TWI735630B - Mask holding device - Google Patents

Abstract

The present invention can stably rotate the photomask in a state where the photomask is fixed to a frame arranged in a substantially vertical direction.

A moving part is placed on the platform, and a mask holding part 40 is placed on the moving part. The mask holding part 40 has a substantially frame-shaped frame 41 that holds the mask M of the inspection object in a substantially vertical direction, and a frame 41 Rotating rotating mechanism 43. The rotating mechanism 43 has: a first nut member 433A and a second nut member 433B, which are provided near both ends of the frame portion located on the lower side of the frame; a first screw member 432A and a second screw member 432B, which are the same as the The 1 nut member 433A and the second nut member 433B are respectively screwed together; and the rotation driving part 431 which rotates the first screw member 432A and the second screw member 432B by different amounts. In addition, the moving part is provided with a first pin 438A and a second pin 438B along a substantially vertical direction. The first screw member 432A is provided above the first pin 438A at a position overlapping the first pin 438A in a plan view. The member 432B is provided above the second pin 438B at a position overlapping the second pin 438B in a plan view.

Description

Mask holding device

The invention relates to a mask holding device.

Patent Document 1 discloses a substrate holder that vertically holds a substrate. The substrate holder has two eccentrically rotatable support rollers near the two ends of the lower side of the substrate, one eccentrically rotatable support roller for the side surface of the substrate to abut, and press the substrate against the supports The spring of the roller rotates the substrate relative to the substrate holder.

[Prior Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2007-504675

However, in the invention described in Patent Document 1, the substrate cannot be firmly fixed to the substrate holder, and the substrate may move relative to the substrate holder due to acceleration or impact of the stage.

The present invention was completed in view of this situation, and its purpose is to provide a A photomask holding device that stably rotates the photomask in a state where the photomask is fixed to a frame arranged in a substantially vertical direction.

In order to solve the above-mentioned problems, the photomask holding device of the present invention is characterized by having a photomask holding portion and a moving portion. The photomask holding portion has, for example, a platform and a substantially frame shape that holds the photomask of the inspection object in a substantially vertical direction. The frame and the rotating mechanism for rotating the frame, the moving part is placed on the platform, and the mask holding part is placed on it, and is arranged to be movable along the length direction of the platform, and the rotating mechanism has : The first nut member and the second nut member are provided near the ends of the frame portion located on the lower side of the frame; the first screw member and the second screw member, etc. are the same as the first nut member and the second 2 nut members are respectively screwed; and a rotation driving part that rotates the first thread and the second thread by different amounts; the moving part is provided with a first pin and a second pin in a substantially vertical direction, and the first A screw member is provided above the first pin at a position overlapping the first pin in a plan view, and the second screw member is provided above the second pin at a position that overlaps the second pin in a plan view. Location.

According to the photomask holding device of the present invention, the moving part is placed on the platform and the photomask holding part is placed on the moving part. The photomask holding part has a substantially frame-shaped frame that holds the photomask of the inspection object in a substantially vertical direction, and Rotating mechanism that rotates the frame. Furthermore, the rotating mechanism has: a first nut member and a second nut member, which are provided near both ends of the frame portion located on the lower side of the frame; a first screw member and a second screw member, which are the same as the first nut member And the second nut member are respectively screwed together; and a rotation driving part that rotates the first screw member and the second screw member by different amounts. With this, the photomask can be fixed to the frame arranged in the substantially vertical direction. Rotate the frame (that is, the photomask). In addition, the moving part is provided with a first pin and a second pin in a substantially vertical direction. The first screw member is provided above the first pin at a position overlapping the first pin in a plan view, and the second screw member is located on the first pin. The upper part of the 2 pin is set at a position overlapping with the 2 pin in a plan view. In this way, the first and second pins with higher rigidity are used to support the load of the mask holding portion, and the first screw member and the second screw member are rotated by different amounts, whereby the frame (that is, the light The cover) rotates.

Here, a mirror for returning light in the incident direction may also be provided on the side surface of the frame, and the rotation driving part has: an actuator; a first sprocket, which is arranged coaxially with the first screw member, The first screw member rotates; the second sprocket is arranged coaxially with the second screw member to rotate the second screw member; and a power transmission unit that connects the drive shaft of the actuator with the first sprocket And the second sprocket; in a plan view, the distance between the reflector and the second screw member is set to distance A, and the distance between the reflector and the first screw member is set to distance B, then the first The number of teeth α of the sprocket and the number of teeth β of the second sprocket have a relationship of the number of teeth α: number of teeth = distance A: distance B. Thereby, the frame can be rotated so that the position where the substantially parallel line connecting the first sprocket and the second sprocket intersects with the substantially vertical line including the mirror does not move. Furthermore, the reflector is a part that becomes the reference for the position determination of the frame. Therefore, the position of the mask obtained by measuring the position of the reflector will not deviate from the position of the mask that should exist.

Here, a groove along the longitudinal direction of the platform may also be formed on the upper surface of the platform, and the moving part has: a lower surface air cushion which sprays air toward the bottom surface of the groove; a side air cushion which sprays air toward the side surface of the groove And the moving member body, which is provided with the lower surface air cushion and the side air cushion; in the first pin and the second pin, the lower end is set in the above The lower surface is air-cushioned and the upper end is arranged on the moving member body, the lower ends of the first screw member and the second screw member are arranged on the moving member body, and the moving member body moves along the groove. Thereby, the load of the mask holding part can be supported by the groove with high rigidity via the lower surface air cushion. In addition, an air layer is formed between the side air cushion and the groove, and between the lower surface air cushion and the bottom surface of the groove, so that the moving part or the mask holding part can be easily moved.

Here, the lower surface air cushion may have a first lower surface air cushion provided near the first end of the moving member body, and a second end provided on the moving member body opposite to the first end. The second lower surface air cushion in the vicinity forms a first opening for blowing air at approximately the center of the bottom surface of the first lower surface air cushion, and a second opening for blowing air is formed at approximately the center of the bottom surface of the second lower surface air cushion. Part, the first screw member and the first pin are provided at a position overlapping the first opening in a plan view, and the second screw member and the second pin are provided at a position overlapping the second opening in a plan view的的位置。 The location. Thereby, the mask holding portion can be stably supported by the air cushions provided on the lower surface near both ends of the moving member body. In addition, the first screw member and the first pin, the second screw member, and the second pin that support the load of the mask holding portion are located in the opening formed on the bottom surface of the lower surface air cushion (formed on the bottom surface of the lower surface air cushion approximately The central part) overlaps in a plan view. Therefore, even if the weight of the mask M of the inspection object changes, it will not cause a torque change to the moving member body. Therefore, the mask holding portion can be stably floated by the air cushion on the lower surface.

Here, on the upper surface side of the moving member body, a first bevel ball bearing may be provided at a position where the central axis is substantially coincident with the first pin, and a first angular ball bearing may be provided at a position where the central axis is substantially coincident with the second pin. 2 Bevel ball bearings, the lower end of the first screw member is pivotally supported by the first bevel ball bearing, and the lower end of the second screw member is pivotally supported on the upper Describe the second angular ball bearing. Thereby, even if a radial load and an axial load are received due to the rotation of the frame, the first screw member or the second screw member can be smoothly rotated.

Here, there may be a first linear motor that moves the moving part along the longitudinal direction of the platform, and a second linear motor driven by following the first linear motor, and the rotor of the first linear motor is provided on the moving part , On the upper side of the frame, a guide member is provided so as to be inclined with respect to the horizontal direction, and the rotor of the second linear motor is provided on the guide member so as to be movable along the guide member, and the rotor of the second linear motor is provided so that the first 2 A fixed member in which the rotor of the linear motor is fixed to the above-mentioned guide member. Thereby, the frame etc. can be moved stably by using the 1st linear motor and the 2nd linear motor. In addition, even if the position of the rotor of the second linear motor changes with the rotation of the frame, it can be readjusted to the correct phase position. Therefore, the upper linear motor can be driven without problems.

According to the present invention, it is possible to stably rotate the photomask in a state where the photomask is fixed to a frame arranged in a substantially vertical direction.

