JP2012068434A - Proximity exposure apparatus, method for aligning proximity exposure apparatus, and method for manufacturing display panel substrate - Google Patents

Abstract

The position of an alignment mark on a mask and the position of an alignment mark on a base pattern on a substrate are detected quickly and accurately, and the alignment between the mask and the substrate is performed with high accuracy in a short time.
During the gap adjustment between the mask and the substrate, the focal position of the first image acquisition device is moved to the height of the lower surface of the mask after the gap adjustment, and the second image acquisition device is obtained. Is moved to the height of the surface of the substrate 1 after the gap alignment. An image of the alignment mark 2a of the mask 2 is acquired by the first image acquisition device 51, the position of the alignment mark 2a of the mask 2 is detected, and the alignment mark 1a of the base pattern of the substrate 1 is detected by the second image acquisition device 52. The position of the alignment mark 1a of the base pattern of the substrate 1 is detected.
[Selection] Figure 15

Description

  The present invention relates to a proximity exposure apparatus that exposes a substrate using a proximity method in manufacturing a display panel substrate such as a liquid crystal display device, an alignment method for the proximity exposure apparatus, and a display panel substrate using the same. In particular, an image acquisition device such as a CCD camera acquires an image of the alignment mark of the mask and the alignment mark of the base pattern of the substrate, detects the position of both by image processing, and the mask and the substrate. The present invention relates to a proximity exposure apparatus that performs position alignment, an alignment method for the proximity exposure apparatus, and a method for manufacturing a display panel substrate using the same.

  Manufacturing of TFT (Thin Film Transistor) substrates, color filter substrates, plasma display panel substrates, organic EL (Electroluminescence) display panel substrates, and the like of liquid crystal display devices used as display panels is performed using photolithography using an exposure apparatus. This is performed by forming a pattern on the substrate by a technique. As an exposure apparatus, a projection method in which a mask pattern is projected onto a substrate using a lens or a mirror, and a minute gap (proximity gap) is provided between the mask and the substrate to transfer the mask pattern to the substrate. There is a proximity method. The proximity method is inferior in pattern resolution performance to the projection method, but the configuration of the irradiation optical system is simple, the processing capability is high, and it is suitable for mass production.

  For example, in manufacturing a color filter substrate of a liquid crystal display device, a new pattern is exposed on a base pattern formed on a substrate, such as when a colored pattern is exposed on a black matrix formed on the substrate. In this case, it is necessary to accurately align the mask and the substrate so that the newly exposed pattern does not deviate from the base pattern. Conventionally, in a proximity exposure apparatus mainly used for exposure of a large substrate, a plurality of alignment marks are provided on a mask and a substrate ground pattern, respectively, and the mask alignment mark and the substrate ground pattern are obtained by an image acquisition device such as a CCD camera. An image of the alignment mark is obtained, the position of both is detected by image processing, and the mask and the substrate are aligned. As such a proximity exposure apparatus, there is one described in Patent Document 1.

JP 2007-256581 A

  In the proximity exposure apparatus, after the gap between the mask and the substrate is aligned, the lower surface of the mask on which the alignment mark is provided and the surface of the substrate on which the alignment mark of the base pattern is formed are separated by the proximity gap. Only a few hundred μm away. On the other hand, the depth of focus of an image acquisition device such as a CCD camera that acquires an image of an alignment mark is about several μm, and an image of an alignment mark of a mask and an image of an alignment mark of a base pattern on a substrate are acquired simultaneously. It is not possible. Therefore, conventionally, the image acquisition device is moved up and down by a moving mechanism such as a ball screw and a motor, and the focus of the image acquisition device is sequentially adjusted to the lower surface of the mask and the surface of the substrate. Therefore, it takes time to detect the position of the alignment mark on the mask and the position of the alignment mark on the base pattern of the substrate, and it takes a long time to align the mask and the substrate, and the tact time of the exposure process is increased. There was a problem.

  An object of the present invention is to quickly and accurately detect the position of an alignment mark on a mask and the position of an alignment mark on a base pattern on a substrate, and perform alignment between the mask and the substrate in a short time with high accuracy. Another object of the present invention is to manufacture a high-quality display panel substrate with high throughput.

  A proximity exposure apparatus of the present invention includes a mask holder that holds a mask, a chuck that supports a substrate on which a base pattern is formed, and a stage that relatively moves the mask holder and the chuck. In a proximity exposure apparatus for transferring a mask pattern to a substrate by providing a small gap between them, a plurality of Z-tilt mechanisms for moving and tilting the mask holder and the chuck relatively in the Z direction, A plurality of first image acquisition devices that acquire images of a plurality of alignment marks provided outside the exposure area and output image signals, and a plurality of first images that move the focal position of the first image acquisition device Focus position moving mechanism and a plurality of alignment marks provided in the exposure area of the mask or a plurality of alignment marks provided on the base pattern of the substrate A plurality of second image acquisition devices that acquire the image and output an image signal, a plurality of second focus position moving mechanisms that move the focal position of the second image acquisition device, and a first image acquisition The image processing device that detects the position of the alignment mark by processing the image signal output from the apparatus and the second image acquisition device, and the mask holder and the chuck are relatively moved in the Z direction by a plurality of Z-tilt mechanisms. And while tilting and performing the gap alignment between the mask and the substrate, the first focal position moving mechanism is controlled to move the focal position of the first image acquisition device to the height of the lower surface of the mask after the gap alignment. The second focus position moving mechanism is controlled to move the focus position of the second image acquisition device to the height of the surface of the substrate after gap alignment, and the image processing device detects after the gap alignment between the mask and the substrate. Mask Control means for aligning the mask and the substrate by relatively moving the mask holder and the chuck by the stage based on the position of the alignment mark and the position of the alignment mark on the base pattern of the substrate. .

  In addition, the proximity exposure apparatus alignment method of the present invention includes a mask holder that holds a mask, a chuck that supports a substrate on which a base pattern is formed, and a stage that relatively moves the mask holder and the chuck. A proximity exposure apparatus alignment method for transferring a mask pattern to a substrate by providing a minute gap between the mask and the substrate, and relatively moving and tilting the mask holder and the chuck in the Z direction. A plurality of first image acquisition devices that acquire images of a plurality of Z-tilt mechanisms, a plurality of alignment marks provided outside the exposure area of the mask, and output image signals; A plurality of first focus position moving mechanisms for moving the focus position, and a plurality of alignment marks or substrate bases provided in the exposure area of the mask A plurality of second image acquisition devices that acquire images of a plurality of alignment marks provided in the turn and output image signals, and a plurality of second focus positions that move the focal positions of the second image acquisition devices A moving mechanism and an image processing device for processing the image signals output from the first image acquisition device and the second image acquisition device to detect the position of the alignment mark are provided, and a mask holder is provided by a plurality of Z-tilt mechanisms. The mask after the gap adjustment of the focal position of the first image acquisition device is performed by the first focal position moving mechanism while the gap between the mask and the substrate is relatively moved and tilted in the Z direction. The focus position of the second image acquisition device is moved to the height of the surface of the substrate after gap alignment by the second focus position moving mechanism, and the mass is moved by the first image acquisition device. An image of the alignment mark is obtained, the position of the alignment mark of the mask is detected by the image processing device, the image of the alignment mark of the base pattern of the substrate is obtained by the second image obtaining device, and the substrate is obtained by the image processing device. After detecting the position of the alignment mark on the base pattern of the substrate and aligning the gap between the mask and the substrate, the mask holder and the chuck are moved by the stage based on the detected position of the alignment mark on the mask and the position of the alignment mark on the base pattern on the substrate It moves relatively and aligns the mask and the substrate.

