JP2013125795A - Substrate positioning device and substrate positioning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate positioning device capable of performing highly accurate substrate positioning while limiting up-sizing as much as possible.SOLUTION: A substrate positioning device 100 positioning a planar substrate 1 while correcting the position includes a substrate mounting stage 5 having small air holes 16 at least floating the substrate 1 and a piping route 21, and a hole 5a formed in the center, and an XYZθ stage 80 having an XYZθ table 8 placed in the hole 5a of the substrate mounting stage 5, a Z-axis stage 14 for vertically moving the XYZθ table 8 in a direction perpendicular to the plane of the substrate being mounted, and a θ stage 11 for rotating the XYZθ table 8 around a rotational axis perpendicular to the plane of the substrate 1 being mounted.

Description

  The present invention relates to a substrate positioning apparatus and a substrate positioning method.

  Currently, display devices such as liquid crystal display devices and organic EL display devices are pixel transistors (thin film transistors) in which an amorphous silicon film on a substrate such as glass or fused quartz is crystallized into a polysilicon film and arranged at the same vertical or horizontal pitch. ) Switching to display an image.

  In order to form a pixel transistor on this substrate, after an amorphous silicon film is formed on a glass substrate, hydrogen present in the film is heat-treated to perform dehydrogenation. After that, crystallization is performed by irradiating an amorphous silicon film with an excimer laser or the like to form a polysilicon film. Since the speed (mobility) of electrons that can move in the crystal by crystallization increases, the switching speed of the thin film transistor increases, and the image of a display device such as a liquid crystal display device or an organic EL display device can be seen clearly. The size of the substrate to be processed is now reaching the eighth generation from the second generation, and it will be necessary to irradiate a large-sized substrate with a side exceeding 2 m with a laser in the future.

  FIG. 17 is a view showing a state in which a 32-inch panel is irradiated by a conventional irradiation method. The size of the pixel is, for example, 0.45 mm × 0.15 mm, in which B region is a region where thin film transistors are arranged and amorphous silicon is deposited, and the size is 0.3 mm × 0.1 mm. It is formed as much as possible. On the other hand, the A region is a portion where amorphous silicon is not deposited. Crystallization into a polysilicon film is performed by irradiating the region B where amorphous silicon is deposited with laser.

  The irradiation laser light is shaped into a long and narrow beam composed of a major axis and a minor axis. For example, as shown in FIG. 18, a laser beam having a major axis of 1 mm and a minor axis of 30 μm can be used. Such a long and narrow beam is scanned in the minor axis direction, scanned in the major axis direction at the substrate end, and scanned again in the minor axis direction. This scanning is performed over the entire substrate, and laser irradiation is performed. Since the overlapping portion of the long beam in the long axis direction is formed in the portion (A region) where there is no amorphous silicon on the substrate, the length in the long axis direction of the beam and the positional accuracy of the long axis direction scanning are about 150 μm unit in FIG. Relative position accuracy is required. This overlapping portion (A area) will become smaller and smaller in the future due to panel size and high definition, and high positional accuracy is required.

  On the other hand, in the minor axis direction of the elongated beam, since the beam is scanned, the start position accuracy needs to be irradiated from a wiring pattern on the inner side of about 5 mm from the end surface of the substrate. The laser irradiation speed in the short axis direction is a constant speed of about several hundred mm / s, and the substrate mounting stage requires a stroke for accelerating and decelerating the stage, and has a stage configuration with a long stroke in the short axis direction. Yes. FIG. 19 shows the configuration of a conventional laser irradiation apparatus. In FIG. 19, a glass substrate 101 is mounted on an X table 54 on an X stage 53, scanned in the X direction, and irradiated with a laser beam from a laser optical system head 51. The laser optical system head 51 moves in the Y direction when the X table 54 reaches the end of the glass substrate 101 by the Y stage 52. By such movement, the entire surface of the substrate is irradiated. In the conventional irradiation apparatus, the Y stage has a gantry configuration with respect to the X stage.

  As a method for positioning a substrate by loading a substrate on a processing table in such an irradiation method and irradiation apparatus, it is conceivable to apply a method used in a color filter manufacturing apparatus as a conventional glass substrate positioning method. . This will be described with reference to FIG.

  FIG. 20 shows a technique disclosed in Patent Document 1. In this patent document, 101 is a glass substrate and 102 is an inkjet head. The glass substrate 101 is mounted on the XYθ table 105 so as to be able to travel relative to the inkjet head 102. An alignment mark 103 is formed on the glass substrate 101, and these are recognized and measured by the coarse adjustment imaging means 104. When the color filter manufacturing apparatus of FIG. 20 is applied to a laser irradiation apparatus, the ink jet head 102 in FIG. 20 can be replaced with the laser optical system head 51 in FIG. Further, the X table 54 in FIG. 19 corresponds to the XYθ table 105 in FIG.

  Next, the substrate positioning operation will be described in order.

  First, the glass substrate 101 is transported to the XYθ table 105 configured on the base 106, and suction and gripping are performed. Generally, transfer is performed using a transfer robot or a conveyor.

  Next, the XYθ table 105 is moved to a position where the alignment mark 103 can be imaged by the coarse adjustment imaging means 104 having two sets of low optical magnifications.