1: Optical mask inspection device

10: Platform

10a: lower surface

10b, 10c: recess

10d: Support surface

10e: upper surface

10f: slot

10g, 10h: side

10i: bottom surface

14f: Board Department

20: Camera Department

21: Column

22, 22a, 22b: camera

23a, 23b: Irradiation part

24: Install components

30: Mobile Department

31: Moving component body

31a, 31b: side

31c, 31d: hole

31e, 31f: hole

32, 33: side air cushion

32a, 33a: front face

32b: Joint

33b: Sliding part

32c, 33c: Air cushion

32d, 33d: through hole

32e, 33e: orifice

33f: Front face

34, 341, 342: lower surface air cushion

34a: Through hole

34b: Orifice

34c: lower surface

34d: side

34e: hole

34f: opening

35: convex

36: Elastic member

37: Stopper

38, 39: Piping

40: Mask holding part

41: Frame

41a: Claw

41b, 41c: reflector

41d: Lower frame part

41e: upper frame part

41f: Holding part

41g: holding member

42: adjustment mechanism

42a: Block 1

42b: The second block

43: Rotating mechanism

51, 52: Vibration damping table

53: light source

54: Light guide member

61: Lower linear motor

61a: Rotor

62: Upper linear motor

62a: Rotor

63: Rotor guide

64: brake mechanism

65: elastic member

71: upper frame

72: positioning pin

73: Board Department

74: Column

141: Input and output devices

142: Network

143: Memory Media

151: CPU

151a: Control Department

152: RAM

153: ROM

154: Input and output interface

155: Communication interface

156: Media Interface

163: Target Coordinate Calculation Department

431: Rotation Drive

431a: output shaft

432A: 1st threaded member

432B: 2nd screw member

433A: The first nut member

433B: 2nd nut member

434, 434a, 435, 436: sprocket

437, 437a, 437b: power transmission part

438A: Pin 1

438B: 2nd pin

438a: spherical part

438b: Rod

438c: hole

439A: 1st bearing

439B: 2nd bearing

FIG. 1 is a perspective view showing the outline of the mask inspection apparatus 1 of the first embodiment.

FIG. 2 is a schematic front view showing the mask inspection device 1.

FIG. 3 is a diagram showing the outline of the moving part 30.

FIG. 4 is a schematic diagram for explaining the moving part 30, and is a plan view showing a part of the mask inspection device 1 enlarged.

FIG. 5 is a diagram showing the outline of the mask holding portion 40, especially the frame 41 and the rotation mechanism 43. As shown in FIG.

FIG. 6 is a diagram showing the outline of the rotating mechanism 43. As shown in FIG.

FIG. 7 is a schematic perspective view showing the reflector 41b and the irradiation part 23a that irradiates light to the reflector 41b.

Fig. 8 is a diagram illustrating the rotor 62a and its moving mechanism.

FIG. 9 is a block diagram showing the electrical structure of the photomask inspection device 1. As shown in FIG.

Fig. 10 is a diagram illustrating the control of the lower linear motor 61 (rotor 61a) and the upper linear motor 62 (rotor 62a) performed by the control unit 151a.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The inspection device of the present invention holds the mask M of the inspected object in a substantially vertical direction, and makes the camera move in the substantially vertical direction to inspect the defects of the pattern formed on the mask M.

In this embodiment, the photomask M set as the inspection object is an exposure photomask for manufacturing a substrate for a display device such as an organic EL or liquid crystal display device. The mask M is formed by forming one or more image device transfer patterns on a large, substantially rectangular substrate with a side of about 1 m. This embodiment is particularly suitable for the inspection of the photomask M for the organic EL display which is formed with high-density patterns and requires high-sensitivity inspection.

<First Embodiment>

FIG. 1 is a perspective view showing the outline of the mask inspection apparatus 1 of the first embodiment. FIG. 2 is a schematic front view showing the mask inspection device 1. In this specification, the direction roughly along the length of the platform 10 (described in detail below) is defined as the x direction, and the lead The straight direction is defined as the y direction, and the direction orthogonal to the x direction and the y direction is defined as the z direction. In addition, in FIGS. 1 and 2, the illustration of a part of the configuration is omitted for description.

The mask inspection apparatus 1 mainly includes a platform 10, an imaging unit 20, a moving unit 30, a mask holding unit 40, and vibration damping tables 51 and 52.

The platform 10 is configured as a carrier, and is supported on the vibration damping tables 51 and 52 installed at multiple locations (6 locations) on the installation surface F.

The platform 10 is a stone member of a substantially rectangular parallelepiped shape (thick plate shape) with a horizontal width W of about 4500 mm, a depth D of about 1200 mm, and a thickness T of about 400 mm. The platform 10 has a lower surface 10a and an upper surface 10e parallel to the lower surface 10a.

On the lower surface 10a of the platform 10, recesses 10b and 10c of substantially cubic shape are formed. The concave portion 10b is formed at each of the four corners of the lower surface 10a, and is formed in one place. The recesses 10c are formed at one place each along the long side of the lower surface 10a, forming two places in total. In order to maintain the strength of the platform 10, the depth D1 of the recesses 10b and 10c is set to be 0.3 to 0.5 times the thickness T of the platform 10. In addition, the depth D1 of the recesses 10b and 10c, that is, the height of the support surface 10d, is set as follows: the angle θ (refer to FIG. 2) of the center of gravity G of the entirety of the mask inspection device 1 as viewed from the support surface 10d is less than 60 degrees Possibly a small angle (for example, approximately 30 degrees).

Inside the recess 10b, a vibration damping table 51 placed on the installation surface F is provided. Inside the recess 10c, a vibration damping table 52 placed on the installation surface F is provided. The damping table 51 is an active damping table, and the damping table 52 is a passive damping table that supports the weight. The vibration damping tables 51 and 52 are already known, so the description is omitted.

The height of the damping tables 51, 52 is higher than the depth D1 of the recesses 10b, 10c. Therefore, the support surface 10d is supported by the vibration damping tables 51 and 52, and the platform 10 is placed on the vibration damping tables 51 and 52 Set face F on. Thereby, it is possible to lower the center of gravity G of the photomask inspection apparatus 1 when the support surface 10d is used as a reference.

On the upper surface 10e of the platform 10, a groove 10f is formed (the upper surface 10e includes the groove 10f). The groove 10f is a guide when the moving part 30 is moved. In order to improve the strength of the platform 10, the groove 10f is formed along the length direction (x direction) of the platform 10 at a position where it does not overlap the recesses 10b and 10c when viewed from the +y direction.

The depth D2 of the groove 10f is much smaller than the thickness T of the platform 10. In addition, in order to make the center of gravity G the lowest, the depth D2 of the groove 10f is set as follows: the optical axis ax of the camera 22 (refer to FIG. 2) when the camera 22a (described in detail below) abuts on the upper surface 10e The lower end of the mask M supported by the moving part 30 (described in detail below) is consistent. In this embodiment, the depth D2 of the groove 10f is about 60 mm. Therefore, even if the groove 10f is formed, the rigidity of the platform 10 can be sufficiently high.

The imaging unit 20 mainly includes a pillar 21 protruding upward from the platform 10, a camera 22 (refer to FIG. 2) provided on the pillar 21, and irradiation parts 23a and 23b (refer to FIG. 1) provided on the pillar 21.

The column 21 is installed on the platform 10 so as to protrude upward (+y direction) from the upper surface 10e. The pillar 21 is formed of ceramics or the like. In order to lower the center of gravity G, it is preferable to make the column 21 hollow.

The camera 22 is, for example, a CCD camera or a TDI camera as a special CCD camera, and has two cameras 22a and 22b. The cameras 22a and 22b respectively have an objective lens that converts g-ray and e-ray into parallel light, and an optical member that separates g-ray and e-ray passing through the objective lens (for example, a member that has the functions of a polarizing beam splitter and a dichroic filter at the same time ), g separated by optical components The two-component imaging lens for forming light and e-rays separately, and the imaging element for imaging the g-ray and e-ray that are imaged by the two-component imaging lens. In this way, the cameras 22a and 22b can simultaneously image the transmitted light and the reflected light. Furthermore, the cameras 22a and 22b can use well-known technologies, and therefore, detailed descriptions are omitted.

Two cameras 22a and 22b are arranged adjacent to each other in the y direction. A moving mechanism (not shown) including an air cushion (not shown) is provided between the camera 22 and the column 21. In the moving mechanism, the camera 22 is set so that the optical axis ax and the z axis are parallel.

The camera 22 moves in the vertical direction (y direction) by a moving mechanism not shown in the figure. The moving mechanism makes the two cameras 22a and 22b move along the column between the initial position where the camera 22a abuts on the upper surface 10e of the platform 10 and the upper end position of the camera 22b near the upper end of the column 21 (refer to the two-dot chain line in FIG. 2). 21 mobile.

