JP2011170144A - Photomask, proximity exposure device, and method for detecting alignment mark of the proximity exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily put an alignment mark of a mask in a field of view of an image acquiring device that acquires an image of the alignment mark, in a short period of time. <P>SOLUTION: A plurality of alignment marks 2aR, 2aG and 2aB are provided at a photomask 2, and around the alignment marks 2aR, 2aG and 2aB, a plurality of position information marks 2b and 2c including information of positions of the alignment marks 2aR, 2aG and 2aB are provided. By acquiring images of the position information marks 2b and 2c by a plurality of image acquiring devices and moving each image acquiring device based on the information of the positions of the alignment marks 2aR, 2aG and 2aB included in the acquired position information marks 2b and 2c, the alignment mark of the mask can be easily put in the field of view of the image acquiring device in a short period of time. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photomask, a proximity exposure apparatus, and a proximity exposure apparatus used in 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. The present invention relates to an alignment mark detection method, and in particular, a photo used in a proximity exposure apparatus that acquires an alignment mark image of a photomask and a substrate by an image acquisition device such as a CCD camera and aligns the photomask and the substrate. The present invention relates to a mask, a proximity exposure apparatus, and an alignment mark detection method for a proximity exposure apparatus.

  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 system that projects a photomask (hereinafter referred to as “mask”) pattern onto a substrate using a lens or a mirror, and a small gap (proximity gap) between the mask and the substrate. There is a proximity method in which a mask pattern is provided and transferred to a substrate. 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 the proximity method mainly used for exposure of a large substrate, a plurality of alignment marks are provided on the mask and the base pattern of the substrate, respectively, and the mask alignment mark and the alignment mark of the substrate are detected by an image acquisition device such as a CCD camera. Images were acquired, the positions of both were detected by image recognition, and the mask and substrate were aligned. As such a proximity exposure apparatus, there is one described in Patent Document 1.

JP 2007-256581 A

  In an image acquisition device such as a CCD camera that acquires an image of an alignment mark, a high-magnification lens is used in order to increase the detection accuracy of the position of the alignment mark by image recognition. For this reason, the field of view of the image acquisition device is narrowed to about 500 μm × 500 μm, for example.

  Usually, the alignment between the mask and the substrate is performed with reference to the alignment mark of the mask, and the position of the image acquisition device is determined according to the position of the alignment mark of the mask. When deciding the position of the image acquisition device, the image acquisition device has been moved by a moving mechanism so that the mask alignment mark is placed in the field of view of the image acquisition device while viewing the image acquired by the image acquisition device. . However, since the field of view of the image acquisition device is narrow, it takes time to put the alignment mark of the mask within the field of view of the image acquisition device.

  Further, when the alignment mark of the mask could not be put in the field of view of the image acquisition device, conventionally, the position of the alignment mark of the mask was confirmed visually and the image acquisition device was moved by the moving mechanism. However, if the mask becomes larger as the substrate becomes larger, the mask holder becomes larger and it becomes difficult to approach the mask, and the distance between the mask and the position where the moving mechanism is operated is increased, and the mask alignment mark It has become difficult to operate the moving mechanism while visually confirming the position.

  An object of the present invention is to easily put an alignment mark of a mask in a short time in a field of view of an image acquisition device that acquires an image of an alignment mark.

  The mask of the present invention has a plurality of alignment marks for alignment with the substrate and a plurality of position information marks provided around the alignment marks and including information on the positions of the alignment marks.

  In addition, the proximity exposure apparatus of the present invention includes a plurality of alignment marks for alignment with the substrate, and a mask having a plurality of position information marks provided around the alignment marks and including information on the positions of the alignment marks. And a plurality of image acquisition devices for acquiring images of alignment marks or position information marks, a moving means for moving each image acquisition device, and a control means for controlling the moving means.

  In the alignment mark detection method of the proximity exposure apparatus of the present invention, a plurality of alignment marks are provided on a mask, and a plurality of position information marks including information on the position of the alignment mark are provided around the alignment mark. The image of the mark is acquired by a plurality of image acquisition devices, and each image acquisition device is moved based on the information on the position of the alignment mark included in the acquired image of the position information mark.