  After the alignment mark 103 is imaged by the two sets of coarse adjustment imaging means 104, the correction amount in the X-axis direction, the correction amount in the Y-axis direction, and the correction amount of the θ angle necessary for correct alignment correction are respectively Calculated.

  Next, based on the calculated correction amount, the XYθ table 105 is actually moved in the X1, X2, Y1, Y2, and θ1, θ2 directions. After the movement, the coarse adjustment imaging unit 104 captures the alignment mark 103 by a fine adjustment imaging unit (not shown) having a high optical magnification, and then uses image processing or the like on the image data to correctly align the image. A correction amount in the X-axis direction, a correction amount in the Y-axis direction, and a correction amount for the θ angle necessary for correction are calculated. Then, the XYθ table 105 is moved according to the amount, and if it is within the standard range, the alignment correction operation is completed.

  For the positioning detection of the XYθ table 105, a linear encoder, a rotary encoder, or the like is used. The linear encoder is positioned with a resolution of micron or submicron, and with a rotary encoder, for example, with a resolution of 1.6 microradians (4 million pulses / rotation). The substrate positioning accuracy is about several microns in the XY direction and about 10 μradian in the θ direction in order to estimate a design margin of 5 to 10 times the resolution.

  In order to improve the substrate positioning accuracy, the recognition accuracy of the imaging means is improved. The image is roughly positioned using the low magnification coarse adjustment imaging means 104 with a wide field of view, and switched to the high magnification fine adjustment imaging means (not shown) to improve the recognition accuracy, and the position correction is performed again. Is called.

  Further, in Patent Document 2, in order to improve the substrate positioning accuracy, a glass substrate is preliminarily centered based on a predetermined number of corrections in the past without using high- and low-magnification imaging means. The position of the high-magnification imaging means is corrected and installed. The alignment mark is prevented from being extremely deviated from the field of view of the image pickup means, and the alignment mark is recognized at substantially the center of the field of view of the image pickup means to improve recognition accuracy.

Japanese Patent Laid-Open No. 2003-29017 JP 2003-247808 JP

  When positioning the substrate in the laser irradiation apparatus of the conventional example (see FIG. 19), if the XYθ table shown in FIG. 20 is used, the XYθ table increases as the substrate increases.

  In particular, in the configuration of the XYθ table disclosed in Patent Document 1, since the XYθ table on which the substrate is mounted is positioned by moving in the XY direction, an increase in the size of the drive system that moves the table is unavoidable. Also for the shaft, the θ rotation drive system becomes large and high torque is required. If the system shown in FIG. 20 is adopted in the apparatus configuration shown in FIG. 19, at least a large-scale high torque θ-axis stage for controlling the rotation of the XYθ table is required. Larger and higher torque motors generate a large amount of heat from the drive system, and there is a concern that positioning accuracy may deteriorate due to thermal expansion due to thermal effects on the components. On the other hand, the θ-axis rotational drive system is required to have high rotational accuracy in addition to the trend toward larger size and higher torque.

  Currently available rotary encoders have a resolution of several microradians, and large substrates such as those with a side exceeding 2 m have a rotational positioning accuracy of about 10 microns at the end of the substrate (the aforementioned numerical value: 10 microradians * 1 m )become. Since the accuracy is about 10 times worse than the positioning accuracy of the XY stage, it is necessary to further increase the accuracy of positioning in the θ direction for large substrates.

  An object of the present invention is to provide a substrate positioning apparatus and a substrate positioning method capable of solving the above-described problems of the prior art, suppressing the increase in size as much as possible, and performing highly accurate substrate positioning.

In order to achieve the above object, the first present invention provides:
A substrate positioning device that positions and corrects a planar substrate,
A substrate mounting stage having at least a floating portion for levitating the substrate, and a hole formed in a central portion;
A table disposed in the hole of the substrate mounting stage, a vertical movement unit for moving the table up and down in a direction perpendicular to the plane of the substrate to be mounted, and a rotation axis perpendicular to the plane of the substrate to be mounted It is a substrate positioning apparatus provided with the center stage which has a rotation part which rotates the said table.

The second aspect of the present invention
A rotation direction moving part for rotating the substrate to be mounted;
The central stage has a suction part for sucking and holding the substrate, and a plane direction moving part for moving the table in a direction parallel to the plane of the substrate,
The said rotation direction moving part is a board | substrate positioning apparatus of 1st this invention which rotates the said board | substrate floated by the said floating part and adsorb | sucked to the said table by the said adsorption part.

The third aspect of the present invention provides
The rotational direction moving part is
It is a board | substrate positioning device of 2nd this invention which has a press member which presses the edge of the said board | substrate adsorbed | sucked to the said table.

The fourth invention relates to
Imaging the stage alignment mark formed on the substrate mounting stage for adjusting the position with the substrate and the substrate alignment mark formed on the substrate for adjusting the position with the substrate mounting stage An imaging unit to
A control unit that controls the rotation unit so as to rotate so that the position of the substrate relative to the substrate mounting stage is within an allowable range from the substrate alignment mark and the stage alignment mark imaged by the imaging unit; It is the board | substrate positioning device of the 1st this invention provided.