In addition, the imaging unit 20 has a transmission illumination light source and a reflection illumination light source which are not shown. The transmitted illumination light source is installed on the back side (-z side) of the mask M, and irradiates the so-called g-ray (for example, light with a wavelength of 435.84 [nm]). The reflected illumination light source is arranged on the front side (+z side) of the mask M, and irradiates the so-called e-ray (for example, light with a wavelength of 546.07 [nm]). The camera 22 simultaneously receives the light of the g-ray irradiated from the transmission illumination light source and the e-ray irradiated from the self-reflective illumination light source, and images them. The inspection of the mask M is performed by comparing the image obtained by using the camera 22 in this way with the pattern information (described in detail below).

Furthermore, the number of cameras 22 is not limited to two, and may be one (one of the cameras 22a and 22b). However, when two cameras 22a and 22b are used, the cameras 22a and 22b are used to photograph the lower part and the upper part of the inspection area of the mask M, and the photographic data of each part is compared with the pattern information. By this, compared with the case of using 1 camera, 2 Times the efficiency. Therefore, it is preferable that the camera 22 has two cameras 22a and 22b.

The irradiation unit 23a is, for example, a linear interferometer, and is provided on the column 21. The light irradiated from the light source 53 (see FIG. 1) is guided to the irradiating portion 23a via the light guide member 54 (see FIG. 1) and the like. The irradiating part 23a irradiates the introduced light toward the reflector 41b in a substantially horizontal direction. The irradiation part 23a will be described in detail below.

The moving part 30 is placed on the platform 10, and a mask holding part 40 including a frame 41 (described in detail below) for holding the mask M is placed. FIG. 3 is a diagram showing the outline of the moving part 30. The moving part 30 mainly includes a moving member body 31, side air cushions 32 and 33, a lower surface air cushion 34 (341, 342 ), and a convex part 35.

The moving member main body 31 is a rod-shaped member in which a mask holding portion 40 is provided on the upper side. In order to reduce the weight, the moving member body 31 is formed of aluminum. On the side surface of the moving member body 31, side air cushions 32 and 33 are provided. The side air cushions 32 and 33 will be described in detail below.

In addition, a lower surface air cushion 34 is provided on the lower side of the moving member main body 31. The bottom surface air cushion 34 is a substantially rectangular member in plan view (when viewed from above (+y direction)), and has a bottom surface air cushion 341 provided on the +x side end of the moving member body 31 and installed on the moving member body 31 The air cushion 342 on the lower surface of the end of the -x side. The lower surface air cushion 341 is provided on the lower side (-y side) of the moving member body 31 via the first pin 438A (illustration omitted in FIG. 3, refer to FIGS. 5 and 6 and described in detail below), and the lower surface air cushion 342 The second pin 438B (illustration omitted in FIG. 3, refer to FIGS. 5 and 6 and described in detail below) is provided on the lower side of the moving member main body 31. In the lower surface air cushion 34, the lower surface air cushion 341 and the lower surface air cushion 342 have the same structure. The lower surface air cushions 341 and 342 will be described in detail below.

On the upper side of the moving member body 31, a convex portion 35 is provided. Convex 35 is plate-shaped As the component, a first bearing 439A or a second bearing 439B is provided inside (illustration is omitted in FIG. 4, and is described in detail below with reference to FIGS. 5 and 6).

FIG. 4 is a schematic diagram for explaining the moving part 30, and is a plan view showing a part of the mask inspection device 1 enlarged. In Figure 4, the flow of air is represented by a thick dashed arrow.

The side air cushions 32 and 33 are substantially cylindrical members. The side air cushion 32 is provided on the side surface 31a of the moving member body 31, and the side air cushion 33 is provided on the side surface 31b opposite to the side surface 31a. The front end surface 32a of the side air cushion 32 opposes the side surface 10g of the groove 10f, and the front end surface 33a of the side air cushion 33 opposes the side surface 10h of the groove 10f. Furthermore, the side surface 10g facing the front end surface 32a is a reference surface, and is formed with high accuracy (for example, the surface accuracy of the side surface 10h is about 2 μm, and the surface accuracy of the non-reference surface 10h is about 5 μm).

The side air cushion 32 has a substantially cylindrical joint portion 32b and a substantially cylindrical air cushion portion 32c. The diameter of the connecting portion 32b is smaller than the diameter of the air cushion portion 32c, so that the front end surface of the connecting portion 32b is in contact with the bottom surface of the hole 31c. The coupling portion 32b is provided inside the hole 31c formed in the main body 31 of the moving member. Between the outer peripheral surface of the coupling portion 32b and the inner peripheral surface of the hole 31c, an elastic member 36 (for example, an O-ring) is provided.

The side air cushion 33 has a sliding portion 33b having a substantially cylindrical shape and an air cushion portion 33c having a substantially cylindrical shape. The diameter of the sliding portion 33b is smaller than the diameter of the air cushion portion 33c. In addition, the sliding portion 33b is movably provided in the hole 31d having a diameter larger than that of the sliding portion 33b so as to be movable relative to the moving member main body 31 (described in detail below). Between the outer circumferential surface of the sliding portion 33b and the inner circumferential surface of the hole 31d, an elastic member 36 is provided so that the supplied air does not escape.

In the side air cushions 32 and 33, through holes 32d and 33d are formed inside, respectively. Inside the through holes 32d and 33d, holes 32e and 33e are formed. The through holes 32d and 33d are formed in The tubular hole 31e of the moving member body 31 is connected. The hole 31e is a passage of air supplied from a pump or the like not shown, and one end is covered by a plug 37, and the other end is connected to a pipe 38, which is connected to a pump or the like. As a result, air is supplied to the space between the hole 31d and the sliding portion 33b and the through holes 32d and 33d through the pipe 38.

The air supplied to the through-hole 32d passes through the orifice 32e and is ejected from the opening on the front end surface 32a side of the through-hole 32d toward the side surface 10g (refer to the thick broken line arrow in FIG. 4). In addition, the air supplied to the through hole 33d passes through the orifice 33e and is ejected from the opening on the front end surface 33a side of the through hole 33d toward the side surface 10h (refer to the thick broken line arrow in FIG. 4). Thereby, a thinner air layer is formed between the side surface 10g and the front end surface 32a of the side air cushion 32 and between the side surface 10h and the front end surface 33a of the side air cushion 33.

The air supplied to the space between the sliding portion 33b and the hole 31d presses the front end surface 33f of the sliding portion 33b to move the sliding portion 33b in the normal direction (z direction) of the side surface 31b. By moving the sliding portion 33b in the z direction, the distance between the side surface 10g and the front end surface 32a and the distance between the side surface 10h and the front end surface 33a are automatically adjusted.

If the area of the front end surface 33f is set to S _PI and the pressure of the air ejected from the through holes 32d and 33d is set to P _PI , the force f applied to the sliding portion 33b, that is, the side air cushion 33 is the difference between S _PI and P _PI Product (f=S _PI ×P _PI ). In order to move the side air cushion 33 according to the width of the groove 10f, _{the area S PI of the} front end surface 33f _{must be reduced compared to the side air cushion 33, that is, the area S Pd} of the front end surface 33a (in this embodiment, the area S _PI is the area 0.5~0.8 times of S _Pd). Cushion 32 side, i.e., the area of the front end face area 32a of the system and the distal end surface 33a of the same area S _Pd, therefore, the movable member body 31 in the groove 10f automatically held in its position.

Between the side surface 10g and the front end surface 32a and between the side surface 10h and the front end surface 33a The thinner air layer formed between the side air cushions 32 and 33 expands the side surface of the groove 10f. Since the platform 10 is made of stone and the size of the groove 10f does not change, the side air cushions 32, 33, that is, the moving part 30, are guided by the groove 10f.

The diameter of the sliding portion 33b is smaller than the diameter of the hole 31d. Therefore, the central axis of the sliding portion 33b can be inclined with respect to the central axis of the hole 31d (the normal direction of the side surface of the movable member body 31 where the hole 31d is formed). Therefore, even when the side surface 10g and the side surface 10h are not parallel, the side surface 10g can be made parallel to the front end surface 32a, and the side surface 10h can be made parallel to the front end surface 33a.

On the lower surface of the air cushions 341, 342 (not shown in FIG. 4), a tubular through hole 34a is formed inside. The through hole 34a is a passage for air supplied from a pump or the like not shown. One end of the through hole 34a is opened on the lower surface 34c, and the other end is opened on the side surface 34d. The opening portion of the through hole 34a that opens on the side surface 34d is connected to a pipe 39, and the pipe 39 is connected to a pump or the like. As a result, air is supplied to the through hole 34a via the pipe 39.

