave portion 10c has a larger lateral dimension (dimension in the x direction) than the concave portion 10b for maintenance of the vibration isolation table 52 and the like.

  The concave portion 10c is not essential, but it is desirable to form at least two concave portions 10c in order to provide as many vibration isolation tables 50 as possible. As in the present embodiment, by forming the concave portion 10c one by one along the long side of the lower surface 10a, the stone surface plate 10 with less distortion can be supported by the small concave portion 10c. The position of the concave portion 10c is not limited to the illustrated position. For example, the positions of the two concave portions 10c in the x direction may be different. However, considering the control of the vibration isolation table 50 and the like, it is desirable that the positions of the two concave portions 10c in the x direction are the same.

  An anti-vibration table 51 mounted on the installation surface F is provided inside the concave portion 10b (see FIG. 3). An anti-vibration table 52 mounted on the installation surface F is provided inside the concave portion 10c (see FIG. 3). The bottom surfaces of the concave portions 10b and 10c are support surfaces 10d supported by the vibration isolation tables 51 and 52.

  As shown in FIG. 1, the height of the vibration isolation tables 51 and 52 is higher than the depth D1 of the concave portions 10b and 10c. Therefore, the base plate 10 is placed on the installation surface F via the vibration isolation tables 51 and 52 because the vibration isolation tables 51 and 52 support the support surface 10d. The stability of the inspection apparatus 1 is based on the position of the support surface 10d.

  As described above, the concave portions 10b and 10c are formed in the thick platen 10, and the anti-vibration tables 51 and 52 are provided inside the concave portions 10b and 10c, so that the center of gravity of the inspection apparatus 1 with respect to the support surface 10d. G decreases. By increasing the thickness T of the surface plate 10 or increasing the depth of the concave portions 10b and 10c, the position G of the center of gravity can be lowered.

  However, the depth D1 of the concave portions 10b and 10c is set to 0.3 to 0.5 times the thickness T of the surface plate 10 in order to maintain the strength of the surface plate 10.

  The depth D1 of the recesses 10b and 10c, that is, the height of the support surface 10d is set so that the angle θ (see FIG. 1) at which the center of gravity G of the entire inspection apparatus 1 is viewed from the support surface 10d is 60 degrees or less. Is done.

  However, it is desirable that the angle at which the center of gravity G is viewed from the support surface 10d be small. In the present embodiment, the concave portions 10b and 10c are formed such that the angle θ at which the center of gravity G is viewed from the support surface 10d is approximately 45 degrees.

  In the present embodiment, the recesses 10b and 10c are formed so that the height H1 of the lower surface 10a is about 100 mm due to the stability of the inspection device 1 and the convenience during transportation and installation.

  A groove 10f is formed on the upper surface 10e of the surface plate 10. The groove 10f is formed along the longitudinal direction (x direction) of the surface plate 10 at a position not overlapping with the concave portions 10b and 10c in plan view (see FIG. 2). As described above, by shifting the horizontal position of the groove 10f and the horizontal position of the concave portions 10b and 10c, the thickness of the portion of the platen 10 below the groove 10f is increased, and the strength of the platen 10 is increased. Can be higher.

  The depth D2 of the groove 10f is sufficiently smaller than the thickness T of the surface plate 10. In the present embodiment, the depth D2 of the groove 10f is about 60 mm, and the thickness of the portion below the groove 10f is about 340 mm. Therefore, even if the groove 10f is formed, the rigidity of the platen 10 can be made sufficiently high.

  The groove 10f supports the mask support 30 so as to be movable in the x direction. By using the groove 10f as a guide for moving the mask support unit 30, the height of the imaging unit 20 and the mask support unit 30 can be reduced, and thereby the center of gravity G can be lowered.

  The depth D2 of the groove 10f is such that the optical axis ax of the camera 22 when the camera 22a (described in detail below) abuts on the upper surface 10e is the lower end of the photomask M supported by the mask support 30 (described in detail below). Is set to match. This state is the state where the center of gravity G is the lowest. In the present embodiment, the depth D2 of the groove 10f is about 60 mm, and the height (pass line) H2 of the lower end of the photomask M at this time is about 680 mm.