The fifth aspect of the present invention relates to
A substrate positioning method for positioning and correcting a planar substrate,
A mounting step of mounting the substrate on a substrate mounting stage;
A levitating step for levitating the substrate on the substrate mounting stage;
A placement step of raising a table disposed in a hole formed in a central portion of the substrate mounting stage and adsorbing the substrate in a contact state;
A rotation step of rotating the table holding the substrate by suction so that the rotation angle of the substrate and the substrate mounting stage is a desired rotation angle;
And a substrate holding step for holding the substrate by suction on the substrate mounting stage.

The sixth invention relates to
Before the placing step, a first moving step for moving the table so that a distance between a center position of the substrate mounting stage and a center position of the substrate in a plane direction parallel to the substrate is equal to or less than a desired distance. When,
It is a board | substrate positioning method of 5th this invention provided with the 2nd movement step which returns the said table to the position before moving by the said 1st movement step after the said mounting step.

The seventh invention relates to
In the substrate holding step, in the substrate positioning method according to the fifth aspect of the present invention, the substrate is sucked in order from the center side to the end of the substrate and the substrate is sucked and held by the substrate mounting stage.

The eighth invention relates to
The substrate mounting stage has a stage alignment mark for adjusting the position with the substrate,
The substrate has a substrate alignment mark for adjusting the position with the substrate mounting stage,
Further comprising a positional relationship detection step of imaging the stage alignment mark and the substrate alignment mark to obtain a relative positional relationship between the substrate and the substrate mounting stage;
The substrate positioning method according to a fifth aspect of the present invention, wherein the rotation step is performed based on the obtained relative positional relationship.

  According to the present invention, it is possible to provide a substrate positioning apparatus and a substrate positioning method capable of suppressing the increase in size as much as possible and performing highly accurate substrate positioning.

The perspective view which showed typically the laser irradiation apparatus in Embodiment 1 concerning this invention The perspective view which showed typically the board | substrate in Embodiment 1 concerning this invention. The perspective view which showed typically the XYZ (theta) stage in Embodiment 1 concerning this invention. The figure which showed the micro hole and groove | channel in Embodiment 1 concerning this invention The flowchart which shows control of the board | substrate positioning method in Embodiment 1 concerning this invention. Sectional drawing which showed typically the state which conveys the board | substrate of the board | substrate positioning method in Embodiment 1 concerning this invention. Sectional drawing which showed typically the state which loads the board | substrate of the board | substrate positioning method in Embodiment 1 concerning this invention. Sectional drawing which showed typically the state which images the board | substrate alignment mark and stage alignment mark of the board | substrate positioning method in Embodiment 1 concerning this invention (A) The top view which showed typically the state which images the stage alignment mark of the substrate positioning method in Embodiment 1 concerning this invention, (b) The substrate alignment of the substrate positioning method in Embodiment 1 concerning this invention. Sectional view schematically showing the state of imaging the mark (A) The top view which showed typically the position shift of the center position of a board | substrate, the center position of a board | substrate mounting stage, and a board | substrate rotation angle in the board | substrate positioning method in Embodiment 1 concerning this invention, (b) FIG. ) Cross-sectional schematic diagram (A) The top view which showed typically the state which moved the XYZ (theta) table according to the center position of the board | substrate in the board | substrate positioning method in Embodiment 1 concerning this invention, (b) The cross-sectional schematic diagram of Fig.11 (a) (A) The top view which showed typically the state which raised the XYZ (theta) table and adsorbed and hold | maintained the board | substrate in the board | substrate positioning method in Embodiment 1 concerning this invention, (b) The cross-sectional schematic diagram of Fig.12 (a) (A) The top view which showed typically the state which moved the XYZ (theta) table to the initial position in the state which adsorbed and hold | maintained the board | substrate in the board | substrate positioning method in Embodiment 1 concerning this invention, (b) FIG. 13 (a). Schematic cross-sectional view of The top view which shows typically the board | substrate rotation method of the board | substrate positioning method in Embodiment 1 concerning this invention Sectional drawing which shows typically the state which adsorb | sucks the board | substrate of the board | substrate positioning method in Embodiment 1 concerning this invention. Sectional drawing which showed typically the state which performs the positioning confirmation of the board | substrate positioning method in Embodiment 1 concerning this invention The figure which showed the laser irradiation pattern to the conventional panel. Figure showing conventional beam shape The perspective view which showed the conventional laser irradiation apparatus typically The perspective view which showed typically the board | substrate positioning apparatus used for the board | substrate positioning method described in patent document 1

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

  FIG. 1 is a perspective view schematically showing a laser irradiation apparatus according to the first embodiment of the present invention. In this laser irradiation apparatus, a laser is applied to a substrate having a rectangular plane shape whose position has been corrected. FIG. 2 is a perspective view schematically showing the substrate of the first embodiment.

  As shown in FIG. 1, the laser irradiation apparatus according to the first embodiment includes a substrate positioning apparatus 100 that positions a substrate 1 and a laser head 2 that irradiates a laser on the substrate 1 that has been positioned. The substrate positioning apparatus 100 according to the first embodiment has a substrate mounting stage 5 mounted on an X stage 6, and the laser head 2 is mounted on a Y stage 7 and emits a line-shaped laser.

