Transport device, transport method, and semiconductor device manufacturing method

Abstract

A conveyance device according to the present embodiment conveys a substrate (100) in order to irradiate, onto the substrate (100), a laser beam forming a linear irradiation region (15a). The conveyance device comprises: a floating unit (10) for floating the substrate on an upper surface thereof; a holding mechanism (12) for holding the substrate (100); and a movement mechanism (13) for moving the holding mechanism (12) in a direction inclined from a direction orthogonal to the longitudinal direction of the linear laser beam in a top view so as to change the irradiation position of the laser beam with respect to the substrate (100).

Description

[Technical Field]

[0001] The present invention relates to a transfer device, a transfer method, and a method for manufacturing a semiconductor device. [Background technology]

[0002] Patent Document 1 discloses a laser annealing apparatus for forming a polycrystalline silicon thin film. In Patent Document 1, a projection lens focuses laser light onto a substrate so that the laser light forms a linear irradiation area. This crystallizes the amorphous silicon film to form a polysilicon film.

[0003] In Patent Document 1, a levitation unit levitates a substrate, and a transport unit transports the substrate. Furthermore, the levitation unit has a common loading and unloading position for the substrate. The transport unit transports the substrate along each side of the levitation unit. Then, the substrate circulates twice above the levitation unit, so that the laser light is irradiated onto almost the entire surface of the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-64048 Summary of the Invention

[0005] It is desirable for such a transport device of a laser irradiation apparatus to transport substrates appropriately so that the laser irradiation process can be carried out quickly and stably.

[0006] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings.

[0007] According to one embodiment, the conveying device is a conveying device that conveys a substrate in order to irradiate the substrate with a line-shaped laser beam, and includes a substrate levitation unit that levitates the substrate on its upper surface, a holding mechanism that holds the substrate, and a moving mechanism that moves the holding mechanism in a direction inclined from a direction perpendicular to the line-shaped laser beam when viewed from above, so as to change the irradiation position of the laser beam on the substrate.

[0008] According to one embodiment, a transport device is a transport device that transports a substrate in order to irradiate the substrate with a line-shaped laser light, and is equipped with: a first substrate levitation unit that is arranged below the substrate and levitates the substrate, the first substrate levitation unit being arranged from the center of the substrate to one end side of the substrate in a top view; a second substrate levitation unit that is arranged below the substrate and levitates the substrate, the second substrate levitation unit being arranged from the center of the substrate to the other end side of the substrate in a top view; a holding mechanism that is arranged below the center of the substrate and adsorbs and holds the substrate; and a moving mechanism that moves the holding mechanism along the gap between the first substrate levitation unit and the second substrate levitation unit in order to move the substrate to the irradiation position of the laser light.

[0009] According to one embodiment, a transport method is a method for transporting a substrate in order to irradiate the substrate with a line-shaped laser beam, and includes the steps of: (a) a step of levitating the substrate with an upper surface of a levitation unit arranged below the substrate; (b) a step of holding the substrate with a holding mechanism; and (c) a step of moving the holding mechanism in a direction tilted from a direction perpendicular to the longitudinal direction of the line-shaped laser beam when viewed from above, so as to change the irradiation position of the laser beam on the substrate.

[0010] According to one embodiment, a transport method is a transport method for transporting a substrate in order to irradiate the substrate with a line-shaped laser light, and includes the steps of: (A) using a first substrate levitation unit arranged below the substrate to levitate one end side of the substrate from the center of the substrate in a top view, and using a second substrate levitation unit arranged below the substrate to levitate the other end side of the substrate from the center of the substrate in a top view; (B) using a holding mechanism arranged below the center of the substrate to adsorb and hold the substrate; and (C) moving the holding mechanism along the gap between the first substrate levitation unit and the second substrate levitation unit to move the substrate relative to the irradiation position of the laser light.

[0011] According to one embodiment, a method for manufacturing a semiconductor device comprises: (s1) forming an amorphous film on a substrate; and (s2) irradiating the substrate with a line-shaped laser beam to anneal the amorphous film so as to crystallize the amorphous film and form a crystallized film, wherein the (s2) annealing step comprises: (sa) a substrate levitation unit levitating the substrate on its upper surface; (sb) holding the substrate with a holding mechanism; and (sc) moving the holding mechanism in a direction tilted from a direction perpendicular to the longitudinal direction of the line-shaped laser beam in a top view so as to change the irradiation position of the laser beam on the substrate.

[0012] According to one embodiment, a method for manufacturing a semiconductor device includes: (S1) forming an amorphous film on a substrate; and (S2) irradiating the substrate with a line-shaped laser beam to anneal the amorphous film so as to crystallize the amorphous film and form a crystallized film, wherein the (S2) annealing step includes: (SA) using a first substrate levitation unit arranged below the substrate to levitate one end of the substrate from a center of the substrate in a top view, and using a second substrate levitation unit arranged below the substrate to levitate the other end of the substrate from the center of the substrate in a top view; (SB) using a holding mechanism arranged below the center of the substrate to suction and hold the substrate; and (SC) moving the holding mechanism along a gap between the first substrate levitation unit and the second substrate levitation unit to move the substrate relative to the irradiation position of the laser beam.