  Since a plurality of position information marks including alignment mark position information are provided around the alignment mark of the mask, images of the position information marks are acquired by a plurality of image acquisition devices, and are included in the acquired image of the position information marks. By moving each image acquisition device based on the information on the position of the alignment mark, the alignment mark of the mask can be easily put in the field of view of the image acquisition device in a short time.

  Furthermore, the mask of the present invention includes a figure in which the position information mark displays the direction in which the alignment mark is located when viewed from the position information mark.

  In addition, the proximity exposure apparatus of the present invention includes a display in which the position information mark includes a figure that displays a direction in which the alignment mark is seen when viewed from the position information mark, and displays an image acquired by each image acquisition device, and a control And an input device for instructing the means to move each image acquisition device.

  In addition, the proximity mark detection method of the proximity exposure apparatus of the present invention includes an image of the position information mark acquired by the image acquisition device including a figure that displays the direction of the alignment mark when viewed from the position information mark. Is displayed on the display device, the image of the position information mark displayed on the display device is viewed, and each image acquisition device is moved in the direction of the alignment mark.

  Since the position information mark includes a graphic that displays the direction of the alignment mark when viewed from the position information mark, the image of the position information mark acquired by the image acquisition device is displayed on the display device, and the position information mark displayed on the display device is displayed. By moving each image acquisition device in the direction in which the alignment mark is located and manually instructing the movement of each image acquisition device, the mask alignment mark is placed in the field of view of the image acquisition device for a short time. Can be easily put in.

  Alternatively, in the mask of the present invention, the position information mark includes a symbol indicating the distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark.

  In the proximity exposure apparatus of the present invention, the position information mark includes a symbol indicating the distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark, and the position information acquired by each image acquisition device An image processing apparatus that processes the image signal of the image of the mark to detect the distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark, and the control means detects the position detected by the image processing apparatus The moving means is controlled based on the distance and direction from the information mark to the alignment mark or the coordinates of the position of the alignment mark.

  The alignment mark detection method of the proximity exposure apparatus of the present invention includes a position information mark including a symbol indicating a distance and a direction from the position information mark to the alignment mark, or a coordinate indicating the position of the alignment mark. The image signal of the position information mark image is processed to detect the distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark, and the distance and direction from the detected position information mark to the alignment mark Alternatively, each image acquisition device is moved based on the coordinates of the position of the alignment mark.

  Since the position information mark includes a symbol indicating the distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark, the image processing device processes the image signal of the image of the position information mark, Detect the distance and direction from the information mark to the alignment mark, or the coordinates of the alignment mark position, and acquire each image based on the detected distance and direction from the position information mark to the alignment mark, or the coordinates of the alignment mark position By moving the apparatus, each image acquisition apparatus can be automatically moved, and the alignment mark of the mask can be easily put in the field of view of the image acquisition apparatus in a short time.

  Further, in the mask of the present invention, the plurality of alignment marks are divided into a plurality of types according to the exposure process, and the position information mark symbol is the distance and direction from the position information mark to the alignment mark for each type of alignment mark. Or the coordinates of the position of the alignment mark.

  In the proximity exposure apparatus of the present invention, the plurality of alignment marks are divided into a plurality of types according to the exposure process, and the position information mark symbol is different from the position information mark to the alignment mark for each type of alignment mark. Indicates the distance and direction, or the coordinates of the position of the alignment mark, and the image processing device processes the image signal of the position information mark image acquired by each image acquisition device for each type of alignment mark corresponding to the exposure process. The distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark are detected.

  The alignment mark detecting method of the proximity exposure apparatus according to the present invention is provided with a plurality of types of alignment marks according to the exposure process on the mask, and the position information mark for each type of alignment mark by the position information mark symbol. This indicates the distance and direction from the alignment mark to the alignment mark, or the coordinates of the position of the alignment mark, and the image processing device processes the image signal of the image of the position information mark for each type of alignment mark according to the exposure process. The distance and direction from the information mark to the alignment mark, or the coordinates of the position of the alignment mark are detected.

  The position information mark symbol indicates the distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark, for each type of alignment mark. To detect the distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark, for each type of alignment mark corresponding to the exposure process. Thus, the alignment mark of the mask corresponding to the exposure process can be easily put in the field of view of the image acquisition apparatus in a short time.