  The imaging unit 20 mainly includes a column 21 provided to protrude upward from the surface plate 10, a camera 22 provided on the column 21, and a support unit 23 that supports the mask support unit 30 at the inspection position ( (See FIG. 1).

  The pillar 21 is attached to the upper surface 10e so as to protrude upward (+ y direction) from the upper surface 10e. The pillar 21 is formed of ceramic or the like. In order to lower the center of gravity G, the column 21 is preferably hollow.

  The camera 22 is, for example, a CCD camera or a TDI camera which is a special CCD camera, and has two cameras 22a and 22b. Two cameras 22a and 22b are provided adjacent to each other along the y direction. A moving unit (not shown) including an air pad (not shown) is provided between the camera 22 and the pillar 21. The camera 22 is provided on a moving unit (not shown) such that its optical axis ax is parallel to the z-axis.

  When the moving unit moves in the vertical direction (y direction), the camera 22 moves in the vertical direction (y direction). The moving unit moves the two cameras 22a and 22b to the initial position where the camera 22a contacts the upper surface 10e of the surface plate 10 and the upper end position where the camera 22b is located near the upper end of the pillar 21 (see a two-dot chain line in FIG. 1). Is moved along the column 21 between the two. When the camera 22a is configured to be able to contact the upper surface 10e, the position G of the center of gravity can be lowered.

  Further, the imaging unit 20 has a transmission illumination light source and a reflection illumination light source (not shown). The transmitted illumination light source is provided on the back side (−z side) of the photomask M, and irradiates a so-called g-line (for example, light having a wavelength of 435.84 [nm]). The reflection illumination light source is provided on the front side (+ z side) of the photomask M and irradiates so-called e-rays (for example, light having a wavelength of 546.07 [nm]). The camera 22 simultaneously receives and images the g-rays emitted from the transmitted illumination light source and the e-rays emitted from the reflection illumination light source.

  Next, the configuration of the camera 22 will be described. The cameras 22a and 22b each include an objective lens that converts g-line and e-line into parallel light, and an optical member that separates g-line and e-line that have passed through the objective lens (for example, a polarizing beam splitter and a dichroic filter). A member having both functions), two sets of image forming lenses for forming the g-line and e-line separated by the optical member, and g-line and e-line formed by the two sets of image forming lenses, respectively. And an imaging element to be formed. As described above, the cameras 22a and 22b can simultaneously image transmitted light and reflected light. Since the cameras 22a and 22b can use a known technique, a detailed description thereof will be omitted.

  However, in case that one of the cameras 22a and 22b fails, the camera 22 preferably has two cameras 22a and 22b provided adjacent to each other in the y direction.

  The support unit 23 supports the mask support unit 30 so that the mask support unit 30 does not tilt in the horizontal direction when the mask support unit 30 is moved to the inspection position. In addition, since the well-known technique can be used for the support part 23, detailed description is omitted.

  The mask support 30 supports the photomask M. The mask support 30 includes a frame 31, an adjustment mechanism 32, and a guide member 33.

  The frame 31 is formed in a frame shape so as to surround the outer periphery of the vertically supported photomask M. The frame 31 supports the photomask M such that the surface (the surface on which the pattern is formed) of the photomask M is parallel to the xy plane.

  An adjustment mechanism 32 is provided below the frame 31. The adjustment mechanism 32 changes the position of the lower side of the photomask M in the height direction (y direction). Since the adjustment mechanism 32 is already known, a detailed description will be omitted.

  The guide member 33 is a member that moves inside the groove 10f. As shown in FIG. 3, the guide member 33 mainly includes a guide member main body 331, side air pads 332 and 333, a lower air pad 334, and pins 335.

  The guide member body 331 is a rod-shaped member on which the frame 31 and the adjustment mechanism 32 are provided. The guide member main body 331 is provided with side air pads 332, 333 and pins 335. The guide member main body 331 is provided with a bottom surface air pad 334 via a pin 335.

  FIG. 4 is a schematic view for explaining the guide member 33, and is a partially enlarged plan view of the inspection apparatus 1. FIG. In FIG. 4, the flow of air is indicated by a thick broken arrow.

  The side air pads 332 and 333 are substantially cylindrical members (see FIG. 3). The side air pad 332 is provided on the side surface 331a of the guide member main body 331, and the side air pad 333 is provided on the side surface 331b opposite to the side surface 331a. The tip surface 332a of the side air pad 332 faces the side surface 10g of the groove 10f, and the tip surface 333a of the side air pad 333 faces the side surface 10h of the groove 10f.