[0013] According to the embodiment, substrate transportation suitable for the laser irradiation process can be realized. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a top view schematically showing a laser irradiation device according to a first embodiment. [Figure 2] 1 is a side cross-sectional view schematically showing a laser irradiation device according to a first embodiment. [Figure 3] FIG. 2 is a diagram for explaining the intensity distribution of pulsed laser light. [Figure 4] 10 is a top view showing the pulse laser light irradiation pitch and the TFT manufacturing pitch. FIG. [Figure 5] 10 is a top view showing the pulse laser light irradiation pitch and the TFT manufacturing pitch. FIG. [Figure 6] FIG. 10 is a top view showing the configuration of a transport device according to a second embodiment. [Figure 7] FIG. 10 is a top view for explaining a transport process in the transport device. [Figure 8] FIG. 10 is a top view for explaining the transport process in the transport device. [Figure 9] FIG. 10 is a top view for explaining the transport process in the transport device. [Figure 10] FIG. 10 is a top view for explaining the transport process in the transport device. [Figure 11] FIG. 10 is a top view for explaining the transport process in the transport device. [Figure 12] FIG. 10 is a top view for explaining the transport process in the transport device. [Figure 13] FIG. 10 is a top view for explaining the transport process in the transport device. [Figure 14] FIG. 10 is a top view for explaining the transport process in the transport device. [Figure 15] FIG. 2 is a perspective view schematically showing a part of a holding mechanism. [Figure 16] FIG. 2 is a schematic diagram showing the configuration of a holding mechanism. [Figure 17] FIG. 2 is a schematic diagram showing an exhaust system of the holding mechanism. [Figure 18] FIG. 10 is a schematic diagram for explaining valve control of the holding mechanism. [Figure 19] FIG. 2 is a side view schematically illustrating the configuration of the transport device. [Figure 20] FIG. 10 is a top view schematically showing a laser irradiation device according to a third embodiment. [Figure 21] FIG. 1 is a schematic diagram for explaining adsorption destruction due to the moment of inertia. [Figure 22] FIG. 1 is a schematic diagram illustrating attraction / separation charging. [Figure 23] FIG. 2 is a top view for explaining the irradiation process according to the first embodiment. [Figure 24] FIG. 10 is a top view for explaining the irradiation process according to the second embodiment. [Figure 25] FIG. 10 is a top view for explaining the irradiation process according to Example 3. [Figure 26] FIG. 1 is a cross-sectional view showing a simplified configuration of an organic EL display. [Figure 27] 1A to 1C are cross-sectional views showing steps in a manufacturing method of a semiconductor device according to an embodiment of the present invention. [Figure 28]1A to 1C are cross-sectional views showing steps in a manufacturing method of a semiconductor device according to an embodiment of the present invention. [Figure 29] FIG. 10 is a top view schematically showing the configuration of Modification 1. [Figure 30] FIG. 10 is a top view schematically showing the configuration of Modification 2. [Figure 31] FIG. 10 is a top view for explaining the configuration of Irradiation Example 1. [Figure 32] FIG. 10 is a top view for explaining the configuration of Irradiation Example 2. [Figure 33] FIG. 10 is a top view for explaining the configuration of Irradiation Example 2. [Figure 34] FIG. 10 is a top view for explaining the configuration of Irradiation Example 3. [Figure 35] FIG. 10 is a top view for explaining the configuration of Irradiation Example 4. [Figure 36] FIG. 10 is a top view for explaining the configuration of Irradiation Example 4. [Figure 37] FIG. 10 is a top view for explaining the configuration of Irradiation Example 5. [Figure 38] FIG. 10 is a top view for explaining the configuration of Irradiation Example 5. [Figure 39] FIG. 10 is a top view schematically showing a configuration for simultaneously transporting two substrates. [Figure 40] FIG. 10 is a top view schematically showing a configuration for simultaneously transporting two substrates. [Figure 41] FIG. 10 is a top view schematically showing a configuration for simultaneously transporting two substrates. [Figure 42] FIG. 10 is a top view schematically showing a configuration for simultaneously transporting two substrates. DETAILED DESCRIPTION OF THE INVENTION

[0015] The transport device according to this embodiment is used in a laser irradiation device such as a laser annealing device. The laser annealing device is, for example, an excimer laser annealing (ELA) device that forms a low temperature polysilicon (LTPS) film. The transport device, laser irradiation device, method, and manufacturing method according to this embodiment will be described below with reference to the drawings.

[0016] Embodiment 1 The configurations of a conveying device and a laser irradiation device according to this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a top view schematically showing the configuration of the laser irradiation device 1. Figure 2 is a side cross-sectional view schematically showing the configuration of the laser irradiation device 1.

[0017] In the following figures, an xyz three-dimensional Cartesian coordinate system is shown where appropriate for ease of explanation. The z direction is the vertical direction, and the y direction is the direction along the linear irradiation area 15a. The x direction is a direction perpendicular to the z direction and the y direction. In other words, the y direction is the longitudinal direction of the linear irradiation area 15a, and the x direction is the lateral direction perpendicular to the longitudinal direction.

[0018] 1 and 2, the laser irradiation device 1 includes a levitation unit 10, a transport unit 11, and a laser irradiation section 14. The levitation unit 10 and the transport unit 11 constitute a transport device.

[0019] As shown in FIG. 2, the levitation unit 10 is configured to eject gas from the surface of the levitation unit 10. The levitation unit 10 levitates the workpiece 16 on its upper surface. The gas ejected from the surface of the levitation unit 10 is sprayed onto the underside of the workpiece 16, causing the workpiece 16 to levitate. For example, the workpiece 16 is a glass substrate. When the workpiece 16 is transported, the levitation unit 10 adjusts the amount of levitation so that the workpiece 16 does not come into contact with other mechanisms (not shown) arranged above the workpiece 16.

[0020] The transport unit 11 transports the floating workpiece 16 in the transport direction. As shown in FIG. 1, the transport unit 11 includes a holding mechanism 12 and a moving mechanism 13. The holding mechanism 12 holds the workpiece 16. For example, the holding mechanism 12 can be configured using a vacuum suction mechanism. The vacuum suction mechanism is made of a metal material such as an aluminum alloy. Alternatively, the holding mechanism 12 may be made of a resin material such as PEEK (polyether ether ketone). The upper surface of the holding mechanism 12 has suction grooves, suction holes, etc. formed thereon. The holding mechanism 12 may also be made of a porous material.

[0021] The holding mechanism 12 (vacuum suction mechanism) is connected to an exhaust port (not shown), which is connected to an ejector, a vacuum pump, etc. Therefore, a negative pressure for sucking gas acts on the holding mechanism 12, and the object 16 to be processed can be held by using the holding mechanism 12.

[0022] The holding mechanism 12 also includes a lifting mechanism (not shown) for performing the suction operation. The lifting mechanism includes, for example, an actuator such as an air cylinder or a motor. For example, the holding mechanism 12 lifts up to the suction position and picks up the workpiece 16. The holding mechanism 12 also lowers to the standby position when the suction is released.

[0023] The holding mechanism 12 holds the object 16 by sucking the surface (lower surface) of the object 16 opposite to the surface (upper surface) irradiated with the laser light 15, that is, the surface of the object 16 facing the levitation unit 10. The holding mechanism 12 also holds the end of the object 16 in the +y direction.

[0024] The moving mechanism 13 provided in the transport unit 11 is connected to the holding mechanism 12. The moving mechanism 13 is configured to be able to move the holding mechanism 12 in the transport direction. The transport unit 11 (holding mechanism 12 and moving mechanism 13) is provided on the end side of the levitation unit 10 in the +y direction, and the object 16 is transported by the moving mechanism 13 moving in the transport direction while the holding mechanism 12 holds the object 16.

[0025] As shown in FIG. 1, for example, the moving mechanism 13 is configured to slide the end of the levitation unit 10 in the +y direction along the transport direction. When the moving mechanism 13 slides the end of the levitation unit 10 along the transport direction, the workpiece 16 is transported along the transport direction. The transport direction is inclined from the x direction. For example, if the angle between the x direction and the transport direction is θ, θ is greater than 0°. It is preferable that θ be 5° or less.

[0026] Therefore, when viewed from above, levitation unit 10 has a trapezoidal shape with four sides. Specifically, levitation unit 10 has two sides parallel to the y direction of levitation unit 10, one side parallel to the x direction, and one side inclined from the x direction (also referred to as inclined side 10e).

[0027] The transport speed of the object 16 can be controlled by controlling the movement speed of the movement mechanism 13. The movement mechanism 13 includes, for example, an actuator such as a motor, a linear guide mechanism, an air bearing, and the like (not shown).