  A plurality of Z-tilt mechanisms that move and tilt the mask holder and the chuck relatively in the Z direction, and a plurality of alignment marks provided outside the exposure area of the mask, and a plurality of images that output image signals The first image acquisition device, a plurality of first focus position moving mechanisms for moving the focus position of the first image acquisition device, and a plurality of alignment marks provided in the exposure area of the mask or a base pattern of the substrate A plurality of second image acquisition devices that acquire images of a plurality of alignment marks provided in the image and output image signals, and a plurality of second focus position moves that move the focal position of the second image acquisition device And a plurality of Z-tilt mechanisms provided with a mechanism and an image processing device that detects the position of the alignment mark by processing the image signals output from the first image acquisition device and the second image acquisition device. The focus position of the first image acquisition device is adjusted by the first focus position moving mechanism while the mask holder and the chuck are relatively moved and tilted in the Z direction to adjust the gap between the mask and the substrate. Since it moves to the height of the lower surface of the subsequent mask and the focal position of the second image acquisition device is moved to the height of the surface of the substrate after the gap adjustment by the second focal position moving mechanism, The operation of sequentially aligning the focus of the image acquisition device with the lower surface of the mask and the surface of the substrate after the gap between the substrate and the substrate is eliminated. Then, the image of the alignment mark of the mask is acquired by the first image acquisition device, the position of the alignment mark of the mask is detected by the image processing device, and the image of the alignment mark of the base pattern of the substrate is acquired by the second image acquisition device. The image processing apparatus detects the position of the alignment mark on the base pattern of the substrate, and after the gap between the mask and the substrate is aligned, the position of the alignment mark on the detected mask and the position of the alignment mark on the base pattern on the substrate are detected. Based on this, the mask holder and chuck are relatively moved by the stage to align the mask and the substrate, so that the mask alignment mark position and the substrate base pattern alignment mark position can be detected quickly and accurately. The mask and substrate can be aligned with high accuracy in a short time. Divide.

  The proximity exposure apparatus of the present invention further includes a plurality of moving means for moving the second image acquisition apparatus from the retracted position during exposure to the sky of the mask, and the control means uses the plurality of Z-tilt mechanisms as the mask. While moving to the position where the gap alignment with the substrate is started, the first focal position moving mechanism is controlled to move the focal position of the first image acquisition device to the height of the lower surface of the mask when starting the gap alignment, The second focus position moving mechanism is controlled to move the focus position of the second image acquisition device to the height of the lower surface of the mask at the start of gap alignment, and the image processing device receives the image signal of the first image acquisition device. Mask alignment mark position at the start of gap alignment detected by processing and mask alignment at the start of gap alignment detected by the image processing device processing the image signal of the second image acquisition device From the position of the over-click, it is intended to detect the positional deviation of the second image acquisition apparatus, based on the detection result, to correct the detection result of the position of the alignment mark of the base pattern on the substrate.

  Also, the proximity exposure apparatus alignment method of the present invention moves the second image acquisition apparatus from the retracted position during exposure to the sky of the mask, and starts a plurality of Z-tilt mechanisms to align the gap between the mask and the substrate. During the movement to the position to be moved, the first focal position moving mechanism moves the focal position of the first image acquisition device to the height of the lower surface of the mask at the start of gap alignment, and the second focal position moving mechanism performs the second movement. The focus position of the image acquisition apparatus is moved to the height of the lower surface of the mask at the start of gap alignment, and the plurality of Z-tilt mechanisms are moved to positions where the gap alignment between the mask and the substrate is started, and then the first image An image of the alignment mark of the mask is acquired by the acquisition device, the position of the alignment mark of the mask is detected by the image processing device, and the alignment of the mask is acquired by the second image acquisition device. An image of the mark is acquired, the position of the alignment mark of the mask is detected by the image processing device, and the image alignment signal of the mask at the start of gap alignment detected by processing the image signal of the first image acquisition device by the image processing device The position shift of the second image acquisition device is detected and detected from the position of the mask and the alignment mark position of the mask at the start of gap alignment detected by processing the image signal of the second image acquisition device by the image processing device. Based on the result, the detection result of the position of the alignment mark on the base pattern of the substrate is corrected.

  Since the alignment mark of the base pattern of the substrate is formed in the exposure region of the substrate irradiated with the exposure light, the second image acquisition device that acquires the image moves to a retracted position that is out of the exposure region during exposure. It is necessary to move from the retracted position at the time of exposure to the sky above the mask when moving and then aligning the mask and the substrate. When the second image acquisition device is moved, the second image acquisition device may be misaligned due to variations in the operation of the moving mechanism. When the second image acquisition device is misaligned, The detection result of the position of the alignment mark of the underlying pattern includes an error due to the positional deviation of the second image acquisition device.

  Therefore, the first focal position moving mechanism moves the focal position of the first image acquisition device to the height of the lower surface of the mask at the start of gap alignment, and the second focal position moving mechanism uses the second image acquisition device. The focal position is moved to the height of the lower surface of the mask at the start of gap alignment, and the plurality of Z-tilt mechanisms are moved to positions where the gap alignment between the mask and the substrate is started, and then the first image acquisition device An image of the alignment mark is acquired, the position of the alignment mark of the mask is detected by the image processing device, an image of the alignment mark of the mask is acquired by the second image acquisition device, and the alignment mark of the mask is acquired by the image processing device. Mask alignment at the start of gap alignment detected by detecting the position and processing the image signal of the first image acquisition device by the image processing device Position shift of the second image acquisition device is detected from the position of the alignment mark of the mask at the start of gap alignment detected by processing the image signal of the second image acquisition device by the image processing device. Based on the detection result, the detection result of the position of the alignment mark on the base pattern of the substrate is corrected. Even if the second image acquisition apparatus is misaligned, the mask and the substrate can be accurately aligned. Then, the first focal position moving mechanism moves the focal position of the first image acquisition device to the height of the lower surface of the mask at the start of gap alignment, and the second focal position moving mechanism acquires the second image. Since the operation of moving the focal position of the apparatus to the height of the lower surface of the mask at the start of gap alignment is performed while moving the plurality of Z-tilt mechanisms to the position at which gap alignment between the mask and the substrate is started, the second operation is performed. The time required to detect the positional deviation of the image acquisition apparatus is shorter.

  The method for producing a display panel substrate according to the present invention exposes a substrate using any one of the above-described proximity exposure apparatuses, or alternatively uses the alignment method of any one of the above-described proximity exposure apparatuses to mask and the substrate. And the substrate is exposed. The position of the alignment mark on the mask and the position of the alignment mark on the base pattern on the substrate are detected quickly and accurately, and the alignment between the mask and the substrate is performed in a short time and with high accuracy. Manufactured with high throughput.

  According to the proximity exposure apparatus and the alignment method of the proximity exposure apparatus of the present invention, a plurality of first image acquisition apparatuses that acquire images of a plurality of alignment marks provided outside the exposure area of the mask, and mask exposure A plurality of second image acquisition devices that acquire images of a plurality of alignment marks provided in the region or a plurality of alignment marks provided on the base pattern of the substrate, and a mask holder by a plurality of Z-tilt mechanisms While moving and tilting the chuck relatively in the Z direction to perform the gap alignment between the mask and the substrate, the focal position of the first image acquisition device is moved to the height of the lower surface of the mask after the gap alignment, By moving the focal position of the second image acquisition device to the height of the surface of the substrate after the gap alignment, the position of the alignment mark on the mask The position of the alignment mark of the fine substrate of the underlying pattern to quickly and accurately detect, alignment of the mask and the substrate can be performed in a short time with high accuracy.

  Furthermore, according to the proximity exposure apparatus and the alignment method of the proximity exposure apparatus of the present invention, the positional deviation of the second image acquisition apparatus is detected, and the position of the alignment mark of the base pattern on the substrate is detected based on the detection result. By correcting the result, the mask and the substrate can be accurately aligned even if the second image acquisition apparatus is misaligned. Then, the first focal position moving mechanism moves the focal position of the first image acquisition device to the height of the lower surface of the mask at the start of gap alignment, and the second focal position moving mechanism acquires the second image. The operation of moving the focal position of the apparatus to the height of the lower surface of the mask at the start of gap alignment is performed by moving a plurality of Z-tilt mechanisms to the position where the gap alignment between the mask and the substrate is started. It is possible to shorten the time required to detect the positional deviation of the second image acquisition device.