  According to the present invention, by providing a plurality of position information marks including alignment mark position information around the mask alignment marks, the mask alignment marks can be easily and quickly placed in the field of view of the image acquisition device. Can be put.

  Furthermore, by including a figure that displays the direction of the alignment mark when viewed from the position information mark in the position information mark, the movement of each image acquisition device is instructed manually, and the mask of the image acquisition device is within the field of view of the image acquisition device. The alignment mark can be easily put in a short time.

  Alternatively, by including a symbol indicating the distance and direction from the position information mark to the alignment mark or the coordinates of the position of the alignment mark in the position information mark, each image acquisition device is automatically moved, and the image acquisition device The mask alignment mark can be easily put in a short time in the field of view.

  Furthermore, the position information mark symbol indicates the distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark, for each type of alignment mark. Thus, the mask alignment mark corresponding to the exposure process can be easily put in the field of view of the image acquisition apparatus in a short time.

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 an example of the alignment mark of a mask. It is a figure which shows an example of the alignment mark of a board | substrate. 6A is a top view of the camera unit moving mechanism, and FIG. 6B is a side view thereof. It is a block diagram of an image processing device. It is a figure which shows an example of the positional information mark of the mask by one embodiment of this invention. 5 is a flowchart showing a mask alignment mark detection method according to an embodiment of the present invention. It is a figure which shows an example of the positional information mark of the mask by other embodiment of this invention. 6 is a flowchart illustrating a mask alignment mark detection method according to another embodiment of the present invention. It is a flowchart which shows the alignment method of the proximity exposure apparatus using the alignment mark detection method of this invention.

  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, an image processing apparatus 50, a camera unit 51, A camera unit moving mechanism, a stage drive circuit 60, a main control device 70, a display device 71, and an input device 72 are included. In FIG. 1, the camera unit moving mechanism is omitted. In FIG. 2, the image processing device 50, the camera unit moving mechanism, the stage drive circuit 60, the main control device 70, the display device 71, and the input device 72 are omitted. 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 image processing device 50, the camera unit moving mechanism, the stage drive circuit 60, the main control device 70, the display device 71, and the input device 72 are omitted. 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, the mask holder 20 is moved in the Z direction (vertical direction in FIG. 3) and tilted by a Z-tilt mechanism (not shown), so that the gap between the mask 2 and the substrate 1 is adjusted. 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 the mask holder 20 in the Z direction and tilting. However, the chuck support 9 is provided with a Z-tilt mechanism. The gap between the mask 2 and the substrate 1 may be adjusted by moving the chuck 10 in the Z direction and tilting. In this embodiment, the mask 10 and the substrate 1 are aligned by moving the chuck 10 in the XY direction by the X stage 5 and the Y stage 7, but the mask holder 20 is moved in the XY direction. The mask 2 may be aligned with the substrate 1 by moving the mask holder 20 in the XY directions.

  FIG. 4 is a diagram showing an example of alignment marks on the mask. This example shows alignment marks of a mask used when exposing a color pattern of R, G, and B on a black matrix formed on a substrate in manufacturing a color filter substrate of a liquid crystal display device. On the surface (lower surface) of the mask 2 facing the substrate, there are provided R colored pattern alignment marks 2aR, G colored pattern alignment marks 2aG, and B colored pattern alignment marks 2aB, respectively. It has been.

  FIG. 5 is a diagram illustrating an example of the alignment mark on the substrate. This example 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. Each base pattern is provided with an alignment mark 1aR for an R coloring pattern at a position corresponding to the position of the alignment mark 2aR on the mask 2, and colored with G at a position corresponding to the position of the alignment mark 2aG on the mask 2. A pattern alignment mark 1aG is provided, and a B colored pattern alignment mark 1aB is provided at a position corresponding to the position of the alignment mark 2aB of the mask 2. The positions of the alignment marks 1aR, 1aG, 1aB, 2aR, 2aG, and 2aB vary depending on the size of the exposure area of the substrate 1.