[0028] The workpiece 16 is irradiated with laser light 15. Here, the irradiation area 15a of the workpiece 16 to which the laser light 15 is applied is linear, with the longitudinal direction being the y direction. That is, the longitudinal direction of the irradiation area 15a is the y direction, and the lateral direction is the x direction.

[0029] For example, the laser irradiation unit 14 has an excimer laser light source that generates laser light. Furthermore, the laser irradiation unit 14 has an optical system that guides the laser light to the workpiece 16. For example, the laser irradiation unit 14 has a cylindrical lens for forming a linear irradiation region 15a. The workpiece 16 is irradiated with linear laser light 15 (line beam) whose focal point extends in the y direction.

[0030] The workpiece 16 is, for example, a glass substrate on which an amorphous film (amorphous silicon film 16b) is formed. The amorphous film can be crystallized by irradiating the amorphous film with laser light 15 and performing an annealing process. For example, the amorphous silicon film 16b can be converted into a polycrystalline silicon film (polysilicon film 16a).

[0031] In the laser irradiation device 1, the workpiece 16 is levitated using the levitation unit 10, while the transport unit 11 holds the lower surface of the workpiece 16 and transports the workpiece 16 in the transport direction. At this time, the transport unit 11 provided in the laser irradiation device 1 transports the workpiece 16 while holding the workpiece 16 at a position that does not overlap with the irradiation region 15a in a plan view (i.e., when viewed from the z direction). In other words, as shown in FIG. 1, when the workpiece 16 is transported in the transport direction, the position at which the transport unit 11 holds the workpiece 16 (corresponding to the position of the holding mechanism 12) does not overlap with the irradiation region 15a.

[0032] For example, the planar shape of the object 16 to be processed is a quadrangle (rectangle) having four sides, and the transport unit 11 (holding mechanism 12) holds only one of the four sides of the object 16 to be processed. The transport unit 11 (holding mechanism 12) holds the object 16 to be processed at a position where it is not irradiated with laser light while being transported.

[0033] With this configuration, the position where the transport unit 11 holds the workpiece 16 (corresponding to the position of the holding mechanism 12) can be separated from the irradiation area 15a. The irradiation area 15a is approximately half of the workpiece 16 on the -y side, and the transport unit 11 holds the end on the +y side. The distance between the irradiation area 15a and a location near the holding mechanism 12 where deflection becomes large can be increased. This reduces the effect of deflection of the workpiece 16 caused by the holding mechanism 12 during laser irradiation.

[0034] In the y direction, the length of the irradiation region 15a is approximately half the length of the workpiece 16. Therefore, when the workpiece 16 passes through the irradiation region 15a once, the amorphous silicon film is crystallized in approximately half of the workpiece 16. Then, after the workpiece 16 is rotated 180 degrees around the z axis by a rotation mechanism (not shown), the transport unit 11 transports the workpiece 16 in the −x direction. Alternatively, after transporting the rotated workpiece 16 in the −x direction, the transport unit 11 may transport it again in the +x direction. Then, the workpiece 16 is irradiated with laser light during transport in the −x direction or during transport in the +x direction again after the 180-degree rotation. As a result, the workpiece 16 passes through the irradiation region 15a, and the amorphous silicon film is crystallized in the remaining half of the workpiece 16. By moving the object 16 back and forth in this manner, the amorphous silicon film is converted into a polycrystalline silicon film over almost the entire object 16 .

[0035] Furthermore, the transport direction is tilted from the x-direction, which is perpendicular to the linear irradiation area 15a. In other words, the rectangular object 16 is transported in a transport direction tilted from the edge of the object 16. By tilting the transport direction from the x-direction in a top view, substrate transport suitable for the laser irradiation process can be achieved. This allows the silicon film crystallization process to be performed appropriately, improving display quality. This configuration can, for example, prevent the occurrence of moire.

[0036] For example, suppose the workpiece 16 is a glass substrate for an organic EL display device. If the display area of ​​the organic EL display device is rectangular, the edges of the display area will be arranged parallel to the edges of the workpiece 16. In other words, the organic EL display device has a rectangular display area with its short sides in the x and y directions. If the transport direction is parallel to the x direction, the workpiece 16 is irradiated with laser light with the pixel arrangement direction and the irradiation area 15a parallel.

[0037] As shown in this embodiment, the laser irradiation process can be performed appropriately by tilting the transport direction from the x-direction. To change the laser irradiation position on the workpiece 16, the moving mechanism 13 moves the holding mechanism 12 in a transport direction tilted from the x-direction perpendicular to the longitudinal direction of the linear irradiation region 15a in a top view. This allows the silicon film crystallization process to be performed appropriately. For example, it is possible to prevent moire from occurring and improve display quality.

[0038] This point will be explained in detail. Fig. 3 is a diagram for explaining the energy intensity distribution when irradiated with pulsed laser light. Here, the laser light 15 is pulsed laser light with a constant repetition frequency. The object 16 to be processed is irradiated with the pulsed laser light while being transported.

[0039] The laser beam 15 has an intensity distribution as shown in Fig. 3. For example, in Fig. 3, the intensity distribution of the laser beam 15 is a Gaussian distribution. The workpiece 16 is transported so that successive pulsed laser beams partially overlap. In other words, the transport distance corresponding to the repetition frequency of the pulsed laser beam is smaller than the spot width of the laser beam in the short direction. On the workpiece 16, the spots of the laser beam 15 partially overlap between one pulse and the next pulse.

[0040] Here, the workpiece 16 is a TFT array substrate. The relationship between the TFT manufacturing pitch and the laser irradiation pitch will be explained using FIGS. 4 and 5. FIGS. 4 and 5 are top views that schematically show the laser irradiation pitch on the workpiece 16. Furthermore, FIGS. 4 and 5 show enlarged views of the workpiece 16. FIG. 4 shows a comparative example in which the direction perpendicular to the line-shaped laser light is parallel to the transport direction. FIG. 5 shows an example in which the direction perpendicular to the line-shaped laser light is tilted from the transport direction.

[0041] In the comparative example of Figure 4, the edge of the workpiece 16 and the linear laser beam are parallel. The edge of the workpiece 16 is parallel to the x-direction or y-direction. The laser beam irradiation line 15f is a straight line indicating the center of the laser beam irradiation area 15a and is parallel to the longitudinal direction of the irradiation area. In Figure 4, the irradiation line 15f is parallel to the y-direction and perpendicular to the transport direction of the workpiece 16. Since the transport speed of the workpiece 16 is constant, the irradiation lines 15f are arranged at equal intervals. The interval between the irradiation lines 15f is referred to as the irradiation pitch. The irradiation pitch is determined by the repetition frequency of the pulsed laser beam and the transport speed.

[0042] The gate electrode 402 and the source electrode 407 are formed parallel to the edge of the object 16 to be processed. In FIG. 4, the gate electrode 402 is parallel to the y direction and parallel to the source electrode 407. The TFTs 313a are arranged along the x and y directions. The manufacturing pitch of the TFTs corresponds to the spacing between the gate electrodes 402.