  The side surface 10g to which the front end surface 332a faces is a reference surface, and is formed with high accuracy (for example, the surface accuracy is approximately 2 μm, and the surface accuracy of the non-reference surface 10h is approximately 5 μm). Therefore, the position of the guide member main body 331 in the z direction and the angle with respect to the xz plane are determined by the distal end surface 332a facing the side surface 10g with the thin air layer interposed therebetween.

  The side air pad 332 has a substantially cylindrical coupling portion 332b and a substantially cylindrical air pad portion 332c. The diameter of the coupling part 332b is smaller than the diameter of the air pad part 332c. The coupling portion 332b is provided inside a hole 331c formed in the guide member main body 331. An elastic member (for example, an O-ring) 341 is provided between the outer peripheral surface of the coupling portion 332b and the inner peripheral surface of the hole 331c. Further, since the diameter of the connecting portion 332b is smaller than the diameter of the air pad portion 332c, the state in which the distal end surface of the connecting portion 332b is in contact with the bottom surface of the hole 331c is maintained. Thus, the angle of the side air pad 332 with respect to the guide member main body 331 is maintained in a constant state.

  The side air pad 333 has a substantially cylindrical sliding portion 333b and a substantially cylindrical air pad portion 333c. The diameter of the sliding portion 333b is smaller than the diameter of the air pad portion 333c. The sliding portion 333b is provided movably with respect to the guide member main body 331 inside a hole 331d having a diameter larger than the diameter of the sliding portion 333b (described later in detail). An elastic member 342 is provided between the outer peripheral surface of the sliding portion 333b and the inner peripheral surface of the hole 331d so that the supplied air does not escape (described later in detail).

  Through holes 332d and 333d are formed inside the side air pads 332 and 333, respectively. Orifices 332e and 333e are formed inside the through holes 332d and 333d. The through holes 332d and 333d are connected to a tubular hole 331e formed in the guide member main body 331. The hole 331e is a passage for air supplied from a pump or the like (not shown). One end is covered by a plug 343, and the other end is connected to a pipe 351 connected to the pump or the like. As a result, air is supplied to the space between the hole 331d and the sliding portion 333b and the through holes 332d and 333d via the pipe 351.

  The air supplied to the through hole 332d is discharged through the orifice 332e from the opening on the tip end surface 332a side of the through hole 332d toward the side surface 10g (see a thick broken arrow in FIG. 4). The air supplied to the through hole 333d is discharged through the orifice 333e from the opening on the tip end surface 333a side of the through hole 333d toward the side surface 10h (see the thick broken arrow in FIG. 4). Thereby, a thin air layer is formed between the side surface 10g and the front end surface 332a of the side air pad 332 and between the side surface 10h and the front end surface 333a of the side air pad 333.

  The air supplied to the space between the sliding portion 333b and the hole 331d presses the distal end surface 333f of the sliding portion 333b, and moves the sliding portion 333b in the normal direction (z direction) of the side surface 331b. . As the sliding portion 333b moves in the z direction, the distance between the side surface 10g and the distal end surface 332a and the distance between the side surface 10h and the distal end surface 333a are automatically adjusted. For example, when the width of the groove 10f is large, the side surface air pad 333 is moved in the direction in which the side surface air pad 333 protrudes from the guide member main body 331 (the -z direction) so that the front end surface 333a of the side surface air pad 333 approaches the side surface 10h.

City area of _{S PI} of the distal end surface 333f, through holes 332d, when the pressure of the air discharged with _{P PI} from 333d, the sliding portion 333b, i.e. the force f exerted on the side air pad _333, and _{S PI} and _{P PI} (F = S _PI × P _PI ). In order to move the side air pad 333 to the width of the groove 10f is a side air pads 333, i.e., it is necessary to reduce the area _{S PI} of the front end surface 333f than the area _{S Pd} of the distal end surface 333a. In this embodiment, the area _{S PI} is 0.5 to 0.8 times the area _{S Pd.}

Area of the side surface air pads 332, i.e. the distal end surface 332a is the same area _{S Pd} as the area of the distal end surface 333a, the guide member body 331 is automatically positioned in the groove 10f is maintained.