  When irradiating a laser beam onto the substrate 1 with this laser irradiation device, the substrate positioning device 100 positions and mounts the substrate 1 on the substrate mounting stage 5, scans the substrate mounting stage 5 in the X1 and X2 directions, and the laser head. The laser beam emitted from the laser beam 2 irradiates the substrate 1 with a line laser beam scanned in the short axis direction. When scanning in the X1 direction ends, the laser head 2 moves in the Y1 or Y2 direction, and scanning in the X2 direction is performed. By performing this operation several times, the entire surface of the substrate 1 can be irradiated.

  In the substrate mounting stage 5, alignment marks 10 a, 10 b, 10 c, and 10 d are formed in the vicinity of the four corners for alignment with the substrate 1. As shown in FIG. 2, alignment marks 3 a, 3 b, 3 c, 3 d are also formed on the substrate 1 in the vicinity of the four corners. Hereinafter, 3a, 3b, 3c, and 3d are referred to as substrate alignment marks, and 10a, 10b, 10c, and 10d are referred to as stage alignment marks. Such a substrate 1 is loaded on the substrate mounting stage 5.

  The center positions formed by the four substrate alignment marks 3a, 3b, 3c, and 3d coincide with the center position of the substrate 1, and the center positions formed by the four stage alignment marks 10a, 10b, 10c, and 10d are the positions of the substrate mounting stage 5. Each alignment mark is arranged so as to coincide with the center position. A hole 5a having a circular cross section is formed at the center of the substrate mounting stage 5, and an XYZθ table 8 movable in the XYZθ direction is installed in the hole 5a.

  Next, the XYZθ stage 80 that moves the XYZθ table 8 in the X, Y, Z, and θ directions will be described.

  FIG. 3 is a perspective view schematically showing the XYZθ stage 80 of the first embodiment.

  The XYZθ stage 80 sucks and floats the substrate 1 by air fine holes or air grooves, the XYZθ table 8 having a circular upper surface, the θ stage 11 that rotates the XYZθ table 8 in the θ1 and θ2 directions, and the XYZθ table 8 as X1. , An X-axis stage 12 that moves minutely in the X2 direction, and a Y-axis stage 13 that moves the XYZθ table 8 minutely in the Y1 and Y2 directions, and a Z-axis stage 14 that moves the substrate up and down together with the XYZθ table 8. The XYZθ stage 80 can perform parallel movement, rotational movement, and vertical movement of the substrate 1. The X-axis stage 12, the Y-axis stage 13, and the Z-axis stage 14 are provided with driving means in the X, Y, and Z directions, but the θ stage 11 has no driving source and is provided only with a brake. . In addition, in order to drive the substrate 1 in the rotation direction, pressing members 9a and 9b (see FIG. 1) for pressing the edge of the substrate 1 are provided. When the predetermined rotational position is reached, the substrate rotation is stopped by this brake.

  FIG. 4 is an enlarged view of the surface of the substrate mounting stage 5.

  As shown in FIG. 4, the substrate mounting stage 5 is formed with minute air holes 16 for supplying and removing air and air grooves 15 that serve as air paths during adsorption and adsorption destruction. The minute air holes 16 and the air grooves 15 allow the substrate 1 to be sucked and held and air-floated. Note that minute air holes 16 and air grooves 15 are also formed on the surface of the XYZθ table 8 in the same manner as the substrate mounting stage 5.

  The substrate 1 adsorbed by the XYZθ table 8 can be rotated in the clockwise and counterclockwise directions by the opposing pressing members 9a and 9b that press the end portions thereof. The substrate alignment marks 3a, 3b, 3c, and 3d of the substrate 1 and the stage alignment marks 10a, 10b, 10c, and 10d of the substrate mounting stage 5 are obtained by imaging units 4a, 4b, 4c, and 4d having moving means that can move in the XY directions. The position is measured.

  Moreover, as shown in FIG. 1, the control part 110 which controls a laser irradiation apparatus is provided. The control unit 110 controls the substrate mounting stage 5 and the laser head 2 at the time of laser irradiation, and also positions the substrate mounting stage 5, the XYZθ stage 80, the pressing members 9a and 9b, and the imaging unit. Control of 4a, 4b, 4c, 4d, etc. is also performed. The control unit 110 performs both the control during laser irradiation and the control during substrate positioning. However, the control during laser irradiation and the control during substrate positioning are performed by separate control units. May be.

  The substrate positioning apparatus 100 according to the first embodiment includes a substrate mounting stage 5, an XYZθ stage 80, pressing members 9a and 9b, imaging units 4a, 4b, 4c, and 4d, a control unit 110, and the like.

  Moreover, an example of the floating part of this invention respond | corresponds to the micro air hole 16 and piping path | route 19a, 19b, 21a, 21b of this Embodiment. An example of the central stage of the present invention corresponds to the XYZθ stage 80 of the present embodiment, and an example of the table of the present invention corresponds to the XYZθ table 8 of the present embodiment. An example of the vertical movement unit of the present invention corresponds to the Z-axis stage 14 of the present embodiment, and an example of the rotation unit of the present invention corresponds to the θ stage 11 of the present embodiment. An example of the plane direction moving unit of the present invention corresponds to the X axis stage 12 and the Y axis stage 13 of the present embodiment, and an example of the rotational direction moving unit of the present invention is the pressing member of the present embodiment. It corresponds to 9a, 9b. Moreover, an example of the adsorption | suction part of this invention respond | corresponds to the micro air hole 16 and the piping path | route 21 of this Embodiment.