  According to the method for manufacturing a display panel substrate of the present invention, the position of the alignment mark on the mask and the position of the alignment mark on the base pattern on the substrate can be detected quickly and accurately, and the mask and substrate can be aligned in a short time. Since it can be performed with high accuracy, a high-quality display panel substrate can be manufactured with high throughput.

It is a figure which shows schematic structure of the proximity exposure apparatus by one embodiment of this invention. 1 is a top view of a proximity exposure apparatus according to an embodiment of the present invention. FIG. It is a side view which shows the state which moved the chuck | zipper to the exposure position. It is a figure which shows a pneumatic support apparatus and a Z-tilt mechanism. FIG. 5A is a front view of the Z-tilt mechanism, and FIG. 5B is a side view of the Z-tilt mechanism. It is a figure which shows schematic structure of a gap sensor. It is a figure which shows an example of the alignment mark of a mask. It is a figure which shows an example of the alignment mark of the base pattern of a board | substrate. FIG. 9A is a top view of the focal position moving mechanism, and FIG. 9B is a side view thereof. 10A is a top view of the camera unit moving mechanism and the focal position moving mechanism, and FIG. 10B is a side view of the same. It is a block diagram of an image processing device. It is a flowchart which shows operation | movement of an exposure process. It is a flowchart which shows the operation | movement of the conventional shot. It is a flowchart which shows the operation | movement of the shot using the alignment method of the proximity exposure apparatus by one embodiment of this invention. It is a figure explaining the alignment method of the proximity exposure apparatus by one embodiment of this invention. It is a flowchart which shows an example of the manufacturing process of the TFT substrate of a liquid crystal display device. It is a flowchart which shows an example of the manufacturing process of the color filter board | substrate of a liquid crystal display device.

  FIG. 1 is a diagram showing a schematic configuration of a proximity exposure apparatus according to an embodiment of the present invention. FIG. 2 is a top view of the proximity exposure apparatus according to the embodiment of the present invention. The proximity exposure apparatus includes a base 3, an X guide 4, an X stage 5, a Y guide 6, a Y stage 7, a θ stage 8, a chuck support base 9, a chuck 10, a mask holder 20, a pneumatic support apparatus, a Z-tilt mechanism, The gap sensor 40, the image processing device 50, the camera units 51 and 52, the focal position moving mechanism, the camera unit moving mechanism, the stage driving circuit 60, the Z-tilt mechanism driving circuit 61, and the main controller 70 are configured. . In FIG. 1, the pneumatic support device, the Z-tilt mechanism, the focal position moving mechanism, and the camera unit moving mechanism are omitted. In FIG. 2, the pneumatic support device, the Z-tilt mechanism, the image processing device 50, the focus position moving mechanism, the camera unit moving mechanism, the stage driving circuit 60, the Z-tilt mechanism driving circuit 61, and the main control device 70 are omitted. Has been. In addition to these, the proximity exposure apparatus carries a substrate 1 into the chuck 10 and also carries a substrate transport robot that unloads the substrate 1 from the chuck 10, an irradiation optical system that irradiates exposure light, and a temperature at which temperature management in the apparatus is performed. A control unit is provided.

  Note that the XY directions in the embodiments described below are examples, and the X direction and the Y direction may be interchanged.

  1 and 2, the chuck 10 is in a load / unload position where the substrate 1 is loaded and unloaded. At the load / unload position, the substrate 1 is carried into the chuck 10 and the substrate 1 is carried out of the chuck 10 by a substrate transfer robot (not shown). The loading of the substrate 1 onto the chuck 10 and the unloading of the substrate 1 from the chuck 10 are performed using a plurality of push-up pins provided on the chuck 10. The push-up pin is housed inside the chuck 10 and is lifted from the inside of the chuck 10 to receive the substrate 1 from the substrate transfer robot and unload the substrate 1 from the chuck 10 when loading the substrate 1 onto the chuck 10. In doing so, the substrate 1 is delivered to the substrate transfer robot. The chuck 10 supports the back surface of the substrate 1 by vacuum suction. A base pattern is formed on the surface of the substrate 1, and a photoresist is applied on the base pattern.

  FIG. 3 is a side view showing a state where the chuck is moved to the exposure position. In FIG. 3, the pneumatic support device, the Z-tilt mechanism, the image processing device 50, the focal position moving mechanism, the camera unit moving mechanism, the stage driving circuit 60, the Z-tilt mechanism driving circuit 61, and the main control device 70 are omitted. Has been. A mask holder 20 for holding the mask 2 is installed above the exposure position. In FIG. 2, the mask holder 20 is provided with an opening 20a through which exposure light passes, and the mask holder 20 vacuum-sucks the peripheral portion of the mask 2 by a suction groove (not shown) provided around the opening 20a. And hold. An irradiation optical system (not shown) is disposed above the mask 2 held by the mask holder 20. At the time of exposure, exposure light from the irradiation optical system passes through the mask 2 and is irradiated onto the substrate 1, whereby the pattern of the mask 2 is transferred to the surface of the substrate 1 and a pattern is formed on the substrate 1.

  1 and 3, the chuck 10 is mounted on the θ stage 8 via the chuck support 9, and a Y stage 7 and an X stage 5 are provided below the θ stage 8. The X stage 5 is mounted on an X guide 4 provided on the base 3 and moves along the X guide 4 in the X direction (the horizontal direction in FIGS. 1 and 3). The Y stage 7 is mounted on a Y guide 6 provided on the X stage 5 and moves in the Y direction (the depth direction in FIGS. 1 and 3) along the Y guide 6. The θ stage 8 is mounted on the Y stage 7 and rotates in the θ direction. The chuck support 9 is mounted on the θ stage 8 and supports the back surface of the chuck 10 at a plurality of locations. The X stage 5, Y stage 7, and θ stage 8 are provided with drive mechanisms (not shown) such as ball screws and motors, linear motors, etc., and each drive mechanism is driven by a stage drive circuit 60 of FIG. The

  The chuck 10 is moved between the load / unload position and the exposure position by the movement of the X stage 5 in the X direction and the movement of the Y stage 7 in the Y direction. At the load / unload position, the substrate 1 mounted on the chuck 10 is pre-aligned by moving the X stage 5 in the X direction, moving the Y stage 7 in the Y direction, and rotating the θ stage 8 in the θ direction. Is done. At the exposure position, the X stage 5 is moved in the X direction and the Y stage 7 is moved in the Y direction, whereby the substrate 1 mounted on the chuck 10 is stepped in the XY direction. Further, a gap between the mask 2 and the substrate 1 is adjusted by moving and tilting the mask holder 20 in the Z direction (vertical direction in FIG. 3) by a Z-tilt mechanism 30 described later. Then, the mask 2 and the substrate 1 are aligned by the movement of the X stage 5 in the X direction, the movement of the Y stage 7 in the Y direction, and the rotation of the θ stage 8 in the θ direction. In FIG. 1, the main controller 70 controls the stage drive circuit 60 to move the X stage 5 in the X direction, move the Y stage 7 in the Y direction, and rotate the θ stage 8 in the θ direction. .

  In the present embodiment, the gap between the mask 2 and the substrate 1 is adjusted by moving and tilting the mask holder 20 in the Z direction. However, the chuck support base 9 is provided with a Z-tilt mechanism, The gap between the mask 2 and the substrate 1 may be adjusted by moving and tilting the chuck 10 in the Z direction.