The air supplied from the pipe 39 to the through hole 34a passes through the orifice 34b (not shown in FIG. 4, refer to FIG. 6), and the opening 34f on the side of the lower surface 34c of the lower surface air cushions 341, 342 faces the bottom surface of the groove 10f 10i squirted. As a result, by the air ejected from the through hole 34a, a thin air layer is formed between the bottom surface 10i and the lower surface 34c (refer to the dashed arrow in FIG. 6). Thereby, the lower surface air cushions 341 and 342 float from the bottom surface of the groove 10f.

Return to the description of Figures 1 and 2. The mask holding portion 40 mainly includes a frame 41, an adjustment mechanism 42 (not shown in FIG. 2) that changes the position of the lower side of the mask M in the height direction (y direction), and a rotation mechanism 43 that rotates the frame 41.

The frame 41 is formed in a substantially frame shape so as to surround the outer periphery of the mask M maintained in a vertical direction. The frame 41 is a reference frame that serves as a reference for position detection and the like.

The frame 41 holds the mask M such that the surface of the mask M (the surface on which the pattern is formed) is parallel to the xy plane. The frame 41 is provided with a plurality of claws 41a for gripping the mask M (illustration omitted in FIG. 2).

On the upper side of the frame 41, a stator 62a (described in detail below) is provided. In addition, on the upper side of the frame 41, a holding portion 41f is provided. The holding portion 41f is staggeredly opened and placed on the back side (-z side) of the frame 41 so as not to overlap the stator 62a. The holding portion 41f is, for example, an air cushion, and sandwiches the thin plate-shaped plate portion 73 provided on the upper frame 71. Thereby, the frame 41 is supported so that the frame 41 does not incline with the x-axis as the center. Furthermore, the air cushion 41 can use a well-known technology, and therefore, a detailed description is omitted.

On the side surface of the frame 41, reflectors 41b and 41c are provided in a manner protruding in the lateral direction (x direction). The reflectors 41b and 41c are mirrors (such as retroreflectors) that return light in the incident direction, and are used to detect the position of the frame 41 in the x direction. The reflector 41b is disposed near the lower end of the frame 41, and the reflector 41c is disposed near the upper end of the frame 41. The reflectors 41b and 41c will be described in detail below.

Below the frame 41, an adjustment mechanism 42 and a rotation mechanism 43 are provided. The adjustment mechanism 42 is formed in plural along the x direction. The adjustment mechanism 42 has a first block 42a whose upper surface is inclined with respect to the xz plane and a second block 42b whose lower surface is inclined with respect to the xz plane, by changing the relative positional relationship between the first block 42a and the second block 42b , And adjust the height. The adjustment mechanism 42 is already known, and therefore, a detailed description is omitted.

The rotating mechanism 43 is arranged near both ends of the frame part located on the lower side of the frame 41. Hereinafter, the rotation mechanism 43 will be described in detail.

FIG. 5 shows the mask holder 40, especially the frame 41 and the rotating mechanism 43 The schematic diagram. In FIG. 5, illustration of the claw portion 41a and the adjustment mechanism 42 is omitted. FIG. 6 is a diagram showing the outline of the rotating mechanism 43. As shown in FIG. In addition, in Fig. 6, the flow of air is indicated by a thick dashed arrow.

Furthermore, the first screw member 432A, the first nut member 433A, the first pin 438A, and the first bearing 439A have the same configuration as the second screw member 432B, the second nut member 433B, the second pin 438B, and the second bearing 439B. . Therefore, in FIG. 6, only the first screw member 432A, the first nut member 433A, the first pin 438A, and the first bearing 439A are illustrated. In addition, in FIG. 6, illustration of the adjustment mechanism 42 and the power transmission portion 437 is omitted.

The rotation mechanism 43 mainly includes a rotation driving portion 431, a first screw member 432A and a second screw member 432B, a first nut member 433A and a second nut member 433B, sprockets 434, 434a, 435, 436, and a power transmission portion 437 (437a , 437b), the first pin 438A and the second pin 438B, and the first bearing 439A and the second bearing 439B.

The first nut member 433A and the second nut member 433B are fitted into the bottom surface portion of the lower frame portion 41d located on the lower side of the frame 41. The first nut member 433A and the second nut member 433B are formed of a material with a small friction coefficient, such as a copper alloy. The first nut member 433A and the second nut member 433B are respectively provided in a substantially vertical direction (y direction).

The first nut member 433A and the second nut member 433B are respectively provided in the vicinity of both ends of the lower frame portion 41d. In FIG. 5, the first nut member 433A is provided near the left end (near the +x end), and the second nut member 433B is provided near the right end (near the -x end).

The first screw member 432A and the second screw member 432B use a screw with high rigidity, such as a trapezoidal screw. The first screw member 432A and the second screw member 432B are respectively provided in a substantially vertical direction (y direction). The first screw member 432A is screwed with the first nut member 433A, and the second screw member 432B is screwed with the second nut member 433B.

Roughly half of the weight of the frame 41 or the mask M (for example, about 200 kg) falls on the first screw member 432A and the second screw member 432B. Therefore, the first screw member 432A and the second screw member 432B must have excellent load resistance . In addition, in order to be able to perform positioning of fine and small amounts (for example, micron units or sub-micron units), it is preferable to set a high-precision thread (ground thread) formed by grinding processing.

The center axis of the first screw member 432A is substantially coincident with the center axis of the first pin 438A and the first bearing 439A. In addition, the center axis of the second screw member 432B is substantially coincident with the center axis of the second pin 438B and the second bearing 439B. In other words, the first screw member 432A is located above the first pin 438A at a position overlapping with the first pin 438A when viewed from the top, and the second screw member 432B is located above the second pin 438B and is located above the second pin 438B when viewed from the top. 438B overlapping position.

The rotation driving unit 431 is an actuator such as an electric motor, and has an output shaft 431a. The sprocket 434 is integrated with the output shaft 431a. In addition, the sprocket 434a and the sprocket 435 are integrated with the first screw 432A, and the sprocket 436 is integrated with the second screw 432B by press fitting or the like. The sprocket 434 and the output shaft 431a, the sprockets 434a, 435 and the first threaded member 432A, the sprocket 436 and the second threaded member 432B can also be integrated by a strong adhesive such as an anaerobic adhesive, or by The key and the thread are integrated.

The number of teeth of sprocket 435 is α, and the number of teeth of sprocket 436 is β. The number of teeth β is more than the number of teeth α. The number of teeth of the sprocket 434a can be arbitrarily determined in such a way that the required reduction ratio can be obtained.

If the distance between the reflector 41b and the second screw member 432B in plan view (the distance in the x direction) is taken as the distance A, the distance between the reflector 41b and the first screw member 432A in plan view (the distance in the x direction) is taken as For distance B, the number of teeth α of sprocket 435 and the number of teeth β of sprocket 436 have the relationship of number of teeth α: number of teeth β=distance A: distance B. For example, if set to distance B =3×distance A, then the number of teeth α: the number of teeth β=1:3. Thereby, the ratio of the movement amount of the first screw member 432A in the y direction to the movement amount of the second screw member 432B in the y direction becomes the inverse ratio of the distance from the reflector 41b.

The sprocket 434 and the sprocket 434a are connected by the power transmission part 437a, and the sprocket 435 and the sprocket 436 are connected by the power transmission part 437b. The power transmission parts 437a and 437b transmit the rotation of the output shaft 431a to the sprockets 435 and 436, and a chain or a timing belt can be used. In this embodiment, chains are used for the power transmission parts 437a and 437b. In addition, when the sprocket 434a is not used, one power transmission part may connect the sprocket 434 and the sprockets 435 and 436.

The first pin 438A and the second pin 438B are rod-shaped members having a substantially hemispherical surface on the lower side, and are provided in a substantially vertical direction. As shown in FIG. 6, the first pin 438A and the second pin 438B have a substantially spherical spherical portion 438a and a rod-shaped portion 438b having a substantially hemispherical hole 438c formed on the lower end surface. The bottom surface of the hole 438c is in contact with the substantially hemispherical surface of the upper end of the spherical portion 438a.