  In FIG. 2, four camera units 51 are installed above the mask 2. Each camera unit 51 is moved by a camera unit moving mechanism, which will be described later, according to the positions of the alignment marks 2aR, 2aG, 2aB of the mask 2. Since the positions of the alignment marks 1aR, 1aG, and 1aB on the substrate 1 vary depending on the exposure conditions when the base pattern is formed, the positions of the camera units 51 are the positions of the alignment marks 2aR, 2aG, and 2aB on the mask 2. Determined based on When performing the exposure processing of the R colored pattern, each camera unit 51 is moved to a predetermined position directly above each alignment mark 2aR. When performing the exposure process of the G coloring pattern, each camera unit 51 is moved to a predetermined position directly above each alignment mark 2aG. When performing the exposure process for the B colored pattern, each camera unit 51 is moved to a predetermined position directly above each alignment mark 2aB.

  6A is a top view of the camera unit moving mechanism, and FIG. 6B is a side view thereof. The camera unit moving mechanism includes a Y guide 54, a Y stage 55, an X guide 56, an X stage 57, ribs 58, 59, 93, motors 81, 86, 96, shaft couplings 82, 87, 97, and bearings 83, 88, 98. , Ball screws 84a, 89a, 99a, nuts 84b, 89b, 99b, a Z base 90, a Z guide 91, a Z stage 92, a mounting base 94, and a motor base 95.

  A top frame 53 on which a camera unit moving mechanism is installed is provided above the exposure position, and an opening 53 a is formed in the top frame 53. A Y guide 54 is provided on the top surface of the top 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 top 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 is inserted into the opening 53 a of the top 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. A motor 96 is installed on a motor base 95 attached to the Z base 90, and the motor 96 is driven by the main controller 70 in FIG. A rotation shaft of the motor 96 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 99 b that is moved by a ball screw 99 a 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 96. 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 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. 1 controls the motors 81 and 86 in accordance with the positions of the alignment marks 2aR, 2aG, and 2aB on the mask 2 to move each camera unit 51 to a predetermined position. Further, the camera unit 51 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 96 to move each camera unit 51 in the Z direction so that the focus of each CCD camera 51a is aligned with the lower surface of the mask 2 and the surface of the substrate 1.

  The CCD camera 51a of each camera unit 51 acquires an image of the lower surface of the mask 2 and an image of the surface of the substrate 1, and outputs image signals to the image processing device 50 and the display device 71 of FIG. In FIG. 1, the display device 71 displays an image acquired by the CCD camera 51 a of each camera unit 51.

  FIG. 7 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. Images of the alignment marks 1aR, 1aG, 1aB, 2aR, 2aG, and 2aB, which serve as references for image recognition, are registered in advance in the arithmetic memory 50d. The image memory 50c stores the image signal output from the CCD camera 51a of each camera unit 51. The arithmetic processing unit 50b processes the image signal stored in the image memory 50c, the images of the alignment marks 1aR, 1aG, 1aB, 2aR, 2aG, 2aB acquired by the CCD camera 51a of each camera unit 51, and the arithmetic memory. Image recognition is performed by comparing the images of alignment marks 1aR, 1aG, 1aB, 2aR, 2aG, and 2aB registered in 50d, and the positions of the recognized alignment marks 1aR, 1aG, 1aB, 2aR, 2aG, and 2aB are detected. .

  In FIG. 7, the main control device 70 includes an image processing control unit 70 a that controls the image processing device 50, a camera unit control unit 70 b that controls the camera unit moving mechanism, and a stage control unit 70 c that controls the stage drive circuit 60. It is comprised including.

  In the present embodiment, a plurality of position information marks including information on the positions of the alignment marks 2aR, 2aG, and 2aB are provided around the alignment marks 2aR, 2aG, and 2aB of the mask 2, and the camera for the alignment marks 2aR, 2aG, and 2aB is provided. When determining the position of the unit 51, an image of the position information mark is acquired by the CCD camera 51a of the camera unit 51, and based on the position information of the alignment marks 2aR, 2aG, 2aB included in the acquired image of the position information mark. The camera unit 51 is moved so that the alignment marks 2aR, 2aG, and 2aB are within the field of view of the CCD camera 51a.