[0043] In the x direction, the laser irradiation pitch and the TFT manufacturing pitch are different. When the two different pitches overlap, the beat of the pattern causes a striped pattern, or moiré, to become visible. Strictly speaking, a slight deviation in the starting position of the laser irradiation will cause the position of the irradiation line to shift between the first laser irradiation (upper half of Figure 4) and the second laser irradiation (lower half of Figure 4).

[0044] In the embodiment of FIG. 5, the irradiation line 15f is inclined with respect to the transport direction of the workpiece 16. Since the workpiece 16 is transported in a direction perpendicular to the longitudinal direction of the laser light, the periodicity of the shape that appeared in the same direction is eliminated. This makes the moire pattern less visible. In this way, by transporting the workpiece 16 in a direction inclined from the direction perpendicular to the longitudinal direction of the linear laser light, as in this embodiment, the occurrence of moire patterns can be prevented.

[0045] Depending on the angle of the irradiation line 15f, the moiré pattern may not be eliminated or a different moiré pattern may occur. In this case, the angle of the irradiation line 15f can be adjusted according to the TFT manufacturing pitch, etc. Strictly speaking, a slight deviation in the starting position of the laser irradiation will cause the position of the irradiation line to deviate between the first laser irradiation (upper half of Figure 4) and the second laser irradiation (lower half of Figure 4).

[0046] In the transport method according to this embodiment, the object 16 is transported so that the object 16 can be irradiated with a linear laser beam 15. The levitation unit 10 levitates the object 16 on its upper surface. The object 16 is held by a holding mechanism 12. In order to change the irradiation position of the laser beam 15 on the object 16, the holding mechanism 12 is moved in a direction tilted from a direction perpendicular to the longitudinal direction of the linear laser beam as viewed from above.

[0047] Embodiment 2 The conveying device according to the second embodiment will be described below with reference to Fig. 6. Fig. 6 is a top view schematically showing a conveying device 600. Note that the description of the contents common to the first embodiment will be omitted as appropriate.

[0048] The transport device 600 has a levitation unit 10 and end levitation units 671 to 676. The levitation unit 10 levitates a substrate (not shown in FIG. 6) that is an object to be processed. As in the first embodiment, the levitation unit 10 has a trapezoidal shape when viewed from above. The levitation unit 10 has two sides parallel to the y direction of the levitation unit 10, one side parallel to the x direction, and one side inclined from the x direction (also referred to as the inclined side 10e). The angle formed by the inclined side 10e and the x direction is preferably greater than 0° and equal to or less than 5°.

[0049] For the sake of explanation, the levitation unit 10 is divided into six regions 60a to 60f when viewed from above. Specifically, the levitation unit 10 includes a first region 60a to a fourth region 60d, a process region 60e, and a transit region 60f. The first region 60a is a trapezoidal region including corners on the -x and +y sides (the upper left corner in FIG. 6). The second region 60b is a trapezoidal region including corners on the +x and +y sides (the upper right corner in FIG. 6). The third region 60c is a rectangular region including corners on the +x and -y sides (the lower right corner in FIG. 6). The fourth region 60d is a rectangular region including corners on the -x and -y sides (the lower left corner in FIG. 6).

[0050] The process area 60e is a trapezoidal area located between the first area 60a and the second area 60b. The process area 60e is an area including the irradiation area 15a where the laser light is irradiated. The passage area 60f is a rectangular area located between the third area 60c and the fourth area 60d.

[0051] The +y-side half of levitation unit 10 (the upper half of FIG. 6) is made up of, in order from the -x side (the left side of FIG. 6), a first region 60a, a process region 60e, and a second region 60b. The -y-side half of levitation unit 10 (the lower half of FIG. 6) is made up of, in order from the +x side, a third region 60c, a passing region 60f, and a fourth region 60d.

[0052] The levitation unit 10 includes a rotation mechanism 68 and alignment mechanisms 69a and 69b. The rotation mechanism 68 rotates the substrate. The alignment mechanisms 69a and 69b align the substrate. The first region 60a and the second region 60b are provided with alignment mechanisms 69a and 69b, respectively. The rotation mechanism 68 is provided in the fourth region 60d. The operations of the rotation mechanism 68 and the alignment mechanisms 69a and 69b will be described later.

[0053] The end levitation units 671 to 676 are arranged outside the levitation unit 10. The end levitation units 671 to 676 are arranged along the outer periphery of the trapezoidal shaped levitation unit 10. The end levitation units 671 to 676 are provided along the end sides of the levitation unit 10. In a top view, the end levitation units 671 to 676 are arranged to surround the outer periphery of the levitation unit 10.

[0054] End levitation units 671 and 672 are arranged on the -x side of levitation unit 10. End levitation unit 673 is arranged on the +y side of levitation unit 10. End levitation unit 674 is arranged on the +x side of levitation unit 10. End levitation units 675 and 676 are arranged on the -y side of levitation unit 10. It is possible to omit at least one of end levitation units 671, 672, 673, 674, 675, and 676. For example, holding mechanism 12 holds the end of substrate 100. Levitation unit 10 levitates parts other than the base end. In this way, it is possible to avoid using the end levitation units around levitation unit 10.

[0055] End floating units 671 and 672 are arranged along the edge on the -x side of floating unit 10. That is, end floating units 671 and 672 are each provided along the y direction. Furthermore, the width of end floating unit 671 in the x direction is wider than that of end floating unit 672. End floating unit 671 is arranged on the -y side of end floating unit 672.

[0056] End levitation units 673 are arranged along the edge on the +y side of levitation unit 10. In other words, end levitation units 673 are provided along inclined side 10e of levitation unit 10. End levitation units 674 are arranged along the edge on the +x side of levitation unit 10. In other words, end levitation units 674 are each provided along the y direction.

[0057] End levitation units 675, 676 are arranged along the edge on the -y side of levitation unit 10. In other words, end levitation units 675, 676 are each provided along the x direction. Furthermore, the width of end levitation unit 676 in the y direction is wider than end levitation unit 675. End levitation unit 676 is arranged on the -x side of end levitation unit 675.

[0058] A transport unit 11a is provided between the floating unit 10 and the end floating unit 671. A transport unit 11a is also disposed between the floating unit 10 and the end floating unit 672. The transport unit 11a is formed along the y direction. The transport unit 11a transports the substrate in the +y direction. That is, the transport unit 11a transports the substrate 100 from the fourth region 60d toward the first region 60a.

[0059] A transport unit 11b is provided between the floating unit 10 and the end floating unit 673. The transport unit 11b is formed along the inclined side 10e. The transport unit 11b transports the substrate in a direction parallel to the inclined side 10e. In other words, the transport unit 11b transports the substrate 100 from the first region 60a toward the second region 60b.

[0060] A transport unit 11c is provided between the floating unit 10 and the end floating unit 674. The transport unit 11c is formed along the y direction. The transport unit 11c transports the substrate 100 in the -y direction. That is, the transport unit 11c transports the substrate 100 from the second region 60b toward the third region 60c.