The rod-shaped portion 438b is inserted into a hole penetrating the moving member body 31 in the vertical direction (y direction) to be integrated. In this embodiment, a male thread (not shown) is formed on the outer peripheral surface of the rod-shaped portion 438b, and the male thread is screwed with a female thread (not shown) formed in the hole 31f, and the hole 31f penetrates and moves in the y direction Component body 31. Thereby, the rod-shaped portion 438 b, that is, the first pin 438A and the second pin 438B are fixed to the moving member main body 31.

The spherical portion 438a is provided in the hole 34e formed on the upper surface of the lower surface air cushions 341, 342. The bottom surface of the hole 34e is a substantially hemispherical surface, and the bottom surface of the hole 34e abuts the substantially hemispherical surface at the lower end of the spherical portion 438a. Therefore, the lower surface air cushions 341 and 342 can swing with respect to the first pin 438A and the second pin 438B (moving member body 31).

The first bearing 439A and the second bearing 439B are installed in the moving member. The inside of the convex portion 35 on the upper surface side of the body 31. The first bearing 439A and the second bearing 439B are preferably angular ball bearings that can move smoothly even under radial load and axial load.

On the upper surface side of the moving member main body 31, a first bearing 439A and a second bearing 439B are respectively provided at positions where the central axis substantially coincides with the first pin 438A and the second pin 438B. The lower end of the first screw member 432A is pivotally supported by the first bearing 439A, and the lower end of the second screw member 432B is pivotally supported by the second bearing 439B.

The load of the frame 41 or the mask M is supported by the first pin 438A and the second pin 438B, which have high rigidity without deformation, via the first screw member 432A and the second screw member 432B, and the first bearing 439A and the second bearing 439B. . The first pin 438A and the second pin 438B are supported by lower surface air cushions 341 and 342, respectively.

In this way, the load of the mask holding portion 40 and the like can be supported by the platform 10 with higher rigidity via the first pin 438A and the second pin 438B with the highest rigidity and the lower surface air cushions 341 and 342. In addition, the lower surface air cushions 341 and 342 are provided in the vicinity of both ends of the moving member main body 31, so that the load of the mask holding portion 40 and the like can be stably supported.

In addition, the first screw member 432A and the first pin 438A are provided at a position overlapping the opening 34f in a plan view (the same applies to the second screw member 432B and the second pin 438B). In this embodiment, the center axis of the opening 34f (refer to the dashed arrow in FIG. 6) through which the air is ejected coincides with the center axis of the first screw member 432A, the first pin 438A, and the like. In addition, the opening 34f is formed at the approximate center of the lower surface air cushions 341, 342 when viewed from above. Therefore, the load of the mask holding portion 40 and the like is applied to the center of the lower surface air cushions 341 and 342, whereby the lower surface air cushions 341 and 342 can stably float the mask holding portion 40 and the like.

Next, a method of rotating the frame 41 by the rotating mechanism 43 will be described. When the rotation driving unit 431 is driven, the output shaft 431a and the sprocket 434 rotate, the sprocket 435 is rotated by the power transmission unit 437a, and the sprocket 436 is rotated by the power transmission unit 437b. The first screw member 432A rotates with the rotation of the sprocket 435, and the second screw member 432B rotates with the rotation of the sprocket 436.

The number of teeth β of the sprocket 436 is more than the number of teeth α of the sprocket 435. Therefore, the first screw member 432A such as the sprocket 435 press-fitting rotates more than the second screw member 432B such as the sprocket 436 press-fitting. Therefore, the movement amount of the first screw member 432A in the y direction is greater than the movement amount of the second screw member 432B in the y direction.

At the position of the first screw member 432A, the frame 41 moves by the movement amount of the first screw member 432A in the y direction, and at the position of the second screw member 432B, the frame 41 moves by the movement amount of the second screw member 432B in the y direction. Thereby, the frame 41 rotates.

In particular, in this embodiment, the number of teeth α: the number of teeth β=distance A: distance B, therefore, based on the position O of the reflector 41b in the x direction, the frame 41 rotates in an arc so that the position O does not move ( Refer to the arrow in Figure 5). Here, the position O refers to a position where a substantially parallel line connecting the sprockets 435 and 436 intersects with a substantially vertical line including the reflector 41b. In addition, the movement amount in the y direction of the position of the first screw member 432A when the frame 41 rotates to the maximum is about ±3 mm.

Furthermore, as the frame 41 rotates, the holding portion 41f provided at the upper end of the frame 41 also rotates. However, since the holding portion 41f clamps the plate portion 73, there is no problem due to a change in the height direction.

In addition, with the rotation of the frame 41, the first screw member 432A and the second screw member The position of the piece 432B in the x direction is also slightly changed. However, there are gaps between the first screw member 432A and the first nut member 433A, and between the second screw member 432B and the second nut member 433B. Therefore, even if the positions of the first screw member 432A and the second screw member 432B in the horizontal direction (x direction) are slightly shifted due to the rotation of the frame 41, no problems will occur.

Furthermore, with the rotation of the frame 41, the extending direction of the first screw member 432A and the second screw member 432B changes obliquely from the substantially vertical direction. However, since the first bearing 439A and the second bearing 439B use angular ball bearings, even if the first screw member 432A and the second screw member 432B are inclined, the first screw member 432A and the second screw member 432B can be rotated.

If the rotation angle of the frame 41 is Φ, the reflector 41b moves only H1×cosΦ in the height direction (y direction). However, since the angle Φ is small, cosΦ is approximately 1, and the position of the reflector 41b in the height direction hardly changes. Therefore, the position detection of the frame 41 using the reflector 41b will not cause problems.

Here, the position detection mechanism of the frame 41 will be described. As shown in FIGS. 1 and 2, the reflector 41b is irradiated with light from the irradiating portion 23a, and the reflector 41c is irradiated with light from the irradiating portion 23b. The illuminating part 23a and the reflector 41b are mainly used to detect the position of the frame 41. The irradiating portion 23b and the reflector 41c are supplementarily used to correct errors caused by the vertical tilt caused by the warpage of the platform 10 during the movement of the frame 41.

FIG. 7 is a schematic perspective view showing the reflector 41b and the irradiation part 23a that irradiates light to the reflector 41b. In addition, the reflector 41b and the reflector 41c, and the irradiation part 23a and the irradiation part 23b have the same structure, so below, the reflector 41b and the irradiation part 23a are demonstrated, and the description of the reflector 41c and the irradiation part 23a is abbreviate|omitted.

The irradiation part 23a is provided on the column 21 via the mounting member 24. The reflector 41b is provided on the side surface of the frame 41 via a holding member 41g, which is formed of a high-performance metal material (for example, super forged steel) with a very small thermal expansion coefficient near room temperature. The reflector 41b is arranged to protrude from the side surface of the frame 41 in the horizontal direction (here, the -x direction). The three bars included in the holding member 41g are reinforced with bars or the like.

The light irradiated from the irradiation part 23a is reflected by the reflector 41b, and enters the irradiation part 23a. Based on the light irradiated from the irradiating portion 23a and reflected by the reflector 41b, the distance between the irradiating portion 23a and the reflector 41b, that is, the position of the frame 41 in the x direction is detected. The illuminating part 23a, the reflector 41b, and the position detection method using these can use a well-known technique, and therefore, description is omitted.

Return to the description of Figures 1 and 2. The mask inspection device 1 has a lower linear motor 61 (refer to FIG. 9) that allows the moving part 30 to move along the groove 10f (or upper surface 10e) of the platform 10, and drives to follow the lower linear motor 61 (described in detail below ) Upper linear motor 62 (refer to Fig. 9).

The lower linear motor 61 mainly includes a rotor 61a and a stator (not shown), and the upper linear motor 62 mainly includes a rotor 62a and a stator 62b. The rotor 61 a is installed on the moving member body 31, and the rotor 62 a is installed on the upper side of the frame 41. The stator (not shown) of the lower linear motor 61 is installed on the platform 10, and the stator 62 b of the upper linear motor 62 is installed on the upper frame 71. Furthermore, as shown in FIG. 2, the upper frame 71 is supported by a column 21 and a column 74 formed of, for example, a hollow square rod made of aluminum.

The moving part 30 is close to the center of gravity G (refer to FIG. 2) of the mask inspection apparatus 1, and therefore, the lower linear motor 61 is mainly used to move the frame 41 and the like (including the moving part 30) in the x direction. However, the height of the frame 41 is about 1.5m~2m. Therefore, when the frame 41 is moved in the x direction, if only the lower linear motor 61 is used, the upper part of the frame 41 will move during acceleration. The delay, as a result, causes the frame 41 to deform into a parallelogram shape. Therefore, an upper linear motor 62 is provided above the frame 41 so that the movement of the upper part of the frame 41 is not delayed during acceleration.