  Next, the substrate positioning method in the laser irradiation apparatus of the first embodiment will be described, and an example of the substrate positioning method of the present invention will also be described.

  FIG. 5 is a flowchart showing the control of the substrate positioning method of the first embodiment. 6 to 16 are diagrams for explaining the substrate positioning operation.

  FIG. 6 is a cross-sectional view schematically showing a state where the substrate 1 is being transferred onto the substrate mounting stage 5 by the robot 17.

  First, as shown in FIG. 6, in step S <b> 1, the substrate 1 is held on the robot arm 18 and transported directly above the substrate mounting stage. Thereafter, as shown in FIG. 7, when the push-up pin 22 rises in the Z1 direction from the lower surface of the substrate mounting stage 5, the robot arm 18 is retracted, the substrate 1 is transferred, and the push-up pin 22 is lowered in the Z2 direction. Step S1 shown in FIGS. 6 and 7 corresponds to an example of the mounting step of the present invention.

  At the time of the descent, air is supplied through the piping paths 19a, 19b, 20a, and 20b on the substrate mounting stage 5 and the piping path 21 on the XYZθ stage 80 in step S2, and the air flow rate and the weight of the substrate 1 are increased. The substrate 1 floats in balance. This step S2 corresponds to an example of the rising step of the present invention.

  The state of the floating substrate 1 is shown in FIG. For example, when the size of the substrate 1 is more than about 2 m, for example, the substrate 1 is deformed as a substrate 1a (indicated by a dotted line in the figure), and the amount of substrate deformation in the thickness direction reaches about 100 μm. The supply air flow rate from the piping paths 19a, 19b, 20a, 20b, and 21 is adjusted so that the substrate 1 floats more than this deformation amount, and the substrate 1 floats to 100 μm or more from the surface of the substrate mounting stage 5 and the XYZθ stage 80. It is done.

  Next, as shown in FIG. 8, FIG. 9A, and FIG. 9B, in step S3, four sets of imaging units 4a, 4b, 4c, and 4d are stage alignment marks 10a on the substrate mounting stage 5, Each of the positions 10b, 10c, and 10d is measured, and then the four sets of imaging units 4a, 4b, 4c, and 4d respectively measure the positions of the substrate alignment marks 3a, 3b, 3c, and 3d. FIG. 8 is a cross-sectional view schematically showing a state in which the substrate alignment marks 3a, 3b, 3c, and 3d and the stage alignment marks 10a, 10b, 10c, and 10d are imaged. FIG. 9A is a plan view schematically showing a state in which the stage alignment marks 10a, 10b, 10c, and 10d are imaged. FIG. 9B is a substrate alignment mark 3a, 3b, 3c, and 3d. It is the top view which showed typically the state which images.

  Here, the controller 110 (see FIG. 1) uses the two measurements to obtain information on the substrate mounting stage center position C1, the information on the substrate center position C2, and the substrate rotation angle θ3 as shown in FIGS. 10 (a) and 10 (b). Obtain information to calculate the difference between the ideal position of the substrate 1 on the substrate mounting stage 5 and the actual position of the substrate 1 on the substrate mounting stage 5 measured by the imaging units 4a, 4b, 4c, and 4d. To do. FIG. 10A is a schematic plan view showing a state in which the substrate 1 is floating, and FIG. 10B is a schematic cross-sectional view of FIG. As shown in FIGS. 10A and 10B, the center position C <b> 2 of the substrate 1 is shifted from the center position C <b> 1 of the substrate mounting stage 5. This step S3 corresponds to an example of the positional relationship detection step of the present invention.

  Next, as shown in FIGS. 11A and 11B, the actual position of the substrate 1 on the substrate mounting stage 5 measured by the imaging units 4a, 4b, 4c, and 4d in step S4, and the ideal The XYZθ table 8 is moved in the X1, X2 direction, Y1, Y2 direction so that the difference from the position becomes a desired value. FIG. 11A is a schematic plan view showing a state in which the position of the θ rotation axis 8 a of the XYZθ table 8 and the center position of the substrate 1 coincide with each other. FIG.11 (b) is a cross-sectional schematic diagram of Fig.11 (a).

  In this way, the position of the θ rotation axis 8a of the XYZθ table 8 and the center position of the substrate 1 are matched. In the present embodiment, the position of the θ rotation axis 8a and the center position C2 of the substrate 1 are matched, but may not be completely matched and may be within a desired range. This step S4 corresponds to an example of the first movement step of the present invention.

  Here, as described above, the substrate mounting stage 5 is formed with the hole 5a having a circular cross section at the center, and the XYZθ table 8 is disposed in the hole. The substrate mounting stage 5 and the θ rotation axis 8a of the XYZθ table 8 are designed to coincide with each other in advance. In this way, the position of the XYZθ table 8 such that the θ rotation axis 8a of the XYZθ table 8 coincides with the center position C1 of the substrate mounting stage 5 is set as the initial position.