[0061] Transport unit 11d is provided between floating unit 10 and end portion floating unit 675. Transport unit 11d is also arranged between floating unit 10 and end portion floating unit 676. Transport unit 11d is formed along the x direction. Transport unit 11a transports the substrate in the -x direction. That is, transport unit 11d transports the substrate from the third region 60c to the fourth region 60d.

[0062] The transport units 11a to 11d each include a holding mechanism 12 and a moving mechanism 13, similar to the first embodiment. The operations of the holding mechanism 12 and the moving mechanism 13 will be described later.

[0063] As in the first embodiment, the laser beam irradiation area 15a has a longitudinal direction in the y direction. That is, a linear irradiation area 15a is formed with the longitudinal direction in the y direction. The laser beam is irradiated onto the substrate while the substrate is transported in a direction parallel to the inclined side 10e. The laser irradiation process is performed while the substrate is moving from the first area 60a to the second area 60b. In the present embodiment, as in the first embodiment, the amorphous silicon film is converted into a polysilicon film by irradiating the substrate with laser beam from a laser generating device.

[0064] In the levitation unit 10, a precision levitation unit 111 is disposed in and around the irradiation region 15a. The precision levitation unit 111 has a higher levitation amount precision than the semi-precision levitation units and rough levitation units in other regions. Therefore, in the process region 60e including the irradiation region 15a, the laser light is irradiated onto the levitated object with a more precise levitation amount than the other regions 60a to 60d and 60f. This allows the laser light to be irradiated onto the object in a stable manner. Furthermore, regions other than the irradiation region 15a, such as the passage region 60f, the third region 60c, and the fourth region 60d, are formed without using the expensive precision levitation unit 111. This reduces the cost of the device.

[0065] Next, the procedure of the transport method using the levitation unit 10 will be described with reference to FIGS. 7 to 13. Here, the fourth region 60d is the loading and unloading position for the substrate 100. The substrate 100 loaded into the fourth region 60d is then transported through the first region 60a, the process region 60e, the second region 60b, the third region 60c, the passing region 60f, and the fourth region 60d in that order. That is, the substrate 100 circles along the edge of the levitation unit 10. Here, the substrate 100 makes two revolutions to irradiate the entire substrate 100 with the laser light. That is, the substrate 100 is transported so as to circulate twice over the levitation unit 10. In this manner, the laser light is irradiated onto almost the entire surface of the substrate 100.

[0066] The transport method will be described in detail below, following the steps. As shown in Fig. 7, the substrate 100 is carried into the fourth region 60d. The substrate 100 carried into the fourth region 60d is floated by the float unit 10 and the edge float units 671, 672, and 676. That is, the edge on the -x side of the substrate 100 is floated by the edge float units 671 and 672, and the center is floated by the float unit 10. The edge on the -y side of the substrate 100 is floated by the edge float unit 676. Then, the holding mechanism 12a of the transport unit 11a holds the substrate 100.

[0067] Next, as shown in Figure 8, substrate 100a in fourth region 60d is transported to first region 60a. In Figure 8, the substrate moved to first region 60a is shown as substrate 100b. Holding mechanism 12a of transport unit 11a holds substrate 100a. Then, movement mechanism 13a moves holding mechanism 12a in the +y direction, thereby moving substrate 100a from fourth region 60d to first region 60a (white arrow in Figure 8).

[0068] Here, in the xy-plane view, the holding mechanism 12a moves in the +y-direction, passing between the levitation unit 10 and the end levitation unit 671. Furthermore, in the xy-plane view, the holding mechanism 12a moves in the +y-direction, passing between the levitation unit 10 and the end levitation unit 672. Therefore, the substrate 100b is levitated by the levitation unit 10 and the end levitation units 672 and 673. That is, the end on the -x side of the substrate 100b is levitated by the end levitation unit 672, and the central portion is levitated by the levitation unit 10. The end on the +y side of the substrate 100b is levitated by the end levitation unit 673.

[0069] Next, as shown in Fig. 9, the alignment mechanism 69a aligns the position and angle of the substrate 100b transported to the first region 60a. For example, the position and rotation angle of the substrate may be slightly shifted due to the loading, transporting, and rotating operations of the substrate 100. The alignment mechanism 69a corrects the position and rotation angle shift. This allows the irradiation position of the laser light on the substrate 100 to be controlled with high precision.

[0070] For example, the alignment mechanism 69a is movable in the y-direction and rotatable around the z-axis. Furthermore, the alignment mechanism 69a is movable in the z-direction. For example, the alignment mechanism 69a includes an actuator such as a motor. The amount of positional deviation and angle deviation are obtained from an image of the substrate 100b captured by a camera or the like. The alignment mechanism 69a performs alignment based on the amount of deviation.

[0071] An alignment mechanism 69a is disposed directly below the center of the substrate 100b. The alignment mechanism 69a holds the substrate 100b. The alignment mechanism 69a may hold the substrate 100b by suction, similar to the holding mechanism 12. The holding mechanism 12a releases its hold on the substrate 100b. As a result, the substrate 100b is transferred from the holding mechanism 12a to the alignment mechanism 69a.

[0072] Then, the alignment mechanism 69a rotates the substrate 100b around the z-axis (shown by the white arrow in FIG. 9). The alignment mechanism 69a rotates the substrate 100b so that the edge of the substrate 100b is parallel to the inclined side 10e of the levitation unit 10. The rotated substrate is shown as substrate 100c. For example, the alignment mechanism 69a rotates the substrate 100b by approximately 5° around the z-axis. The edge of the substrate 100c is now parallel to the inclined side 10e of the levitation unit 10. After the alignment is complete, the holding mechanism 12b of the transport unit 11b holds the substrate 100b, and the alignment mechanism 69a releases its hold. This transfers the substrate 100c from the alignment mechanism 69a to the holding mechanism 12b of the transport unit 11b.

[0073] Next, as shown in FIG. 10, the transport unit 11b moves the substrate 100d. As a result, the substrate 100d passes through the process area 60e. Here, in the xy plan view, the holding mechanism 12b passes between the floating unit 10 and the end floating unit 673 and moves in a direction parallel to the inclined side 10e. As a result, approximately half of the area of ​​the substrate 100d passes through the irradiation area 15a. The laser light is irradiated onto the substrate 100d, which is moving in an inclined direction inclined from the x direction orthogonal to the irradiation area 15a.

[0074] In the xy plane view, the holding mechanism 12b passes between the levitation unit 10 and the end levitation unit 673 and moves in a direction parallel to the inclined side 10e. Therefore, the substrate 100d is levitated by the levitation unit 10 and the end levitation unit 673. That is, the end on the +y side of the substrate 100d is levitated by the end levitation unit 673, and the center is levitated by the levitation unit 10. A laser irradiation process is carried out while the substrate 100d moves from the first region 60a to the second region 60b.

[0075] Next, as shown in Fig. 11, when substrate 100e moves to second region 60b, alignment mechanism 69b aligns substrate 100e. Here, alignment mechanism 69b rotates substrate 100e (white arrow in Fig. 11). In Fig. 11, the rotated substrate is shown as substrate 100f.