However, in this embodiment, the frame 41 rotates, and therefore, the position of the rotor 62a in the horizontal direction (x direction) and the vertical direction (y direction) changes with the rotation of the frame 41. In particular, the movement in the horizontal direction causes the phase shift of the upper linear motor 62. Therefore, a moving mechanism for moving the position of the rotor 62a in the horizontal direction (x direction) and the vertical direction (y direction) is provided. Furthermore, the rotor 61a is provided in the moving part 30 that does not move in the y direction and the Z direction, so the horizontal and vertical movement caused by the rotation of the frame 41 can be ignored.

Fig. 8 is a diagram illustrating the rotor 62a and its moving mechanism. The moving mechanism mainly includes a rail 63, a slider 64, an elastic member 65, and a braking mechanism 66.

The rail 63 is installed in the upper frame portion 41e located on the upper side of the frame 41 obliquely with respect to the horizontal direction. The inclination of the rail 63 is substantially along the base of the isosceles triangle with the rotation center O of the frame 41 as the vertex (refer to FIG. 5). In the rail 63, a groove 63a is formed along the length direction.

字形狀，設置於軌道63。於滑塊64之對向之2個側面，分別以向內側突出之方式形成插入至槽63a之凸部(未圖示)。於該凸部設置多個鋼球(未圖示)，於滑塊64沿軌道63移動時，該鋼球滾動，藉此，滑塊64順暢地移動。 The slider 64 is approximately

The shape of the character is set on the track 63. On the two opposite side surfaces of the slider 64, a convex portion (not shown) inserted into the groove 63a is formed so as to protrude inward, respectively. A plurality of steel balls (not shown) are provided on the convex portion, and when the slider 64 moves along the rail 63, the steel balls roll, whereby the slider 64 moves smoothly.

A rotor 62a is provided on the slider 64. Therefore, the rotor 62a can move along the rail 63 like the slider 64.

The elastic member 65 applies a force to the rotor 62a in the lower left direction in FIG. 8 (refer to the arrow in FIG. 8) in a pulling direction. As the elastic member 65, for example, a coil spring can be used.

The brake mechanism 66 has a clamp (not shown). The brake mechanism 66 The clamp is enclosed to open the clamp, and the clamp is pressed against the side surface 63b of the rail 63 by evacuating air, thereby fixing the slider 64 with respect to the rail 63. The rail 63, the slider 64, the elastic member 65, and the braking mechanism 66 can use well-known technologies, and therefore, detailed descriptions are omitted.

A positioning pin 72 is provided on the upper frame 71 (illustration omitted in FIG. 1) of the mask inspection device 1. By moving the frame 41 in the +x direction, the rotor 62a is brought into contact with the positioning pin 72. By further moving the frame 41 in the +x direction, the rotor 62a overcomes the pressure of the elastic member 65 and moves along the rail 63 in the −x direction (refer to the hollow arrow in FIG. 8).

The positioning pin 72 is provided when the frame 41 is in the loading position (the replacement position of the mask M, shown in FIG. 1 shows the state in which the frame 41 is in the loading position) or closer to the -x side when the rotor 62a abuts against the positioning The location of the pin 72.

If the rotor 62a moves to the correct position, the rotor 62a is fixed to the rail 63 by the braking mechanism 66. Furthermore, the so-called correct position refers to the position where the phase of the lower linear motor 61 is equal to the phase of the upper linear motor 62, and is the position where the correct torque can be output at the moment of acceleration.

Furthermore, the rail 63 is rod-shaped, and although the rotor 62a moves linearly, since the distance from the rotation center O is relatively long, it is substantially the same as the movement trajectory (arc) of the rotor 62a caused by the rotation of the frame 41.

Furthermore, the rotor 62a is preferably arranged as close as possible to the rotation center of the frame 41, that is, near the -x end of the upper frame portion 41e of the frame 41. In addition, it is desirable that the position of the rotor 62a in the z direction (front-rear direction) substantially coincides with the center of gravity G as shown in FIG. 2.

FIG. 9 is a block diagram showing the electrical structure of the photomask inspection device 1. As shown in FIG. The mask inspection device 1 has a CPU (Central Processing Unit) 151, RAM (Random Access Memory) 152, ROM (Read Only Memory) 153, input and output interface (I/F) 154, communication interface (I/F) 155, and media interface (I/F) 156, which are related to cameras 22a, 22b, illumination unit 23a, 23b, the claw portion 41a, the adjustment mechanism 42, the rotation driving portion 431, the light source 53, the lower linear motor 61, the upper linear motor 62, the braking mechanism 66, and the like are connected to each other.

The CPU 151 operates based on the programs stored in the RAM 152 and the ROM 153 to control each part. Signals are input to the CPU 151 from the cameras 22a and 22b, the irradiation units 23a and 23b, and the like. The signal output from the CPU 151 is output to the adjustment mechanism 42, the rotation driving unit 431, the light source 53, the lower linear motor 61, the upper linear motor 62, the braking mechanism 66, and the like.

RAM152 is a volatile memory. ROM153 is a non-volatile memory with various control programs. The CPU 151 operates based on the programs stored in the RAM 152 and the ROM 153 to control each part. The ROM 153 stores the startup program performed by the CPU 151 when the photomask inspection device 1 is activated, or the program that depends on the hardware of the photomask inspection device 1, etc. In addition, the ROM 153 stores information related to the position and shape of the pattern drawn on the mask M, that is, pattern information (for example, design information), and returns the light irradiated from the irradiating parts 23a, 23b by the reflectors 41b, 41c to The position information that associates the time of the irradiating parts 23a and 23b with the position of the frame 41 in the x direction, the rotation information that associates the driving amount of the rotation driving part 431 with the rotation angle of the frame 41, and so on. RAM152 stores programs executed by CPU151 and data used by CPU151.

The CPU 151 controls an input and output device 141 such as a keyboard or a mouse through the input and output interface 154. The communication interface 155 receives data from other machines via the network 142 and sends it to the CPU 151, and sends data generated by the CPU 151 to other machines via the network 142.

The media interface 156 reads programs or data stored in the storage medium 143 and stores them in the RAM 152. Furthermore, the storage medium 143 is, for example, an IC card, SD card, DVD, or the like.

Furthermore, a program for realizing each function is read from the storage medium 143, installed in the photomask inspection apparatus 1 via the RAM 152, and executed by the CPU 151.

The CPU 151 has a function of controlling the control unit 151a of each part of the photomask inspection apparatus 1 based on the input signal. The control unit 151a is constructed by executing a specific program read by the CPU151. The processing performed by the control unit 151a will be described in detail below.

The configuration of the photomask inspection device 1 shown in FIG. 9 was described in the description of the main configuration of the features of the present embodiment, and does not exclude, for example, the configuration of a general information processing device. The constituent elements of the mask inspection device 1 may be classified into more constituent elements according to the processing content, or a single constituent element may perform processing of a plurality of constituent elements.

Next, the operation of the photomask inspection device 1 will be described. First, the control portion 151a controls the claw portion 41a and the like to hold the mask M to the frame 41. In addition, the control unit 151a adjusts the position of the lower side of the mask M in the height direction (y direction) by the adjustment mechanism 42. At this time, the moving part 30 is located at the loading position near the end of the platform 10 in the +x direction.

Next, the control unit 151a controls the lower linear motor 61 and the upper linear motor 62 to move the moving unit 30 in the −x direction along the groove 10f to move the mask M from the mounting position to the inspection position.

Specifically, the control unit 151a supplies air to the side air cushions 32 and 33 from a pump or the like not shown, and ejects air from the through holes 32d and 33d. In addition, air is supplied to the lower surface air cushion 34 from a pump or the like not shown in the moving part 30, and air is ejected from the through hole 34a.

Then, the control unit 151 a controls the lower linear motor 61 and the upper linear motor 62 to apply a force in the −x direction to the moving member body 31. FIG. 10 illustrates the control of the lower linear motor 61 (rotor 61a) and the upper linear motor 62 (rotor 62a) performed by the control unit 151a 之图.

The lower linear motor 61 (rotor 61a) and the upper linear motor 62 (rotor 62a) are connected in parallel. Therefore, the control unit 151a simultaneously outputs signals to the rotor 61a of the lower linear motor 61 and the rotor 62a of the upper linear motor 62.