  FIG. 8 is a diagram showing an example of a mask position information mark according to an embodiment of the present invention. The alignment marks 2aR, 2aG, 2aB of the mask 2 are provided with type marks 2R, 2G, 2B indicating the types of the alignment marks 2aR, 2aG, 2aB, respectively. The type marks 2R, 2G, and 2B have different positions depending on the types of the alignment marks 2aR, 2aG, and 2aB. In the example illustrated in FIG. 8, the type mark 2R is disposed at the upper left of the alignment mark 2aR, and the type mark 2G Is arranged in the upper right part of the alignment mark 2aG, and the type mark 2B is arranged in the lower right part of the alignment mark 2aB. In order to facilitate image recognition of the alignment marks 2aR, 2aG, and 2aB, the alignment marks 2aR, 2aG, and 2aB have the same shape. The type of 2aB is identified.

  The position information mark 2b according to the present embodiment is a figure that displays the direction in which the alignment marks 2aR, 2aG, and 2aB are present when viewed from the position information mark 2b, and an arrow is used in the example of FIG. The figure for displaying the direction with the alignment mark is not limited to the arrow, but may be any graphic that can visually determine the direction with the alignment mark.

  FIG. 9 is a flowchart showing a mask alignment mark detection method according to an embodiment of the present invention. In the present embodiment, when the alignment marks 2aR, 2aG, and 2aB are put in the field of view of the CCD camera 51a, the movement of the camera unit 51 is instructed manually. Hereinafter, although the case where the position of the camera unit 51 with respect to the alignment mark 2aR is determined will be described, the same applies to the case where the position of the camera unit 51 with respect to the alignment marks 2aG and 2aB is determined.

  First, the mask 2 is transferred to the mask holder 20 by a mask transfer robot (not shown) (step 301). The camera unit controller 70b of the main controller 70 controls the motor 96 of the camera unit moving mechanism to focus the CCD camera 51a on the lower surface of the mask 2 (step 302).

  The operator looks at the image of the lower surface of the mask 2 displayed on the display device 71, and determines whether or not the alignment mark 2aR is within the field of view of the CCD camera 51a (step 303). When the alignment mark 2aR is not in the field of view of the CCD camera 51a, the operator looks at the image on the lower surface of the mask 2 displayed on the display device 71 to determine whether the position information mark 2b is in the field of view of the CCD camera 51a. Is determined (step 304). If the position information mark 2b is not in the field of view of the CCD camera 51a, the operator instructs the movement of the camera unit 51 through the input device 72 (step 305). The camera unit controller 70b moves the camera unit 51 by controlling the motors 81 and 86 of the camera unit moving mechanism in accordance with an instruction from the operator (step 306). Steps 303 to 306 are repeated until the alignment mark 2aR or the position information mark 2b enters the field of view of the CCD camera 51a.

  When the position information mark 2b is within the field of view of the CCD camera 51a, the operator looks at the image of the position information mark 2b displayed on the display device 71 and uses the input device 72 to place the camera unit 51 on the alignment mark 2aR. The movement of the camera unit 51 is instructed to move in the direction (step 307). The camera unit control unit 70b moves the camera unit 51 by controlling the motors 81 and 86 of the camera unit moving mechanism in accordance with instructions from the operator (step 308). The operator looks at the image of the lower surface of the mask 2 displayed on the display device 71 to determine whether or not the alignment mark 2aR is within the field of view of the CCD camera 51a (step 309), and within the field of view of the CCD camera 51a. Steps 307 to 309 are repeated until the alignment mark 2aR enters.

  In steps 303 and 309, when the alignment mark 2aR is within the field of view of the CCD camera 51a, the image processing apparatus 50 performs image recognition of the alignment mark 2aR and position detection of the alignment mark 2aR (step 310). The image processing control unit 70a of the main control device 70 detects the positional deviation amount of the mask 2 from the positions of the plurality of alignment marks 2aR detected by the image processing device 50 and the movement amount of each camera unit 51 (step 311). ), The mask 2 is positioned by a positioning mechanism (not shown) (step 312). After positioning the mask 2, the position of the mask 2 is measured using a measuring device (not shown) such as a laser length measuring system (step 313), and the position of each camera unit 51 is finely adjusted based on the measurement result (step 314). . The camera unit controller 70b registers the position of each camera unit 51 after fine adjustment (step 315), and moves each camera unit 51 to the registered position when performing exposure processing of the R colored pattern.