[0076] An alignment mechanism 69b is disposed directly below the center of the substrate 100e. The alignment mechanism 69b holds the substrate 100e. The alignment mechanism 69b may hold the substrate 100e by suction, similar to the holding mechanism 12. Furthermore, the holding mechanism 12b releases its hold on the substrate 100e. The substrate 100e is transferred from the holding mechanism 12b of the transfer unit 11b to the alignment mechanism 69b.

[0077] The alignment mechanism 69b rotates the substrate 100e around the z-axis (shown by the hollow arrow in FIG. 11). The alignment mechanism 69a rotates the substrate 100e so that the edge of the substrate 100e is parallel to the inclined edge 10e of the floating unit 10. After rotation, the edge of the substrate 100f is parallel to the x-direction or y-direction. After alignment is complete, the holding mechanism 12c of the transport unit 11c holds the substrate 100f, and the alignment mechanism 69b releases its hold. This transfers the substrate 100f from the alignment mechanism 69b to the holding mechanism 12c of the transport unit 11c.

[0078] Substrate 100e is levitated by levitation unit 10 and edge levitation units 673 and 674. That is, the +y side edge of substrate 100e is levitated by edge levitation unit 673. The +x side edge of substrate 100e is levitated by edge levitation unit 674, and the center is levitated by levitation unit 10.

[0079] Next, as shown in Figure 12, substrate 100f in second region 60b is transported to third region 60c. The substrate moved to third region 60c is shown as substrate 100g. In Figure 12, holding mechanism 12c of transport unit 11c holds substrate 100f. Then, movement mechanism 13c moves holding mechanism 12c in the -y direction, thereby moving substrate 100f from second region 60b to third region 60c (white arrow in Figure 12).

[0080] Here, in the xy plane view, the holding mechanism 12c moves in the -y direction, passing between the levitation unit 10 and the end levitation unit 674. Therefore, the substrate 100e is levitated by the levitation unit 10 and the end levitation units 674 and 675. The end on the +x side of the substrate 100e is levitated by the end levitation unit 674, and the central portion is levitated by the levitation unit 10. The end on the -y side of the substrate 100e is levitated by the end levitation unit 675.

[0081] Then, the holding mechanism 12d of the transport unit 11d holds the substrate 100g, and the holding mechanism 12c releases its hold, thereby transferring the substrate 100g from the holding mechanism 12c of the transport unit 11c to the holding mechanism 12d of the transport unit 11d.

[0082] Next, as shown in Figure 13, substrate 100g in the third region 60c is transported to the fourth region 60d. The substrate that has moved to the fourth region 60d is shown as substrate 100h. In Figure 13, holding mechanism 12d of transport unit 11d holds substrate 100g. Then, movement mechanism 13d moves holding mechanism 12d in the -x direction, causing substrate 100f to move from the third region 60c to the fourth region 60d (white arrow in Figure 13).

[0083] Here, in the xy-plane view, the holding mechanism 12d moves in the -x direction, passing between the levitation unit 10 and the edge levitation unit 675. In the xy-plane view, the holding mechanism 12d moves in the -x direction, passing between the levitation unit 10 and the edge levitation unit 676. Therefore, the substrate 100h is levitated by the levitation unit 10 and the edge levitation unit 676. The edge on the -y side of the substrate 100h is levitated by the edge levitation unit 676, and the central portion is levitated by the levitation unit 10. The edge on the -x side of the substrate 100h is levitated by the edge levitation unit 671.

[0084] In this way, the substrate 100 that was in the fourth region 60d moves in the order of the first region 60a, the process region 60e, the second region 60b, the third region 60c, the passing region 60f, and the fourth region 60d. In other words, the substrate 100 circles along the edge of the levitation unit 10.

[0085] 14, the rotation mechanism 68 rotates the substrate 100h by 180° around the z-axis. That is, the substrate 100h is transferred from the holding mechanism 12d to the rotation mechanism 68. After the rotation mechanism 68 rotates the substrate 100h, the substrate 100h is transferred from the rotation mechanism 68 to the holding mechanism 12d.

[0086] As in the above, the transport units 11a to 11d again move the substrate 100h through the first region 60a, the process region 60e, the second region 60b, the third region 60c, the passing region 60f, and the fourth region 60d in that order. That is, as shown in Figures 7 to 13, the substrate 100 circles along the edge of the levitation unit 10.

[0087] Here, the rotation mechanism 68 rotates the substrate 100h by 180°. When the substrate 100e passes through the process region 60e for the second time, the remaining half of the region that was not irradiated with laser light during the first pass is irradiated with laser light. In this manner, the substrate 100 circulates twice along the edge of the floating unit 10. Because the substrate 100 rotates 180° between the first and second laser irradiations, the laser light is irradiated onto almost the entire surface of the substrate 100. Note that the position at which the substrate 100 is rotated is not limited to the first region 60a. For example, the rotation may be performed in the second region 60b, the third region 60c, the fourth region 60d, or the like.

[0088] In this embodiment, the moving mechanism 13b also moves the holding mechanism 12b in a direction tilted from the x-direction perpendicular to the irradiation area 15a. This allows the crystallization process of the silicon film to be performed appropriately. For example, it is possible to prevent the occurrence of moire and improve display quality.

[0089] (holding mechanism 12) Next, an example of the holding mechanism 12 will be described with reference to Fig. 15. Fig. 15 is a perspective view showing the configuration of a portion of the holding mechanism 12. Fig. 15 shows a holding mechanism 12 whose movement direction is the y direction, such as the holding mechanism 12c shown in Fig. 13. Fig. 15 shows the configuration of the end portion on the -y side of the holding mechanism 12.

[0090] The holding mechanism 12 includes a plurality of adsorption cells 121. The plurality of adsorption cells 121 are arranged along the transport direction. A recess 122 is provided between two adsorption cells 121. The holding mechanism 12 is made of a metal material such as aluminum. For example, the plurality of adsorption cells 121 can be integrally formed from an aluminum alloy such as A5052.

[0091] The upper surface of the adsorption cell 121 serves as an adsorption surface 121a that adsorbs the substrate 100 (not shown in FIG. 15). FIG. 16 shows an enlarged view of the adsorption surface 121a and a cross-sectional view of the adsorption cell 121. The adsorption surface 121a is provided with adsorption grooves 126. Furthermore, the adsorption grooves 126 are connected to intake holes 125. The intake holes 125 are connected to an internal space 127 provided in the adsorption cell 121. When the internal space 127 is evacuated by a pump or the like, the intake holes 125 and the adsorption grooves 126 become negative pressure. As a result, the substrate 100 is vacuum-adsorbed onto the adsorption surface 121a of each adsorption cell 121.

[0092] 17, it is preferable to provide a valve 129 for each of the plurality of adsorption cells 121. For example, each of the adsorption cells 121 is connected to an exhaust port 128. The exhaust port 128 is connected to a pipe 130 via the valve 129. The pipe 130 is common to the plurality of exhaust ports 128. The pipe 130 is then connected to an exhaust means 131 such as a vacuum pump or an ejector. Thus, the exhaust means 131 can reduce the pressure in the internal space 127 of each of the adsorption cells 121.