  Next, as shown in FIGS. 12A and 12B, the substrate 1 that has floated in step S <b> 5 is sucked and held by the XYZθ table 8. 12A is a schematic plan view showing a state in which the substrate 1 is adsorbed by the XYZθ table 8, and FIG. 12B is a schematic cross-sectional view of FIG. The XYZθ table 8 is raised in the Z1 direction by the Z-axis stage 14 in order to suck and hold the substrate 1 that has floated on the air at the center. After rising, the substrate 1 is vacuum-sucked from the piping path 21 on the XYZθ table 8. This step S5 corresponds to an example of the placing step of the present invention.

  That is, the control unit 110 moves the XYZθ table 8 so that the center position of the XYZθ table 8 is aligned with the center position of the substrate 1 that has floated on the substrate mounting stage 5 and the XYZθ stage 80, and then moves up and moves the substrate 1. Hold by adsorption. In this way, the substrate 1 is sucked and held on the XYZθ table 8 in a state where the center position of the substrate 1 and the center position of the XYZθ table 8 coincide.

  On the other hand, in the substrate mounting stage 5, air is supplied through the piping paths 19 a, 19 b, 20 a, and 20 b and the portions other than the central portion of the substrate 1 remain floating. In the state where the substrate 1 is adsorbed only at the central portion, for example, when the substrate 1 is adsorbed in an area of about 30 cm in diameter at the central portion, the adsorbing force between the substrate 1 and the XYZ table 8 becomes about 5 kg. When the substrate 1 is attracted to the XYZθ table 8, it can be said that there is no relative positional deviation unless an external force is applied.

  Next, as shown in FIGS. 13A and 13B, the XYZθ table 8 returns to the central portion (initial position) of the substrate mounting stage 5 with the substrate 1 being sucked and held in step S6. FIG. 13A is a schematic plan view showing a state in which the XYZθ table 8 is moved to the initial position while the substrate 1 is sucked and held, and FIG. 13B is a schematic cross-sectional view of FIG. is there. This step S6 corresponds to an example of the second movement step of the present invention.

  When the flying height of the substrate 1 is 100 μm or less, the substrate 1 locally comes into contact with the substrate mounting stage 5, and since the warpage and the deformation amount are different for each substrate, the frictional force due to the contact changes. When the flying height of the substrate 1 is 100 μm or more (see FIG. 13B: dimension B), the substrate 1 is completely lifted from the substrate mounting stage 5 and the friction coefficient or friction force between the substrate 1 and the substrate mounting stage 5 is low. It becomes constant and the friction coefficient is about 0.001. For example, when the weight of the substrate 1 is 10 kg, the weight of the substrate 1 is only 0.1 kg on the substrate mounting stage 5. On the XYZθ table 8, the weight of the substrate 1 is further reduced.

  That is, since air is blown from the substrate mounting stage 5 and a force acts so as to float the substrate 1, the XYZθ table 8 takes almost no weight even if the substrate 1 is sucked and held.

  For this reason, most of the loading loads of the X-axis stage 12, the Y-axis stage 13, and the Z-axis stage 14 are due to the stage's own weight, and since the load fluctuation of the frictional force is small, the small stage (XYZθ stage 80) with a small thrust forces the substrate 1 On the substrate mounting stage 5 in the front direction (X2 direction in FIG. 2), the back direction (X1 direction in FIG. 2) and the Y1 and Y2 directions in the direction perpendicular to the paper surface, and the center position of the substrate 1 is moved to the substrate mounting stage. 5 can be adjusted to the center position with high accuracy.

  During such parallel movement, the substrate 1 is sucked and held by the XYZθ table 8, so that there is no relative displacement. On the other hand, when the substrate 1 is rotated, the rotational inertia of the substrate 1 does not change even when air levitates. Therefore, a large torque is required to rotate the substrate 1 even in the levitation state. Therefore, in order to perform θ rotation of a large substrate, a power source is not installed near the rotation center and the substrate is rotated, but the end of the substrate 1 is pressed with the center of the substrate 1 as the rotation axis, and the amount of movement of the rotation By controlling this, the substrate can be rotated with a small thrust with high accuracy.

  Even during the rotation of the substrate, the θ stage 11 does not require a drive source and can be miniaturized. On the other hand, controlling the flying height not only eliminates fluctuations in the frictional force but also prevents contamination such as fine dust generated by contact.

  Then, as shown in FIG. 14, in step S7, the substrate 1 is rotated based on the rotation angle calculated in step S3. FIG. 14 is a schematic plan view showing a state where the substrate rotation angle is corrected by the pressing members 9a and 9b with the center of the XYZθ table 8 as the rotation axis.

  As shown in FIG. 14, the center of the contact portion between the pressing portion 90a of the pressing member 9a and the substrate 1 (see S in the drawing) and the center of the contact portion between the pressing portion 90b of the pressing member 9b and the substrate 1 (T in the drawing). The straight line connecting the reference XYZ θ table 8 is eccentric with respect to the θ rotation axis 8a which is the rotation center of the XYZ θ table 8. That is, the straight line connecting the contact portion between the pressing portion 90a of the pressing member 9a and the substrate 1, the contact portion between the pressing portion 90b of the pressing member 9b and the substrate 1, and the θ rotation shaft 8a of the XYZθ table 8 are The XYZθ table 8 and the pressing members 9a and 9b are arranged so as to leave a predetermined distance.