  At this time, since the diameter of the sliding portion 333b is smaller than the diameter of the hole 331d, the central axis of the sliding portion 333b is the central axis of the hole 331d (the direction normal to the side surface of the guide member main body 331 where the hole 331d is formed). Can lean against. Therefore, even when the side face 10g and the side face 10h are not parallel, the side face 10g and the tip face 332a can be made parallel, and the side face 10h and the tip face 333a can be made parallel.

  The side air pads 332 and 333 spread the side surfaces of the groove 10f through a thin air layer formed between the side surface 10g and the front end surface 332a and between the side surface 10h and the front end surface 333a. Since the groove 10f is made of stone and does not change its dimensions, the side air pads 332, 333, that is, the guide member 33 is guided by the groove 10f.

  In the embodiment shown in FIG. 4, since air is supplied from the hole 331e to the space between the sliding portion 333b and the hole 331d and the through hole 333d, the pressure of the air pressing the distal end surface 333f and the through hole Although the pressure of the air supplied to the 333d is the same, the pressure of the air applied to the front end surface 333f may be different from the pressure of the air supplied to the through hole 333d. For example, the flow path of the air supplied from the hole 331e to the space between the sliding portion 333b and the hole 331d and the flow path of the air supplied from the hole 331e to the through hole 333d are partially different. Different regulators may be provided for different parts.

  The lower surface air pad 334 is a member having a substantially rectangular shape in plan view (when viewed from above (+ y direction)), and is provided below the guide member main body 331 (−y side) via a pin 335 (see FIGS. 3 and 5). Provided. The lower surface air pad 334 has a tubular through hole 334a formed therein. The through hole 334a is a passage for air supplied from a not-shown pump or the like. One end of the through hole 334a is opened on the lower surface 334c (see FIG. 5), and the other end is opened on the side surface 334d. The opening that opens to the side surface 334d of the through hole 334a is connected to a pipe 352 that is connected to a pump or the like. As a result, air is supplied to the through hole 334a via the pipe 352.

  FIG. 5 is a schematic diagram for explaining the guide member 33, and is a cross-sectional view along the line AA in FIG. In FIG. 5, the flow of air is indicated by thick broken arrows.

  The pin 335 is a rod-shaped member having a substantially hemispherical upper and lower surface. The pin 335 penetrates the guide member main body 331 in the up-down direction (y-direction). In the present embodiment, a male screw (not shown) is formed on the outer peripheral surface of the pin 335, and the male screw (not shown) is formed in a hole 331f passing through the guide member main body 331 in the y direction. ). As a result, the pin 335 is fixed to the guide member main body 331.

  The lower end of the pin 335 is provided in a hole 334 e formed on the upper surface of the lower surface air pad 334. The bottom surface of the hole 334e is a substantially hemispherical surface, and the bottom surface of the hole 334e and the substantially hemispherical surface at the lower end of the pin 335 abut.

  The upper end of the pin 335 is an end surface 335a that is a substantially hemispherical surface. The end surface 335a is in contact with the bottom surface 32a of the adjustment mechanism 32. In the present embodiment, the end surface 335a contacts the concave portion 32b formed on the bottom surface 32a. Since the end face 335a is substantially hemispherical, even if the adjustment mechanism 32 is inclined with respect to the pin 335, the position of the adjustment mechanism 32 can be determined with respect to the position of the end face 335a, and this is inconvenient for the air pads 332 and 334. Uneven loads can be avoided. The concave portion 32b is not essential, and the shape of the concave portion 32b is not limited to this.

  The pin 335 is provided for each lower surface air pad 334. Therefore, the frame 31 and the adjustment mechanism 32 are supported by the two lower surface air pads 334 via the two pins 335.

  An orifice 334b is formed inside the through hole 334a. The air supplied to the through hole 334a from the pipe 352 (see FIG. 4) passes through the orifice 334b and is discharged from the opening on the lower surface 334c side of the lower surface air pad 334 toward the bottom surface 10i of the groove 10f. As a result, a thin layer of air is formed between the bottom surface 10i and the lower surface 334c by the air discharged from the through holes 334a (see the broken arrows in FIG. 5). Thereby, the lower surface air pad 334, that is, the guide member 33 rises from the bottom surface of the groove 10f against the weight of the frame 31, the adjusting mechanism 32, the photomask M, and the like. Thus, the heavy frame 31 and the adjusting mechanism 32 can be supported by the highly rigid groove 10f.