  According to the embodiment shown in FIG. 8 and FIG. 9, each camera unit 51 includes the position information mark 2b including a figure displaying the direction in which the alignment marks 2aR, 2aG, and 2aB are located when viewed from the position information mark. Can be manually placed in the field of view of the CCD camera 51a, and the alignment marks 2aR, 2aG, 2aB of the mask 2 can be easily placed in a short time.

  FIG. 10 is a diagram showing an example of a mask position information mark according to another embodiment of the present invention. The position information mark 2c of the present embodiment is a symbol indicating the distance and direction from the position information mark 2c to the alignment marks 2aR, 2aG, 2aB, or the coordinates of the positions of the alignment marks 2aR, 2aG, 2aB. In this example, a two-dimensional code is used. The symbol indicating the distance and direction from the position information mark to the alignment mark or the coordinates of the position of the alignment mark is not limited to a two-dimensional code, and any symbol can be used as long as such information can be detected by image processing. The symbol of the position information mark 2c includes the distance and direction from the position information mark 2c to the alignment marks 2aR, 2aG, 2aB, or the position of the alignment marks 2aR, 2aG, 2aB for each type of the alignment marks 2aR, 2aG, 2aB. The coordinates are shown.

  FIG. 11 is a flowchart illustrating a mask alignment mark detection method according to another embodiment of the present invention. In the present embodiment, the camera unit 51 is automatically moved when the alignment marks 2aR, 2aG, and 2aB are put in the field of view of the CCD camera 51a. Hereinafter, although the case where the position of the camera unit 51 with respect to the alignment mark 2aR is determined will be described, the same applies to the case where the position of the camera unit 51 with respect to the alignment marks 2aG and 2aB is determined.

  First, the mask 2 is transferred to the mask holder 20 by a mask transfer robot (not shown) (step 401). The camera unit controller 70b of the main controller 70 controls the motor 96 of the camera unit moving mechanism to focus the CCD camera 51a on the lower surface of the mask 2 (step 402).

  The arithmetic processing unit 50b of the image processing device 50 compares the image stored in the image memory 50c with the image of the alignment mark 2aR registered in the arithmetic memory 50d, and the alignment mark 2aR is within the field of view of the CCD camera 51a. It is determined whether or not there is (step 403). When the alignment mark 2aR is not in the visual field of the CCD camera 51a, the arithmetic processing unit 50b processes the image signal stored in the image memory 50c, and determines whether or not the position information mark 2c is in the visual field of the CCD camera 51a. Is determined (step 404). If the position information mark 2c is not within the field of view of the CCD camera 51a, the camera unit controller 70b controls the motors 81 and 86 of the camera unit moving mechanism to move the camera unit 51 (step 405). Steps 403 to 405 are repeated until the position information mark 2c enters the field of view of the CCD camera 51a.

  When the position information mark 2c is within the field of view of the CCD camera 51a, the arithmetic processing unit 50b processes the image signal stored in the image memory 50c, and the distance and direction from the position information mark 2c to the alignment mark 2aR, or The coordinates of the position of the alignment mark 2aR are detected (step 406). When the coordinates of the position of the alignment mark 2aR are detected, the arithmetic processing unit 50b detects the position of the center point of the position information mark 2c and detects the position of the position information mark 2c itself. The camera unit controller 70b is configured to detect the distance and direction from the position information mark 2c detected by the arithmetic processing unit 50b to the alignment marks 2aR, 2aG, and 2aB, or the coordinates of the positions of the alignment marks 2aR, 2aG, and 2aB and the position information mark 2c. Based on the position, the motors 81 and 86 of the camera unit moving mechanism are controlled to move the camera unit 51 so that the alignment mark 2aR is within the field of view of the CCD camera 51a (step 407). Steps 410 to 415 are the same as steps 310 to 315 in FIG.

  10 and 11, according to the position information mark 2c, the distance and direction from the position information mark to the alignment marks 2aR, 2aG, 2aB, or the coordinates of the position of the alignment marks 2aR, 2aG, 2aB. By including the symbol indicating, the movement of each camera unit 51 is automatically performed, and the alignment marks 2aR, 2aG, 2aB of the mask 2 can be easily put in the field of view of the CCD camera 51a in a short time.