[0093] A valve 129 is provided for each adsorption cell 121. The multiple valves 129 can be opened and closed independently. A substrate 100 is placed on an adsorption surface 121a. By opening all the valves 129, each adsorption cell 121 vacuum-adsorbs the lower surface of the substrate 100.

[0094] Here, due to a transport error of the substrate 100, the adsorption surfaces 121a of some of the adsorption cells 121 may not be covered by the substrate 100. As shown in FIG. 18, the adsorption surfaces 121a of the adsorption cells 121 may not be completely covered by the substrate 100. In this case, the valve 129 of the adsorption cell 121 whose adsorption surface 121a is not covered is closed. For example, in FIG. 18, the substrate 100 is misaligned from the adsorption surface 121a of the right adsorption cell 121 of the two adsorption cells 121. Therefore, the valve 129 of the right adsorption cell 121 is closed. In FIG. 18, the substrate 100 is held only by the left adsorption cell 121. For example, when the gas suction flow rate at the exhaust port 128 exceeds a threshold, the valve 129 is closed. This allows the substrate 100 to be appropriately vacuum-adsorbed. This enables substrate transport suitable for the laser irradiation process.

[0095] Fig. 19 is a side view schematically showing an example of the overall configuration of a transport device 600. The transport device 600 includes an area base 610, a stand 620, and a transport stage 630. As described above, the transport device 600 also includes a levitation unit 10, a holding mechanism 12, a moving mechanism 13, and an end levitation unit 670. As shown in Fig. 17 and other figures, a pipe 130 is connected to the holding mechanism 12 by a joint or the like.

[0096] An area base 610 is provided on the mount 620. A levitation unit 10 and an end levitation unit 670 are provided on the area base 610. The end levitation unit 670 is any one of the end levitation units 671 to 676 shown in FIGS. 6 to 14.

[0097] The levitation unit 10 includes a semi-precise levitation unit 112 and a rough levitation unit 113. The semi-precise levitation unit 112 has lower levitation accuracy than the precision levitation unit 111. The rough levitation unit 113 has lower levitation accuracy than the semi-precise levitation unit 112 and the precision levitation unit 111.

[0098] A holding mechanism 12 is disposed between the floating unit 10 and the end portion floating unit 670. A moving mechanism 13 is disposed on the transfer stage 630. The moving mechanism 13 has a guide mechanism and the like provided along the moving direction. The moving mechanism 13 moves the holding mechanism 12 as described above. Therefore, the holding mechanism 12 moves along the end side of the floating unit 10 in the space (gap) between the floating unit 10 and the end portion floating unit 670. With this configuration, the substrate 100 can be irradiated with laser light while being moved.

[0099] Embodiment 3 A transport device 600A according to the third embodiment will be described with reference to FIG. 20. FIG. 20 is a top view schematically showing the configuration of the transport device 600A. In this embodiment, the levitation unit is divided into two units, a first levitation unit 10A and a second levitation unit 10B, in order to transport a larger substrate 100. For example, the substrate 100 is a glass substrate of G10 size (3130 mm x 2880 mm). Note that the configuration other than the first levitation unit 10A and the second levitation unit 10B is the same as in the first and second embodiments, and therefore description thereof will be omitted where appropriate.

[0100] A gap 10C is provided between the first levitation unit 10A and the second levitation unit 10B. That is, the first levitation unit 10A and the second levitation unit 10B are disposed with the gap 10C between them. As shown in the first and second embodiments, the first levitation unit 10A and the second levitation unit 10B are disposed below the substrate 100, which is the object to be processed. The first levitation unit 10A and the second levitation unit 10B eject gas onto the underside of the substrate 100, thereby air-levitating the substrate 100. While the levitated substrate 100 is being moved, it is irradiated with laser light. The irradiation area 15a of the laser light is linear and extends along the y direction. The irradiation area 15a is formed in the first levitation unit 10A.

[0101] In Figure 20, the holding mechanism 12 is moved along the x direction by the moving mechanism 13 (not shown in Figure 20). In top view, the transport direction of the substrate 100 is parallel to the x direction. The holding mechanism 12 moves along the gap 10C. The holding mechanism 12 suction-holds the central portion of the substrate 100, not the end portion. In top view, the first levitation unit 10A is arranged on one end side from the central portion of the substrate 100. In top view, the second levitation unit 10B is arranged on the other end side from the central portion of the substrate 100.

[0102] 20, first levitation unit 10A is disposed on the -y side of holding mechanism 12, and second levitation unit 10B is disposed on the +y side of holding mechanism 12. Therefore, first levitation unit 10A air-floats substrate 100 from the center to the edge on the -y side. Second levitation unit 10B air-floats substrate 100 from the center to the edge on the +y side. In this manner, in this embodiment, first levitation unit 10A and second levitation unit 10B are provided to air-float the center of substrate 100. Holding mechanism 12 holds the inner portion of substrate 100, not the edge.

[0103] The holding mechanism 12 holds the center portion of the substrate 100, thereby enabling the substrate 100 to be reliably sucked and held. This point will be described with reference to Fig. 21. Fig. 21 is a diagram for explaining the case where the edge portion of the substrate 100 is held.

[0104] When a rotational force about the z-axis is applied to the substrate 100, a moment of inertia M acts on the portion held by the holding mechanism 12. When the holding mechanism 12 holds the edge of the substrate 100, the moment of inertia M is larger than when the holding mechanism 12 holds the center of the substrate 100. The larger the substrate 100, the larger the moment of inertia M. If the moment of inertia M becomes larger, there is a risk that the vacuum suction of the holding mechanism 12 will be released.

[0105] The chucking force can be increased by increasing the width of the holding mechanism 12 in the y direction. However, increasing the width of the holding mechanism 12 increases the contact area between the substrate 100 and the holding mechanism 12. Therefore, as shown in FIG. 22, charging of the substrate 100 becomes a problem. For example, the substrate 100 becomes charged due to charging caused by adhesion and separation when the substrate 100 is broken by adhesion (upper diagram of FIG. 22). The amount of charge increases in proportion to the contact area between the substrate 100 and the holding mechanism 12.

[0106] The holding mechanism 12 is made of a metal material. The charge of the holding mechanism 12 can be released by grounding the holding mechanism 12. On the other hand, the substrate 100 is an insulator such as glass. Therefore, the charge of the charged substrate 100 remains on the substrate 100. A Coulomb force is generated between the substrate 100 and the levitation unit 10, and the substrate 100 is attracted toward the levitation unit 10 (lower diagram in Figure 22). In this case, the substrate 100 and the levitation unit 10 may come into contact with each other, potentially damaging both of them.