  FIG. 4 is a diagram illustrating the pneumatic support device and the Z-tilt mechanism. In FIG. 4, the image processing device 50, the camera units 51 and 52, the focal position moving mechanism, and the camera unit moving mechanism are omitted. A top frame 22 is installed above the exposure position. The top frame 22 is configured to form a rectangular frame when viewed from above, but in FIG. 4, the front side and the back side of the rectangular frame are omitted, and the left and right parts of the rectangular frame are omitted. Only the cross section is shown. A holder frame 21 is attached to the top frame 22 via a plurality of pneumatic support devices 23. A mask holder 20 is attached to the holder frame 21. The pneumatic support device 23 is constituted by, for example, an air cushion, and supports the loads of the mask holder 20 and the holder frame 21 by the internal air pressure. Z-tilt mechanisms 30 are attached between the top frame 22 and the holder frame 21 at a total of three locations, one on the front side of the drawing and two on the back side of the drawing.

  FIG. 5A is a front view of the Z-tilt mechanism, and FIG. 5B is a side view of the Z-tilt mechanism. The Z-tilt mechanism 30 includes a casing 31, a linear motion guide 32, a movable block 33, a motor 34, a shaft coupling 35, a ball screw 36a, a nut 36b, and a ball 37. As shown in FIG. 5B, the casing 31 is attached to the side surface of the top frame 22. As shown in FIG. 5A, a linear motion guide 32 is provided inside the casing 31, and a movable block 33 is mounted on the linear motion guide 32. A motor 34 is installed above the casing 31, and a ball screw 36 a is connected to the rotating shaft of the motor 34 via a shaft coupling 35. A nut 36 b that is moved by a ball screw 36 a is attached to the movable block 33, and the movable block 33 moves up and down along the linear guide 32 by the rotation of the motor 34.

  As shown in FIG. 5B, a tilt arm 24 is provided on the lower surface of the holder frame 21. A ball 37 is attached to the lower surface of the movable block 33, and the ball 37 is pressed against the tilt arm 24 by the movable block 33. In FIG. 4, the three Z-tilt mechanisms 30 are supported by the pneumatic support device 23 by moving the movable block 33 up and down and changing the height of the ball 37 that pushes the tilt arm 24. The height of the holder frame 21 is changed at three locations, and the mask holder 20 is moved and tilted in the Z direction. The Z-tilt mechanism drive circuit 61 drives the motor 34 of each Z-tilt mechanism 30 under the control of the main controller 70.

  In FIG. 2, four gap sensors 40 are provided above the mask 2 held by the mask holder 20. When the gap between the mask 2 and the substrate 1 is aligned, each gap sensor 40 is moved above the four corners of the opening 20a of the mask holder 20 by a moving mechanism (not shown), and the gap between the mask 2 and the substrate 1 is changed to the mask. Measure at the four corners. After the gap alignment between the mask 2 and the substrate 1 is completed, each gap sensor 40 is moved outside the opening 20a of the mask holder 20 by a moving mechanism (not shown).

  FIG. 6 is a diagram illustrating a schematic configuration of the gap sensor. The gap sensor 40 includes a laser light source 41, a collimation lens group 42, a projection lens 43, mirrors 44 and 45, an imaging lens 46, and a CCD line sensor 47. Laser light generated from the laser light source 41 passes through the collimation lens group 42 and the projection lens 43 and is irradiated obliquely from the mirror 44 to the mask 2. A part of the laser light applied to the mask 2 is reflected by the upper surface of the mask 2, and a part of the laser light is transmitted into the mask 2. A part of the laser light transmitted to the inside of the mask 2 is reflected by the lower surface of the mask 2, and a part of the laser light is irradiated to the surface of the substrate 1 from the lower surface of the mask 2. A part of the laser light applied to the surface of the substrate 1 is reflected by the surface of the substrate 1 and a part of the laser light is transmitted to the inside of the substrate 1. The laser light reflected by the lower surface of the mask 2 and the laser light reflected by the surface of the substrate 1 are emitted from the upper surface of the mask, then reflected by the mirror 45, pass through the imaging lens 46, and pass through the CCD line sensor 47. An image is formed on the light receiving surface. The CCD line sensor 47 outputs a detection signal corresponding to the intensity of light received by the light receiving surface. The gap G between the mask 2 and the substrate 1 is determined from the position of the detection signal of the laser beam reflected from the lower surface of the mask 2 of the CCD line sensor 47 and the position of the detection signal of the laser beam reflected from the surface of the substrate 1. Measured.

  The base pattern formed on the mask 2 and the substrate 1 is provided with a plurality of alignment marks for aligning the mask 2 and the substrate 1. FIG. 7 is a diagram illustrating an example of an alignment mark of a mask. In FIG. 7, the exposure area 20b corresponding to the opening 20a through which the exposure light of the mask holder 20 passes is indicated by a broken line. On the surface (lower surface) of the mask 2 facing the substrate 1, two alignment marks 2a are provided outside the exposure region 20b and four in the exposure region 20b. FIG. 8 is a diagram showing an example of alignment marks on the base pattern of the substrate. FIG. 8 shows an example in which exposure is performed by dividing one surface of the substrate 1 into four exposure regions divided by broken lines. A base pattern is formed in each exposure region on the surface of the substrate 1. In the base pattern, alignment marks 1 a are provided at positions corresponding to the positions of the alignment marks 2 a provided in the exposure region 20 b of the mask 2. The positions of the alignment marks 1a and 2a vary depending on the size of the exposure area of the substrate 1.

  In FIG. 2, two camera units 51 and four camera units 52 are installed above the mask 2. Each camera unit 51 is installed above the alignment mark 2 a provided outside the exposure area 20 b of the mask 2. Each camera unit 52 is moved above the alignment mark 2a provided in the exposure region 20b of the mask 2 when the mask 2 and the substrate 1 are aligned by a camera unit moving mechanism described later. When performing this exposure, the mask 2 is moved to a retracted position that is out of the exposure area 20b of the mask 2.

  Each camera unit 51 is provided with a focal position moving mechanism for moving the focal position of each camera unit 51. FIG. 9A is a top view of the focal position moving mechanism, and FIG. 9B is a side view thereof. The focal position moving mechanism includes a rib 58, a Z base 90, a Z guide 91, a Z stage 92, a rib 93, a mounting base 94, a motor base 95, a motor 96a, a shaft coupling 97, a bearing 98, a ball screw 99a, and a nut 99b. It is configured to include. A frame 53 on which a focal position moving mechanism is installed is provided above the exposure position. A Z base 90 is attached to the frame 53 by ribs 58, and the Z base 90 extends downward outside the frame 53.

  A Z guide 91 is provided on the Z base 90, and a Z stage 92 is mounted on the Z guide 91. Further, a motor 96a is installed on a motor base 95 attached to the Z base 90, and the motor 96a is driven by the main controller 70 of FIG. The rotating shaft of the motor 96a is connected to a ball screw 99a by a shaft coupling 97, and the ball screw 99a is rotatably supported by a bearing 98. A nut 99b that is moved by a ball screw 99a is attached to the Z stage 92, and the Z stage 92 is moved in the Z direction along the Z guide 91 by the rotation of the motor 96a. A mounting base 94 is attached to the Z stage 92 by ribs 93, and the camera unit 51 is attached to the mounting base 94. The camera unit 51 includes a CCD camera 51a and a lens 51b.

  The camera unit 51 is moved in the Z direction by the movement of the Z stage 92 in the Z direction. In FIG. 1, the main controller 70 controls the motor 96a to move each camera unit 51 to Z so that the focus of each camera unit 51 is aligned with the alignment mark 2a provided outside the exposure area 20b of the mask 2. Move in each direction.

  On the other hand, a camera unit moving mechanism that moves each camera unit 52 and a focal position moving mechanism that moves the focal position of each camera unit 52 are attached to each camera unit 52. 10A is a top view of the camera unit moving mechanism and the focal position moving mechanism, and FIG. 10B is a side view of the same. The camera unit moving mechanism includes a Y guide 54, a Y stage 55, an X guide 56, an X stage 57, ribs 58 and 59, motors 81 and 86, shaft couplings 82 and 87, bearings 83 and 88, ball screws 84a and 89a, and nuts. 84b and 89b, and the Z base 90 are comprised. The focal position moving mechanism includes a Z guide 91, a Z stage 92, a rib 93, a mounting base 94, a motor base 95, a motor 96b, a shaft coupling 97, a bearing 98, a ball screw 99a, and a nut 99b. Yes.