  Return to the description of FIGS. As shown in FIG. 3, the vibration isolation table 50 includes a vibration isolation table 51 that is an active vibration isolation table and a vibration isolation table 52 that is a passive vibration isolation table that supports weight.

  The anti-vibration table 52 has a passive spring element movable in the z direction. The anti-vibration table 51 includes, on the anti-vibration table 52, actuators 51a and 51b movable in the x direction and the y direction, respectively, and a sensor provided on each of the actuators 51a and 51b for controlling the actuators 51a and 51b ( (Not shown) and a control circuit (not shown) for controlling the actuators 51a and 51b so as to suppress vibration input from the outside based on a signal from a sensor (not shown). Since the anti-vibration tables 51 and 52 are already known, detailed description will be omitted.

  As shown in FIG. 1, since the vibration isolation tables 51 and 52 support the support surface 10d, the height of the vibration isolation tables 51 and 52 is higher than the depth D1 of the concave portions 10b and 10c. The diameter of the vibration isolation tables 51 and 52 is equal to or less than the length of the side of the support surface 10d. This allows the vibration isolation tables 51 and 52 to be accommodated in the recesses 10b and 10c, thereby saving space. However, the diameter of the anti-vibration tables 51 and 52 does not need to be equal to or less than the length of the sides of the concave portions 10b and 10c.

  Next, the operation of the inspection device 1 will be described. First, the photomask M is attached to the frame 31, and the position of the lower side of the photomask M in the height direction (y direction) is adjusted by the adjustment mechanism 32. At this time, the mask support 30 is located at a mounting position near the end of the surface plate 10 in the + direction.

  Next, the guide member 33 is moved in the -x direction along the groove 10f to move the photomask M from the mounting position to the inspection position.

  Specifically, air is supplied to the side surface air pads 332 and 333 from a pump or the like (not shown) of the guide member 33, and the air is discharged from the through holes 332d and 333d. Further, air is supplied to the lower surface air pad 334 from a pump or the like (not shown) of the guide member 33, and the air is discharged from the through hole 334a.

  Then, a driving mechanism (not shown) of the guide member 33 (for example, a linear motor or the like) urges the guide member main body 331 with a force in the −x direction. Since a layer of air is formed between the side air pads 332, 333 and the side surfaces 10g, 10h of the groove 10f and between the lower surface air pad 334 and the bottom surface 10i of the groove 10f, a force is urged on the guide member main body 331. By doing so, the guide member 33 can be easily moved.

  When the photomask M moves to the inspection position, the imaging unit 20 inspects the photomask M. In the present embodiment, g-rays are emitted from the transmitted illumination light source, and e-rays are emitted from the reflected illumination light source, and these are simultaneously received by the cameras 22a and 22b to form an image. Then, an image captured by the camera 22a and an image captured by the camera 22b are subtracted to obtain a difference between the two images, thereby finding a pattern defect or the like. However, the method of finding a defect or the like of a pattern is not limited to this. For example, a pattern defect or the like may be found by comparing each of the image captured by the camera 22a and the image captured by the camera 22b with an image generated based on design data.

  As described above, by performing the inspection using the image based on the transmitted light and the image based on the reflected light, the inspection can be performed quickly and various defects can be found.

  This inspection is first performed at an initial position where the camera 22a contacts the upper surface 10e of the surface plate 10. The imaging unit 20 moves the transmission illumination light source, the reflection illumination light source, and the cameras 22a and 22b upward (in the + y direction) along the column 21 while simultaneously irradiating g-line from the transmission illumination light source and e-line from the reflection illumination light source. Move. In this manner, the pattern formed on the photomask M supported by the mask support 30 is sequentially imaged.

  As described above, when an image is captured while moving the cameras 22a and 22b from the initial position to the upper end position, the imaging unit 20 returns the cameras 22a and 22b to the initial position. Then, the guide member 33, that is, the photomask M is moved in the -x direction by a predetermined distance. The imaging unit 20 similarly captures an image while moving the cameras 22a and 22b.