Specifically, the control unit 151a outputs signals to the U-phase, V-phase, and W-phase of the rotors 61a, 62a, respectively, and the control unit 151a obtains the U-phase, V-phase, and W-phase powers of the rotors 61a, 62a in advance based on the results. Factor (power factor information). Then, the control unit 151a calculates the target coordinates (position command) at the current time point based on the pulses output from the CPU 151 and the like. Furthermore, the control unit 151a calculates a first-order derivative term that differentiates the calculated position command first, and a second-order derivative term that performs second-order differentiation on the position command.

The control unit 151a performs PID control combining proportional action, integral action, and derivative action, and feeds forward based on the position command, the first derivative term, the second derivative term, and the origin signal that becomes the reference for managing the positions of the rotors 61a and 62a. control. Then, the control unit 151a generates a driving signal based on the control result, power factor information, and the like. The driving signal is a signal corresponding to each of the U-phase, V-phase, and W-phase. After being amplified by an amplifier (not shown), they are respectively output to the U-phase, V-phase, and W-phase coils of the rotors 61a and 62a.

In this embodiment, a relatively large current is supplied to the linear motor 61 (rotor 61a) below the center of gravity G, and a relatively small current is supplied to the linear motor 62 (rotor 62a) above the center of gravity G far from it. For example, the ratio of the current value flowing through the rotor 61a to the current value flowing through the rotor 62a is inversely proportional to the distance between the rotor 61a and the center of gravity G and the distance between the rotor 62a and the center of gravity G.

For example, the currents flowing through the rotor 61a of the lower linear motor 61 are set to i _1u , i _1v , and i _1w , and the currents flowing through the rotor 62a of the upper linear motor 62 are set to i _2u , i _2v , and i _2w . _{If the distance H high} between the rotor 62a and the center of gravity G in the height direction (refer to Figure 2) is 4 times _{the distance H low} (refer to Figure 2) between the rotor 61a and the center of gravity G in the height direction _{(H high} = H _low × 4), then Set i _1u =4×i _2u , i _1v =4×i _2v , and i _1w =4×i _2w . For this reason, the internal resistances R _1u , R _1v , R _{1w of the} rotor 61 a, the internal resistances R _2u , R _2v , R _{2w of the} rotor 62 a, and the resistances Ru, Rv, Rw inserted between the control part 151 a and the rotor 61 a R _1u : (R _2u +Ru)=1:4, R _1v :(R _2v +Rv)=1:4, R _1w :(R _2w +Rw)=1:4. Thereby, the upper linear motor 62 follows the lower linear motor 61 and is driven with a weaker force than the lower linear motor 61.

When driving the lower linear motor 61 and the upper linear motor 62, an air layer is formed between the side air cushions 32, 33 and the side surfaces 10g, 10h of the groove 10f, and between the lower surface air cushion 34 and the bottom surface 10i of the groove 10f. The moving part 30 or the mask holding part 40 is easily moved.

The control part 151a controls the light source 53, etc., and irradiates light from the irradiation part 23a. In addition, the control unit 151a obtains information from the irradiation unit 23a about the time from the time the light irradiated from the irradiation unit 23a is reflected by the reflector 41b to the time it is received by the irradiation unit 23a, and compares it with the position information (stored in the ROM153) Etc., thereby detecting the position of the frame 41 in the x direction. While detecting the position of the frame 41 in this way, the control portion 151a controls the lower linear motor 61 and the upper linear motor 62 to move the frame 41 to a predetermined specific position.

Moreover, the control part 151a controls the light source 53, etc., and irradiates light from the irradiation part 23b. Then, the position of the frame 41 in the x direction is detected in the same manner as the processing performed on the irradiation section 23a. However, the control unit 151a uses the distance obtained based on the irradiation unit 23b to detect the deformation of the frame 41, and not to control the position of the frame 41.

When the mask M is moved to the inspection position, the control unit 151a controls the imaging unit 20 to detect the pattern formed on the mask M. Then, the control unit 151a obtains the information of the pattern and detects In the pattern, the pattern along the x direction (hereinafter referred to as pattern x) is inclined to the x direction.

After detecting the tilt of the pattern x, the control unit 151a controls the rotation driving unit 431 to rotate the frame 41 based on the rotation information (stored in the ROM 153) so that the horizontal component in the pattern is substantially level (corrected tilt).

After the control unit 151a rotates the frame 41, it controls the lower linear motor 61 and the upper linear motor 62 to move the frame 41 in the +x direction to a predetermined position (stored in the ROM 153). This position is a position where the rotor 62a abuts against the positioning pin 72, and the positioning pin 72 moves the rotor 62a to a position where the phase of the lower linear motor 61 and the phase of the upper linear motor 62 coincide.

After that, the control unit 151a controls the lower linear motor 61 and the upper linear motor 62 to move the frame 41 (mask M) to the inspection position again. Then, the control unit 151a performs inspection of the mask M by the imaging unit 20. In this embodiment, the g-ray is irradiated from the transmission illuminating light source at the same time, and the e-ray is irradiated from the reflection illuminating light source at the same time, and the cameras 22a and 22b are used to simultaneously receive these to make the images. Then, the image captured by the camera 22a and the image captured by the camera 22b are respectively compared with the image generated based on the pattern information (stored in the ROM 153), thereby discovering the defects of the pattern and the like. Furthermore, the control unit 151a can also perform a difference calculation between the image captured by the camera 22a and the image captured by the camera 22b to find the difference between the two images, thereby discovering pattern defects and the like. The inspection method of the mask M can use the well-known technology, therefore, the detailed description is omitted.

After the inspection of the entire surface of the mask M is completed, the control unit 151a controls the lower linear motor 61 and the upper linear motor 62 to move the frame 41 (mask M) to the loading position again. Then, Replace the mask M and move to the inspection of the next mask M.

According to this embodiment, it is possible to firmly fix the mask M to the frame 41 provided in the substantially vertical direction while rotating the mask M (frame 41). Thereby, the line parallel to the x-axis of the pattern formed on the mask M can be made parallel to the x-axis. In particular, the amount of rotation of the first screw member 432A and the second screw member 432B can be finely adjusted. Therefore, the amount of rotation of the mask M (frame 41) can be finely adjusted, and the line parallel to the x-axis of the pattern can be made finely. It is approximately completely parallel to the x-axis. Specifically, the offset in the height direction of the line parallel to the x-axis of the pattern can be set to within 0.5~1μm under the distance of 1m between the positions in the x direction.

For example, when using image processing (active alignment) to correct the inclination of the line parallel to the x-axis of the pattern, the correction of about 12~24μm is the limit. In addition, if the line parallel to the x-axis of the pattern is interrupted, it cannot be handled by image processing, and inspection cannot be performed. On the other hand, by rotating the mask M (frame 41), even when the situation cannot be dealt with by image processing, the inspection can be performed reliably.

Furthermore, according to this embodiment, the number of teeth of the sprocket 435 α: the number of teeth of the sprocket 436 β=the distance between the reflector 41b and the second screw member 432B in the x direction A: the difference between the reflector 41b and the first screw member 432A in the x direction The distance B therefore makes it possible to rotate the frame 41 based on the position O of the reflector 41b in the x direction. Therefore, even if the frame 41 is rotated, the position of the reflector 41b in the y direction hardly changes. As a result, when the position of the frame 41 as the reference frame is checked by the laser interferometer (including the irradiating part 23a and the light source 53), there will be no defects in the position detection, and the mask M can be firmly fixed to the frame 41 In this state, the frame 41 is rotated.

In addition, according to the present embodiment, by rotating itself, a simple mechanism can be made to prevent defects caused by the complexity of the mechanism. For example, in the reference frame (here frame 41) A frame (inner frame) is further provided on the inner side, and when the mask M is rotated by rotating the inner frame, the mechanism becomes complicated, which results in the thickening of the frame or the reduction of the strength of the frame. Furthermore, when the inner frame is rotated, force is applied to the inner frame. Therefore, even if the reference frame and the inner frame are fixed, the inner frame may move microscopically relative to the reference frame due to external forces such as acceleration of the moving part 30. Similarly, when the photomask M is rotated relative to the reference frame, force is also applied to the photomask M. Therefore, even if the photomask M is fixed relative to the reference frame, the photomask M may be relative to the reference frame due to external force. The fear of microscopic movement. As a result, the position of the mask M obtained by measuring the position of the reference frame cannot be offset from the position of the mask M that should exist.