  Further, depending on the symbol of the position information mark 2c, the distance and direction from the position information mark 2c to the alignment marks 2aR, 2aG, 2aB or the position of the alignment marks 2aR, 2aG, 2aB for each type of the alignment marks 2aR, 2aG, 2aB. By indicating the coordinates, the movement of each camera unit 51 is automatically performed, and the alignment marks 2aR, 2aG, 2aB of the mask 2 corresponding to the exposure process are easily put in the field of view of the CCD camera 51a in a short time. be able to.

  FIG. 12 is a flowchart showing an alignment method of the proximity exposure apparatus using the alignment mark detection method of the present invention. Hereinafter, in the manufacture of the color filter substrate of the liquid crystal display device, the case where the exposure process of the R colored pattern is performed will be described, but the same applies to the case where the exposure process of the G, B colored pattern is performed.

  The camera unit controller 70b of the main controller 70 controls the motors 81 and 86 of the camera unit moving mechanism to move each camera unit 51 to the position registered for the alignment mark 2aR of the mask 2 (step 501). . After performing the gap alignment between the mask 2 and the substrate 1, the camera unit control unit 70b controls the motor 96 of the camera unit moving mechanism to focus each CCD camera 51a on the lower surface of the mask 2 (step 502). . Each CCD camera 51a acquires an image of the alignment mark 2aR of the mask 2, and the image processing apparatus 50 performs image recognition of the alignment mark 2aR of the mask 2 and position detection of the alignment mark 2aR of the mask 2 (step 503). ).

  Subsequently, the camera unit control unit 70b controls the motor 96 of the camera unit moving mechanism to focus each CCD camera 51a on the surface of the substrate 1 (step 504). Each CCD camera 51a acquires an image of the alignment mark 1aR on the substrate 1, and the image processing apparatus 50 performs image recognition of the alignment mark 1aR on the substrate 1 and position detection of the alignment mark 1aR on the substrate 1 (step 505). ).

  The image processing control unit 70a of the main controller 70 determines the positions of the mask 2 and the substrate 1 from the positions of the plurality of alignment marks 2aR of the mask 2 and the positions of the plurality of alignment marks 1aR of the substrate 1 detected by the image processing device 50. The amount of deviation is detected (step 506), and it is determined whether or not the amount of positional deviation between the two is below a predetermined value (step 507). When it is equal to or smaller than the predetermined value, the main controller 70 ends the alignment between the mask 2 and the substrate 1.

  When the amount of positional deviation between the mask 2 and the substrate 1 is not less than or equal to a predetermined value, the stage control unit 70c of the main controller 70 determines X based on the amount of positional deviation between the mask 2 and the substrate 1 detected by the image processing control unit 70a. The amount of movement of the stage 5 and Y stage 7 and the amount of rotation of the θ stage 8 are calculated (step 508). Then, the stage control unit 70c controls the stage drive circuit 60 to move the X stage 5 and the Y stage 7 by the calculated movement amount, and rotates the θ stage 8 by the calculated rotation amount (step 509). Return to step 505.

  According to the embodiment described above, by providing a plurality of position information marks 2b, 2c including information on the positions of the alignment marks 2aR, 2aG, 2aB around the alignment marks 2aR, 2aG, 2aB of the mask 2, The alignment marks 2aR, 2aG, 2aB of the mask 2 can be easily put in the field of view of the CCD camera 51a in a short time.

DESCRIPTION OF SYMBOLS 1 Substrate 1aR, 1aG, 1aB, 2aR, 2aG, 2aB Alignment mark 2 Mask 2b, 2c Position information mark 3 Base 4 X guide 5 X stage 6 Y guide 7 Y stage 8 θ stage 9 Chuck support 10 Chuck 20 Mask holder 50 Image processing apparatus 50a Control unit 50b Arithmetic processing unit 50c Image memory 50d Arithmetic memory 51 Camera unit 51a CCD camera 51b Lens 53 Top frame 54 Y guide 55 Y stage 56 X guide 57 X stage 58, 59 Rib 60 Stage drive circuit 70 Main control Device 70a Image processing control unit 70b Camera unit control unit 70c Stage control unit 71 Display device 72 Input device 81, 86, 96 Motor 82, 87, 97 Shaft joint 83, 88, 98 Bearing 84a, 89 a, 99a Ball screw 84b, 89b, 99b Nut 90 Z base 91 Z guide 92 Z stage 93 Rib 94 Mounting base 95 Motor base