  By repeating such an operation, the entire surface of the photomask M can be inspected. The moving speed of the cameras 22a and 22b in the vertical direction and the moving speed of the guide member 33 in the horizontal direction are adjusted by the visual field range and performance of the cameras 22a and 22b.

  When the inspection of the entire surface of the photomask M is completed, a force in the + x direction is applied to the guide member main body 331 by a driving mechanism (not shown) of the guide member 33 to move the mask support portion 30 to the mounting position. Then, the photomask M is replaced, and the process proceeds to the inspection of the next photomask M.

  According to the present embodiment, concave portions 10b and 10c are formed on lower surface 10a of surface plate 10, and anti-vibration tables 51 and 52 placed on installation surface F are bottom surfaces of concave portions 10b and 10c (support surface 10d). , The center of gravity G of the inspection apparatus 1 with respect to the support surface 10d can be lowered. Since the inspection device 1 supports the photomask M in the vertical direction, the position G of the center of gravity tends to be high. However, by providing the vibration isolation tables 51 and 52 inside the concave portions 10b and 10c, the gravity center position G of the inspection apparatus 1 can be lowered while providing the vibration isolation tables 51 and 52 below the surface plate 10. . Further, since the vibration isolation tables 51 and 52 are provided, the vibration resistance of the inspection device 1 can be increased. Further, by providing the vibration isolation tables 51 and 52 inside the concave portions 10b and 10c, the inspection apparatus 1 can save space.

  For example, when the vibration isolation tables 51 and 52 are provided below the surface plate where no concave portion is formed, the center of gravity G increases. In addition, when the vibration isolation tables 51 and 52 are provided outside the surface plate where no concave portion is formed, the outer shape of the inspection device becomes large. On the other hand, by forming the concave portions 10b and 10c in the thick platen 10 and providing the anti-vibration tables 51 and 52 inside the concave portions 10b and 10c, it is possible to make the inspection apparatus 1 smaller while lowering the center of gravity position G. it can.

  Further, according to the present embodiment, by forming grooves 10f on upper surface 10e of surface plate 10 at positions not overlapping concave portions 10b and 10c in plan view, center of gravity G while maintaining the strength of surface plate 10 is maintained. Can be lowered. For example, if a rail is formed on the upper surface 10e of the surface plate 10 and a mask support is provided thereon, the position G of the center of gravity increases. On the other hand, by providing the mask supporting portion 30 in the groove 10f, the position G of the center of gravity can be lowered.

  Further, according to the present embodiment, in order to form the groove 10f, by discharging air from the side air pads 332, 333 and the lower surface air pad 334, the air is discharged between the side air pads 332, 333 and the side surfaces 10g, 10h of the groove 10f. , And an air layer can be formed between the lower surface air pad 334 and the bottom surface 10i of the groove 10f. Thereby, the guide member 33 is floated from the groove 10f, and the guide member 33 can be easily moved. Such a configuration and effect can be realized only by directly forming the groove 10f in a hard material such as the surface plate 10.

  For example, when a convex rail made of ceramic or stone is formed on the upper surface 10e of the surface plate 10 and a mask supporting portion is provided thereon, rigidity is low, dimensional accuracy is reduced, and the mask supporting portion 30 There is a problem that the installation position becomes high. On the other hand, when the groove 10f is formed in the surface plate 10, the rigidity is high and the dimensional accuracy is high. Therefore, the guide member 33 can be smoothly moved with less vibration. Furthermore, since the groove 10f is strong, air can be discharged from the through holes 332d, 333d, and 334a at a high pressure. Therefore, the guide member 33 can be reliably lifted from the groove 10f, and the guide member 33 can be moved more smoothly. Further, by forming the groove 10 f in the surface plate 10, the installation position of the mask support 30 can be lowered.

  As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes a design change or the like without departing from the gist of the present invention. .

  Further, in the present invention, “substantially” is a concept including not only a case in which they are strictly the same but also an error or a deformation that does not lose the identity. For example, a substantially cubic shape is not limited to a strictly cubic shape. For example, the surface plate 10 is formed with a concave portion 10b and the like, but the surface plate 10 has a substantially cubic shape when viewed as a whole. Further, for example, the expression “vertical, coincident, etc.” includes not only the case of strictly vertical, coincident, etc., but also the case of approximately vertical, approximately coincident, etc.