  A frame 53 on which a camera unit moving mechanism is installed is provided above the exposure position. A Y guide 54 is provided on the upper surface of the frame 53, and a Y stage 55 is mounted on the Y guide 54. Further, a motor 81 is installed on the upper surface of the frame 53, and the motor 81 is driven by the main controller 70 of FIG. A rotation shaft of the motor 81 is connected to a ball screw 84 a by a shaft coupling 82, and the ball screw 84 a is rotatably supported by a bearing 83. A nut 84 b that is moved by a ball screw 84 a is attached to the lower surface of the Y stage 55, and the Y stage 55 is moved in the Y direction along the Y guide 54 by the rotation of the motor 81.

  An X guide 56 is provided on the upper surface of the Y stage 55, and an X stage 57 is mounted on the X guide 56. Further, a motor 86 is installed on the upper surface of the Y stage 55, and the motor 86 is driven by the main controller 70 of FIG. A rotation shaft of the motor 86 is connected to a ball screw 89 a by a shaft coupling 87, and the ball screw 89 a is rotatably supported by a bearing 88. A nut 89 b that is moved by a ball screw 89 a is attached to the lower surface of the X stage 57, and the X stage 57 is moved in the X direction along the X guide 56 by the rotation of the motor 86. A Z base 90 is attached to the side surface of the X stage 57 by ribs 58 and 59, and the Z base 90 extends downward outside the frame 53.

  A Z guide 91 is provided on the Z base 90, and a Z stage 92 is mounted on the Z guide 91. Further, a motor 96b is installed on a motor base 95 attached to the Z base 90, and the motor 96b is driven by the main controller 70 of FIG. The rotating shaft of the motor 96b is connected to a ball screw 99a by a shaft coupling 97, and the ball screw 99a is rotatably supported by a bearing 98. A nut 99b that is moved by a ball screw 99a is attached to the Z stage 92, and the Z stage 92 is moved in the Z direction along the Z guide 91 by the rotation of the motor 96b. A mounting base 94 is attached to the Z stage 92 by ribs 93, and the camera unit 52 is attached to the mounting base 94. The camera unit 52 includes a CCD camera 52a and a lens 52b.

  The camera unit 52 is moved in the XY direction by the movement of the X stage 57 in the X direction and the movement of the Y stage 55 in the Y direction. When the main controller 70 in FIG. 1 controls the motors 81 and 86 to align the mask 2 and the substrate 1, each camera unit 52 is aligned with the alignment mark 2 a provided in the exposure region 20 b of the mask 2. When the substrate 1 is exposed, the camera units 52 are moved to the retracted positions outside the exposure region 20b of the mask 2, respectively. Further, the camera unit 52 is moved in the Z direction by the movement of the Z stage 92 in the Z direction. The main controller 70 controls the motor 96b so that the focus of each camera unit 52 is aligned with the alignment mark 2a provided in the exposure region 20b of the mask 2 and the alignment mark 1a of the base pattern of the substrate 1. The camera unit 52 is moved in the Z direction.

  FIG. 11 is a block diagram of the image processing apparatus. The image processing apparatus 50 includes a control unit 50a, a calculation processing unit 50b, an image memory 50c, and a calculation memory 50d. In the arithmetic memory 50d, images of the alignment marks 1a and 2a serving as a reference for image recognition are registered in advance. The image memory 50c stores image signals output from the CCD cameras 51a and 52a of the camera units 51 and 52, respectively. The arithmetic processing unit 50b processes the image signal stored in the image memory 50c, and registers the images of the alignment marks 1a and 2a acquired by the CCD cameras 51a and 52a of the camera units 51 and 52 and the arithmetic memory 50d. Image recognition is performed by comparing the images of the alignment marks 1a and 2a, and the positions of the alignment marks 1a and 2a are detected. The control unit 50a sets a determination condition when the arithmetic processing unit 50b performs image recognition.

  Hereinafter, an alignment method for a proximity exposure apparatus according to an embodiment of the present invention will be described. In FIG. 11, the main controller 70 includes a camera unit controller 70a for controlling the focal position moving mechanism and the camera unit moving mechanism, a stage controller 70b for controlling the stage driving circuit 60 and the Z-tilt mechanism driving circuit 61, And a memory 70c. The camera unit controller 70a focuses the gap between the mask 2 and the substrate 1 in advance for each shot before starting the exposure process or when exposing the first substrate. The focal positions of the camera units 51 and 52 at the start of gap alignment are determined in accordance with the lower surface of the mask 2 at the start. The camera unit control unit 70a registers the determined focal positions of the camera units 51 and 52 at the start of gap alignment in the memory 70c.

  Further, the camera unit control unit 70a previously focuses each camera unit 51 on the gap between the mask 2 and the substrate 1 for each shot before the exposure process is started or when the first substrate is exposed. The focal position of each camera unit 51 after the gap alignment is determined in accordance with the lower surface of the subsequent mask 2, and the focus of each camera unit 52 is aligned with the surface of the substrate 1 after the gap alignment between the mask 2 and the substrate 1. The focal position of each camera unit 52 after the gap adjustment is determined. The camera unit control unit 70a registers the determined focal positions of the camera units 51 and 52 after the gap adjustment in the memory 70c. The focal position of each camera unit 52 after the gap alignment may be determined for each substrate production lot or for a predetermined number of substrates in consideration of the variation in the thickness of the substrate 1.

  FIG. 12 is a flowchart showing the operation of the exposure process. First, the substrate 1 is loaded onto the chuck 10 at the load / unload position (step 301). The main controller 70 drives the X stage 5, Y stage 7 and θ stage 8 by the stage drive circuit 60, moves the chuck 10 in the XY direction and rotates it in the θ direction at the load / unload position, and Pre-alignment is performed (step 302). Next, the main controller 70 drives the X stage 5 and the Y stage 7 by the stage drive circuit 60, moves the chuck 10 to the exposure position, and moves the substrate 1 to the position where the first shot of the exposure position is performed. (Step 303).

  Subsequently, the first shot is performed at the exposure position (step 304). After each shot, main controller 70 determines whether all shots have been completed (step 305). If all shots have not been completed, main controller 70 drives each Z-tilt mechanism 30 by Z-tilt mechanism drive circuit 61 to widen the gap between mask 2 and substrate 1 (step 306). Subsequently, the main controller 70 drives the X stage 5 and the Y stage 7 by the stage driving circuit 60, performs step movement of the substrate 1 in the XY directions (step 307), and performs the next shot on the substrate 1. Move to position. Then, the process returns to step 304, and steps 304 to 307 are repeated until all shots are completed.

  When all shots are completed, the main controller 70 drives each Z-tilt mechanism 30 by the Z-tilt mechanism driving circuit 61 to widen the gap between the mask 2 and the substrate 1 (step 308), and then the stage. The X stage 5 and the Y stage 7 are driven by the drive circuit 60, and the chuck 10 is moved to the load / unload position (step 309). Then, at the load / unload position, the substrate 1 is unloaded from the chuck 10 (step 310).

  FIG. 13 is a flowchart showing a conventional shot operation. First, each Z-tilt mechanism 30 is moved to a position where the gap alignment between the mask 2 and the substrate 1 is started (step 501). Next, the mask holder 20 is moved and tilted in the Z direction by each Z-tilt mechanism 30 to perform gap alignment between the mask 2 and the substrate 1 (step 502).

  After the gap alignment between the mask 2 and the substrate 1 is completed, the focal position of each camera unit 52 is moved to the height of the lower surface of the mask 2 (step 503). The CCD camera 52a of each camera unit 52 acquires an image of the alignment mark 2a provided in the exposure area 20b of the mask 2, and the image processing device 50 receives the image signal output from the CCD camera 52a of each camera unit 52. Processing is performed to detect the position of the alignment mark 2a provided in the exposure region 20b of the mask 2 (step 504).