In contrast, in the present embodiment, the reference frame (frame 41) itself is moved. Therefore, the mask M does not move relative to the reference frame, and the position of the mask M obtained by measuring the position of the frame 41 is compared with The position of the mask M that should exist will not shift.

In addition, according to the present embodiment, the lower linear motor 61 and the upper linear motor 62 are provided, and the rotor 62a is provided so as to be movable in the x direction, so that even if the position of the rotor 62a changes with the rotation of the frame 41, The upper linear motor 62 can be driven without any problem by moving the rotor 62a.

Furthermore, in this embodiment, the moving part 30 moves along the groove 10f formed on the upper surface 10e of the platform 10. However, the moving part 30 may be moved on the upper surface 10e without forming a groove in the platform 10. For example, a rail or the like may be provided on the upper surface 10e, and the moving part 30 may be moved along the rail or the like.

As mentioned above, the embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to the embodiment, and also includes design changes that do not depart from the scope of the spirit of the present invention.

In particular, the present invention can provide a photomask holding device (a photomask holding portion), and can also provide a photomask inspection device. The photomask inspection device includes: a photomask holding device; It is arranged on the platform in a manner protruding upward; the imaging part is arranged on the pillar to photograph the pattern formed on the mask; the light irradiation part is arranged on the pillar to irradiate light to the mirror; and the control part, which is captured by the camera For the information of the pattern captured by the part, the rotation driving part is controlled so that the horizontal component in the pattern becomes approximately horizontal, and the light irradiating part is controlled to detect the horizontal position of the frame.

In addition, in the present invention, the term "approximately" not only includes the exact same conditions, but also includes the concept of errors or distortions to the extent that they do not lose identity. For example, the so-called substantially cubic shape is not limited to the case of strictly cubic shape. For example, although the recessed part 10b etc. are formed in the platform 10, if the platform 10 is regarded as a whole, it will become a substantially cubic shape. In addition, for example, when expressing only the case of verticality, uniformity, etc., not only the case of strictly verticality, uniformity, etc., but also the case of substantially verticality, substantially uniformity, etc. are included.

In addition, in the present invention, the so-called "nearby" refers to the following concept: for example, when it is in the vicinity of A, it means the vicinity of A and may or may not include A.

31‧‧‧Moving component body

40‧‧‧Mask holding part

41‧‧‧Frame

41b‧‧‧Reflector

41c‧‧‧Reflector

41d‧‧‧The lower frame part

41e‧‧‧Upper frame part

41f‧‧‧Retention Department

43‧‧‧Rotating mechanism

62a‧‧‧Rotor

63‧‧‧Rotor guide

64‧‧‧Brake mechanism

65‧‧‧Elastic member

341‧‧‧Lower surface air cushion

342‧‧‧Lower surface air cushion

431‧‧‧Rotation drive unit

431a‧‧‧Output shaft

432A‧‧‧First threaded member

432B‧‧‧Second threaded member

433A‧‧‧The first nut member

433B‧‧‧Second nut member

434‧‧‧Sprocket

434a‧‧‧Sprocket

435‧‧‧Sprocket

436‧‧‧Sprocket

437‧‧‧Power Transmission Department

437a‧‧‧Power Transmission Department

437b‧‧‧Power Transmission Department

438A‧‧‧1st pin

438B‧‧‧Second pin

439A‧‧‧The first bearing

439B‧‧‧Second bearing

A‧‧‧Distance

B‧‧‧Distance

H1‧‧‧Distance

O‧‧‧Location

M‧‧‧Mask

Φ‧‧‧Rotation angle

Claims (9)

A photomask holding device, characterized by comprising: a platform; a photomask holding portion having a substantially frame-shaped frame for holding the photomask of an object under inspection in a substantially vertical direction, and a rotating mechanism for rotating the frame; and moving Section, which is placed on the platform and for placing the mask holding section, and is provided in a manner movable along the length direction of the platform; the rotation mechanism has: a first nut member and a second nut member, etc. In the vicinity of both ends of the frame portion located on the lower side of the frame; a first threaded member and a second threaded member, which are respectively screwed with the first nut member and the second nut member; and a rotation drive part which makes The first screw member and the second screw member rotate by different amounts; the moving part is provided with a first pin and a second pin in a substantially vertical direction, and the first screw member is installed above the first pin At a position overlapping with the first pin in a plan view, and the second screw member is provided above the second pin at a position overlapping with the second pin in a plan view. For example, the mask holding device of the first item of the scope of patent application, wherein a mirror for returning light in the incident direction is provided on the side of the frame, and the rotation driving part has: an actuator; a first sprocket, which is connected with The first screw member is provided coaxially to rotate the first screw member; a second sprocket is provided coaxially with the second screw member to rotate the second screw member; and a power transmission portion that will actuate The drive shaft of the gear is connected to the first sprocket and the second sprocket; and In a plan view, assuming that the distance between the mirror and the second screw member is a distance A, and the distance between the mirror and the first screw member is a distance B, the number of teeth α of the first sprocket is equal to that of the first screw member. 2 The number of teeth β of the sprocket has the relationship of the number of teeth α: the number of teeth β=distance A: distance B. For example, the mask holding device of item 1 or 2 of the scope of patent application, wherein a groove along the length direction of the platform is formed on the upper surface of the platform, and the moving part has: a lower surface air cushion, which sprays air toward the bottom surface of the groove Side air cushion, which sprays air toward the side of the groove; and the moving member body, which is provided with the lower surface air cushion and the side air cushion; in the first pin and the second pin, the lower end is set on the lower surface air cushion, and the upper end The lower end of the movable member body is provided in the movable member body, the first screw member and the second screw member, and the lower end is provided in the movable member body, and the movable member body moves along the groove. For example, the mask holding device of item 3 of the scope of patent application, wherein the lower surface air cushion has: a first lower surface air cushion disposed near the first end of the moving member body; and a second lower surface air cushion disposed on the above Near the second end of the moving member body on the opposite side to the first end; in the approximate center of the bottom surface of the first lower surface air cushion, a first opening for ejecting air is formed, and the bottom surface of the second lower surface air cushion is approximately In the center part, a second opening for blowing out air is formed, The first screw member and the first pin are provided at a position overlapping with the first opening in a plan view, and the second screw member and the second pin are provided at a position overlapping with the second opening in a plan view的的位置。 The location. For example, the mask holding device of item 3 of the scope of patent application, wherein on the upper surface side of the moving member body, first angular ball bearings are respectively provided at positions where the central axis and the first pin are approximately the same, and the central axis and the above A second angled ball bearing is provided at a position substantially coincident with the second pin, and the lower end of the first screw member is pivotally supported by the first angled ball bearing, and the lower end of the second screw member is pivotally supported by the second angled ball bearing. Angular ball bearings. For example, the mask holding device of item 1 or 2 of the scope of patent application has a first linear motor that moves the moving part along the length of the platform, and a second linear motor that follows the first linear motor to drive, and The moving part is provided with the rotor of the first linear motor, a guide member is provided on the upper side of the frame so as to be inclined with respect to the horizontal direction, and the guide member is provided so as to be movable along the guide member The rotor of the second linear motor is further provided with a fixing member that fixes the rotor of the second linear motor with respect to the guide member. For example, the mask holding device of item 3 of the scope of patent application has a first linear motor that moves the moving part along the length of the platform, and a second linear motor that follows the first linear motor to drive, The rotor of the first linear motor is installed in the moving part, a guide member is installed on the upper side of the frame so as to be inclined with respect to the horizontal direction, and the guide member is movable along the guide member The rotor of the second linear motor is provided, and a fixing member that fixes the rotor of the second linear motor with respect to the guide member is provided. For example, the mask holding device of the fourth item of the patent application has a first linear motor that moves the moving part along the length of the platform, and a second linear motor that follows the first linear motor and drives it to move Section, the rotor of the first linear motor is provided, a guide member is provided on the upper side of the frame so as to be inclined with respect to the horizontal direction, and the guide member is provided so as to be movable along the guide member. 2 The rotor of the linear motor is provided with a fixing member that fixes the rotor of the second linear motor with respect to the guide member. For example, the mask holding device of item 5 of the scope of patent application has a first linear motor that moves the moving part along the length of the platform, and a second linear motor that follows the first linear motor and drives it to move Section, the rotor of the first linear motor is provided, a guide member is provided on the upper side of the frame so as to be inclined with respect to the horizontal direction, and the guide member is provided so as to be movable along the guide member. 2-wire The rotor of the linear motor is provided with a fixing member that fixes the rotor of the second linear motor with respect to the guide member.

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