  In the pressing members 9a and 9b, when the substrate 1 is rotated in the clockwise direction, the pressing member 9a presses the substrate 1, and when the substrate 1 is rotated in the counterclockwise direction, the pressing member 9b presses the substrate 1. One of the pressing members 9a and 9b is provided with a function of relaxing the restriction by the spring mechanism.

  Here, the control unit 110 measures the positions of the substrate alignment marks 3a, 3b, 3c, and 3d by the imaging units 4a, 4b, 4c, and 4d, and the substrate rotation angle is zero or standard (desired to be desired). The substrate 10 is pressed by the pressing members 9a and 9b until it falls within the value). After the rotation angle of the substrate 1 satisfies zero or a standard (desired value), the control unit 110 stops the rotation of the θ stage 11 using a brake, and stops the rotation of the substrate 1 completely. By this operation, a highly accurate substrate rotation movement process can be performed.

  That is, the pressing members 9a and 9b are moved by the control unit 110 based on the imaging information of the imaging units 4a, 4b, 4c, and 4d so that the position of the substrate 1 on the substrate mounting stage 5 becomes a predetermined position. In operation, the substrate 1 is rotated about the θ rotation axis 8a of the XYZθ table 8 as the rotation center. Thus, the substrate 1 is rotated, and position correction is performed so that the angle of the substrate 1 with respect to the substrate mounting stage 5 around the θ rotation axis perpendicular to the plane of the substrate 1 becomes a predetermined angle.

  Thereafter, in order to attract the substrate 1 to the substrate mounting stage 5, the pressing members 9a and 9b retreat in the directions Y3 and Y4 where the substrate 1 is not pressed. FIG. 15 is a schematic cross-sectional view showing a state where the pressing members 9a and 9b are retracted in the Y3 and Y4 directions. The substrate 1 is lowered in the Z2 direction by the Z-axis stage 14 while its central portion is adsorbed by the XYZθ table 8.

  Next, as shown in FIG. 16, the piping paths 19 a, 19 b, 20 a, and 20 b that have been supplied with air in step S <b> 8 perform air exhaust, and the substrate 1 is the substrate from the central portion side to the substrate peripheral portion in the end. Adsorbed to the mounting stage 5. The substrate 1 is completely attracted to the substrate mounting stage 5 and the XYZθ stage 80 by the piping paths 19 a, 19 b, 20 a, 20 b of the substrate mounting stage 5 and the piping path 21 of the XYZθ stage 80. This step S8 corresponds to an example of the substrate holding step of the present invention.

  In FIG. 16, there are only five piping paths including the substrate mounting table 5 and the XYZθ stage 80. However, it is necessary to increase the number of piping paths in order to prevent air accumulation depending on the size of the board. Even when it is increased, the order of exhausting is performed from the piping system close to the center of the substrate, and finally the periphery of the substrate is adsorbed. Note that the imaging units 4a, 4b, and 4c4d monitor and measure whether the position of the substrate 1 is not misaligned even while the substrate 1 is attracted to the substrate mounting stage 5. As shown in FIG. 16, when the substrate 1 is adsorbed on the entire surface, the position of the substrate 1 is confirmed. This is a substrate confirmation process for confirming whether the substrate position has changed due to the floating and suction of the substrate 1. When the imaging units 4a, 4b, 4c, and 4d use a lens system that has a sufficient depth of focus for the floating adsorption of the substrate 1, the focus adjustment function is unnecessary, and the recognition measurement error is small and the substrate positioning accuracy is improved.

  As described above, the substrate can be moved and rotated by the minutely movable XYZθ table located in the center without moving and rotating the XYθ stage which is enlarged when positioning the substrate, and the enlargement can be avoided.

  Further, in order to improve the rotation accuracy, the substrate 1 is rotated by pressing the end portion of the substrate 1 and the amount of displacement of the substrate by the pressing is controlled, so that the rotational positioning accuracy of several microns can be achieved at the end portion of the substrate 1.

  In addition, since parallel movement and rotational movement of each process can be controlled independently, the positioning operation algorithm and mechanism operation can be simplified, and high-speed and high-accuracy substrate positioning can be performed.

  Further, since the substrate 1 is levitated from the substrate mounting stage 5 by air, the frictional force between the substrate 1 and the substrate mounting stage 5 is small, so that the substrate 1 can be translated with a low thrust, and the XYZθ table 8 at the center has a low thrust. Orthogonal movement and rotation can be performed.

  Further, when the substrate that has floated is rotated by θ, the rotation is performed in response to the pressing from the end portion, so that it can be performed with a small thrust. As described above, the substrate can be positioned with high accuracy while preventing the deterioration of accuracy due to the increase in the size and torque of the stage and the generation of heat.

  Further, in step S8, the substrate is sucked in order so that the end of the substrate is finally sucked in order from the center of the substrate, thereby preventing air from being accumulated between the substrate 1 and the substrate mounting stage 5. The entire surface can be adsorbed.

  Therefore, it is possible to prevent recognition accuracy deterioration due to substrate displacement due to air accumulation, substrate deformation due to air accumulation, and accompanying height change of the alignment mark position.

  In addition, by setting the substrate flying height to 100 μm or more, even if the substrate is bent or deformed, the substrate can be completely lifted from the substrate mounting stage, and the frictional force with the substrate mounting stage is constant, and the load fluctuation Orthogonal movement and rotational movement with low thrust can be performed with high accuracy.