  Subsequently, the focal position of each camera unit 52 is moved to the height of the surface of the substrate 1 (step 505). The CCD camera 52a of each camera unit 52 acquires an image of the alignment mark 1a of the base pattern of the substrate 1, and the image processing device 50 processes the image signal output from the CCD camera 52a of each camera unit 52 to obtain the substrate. The position of the alignment mark 1a of the first ground pattern is detected (step 506).

  Then, based on the position of the alignment mark 2a provided in the exposure area 20b of the mask 2 detected by the image processing apparatus 50 and the position of the alignment mark 1a of the base pattern of the substrate 1, the alignment between the mask 2 and the substrate 1 is performed. Is performed (step 507), and each shot is exposed (step 508).

  Thus, conventionally, after the gap alignment between the mask 2 and the substrate 1 (step 502) is completed, the camera unit 52 is focused on the lower surface of the mask 2 and the surface of the substrate 1 in order (step 503, step 503). 505), the image of the alignment mark 2a provided in the exposure area 20b of the mask 2 and the image of the alignment mark 1a of the base pattern of the substrate 1 were obtained in order using the same camera unit 52. Therefore, it takes time to detect the position of the alignment mark 2a of the mask 2 and the position of the alignment mark 1a of the base pattern of the substrate 1, and it takes a long time to align the mask 2 and the substrate 1, and exposure processing is performed. There was a problem that the tact time was long.

  FIG. 14 is a flowchart showing a shot operation using the alignment method of the proximity exposure apparatus according to the embodiment of the present invention. FIG. 15 is a diagram for explaining an alignment method of a proximity exposure apparatus according to an embodiment of the present invention. In FIG. 14, first, the stage controller 70 b of the main controller 70 controls the Z-tilt mechanism drive circuit 61 to position each Z-tilt mechanism 30 to start the gap alignment between the mask 2 and the substrate 1. (Step 401). In parallel with this, the camera unit control unit 70a of the main controller 70 drives the motor 96a of the focal position moving mechanism to set the focal position of each camera unit 51 at the start of gap alignment registered in the memory 70c. Each camera unit 51 is moved to the focal position (the height of the lower surface of the mask 2 at the start of gap alignment) (step 402), and the motor 96b of the focal position moving mechanism is controlled to adjust the focal point of each camera unit 52. The position is moved to the focal position (the height of the lower surface of the mask 2 at the start of gap alignment) of each camera unit 52 registered in the memory 70c at the start of gap alignment (step 403). FIG. 15A shows a state in which the focal positions of the camera units 51 and 52 are moved to the height of the lower surface of the mask 2 at the start of gap alignment.

  In FIG. 14, after each Z-tilt mechanism 30 is moved to a position where the gap alignment between the mask 2 and the substrate 1 is started (step 401), the CCD camera 51 a of each camera unit 51 is in the exposure area 20 b of the mask 2. An image of the alignment mark 2a provided on the outside is acquired and an image signal is output to the image memory 50c. The CCD camera 52a of each camera unit 52 receives the alignment mark 2a provided in the exposure area 20b of the mask 2. An image is acquired and an image signal is output to the image processing device 50. The image memory 50 c of the image processing apparatus 50 stores image signals output from the CCD camera 51 a of each camera unit 51 and the CCD camera 52 a of each camera unit 52.

  The arithmetic processing unit 50b of the image processing device 50 processes the image signal stored in the image memory 50c, and the image of the alignment mark 2a acquired by the CCD camera 51a of each camera unit 51 and the image registered in the arithmetic memory 50d. Image recognition is performed by comparing with the image of the alignment mark 2a, and the position of the alignment mark 2a provided outside the exposure area 20b of the mask 2 is detected (step 404). The arithmetic processing unit 50b processes the image signal stored in the image memory 50c, and the image of the alignment mark 2a provided in the exposure area 20b of the mask 2 acquired by the CCD camera 52a of each camera unit 52. Then, the image of the alignment mark 2a registered in the arithmetic memory 50d is compared with the image to perform image recognition, and the position of the alignment mark 2a provided in the exposure area 20b of the mask 2 is detected (step 405).

  Each camera unit 52 is moved to a retracted position out of the exposure area at the time of exposure, and then moved from the retracted position at the time of exposure to above the mask 2 when aligning the mask 2 and the substrate 1. . When each camera unit 52 is moved, there is a possibility that a position shift of each camera unit 52 may occur due to variation in operation of the camera unit moving mechanism. The camera unit controller 70a of the main controller 70 detects the position of the alignment mark 2a of the mask 2 at the start of gap alignment detected by the image processor 50 by processing the image signal of the CCD camera 51a of the camera unit 51, and the image processing. The position shift of the camera unit 52 is detected from the position of the alignment mark 2a of the mask 2 at the start of gap alignment detected by the apparatus 50 processing the image signal of the CCD camera 52a of the camera unit 52 (step 406).

  Subsequently, the stage controller 70 b of the main controller 70 drives each Z-tilt mechanism 30 by the Z-tilt mechanism driving circuit 61 based on the measurement results of the four gap sensors 40, and the mask 2, the substrate 1, and the like. (Step 407). In parallel with this, the camera unit control unit 70a of the main controller 70 controls the motor 96a of the focal position moving mechanism to set the focal position of each camera unit 51 to the respective positions after gap adjustment registered in the memory 70c. Each of the camera units 52 is moved to the focal position of the camera unit 51 (the height of the lower surface of the mask 2 after the gap alignment) (step 408), and the focal position of each camera unit 52 is controlled by controlling the motor 96b of the focal position moving mechanism. Then, it moves to the focal position (the height of the surface of the substrate 1 after gap alignment) of each camera unit 52 after gap alignment registered in the memory 70c (step 409). In FIG. 15B, the focal position of the camera unit 51 is moved to the height of the lower surface of the mask 2 after gap alignment, and the focal position of the camera unit 52 is moved to the height of the surface of the substrate 1 after gap alignment. FIG. 15C shows a state in which the gap alignment between the mask 2 and the substrate 1 has been completed thereafter.

  In the gap alignment between the mask 2 and the substrate 1 in FIG. 14 (step 407), the height of the surface of the mask 2 is such that the CCD camera 51a of each camera unit 51 is provided outside the exposure area 20b of the mask 2. When reaching the range where the image of 2a can be acquired, the CCD camera 51a of each camera unit 51 acquires the image of the alignment mark 2a provided outside the exposure area 20b of the mask 2, and the image signal is stored in the image memory 50c. Output to. On the other hand, the CCD camera 52 a of each camera unit 52 acquires an image of the alignment mark 1 a of the base pattern of the substrate 1 and outputs an image signal to the image processing device 50. The image memory 50 c of the image processing apparatus 50 stores image signals output from the CCD camera 51 a of each camera unit 51 and the CCD camera 52 a of each camera unit 52.

  The arithmetic processing unit 50b of the image processing device 50 processes the image signal stored in the image memory 50c, and the image of the alignment mark 2a acquired by the CCD camera 51a of each camera unit 51 and the image registered in the arithmetic memory 50d. Image recognition is performed by comparing with the image of the alignment mark 2a, and the position of the alignment mark 2a provided outside the exposure area 20b of the mask 2 is detected (step 410). The arithmetic processing unit 50b processes the image signal stored in the image memory 50c, and stores the image of the alignment mark 1a of the base pattern of the substrate 1 obtained by the CCD camera 52a of each camera unit 52 and the arithmetic memory 50d. Image recognition is performed by comparing with the registered image of the alignment mark 1a, and the position of the alignment mark 1a on the base pattern of the substrate 1 is detected (step 411).