Claims (12)

A plurality of alignment marks for alignment with the substrate;
A photomask comprising a plurality of position information marks provided around the alignment marks and including information on positions of the alignment marks.   2. The photomask according to claim 1, wherein the position information mark includes a figure that displays a direction in which the alignment mark is located when viewed from the position information mark.   2. The photomask according to claim 1, wherein the position information mark includes a symbol indicating a distance and a direction from the position information mark to the alignment mark or coordinates of the position of the alignment mark. The plurality of alignment marks are divided into a plurality of types according to the exposure process,
The symbol of the position information mark indicates a distance and a direction from the position information mark to the alignment mark or a coordinate of the position of the alignment mark for each type of the alignment mark. Photo mask. A plurality of alignment marks for alignment with the substrate, and a photomask having a plurality of position information marks provided around the alignment marks and including information on the positions of the alignment marks;
A plurality of image acquisition devices for acquiring an image of the alignment mark or the position information mark;
Moving means for moving each image acquisition device;
Proximity exposure apparatus comprising control means for controlling the moving means. The position information mark includes a figure that displays a direction in which the alignment mark is seen from the position information mark,
A display device for displaying an image acquired by each image acquisition device;
6. The proximity exposure apparatus according to claim 5, further comprising an input device for instructing the control means to move each image acquisition device. The position information mark includes a distance and direction from the position information mark to the alignment mark, or a symbol indicating coordinates of the position of the alignment mark,
An image processing device that processes an image signal of the image of the position information mark acquired by each image acquisition device and detects a distance and a direction from the position information mark to the alignment mark, or a coordinate of the position of the alignment mark. Prepared,
The control means controls the moving means based on a distance and direction from the position information mark to the alignment mark detected by the image processing apparatus, or coordinates of the position of the alignment mark. Item 6. The proximity exposure apparatus according to Item 5. The plurality of alignment marks are divided into a plurality of types according to the exposure process,
The symbol of the position information mark indicates the distance and direction from the position information mark to the alignment mark for each type of the alignment mark, or the coordinates of the position of the alignment mark,
The image processing device processes an image signal of the image of the position information mark acquired by each image acquisition device, and for each type of the alignment mark according to an exposure process, from the position information mark to the alignment mark. The proximity exposure apparatus according to claim 7, wherein a distance and a direction, or coordinates of the position of the alignment mark are detected. A plurality of alignment marks are provided on the photomask,
A plurality of position information marks including information on the position of the alignment mark are provided around the alignment mark.
Acquire images of position information marks with multiple image acquisition devices,
An alignment mark detection method for a proximity exposure apparatus, wherein each image acquisition apparatus is moved based on position information of an alignment mark included in an acquired image of a position information mark. Including the figure that displays the direction of the alignment mark as seen from the position information mark,
Display the position information mark image acquired by the image acquisition device on the display device,
The alignment mark detection method for a proximity exposure apparatus according to claim 9, wherein each image acquisition apparatus is moved in a direction in which the alignment mark is present while viewing an image of the position information mark displayed on the display device. In the position information mark, include a symbol indicating the distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark,
The image processing device processes the image signal of the image of the position information mark, detects the distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark,
The alignment mark of a proximity exposure apparatus according to claim 9, wherein each image acquisition apparatus is moved based on the distance and direction from the detected position information mark to the alignment mark, or the coordinates of the position of the alignment mark. Detection method. Provide multiple types of alignment marks according to the exposure process on the photomask,
The position information mark symbol indicates the distance and direction from the position information mark to the alignment mark, or the coordinates of the position of the alignment mark, for each type of alignment mark.
The image processing device processes the image signal of the image of the position information mark, and calculates the distance and direction from the position information mark to the alignment mark or the coordinates of the position of the alignment mark for each type of alignment mark corresponding to the exposure process. The alignment mark detection method of a proximity exposure apparatus according to claim 11, wherein the detection is performed.

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