  In the above embodiment, four sets of substrate alignment marks and stage alignment marks are used, but at least three sets or more may be used to determine the center position. The mark installation position is also set at each corner, but it may be the center of each side of the substrate or stage. Further, although minute air holes and air grooves are used for substrate adsorption and levitation, adsorption and levitation may be performed using a porous sintered material.

  In the above embodiment, the two pressing members 9a and 9b are provided. However, only one pressing member movable in the X1 and X2 directions may be provided. For example, as shown in FIG. 14, when the substrate 1 is inclined from the upper left to the lower right, the substrate 1 can be rotated to the right by pressing the substrate 1 at the position of the pressing member 9a shown in FIG. When 1 is inclined from the upper right to the lower left, the substrate 1 can be rotated counterclockwise by pressing the substrate 1 by moving the pressing member 9a in the direction X1.

  In the above embodiment, the substrate 1 is rotated by the pressing members 9a and 9b. However, the XYZθ stage 80 includes a drive system for rotating the XYZθ table 8, and the substrate 1 is rotated by rotating the XYZθ table 8. You may comprise so that it may rotate.

  The substrate positioning apparatus and the substrate positioning method of the present invention have the effect of suppressing the increase in size as much as possible and performing highly accurate substrate positioning, and apply laser light to an amorphous silicon film formed on a large glass substrate. It is useful as a laser irradiation method and a laser irradiation apparatus for crystallizing crystal grains by irradiation, and can be applied to the manufacture of a display device represented by a liquid crystal display device or an organic EL display device.

DESCRIPTION OF SYMBOLS 1 Substrate 1a Deformed substrate 2 Laser head 3a, 3b, 3c, 3d Substrate alignment mark 4a, 4b, 4c, 4d Imaging unit 5 Substrate mounting stage 6 X stage 7 Y stage 8 XYZθ table 9a, 9b Pressing unit 10a, 10b, 10c, 10d Stage alignment mark 11 θ stage 12 X-axis stage 13 Y-axis stage 14 Z-axis stage 15 Air groove 16 Micro air hole 17 Robot 18 Robot arm 19a, 19b Piping path 20a, 20b Piping path 21 Piping path 22 Push-up pin 80 XYZθ stage 100 Substrate positioning device

Claims (8)

A substrate positioning device that positions and corrects a planar substrate,
A substrate mounting stage having at least a floating portion for levitating the substrate, and a hole formed in a central portion;
A table disposed in the hole of the substrate mounting stage, a vertical movement unit for moving the table up and down in a direction perpendicular to the plane of the substrate to be mounted, and a rotation axis perpendicular to the plane of the substrate to be mounted A substrate positioning apparatus comprising: a central stage having a rotating part that rotates the table. A rotation direction moving part for rotating the substrate to be mounted;
The central stage has a suction part for sucking and holding the substrate, and a plane direction moving part for moving the table in a direction parallel to the plane of the substrate,
The substrate positioning apparatus according to claim 1, wherein the rotation direction moving unit rotates the substrate that is levitated by the floating part and is adsorbed to the table by the adsorption unit. The rotational direction moving part is
The substrate positioning device according to claim 2, further comprising a pressing member that presses an edge of the substrate that is attracted to the table. Imaging the stage alignment mark formed on the substrate mounting stage for adjusting the position with the substrate and the substrate alignment mark formed on the substrate for adjusting the position with the substrate mounting stage An imaging unit to
A control unit that controls the rotation unit so as to rotate so that the position of the substrate relative to the substrate mounting stage is within an allowable range from the substrate alignment mark and the stage alignment mark imaged by the imaging unit; The board | substrate positioning apparatus of Claim 1 provided. A substrate positioning method for positioning and correcting a planar substrate,
A mounting step of mounting the substrate on a substrate mounting stage;
A levitating step for levitating the substrate on the substrate mounting stage;
A placement step of raising a table disposed in a hole formed in a central portion of the substrate mounting stage and adsorbing the substrate in a contact state;
A rotation step of rotating the table holding the substrate by suction so that the rotation angle of the substrate and the substrate mounting stage is a desired rotation angle;
A substrate positioning method comprising: a substrate holding step for holding the substrate by suction on the substrate mounting stage. Before the placing step, a first moving step for moving the table so that a distance between a center position of the substrate mounting stage and a center position of the substrate in a plane direction parallel to the substrate is equal to or less than a desired distance. When,
6. The substrate positioning method according to claim 5, further comprising a second moving step for returning the table to a position before moving in the first moving step after the placing step.   The substrate positioning method according to claim 5, wherein in the substrate holding step, the substrate is sucked in order from the center side to the end of the substrate, and the substrate is sucked and held by the substrate mounting stage. The substrate mounting stage has a stage alignment mark for adjusting the position with the substrate,
The substrate has a substrate alignment mark for adjusting the position with the substrate mounting stage,
Further comprising a positional relationship detection step of imaging the stage alignment mark and the substrate alignment mark to obtain a relative positional relationship between the substrate and the substrate mounting stage;
The substrate positioning method according to claim 5, wherein the rotation step is performed based on the obtained relative positional relationship.