  The camera unit control unit 70a of the main controller 70 corrects the detection result of the position of the alignment mark 1a of the base pattern of the substrate 1 detected by the arithmetic processing unit 50b based on the positional deviation of the camera unit 52 detected in step 406. (Step 412). The stage controller 70b of the main controller 70 is provided outside the exposure area 20b of the mask 2 detected by the image processing apparatus 50 after the gap alignment (step 407) between the mask 2 and the substrate 1 is completed. The stage drive circuit 60 is controlled based on the position of the alignment mark 2a and the position of the alignment mark 1a on the corrected base pattern of the substrate 1, and the chuck 10 is moved in the XY direction by the X stage 5, the Y stage 7, and the θ stage 8. Then, the mask 2 and the substrate 1 are aligned with each other by rotating in the θ direction (step 413). Then, each shot is exposed (step 414).

  While the mask holder 20 is moved and tilted in the Z direction by the plurality of Z-tilt mechanisms 30 to perform the gap alignment between the mask 2 and the substrate 1 (step 407), the focal position of the camera unit 51 is adjusted by the focal position moving mechanism. Since it moves to the height of the lower surface of the mask 2 after the gap alignment (step 408), the focal position of the camera unit 52 is moved to the height of the surface of the substrate 1 after the gap alignment by the focal position moving mechanism (step 409). As in the prior art, after the gap between the mask 2 and the substrate 1 is aligned, the operation of sequentially aligning the focus of the camera unit 52 with the lower surface of the mask 2 and the surface of the substrate 1 becomes unnecessary. Then, the image of the alignment mark 2a of the mask 2 is acquired by the camera unit 51, the position of the alignment mark 2a of the mask 2 is detected by the image processing apparatus 50 (step 410), and the base pattern of the substrate 1 is detected by the camera unit 52. An image of the alignment mark 1a is acquired, the position of the alignment mark 1a of the base pattern of the substrate 1 is detected by the image processing apparatus 50 (step 411), and after the gap between the mask 2 and the substrate 1 is aligned, the detected mask 2 Based on the position of the alignment mark 2a and the position of the alignment mark 1a on the base pattern of the substrate 1, the chuck 10 is moved in the XY direction and rotated in the θ direction by the X stage 5, the Y stage 7 and the θ stage 8, and the mask 2 Since the alignment with the substrate 1 (step 413) is performed, the mask The position of the second alignment mark 2a and the position of the alignment mark 1a on the base pattern of the substrate 1 are detected quickly and accurately, and the alignment between the mask 2 and the substrate 1 is performed in a short time with high accuracy.

  Further, the focal position of the camera unit 51 is moved to the height of the lower surface of the mask 2 at the start of the gap alignment by the focal position moving mechanism (step 402), and the focal position of the camera unit 52 is started by the focal position moving mechanism. Is moved to the height of the lower surface of the mask 2 (step 403), the plurality of Z-tilt mechanisms 30 are moved to positions where the gap alignment between the mask 2 and the substrate 1 is started, and then the alignment of the mask 2 is performed by the camera unit 51. The image of the mark 2a is acquired, the position of the alignment mark 2a of the mask 2 is detected by the image processing device 50 (step 404), the image of the alignment mark 2a of the mask 2 is acquired by the camera unit 52, and the image processing device 50, the position of the alignment mark 2a of the mask 2 is detected (step 405), and the image The position of the alignment mark 2a of the mask 2 at the start of gap alignment detected by processing the image signal of the camera unit 51 by the processing device 50 and the gap alignment detected by processing the image signal of the camera unit 52 by the image processing device 50 The position shift of the camera unit 52 is detected from the position of the alignment mark 2a of the mask 2 at the start (step 406), and the detection result of the position of the alignment mark 1a of the base pattern on the substrate 1 is corrected based on the detection result (step 406). Therefore, even if the camera unit 52 is misaligned, the mask 1 and the substrate 1 are accurately aligned. Then, the focal position moving mechanism moves the focal position of the camera unit 51 to the height of the lower surface of the mask 2 at the start of gap alignment (step 402), and the focal position moving mechanism aligns the focal position of the camera unit 52 with the gap. The operation of moving to the height of the lower surface of the mask 2 at the start (step 403) is performed while the plurality of Z-tilt mechanisms 30 are moved to the position where the gap alignment between the mask 2 and the substrate 1 is started (step 401). As a result, the time required to detect the displacement of the camera unit 52 can be shortened.

  According to the embodiment described above, the plurality of camera units 51 that acquire images of the plurality of alignment marks 2 a provided outside the exposure area 20 b of the mask 2 and the plurality of cameras units 51 provided in the exposure area 20 b of the mask 2. And a plurality of camera units 52 for acquiring images of a plurality of alignment marks 1 a provided on the underlying pattern of the substrate 1, and the mask holder 20 is moved in the Z direction by a plurality of Z-tilt mechanisms 30. While performing the gap alignment between the mask 2 and the substrate 1 by tilting, the focal position of the camera unit 51 is moved to the height of the lower surface of the mask 2 after the gap alignment, and the focal position of the camera unit 52 is adjusted after the gap alignment. By moving to the height of the surface of the substrate 1, the position of the alignment mark 2 a of the mask 2 and the underlying pattern of the substrate 1 are Down of the alignment mark 1a position quickly and accurately detected, and the alignment of the mask 2 and the substrate 1 can be performed in a short time with high accuracy.

  Furthermore, even if the positional deviation of the camera unit 52 occurs, the positional deviation of the camera unit 52 is detected, and the detection result of the position of the alignment mark 1a of the base pattern of the substrate 1 is corrected based on the detection result. 2 and the substrate 1 can be accurately aligned. Then, the operation of moving the focal position of the camera unit 51 to the height of the lower surface of the mask 2 at the start of gap alignment by the focal position moving mechanism, and the mask at the time of starting the gap alignment of the camera unit 52 by the focal position moving mechanism. The position of the camera unit 52 is detected by moving the plurality of Z-tilt mechanisms 30 to the position where the gap alignment between the mask 2 and the substrate 1 is started. The time required to do this can be shortened.

  By exposing the substrate using the proximity exposure apparatus of the present invention, or by aligning the mask and the substrate using the alignment method of the proximity exposure apparatus of the present invention, For high-quality display, the position of the alignment mark on the mask and the position of the alignment mark on the base pattern on the substrate can be detected quickly and accurately, and the mask and substrate can be aligned with high accuracy in a short time. Panel substrates can be manufactured with high throughput.

  For example, FIG. 16 is a flowchart showing an example of the manufacturing process of the TFT substrate of the liquid crystal display device. In the thin film formation step (step 101), a thin film such as a conductor film or an insulator film, which becomes a transparent electrode for driving liquid crystal, is formed on the substrate by sputtering, plasma chemical vapor deposition (CVD), or the like. In the resist coating process (step 102), a photosensitive resin material (photoresist) is applied by a roll coating method or the like to form a photoresist film on the thin film formed in the thin film forming process (step 101). In the exposure step (step 103), the mask pattern is transferred to the photoresist film using a proximity exposure apparatus, a projection exposure apparatus, or the like. In the development step (step 104), a developer is supplied onto the photoresist film by a shower development method or the like to remove unnecessary portions of the photoresist film. In the etching process (step 105), a portion of the thin film formed in the thin film formation process (step 101) that is not masked by the photoresist film is removed by wet etching. In the stripping step (step 106), the photoresist film that has finished the role of the mask in the etching step (step 105) is stripped with a stripping solution. Before or after each of these steps, a substrate cleaning / drying step is performed as necessary. These steps are repeated several times to form a TFT array on the substrate.

  FIG. 17 is a flowchart showing an example of the manufacturing process of the color filter substrate of the liquid crystal display device. In the black matrix forming step (step 201), a black matrix is formed on the substrate by processing such as resist coating, exposure, development, etching, and peeling. In the colored pattern forming step (step 202), a colored pattern is formed on the substrate by a dyeing method, a pigment dispersion method, a printing method, an electrodeposition method, or the like. This process is repeated for the R, G, and B coloring patterns. In the protective film forming step (step 203), a protective film is formed on the colored pattern, and in the transparent electrode film forming step (step 204), a transparent electrode film is formed on the protective film. Before, during or after each of these steps, a substrate cleaning / drying step is performed as necessary.