  In the present invention, “near” is a concept indicating that, for example, when it is near A, it is near A, and it may or may not include A.

1: Inspection device 10: Surface plate 10a: Lower surface 10b, 10c: Recess 10d: Support surface 10e: Upper surface 10f: Groove 10g, 10h: Side surface 10i: Bottom surface 20: Imaging unit 21: Pillar 22: Cameras 22a, 22b: Camera 23 : Supporting part 30: Mask supporting part 31: Frame 32: Adjusting mechanism 32a: Bottom surface 32b: Recess 33: Guide member 50: Vibration isolation table 51: Vibration isolation tables 51a, 51b: Actuator 52: Vibration isolation table 331: Guide member body 331a: Side surface 331b: Side surface 331c: Hole 331d: Hole 331e: Hole 331f: Hole 332: Side air pad 332a: Tip surface 332b: Joint 332c: Air pad portion 332d: Through hole 332e: Orifice 333: Side air pad 333b: Tip surface 333 : Sliding part 333c: Air pad part 333d: Penetration 333e: orifice 333f: tip surface 334: lower surface air pad 334a: through hole 334b: orifice 334c: lower surface 334d: side surface 334e: hole 335: pin 335a: end surface 343: plug 341, 342: elastic member 351, 352: piping M: photo mask

Claims (7)

A mask inspection apparatus for inspecting a mask to be inspected supported in a substantially vertical direction,
A surface plate having a lower surface and an upper surface parallel to the lower surface, and formed such that a distance between the lower surface and the upper surface is shorter than a short side of the upper surface;
A pillar provided on the upper surface so as to protrude upward from the upper surface,
An imaging unit provided on the pillar,
An anti-vibration table placed on the installation surface,
A mask supporting portion that supports the mask in a substantially vertical direction,
With
On the lower surface, substantially cubic concave portions are formed at four corners, respectively.
The vibration isolation table is higher than the depth of the recess,
The bottom surfaces of the concave portions are respectively supported by the vibration isolation table ,
On the upper surface, at a position that does not overlap with the concave portion in plan view, a groove is formed along the longitudinal direction of the surface plate,
The inspection device according to claim 1 , wherein the mask support moves within the groove . The depth of the recess, the inspection apparatus according to claim 1, characterized in that it is formed to be 0.3 to 0.5 times the distance between the lower surface and the upper surface. The imaging unit is provided movably along the pillar,
The groove is such that when the imaging unit contacts the surface plate, the height of the lower end surface of the opening formed in the mask support unit is substantially equal to the height of the optical axis of the imaging unit. The inspection device according to claim 1 , wherein the inspection device is formed at a depth. The concave portion includes four first concave portions provided at the four corners of the lower surface, and two second concave portions provided along respective long sides of the lower surface,
Wherein one of the second recess in plan view, the inspection apparatus according to any one of claims 1 to 3, wherein a portion is formed at a position overlapping a portion of said post. The mask support has a guide member that moves inside the groove,
The guide member, a bottom surface air pad that discharges air toward the bottom surface of the groove, a side surface air pad that discharges air toward the side surface of the groove, a guide member body provided with the bottom surface air pad and the side surface air pad, The inspection device according to claim 1 , comprising: The side surface air pad is a first side surface air pad fixed to a first side surface of the guide member main body, and a second side surface air pad provided in a hole formed in a second side surface opposite to the first side surface, A second side air pad movably provided with respect to the guide member main body,
The guide member body supplies air to a through hole formed in the first side air pad, a through hole formed in the second side air pad, and a space between the hole and the second side air pad. A flow path is formed,
The inspection apparatus according to claim 5 , wherein the second side air pad is moved with respect to the guide member main body by air supplied to a space between the hole and the second side air pad. The mask support portion is a frame that holds the mask, and an adjustment mechanism provided below the frame, and has an adjustment mechanism that adjusts the height of the frame,
The guide member main body is provided with a pin that penetrates in a vertical direction and has a top end surface that is substantially hemispherical.
It said pin has a lower end is provided on the bottom surface air pad inspection apparatus according to claim 5 or 6 the upper end is equal to or abutting the bottom surface of the adjusting mechanism.

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