  In the TFT substrate manufacturing process shown in FIG. 16, in the exposure process (step 103), in the color filter substrate manufacturing process shown in FIG. 17, in the exposure process of the colored pattern forming process (step 202), the proxy of the present invention. The alignment method of the proximity exposure apparatus or proximity exposure apparatus of the present invention can be applied.

DESCRIPTION OF SYMBOLS 1 Substrate 1a, 2a Alignment mark 2 Mask 3 Base 4 X guide 5 X stage 6 Y guide 7 Y stage 8 θ stage 9 Chuck support stand 10 Chuck 20 Mask holder 21 Holder frame 22 Top frame 23 Pneumatic support device 24 Tilt arm 30 Z-tilt mechanism 31 Casing 32 Linear motion guide 33 Movable block 34 Motor 35 Shaft coupling 36a Ball screw 36b Nut 37 Ball 40 Gap sensor 41 Laser light source 42 Collimation lens group 43 Projection lens 44, 45 Mirror 46 Imaging lens 47 CCD line sensor DESCRIPTION OF SYMBOLS 50 Image processing apparatus 50a Control part 50b Operation processing part 50c Image memory 50d Operation memory 51,52 Camera unit 51a, 52a CCD camera 51b, 52b Lens 53 Frame 54 Y guide 55 Y stage 56 X guide 57 X stage 58, 59 Rib 60 Stage drive circuit 61 Z-tilt mechanism drive circuit 70 Main controller 70a Camera unit controller 70b Stage controller 70c Memory 81, 86, 96a, 96b Motor 82, 87, 97 Shaft coupling 83, 88, 98 Bearing 84a, 89a, 99a Ball screw 84b, 89b, 99b Nut 90 Z base 91 Z guide 92 Z stage 93 Rib 94 Mounting base 95 Motor stand

Claims (6)

A mask holder for holding a mask, a chuck for supporting a substrate on which a base pattern is formed, and a stage for moving the mask holder and the chuck relative to each other, and a minute gap is formed between the mask and the substrate. In a proximity exposure apparatus for transferring a mask pattern to a substrate,
A plurality of Z-tilt mechanisms for relatively moving and tilting the mask holder and the chuck in the Z direction;
A plurality of first image acquisition devices for acquiring images of a plurality of alignment marks provided outside the exposure area of the mask and outputting image signals;
A plurality of first focal position moving mechanisms for moving a focal position of the first image acquisition device;
A plurality of second image acquisition devices for acquiring images of a plurality of alignment marks provided in an exposure area of a mask or a plurality of alignment marks provided on a base pattern of a substrate, and outputting an image signal;
A plurality of second focal position moving mechanisms for moving a focal position of the second image acquisition device;
An image processing device for processing the image signals output by the first image acquisition device and the second image acquisition device to detect the position of the alignment mark;
The first focus position moving mechanism is controlled while the mask holder and the chuck are relatively moved and tilted in the Z direction by the plurality of Z-tilt mechanisms to adjust the gap between the mask and the substrate. The focus position of the first image acquisition device is moved to the height of the lower surface of the mask after the gap alignment, and the focus position of the second image acquisition device is controlled by controlling the second focus position moving mechanism. The stage is moved to the height of the surface of the substrate after alignment, and after the gap between the mask and the substrate is aligned, the stage is determined based on the position of the alignment mark of the mask detected by the image processing apparatus and the position of the alignment mark of the base pattern of the substrate And a control means for relatively moving the mask holder and the chuck to align the mask and the substrate. Proximity exposure apparatus. A plurality of moving means for moving the second image acquisition device from the retracted position during exposure to the sky of the mask;
The control means controls the first focus position moving mechanism to move the plurality of Z-tilt mechanisms to a position where the gap alignment between the mask and the substrate is started, and thereby the focus of the first image acquisition device. The position is moved to the height of the lower surface of the mask at the start of gap alignment, and the second focal position moving mechanism is controlled to adjust the focal position of the second image acquisition device to the height of the lower surface of the mask at the start of gap alignment. The position of the alignment mark of the mask at the start of gap alignment detected by the image processing device processing the image signal of the first image acquisition device, and the image processing device of the second image acquisition device The position shift of the second image acquisition device is detected from the position of the alignment mark of the mask at the start of gap alignment detected by processing the image signal, and the base pattern of the substrate is detected based on the detection result. Proximity exposure device according to claim 1, characterized in that to correct the detection result of the position of the alignment mark. A mask holder that holds the mask, a chuck that supports the substrate on which the base pattern is formed, and a stage that relatively moves the mask holder and the chuck, and a minute gap is provided between the mask and the substrate. A proximity exposure apparatus alignment method for transferring a mask pattern onto a substrate,
A plurality of Z-tilt mechanisms that move and tilt the mask holder and the chuck relatively in the Z direction, and a plurality of alignment marks provided outside the exposure area of the mask, and a plurality of images that output image signals The first image acquisition device, a plurality of first focus position moving mechanisms for moving the focus position of the first image acquisition device, and a plurality of alignment marks provided in the exposure area of the mask or a base pattern of the substrate A plurality of second image acquisition devices that acquire images of a plurality of alignment marks provided in the image and output image signals, and a plurality of second focus position moves that move the focal position of the second image acquisition device A mechanism and an image processing device that detects the position of the alignment mark by processing the image signal output by the first image acquisition device and the second image acquisition device;
While the mask holder and the chuck are relatively moved and tilted in the Z direction by a plurality of Z-tilt mechanisms to perform the gap alignment between the mask and the substrate, the first focus position moving mechanism causes the first image acquisition device to The focus position of the second image acquisition device is moved to the height of the surface of the substrate after the gap alignment by the second focus position moving mechanism.
An image of the mask alignment mark is acquired by the first image acquisition device, the position of the alignment mark of the mask is detected by the image processing device, and an image of the alignment mark of the base pattern of the substrate is acquired by the second image acquisition device. Then, the position of the alignment mark of the base pattern of the substrate is detected by the image processing device,
After aligning the gap between the mask and the substrate, the stage is moved relative to the mask holder and the chuck based on the detected position of the alignment mark on the mask and the position of the alignment mark on the base pattern on the substrate, and An alignment method for a proximity exposure apparatus, wherein alignment is performed. Move the second image acquisition device from the retracted position during exposure to the sky of the mask,
While moving the plurality of Z-tilt mechanisms to the position where the gap alignment between the mask and the substrate is started, the first focal position moving mechanism moves the focal position of the first image acquisition device to the lower surface of the mask when the gap alignment starts. Move to the height, move the focal position of the second image acquisition device to the height of the lower surface of the mask at the start of gap alignment by the second focal position movement mechanism,
After moving the plurality of Z-tilt mechanisms to a position where the gap alignment between the mask and the substrate is started, an image of the alignment mark of the mask is acquired by the first image acquisition device, and the alignment mark of the mask is acquired by the image processing device. Detecting the position, acquiring an image of the alignment mark of the mask with the second image acquisition device, detecting the position of the alignment mark of the mask with the image processing device,
The position of the alignment mark of the mask at the start of gap alignment detected by processing the image signal of the first image acquisition device by the image processing device and the image signal of the second image acquisition device detected by the image processing device From the position of the alignment mark of the mask at the start of the gap alignment, the positional deviation of the second image acquisition device is detected,
4. The proximity exposure apparatus alignment method according to claim 3, wherein the detection result of the position of the alignment mark of the base pattern on the substrate is corrected based on the detection result.   A method for manufacturing a display panel substrate, comprising: exposing a substrate using the proximity exposure apparatus according to claim 1.   5. A method for manufacturing a display panel substrate, wherein the alignment of the proximity exposure apparatus according to claim 3 or 4 is used to align the mask and the substrate to expose the substrate.

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