[0107] Therefore, in this embodiment, the holding mechanism 12 holds the center portion of the substrate 100, not the end portion. In this way, it is possible to reduce the moment of inertia generated in the portion held by the holding mechanism 12, and therefore it is possible to reduce the planar size of the holding mechanism 12. In other words, even if the planar size of the holding mechanism 12 is reduced, it is possible to prevent the substrate 100 from coming loose from being adsorbed and held due to the moment of inertia.

[0108] The holding mechanism 12 holds the center of the substrate 100, not the edge. That is, in a top view, the second levitation unit 10B is disposed from the edge of the substrate 100 to the center. The center of the substrate 100 may be, for example, a position where the substrate 100 would bend and come into contact with the second levitation unit 10B if gas were not blown out from the second levitation unit 10B. That is, if the gas release from the second levitation unit 10B is stopped during transport while the holding mechanism 12 is holding the center of the substrate 100, the substrate 100 would come into contact with the second levitation unit 10B. Furthermore, the edge of the substrate 100 may be, for example, a position where the substrate 100 would not come into contact with the second levitation unit 10B even if it bends if gas is not blown out from the second levitation unit 10B. Even if the gas release from the second levitation unit 10B is stopped while the holding mechanism 12 is transporting the substrate 100 while holding the edge of the substrate 100, the substrate 100 will not come into contact with the second levitation unit 10B.

[0109] In the transport method according to this embodiment, the substrate 100 is transported so that the substrate 100 is irradiated with laser light that forms a linear irradiation area 15a. A first levitation unit 10A arranged below the substrate 100 is used to levitate one end of the substrate 100 from the center of the substrate 100 as viewed from above, and a second levitation unit 10B arranged below the substrate 100 is used to levitate the other end of the substrate 100 from the center of the substrate 100 as viewed from above. The substrate 100 is adsorbed and held using a holding mechanism 12 arranged below the center of the substrate 100. To move the substrate 100 to the irradiation position of the laser light 15, the holding mechanism 12 is moved along a gap 10C between the first levitation unit 10A and the second levitation unit 10B.

[0110] (Example of irradiation process) An example of the irradiation process according to this embodiment will be described below with reference to Figs. 23 to 25. Figs. 23 to 25 each show a schematic diagram of the irradiation position of the laser light on the substrate 100. In Figs. 23 to 25, the substrate 100 is a mother glass substrate for forming a plurality of display panels. For example, the substrate size is 3130 mm x 2880 mm.

[0111] Example 1 Example 1 shown in FIG. 23 illustrates an example of an eight-panel cutout in which eight display panels P1 to P8 are manufactured from one substrate 100. The substrate size in the x direction is 3130 mm, and the substrate size in the y direction is 2880 mm. The panel size of each display panel is 764 mm × 1341 mm. In this case, the size of the irradiation area 15a in the y direction is 1341 mm or more. By irradiating the laser light while transporting the substrate 100 in the x direction, the laser light is irradiated onto approximately half of the substrate 100. In the area irradiated with the laser light, the amorphous silicon film is crystallized to form a polysilicon film. Then, by performing two irradiation processes, the polysilicon film can be formed over approximately the entire substrate 100.

[0112] In the first irradiation process, the laser light is irradiated onto approximately half of the area of ​​the substrate 100. That is, in the first irradiation process, the laser light is irradiated onto half of a rectangular area on one end side of the substrate 100. The laser light is irradiated onto areas that will become display panels P1 to P4. In the first irradiation process, the substrate 100 is transported in the x direction while the holding mechanism 12 (not shown in FIG. 23) holds areas that will become one or more of the display panels P5 to P8.

[0113] After the first irradiation process, the substrate 100 is rotated 180° around the z-axis. In the second irradiation process, the remaining half of the substrate 100 is irradiated with laser light. That is, in the second irradiation process, half of the rectangular area on the other end side of the substrate 100 is irradiated with laser light. The laser light is irradiated onto the areas that will become the display panels P5 to P8. In the second irradiation process, the substrate 100 is transported in the x-direction while the holding mechanism 12 holds the areas that will become one or more of the display panels P1 to P4. By performing the two irradiation processes, the laser light is irradiated onto almost the entire surface of the substrate 100.

[0114] Example 2 Example 2 shown in FIG. 24 illustrates an example of a six-panel manufacturing process in which six display panels P1 to P6 are manufactured from a single substrate 100. The substrate size in the x direction is 3130 mm, and the substrate size in the y direction is 2880 mm. The panel size of each display panel is 1546 mm × 888 mm. In this case, the size of the irradiation area 15a in the y direction is 888 mm or more. By irradiating the laser light while transporting the substrate 100 in the x direction, the laser light is irradiated onto approximately one-third of the substrate 100. In the area irradiated with the laser light, the amorphous silicon film is crystallized to form a polysilicon film. Then, by performing three irradiation processes, the polysilicon film can be formed over almost the entire substrate 100.

[0115] In the first irradiation process, the laser light is irradiated onto approximately ⅓ of the area of ​​the substrate 100. The laser light is irradiated onto a rectangular area of ​​⅓ on one end side of the substrate 100. In other words, the laser light is irradiated onto the areas that will become the display panels P1 to P2. In the first irradiation process, the substrate 100 is transported in the x direction while the holding mechanism 12 (not shown in FIG. 24) holds the areas that will become one or more of the display panels P3 to P6.

[0116] After the first irradiation process, the substrate 100 is transported in the -y direction. In the second irradiation process, the laser light is irradiated onto approximately the central ⅓ of the substrate 100. In the second irradiation process, the laser light is irradiated onto a rectangular ⅓ area including the center of the substrate 100. The laser light is irradiated onto areas that will become display panels P3 and P4. In the third irradiation process, the substrate 100 is transported in the x direction while the holding mechanism 12 holds areas that will become one or more of the display panels P5 and P6. Through the two irradiation processes, the laser light is irradiated onto approximately ⅔ of the substrate 100.

[0117] After the second irradiation process, the substrate 100 is rotated 180° around the z-axis and transported in the y-direction. In the third irradiation process, the laser light is irradiated onto a rectangular region that occupies one-third of the other end of the substrate 100. The laser light is irradiated onto the regions that will become the display panels P5 to P6. In the third irradiation process, the substrate 100 is transported in the x-direction while the holding mechanism 12 holds the regions that will become one or more of the display panels P1 to P4. Through the three irradiation processes, the laser light is irradiated onto almost the entire substrate 100.

[0118] The order of the laser light irradiation process is not particularly limited. For example, the laser light may be irradiated onto the areas that will become display panels P5 and P6, and then onto the areas that will become display panels P3 and P4. Alternatively, the laser light may be irradiated onto the areas that will become display panels P3 and P4 in the first irradiation process.

[0119] Example 3 Example 3 shown in FIG. 25 illustrates an example of a six-panel manufacturing process in which three display panels P1 to P3 are manufactured from one substrate 100. The substrate size in the x direction is 2880 mm, and the substrate size in the y direction is 3130 mm. The panel size of each display panel is 1806 mm × 1029 mm. In this case, the size of the irradiation area 15a in the y direction is 1029 mm or more. By irradiating the laser light while transporting the substrate 100 in the x direction, the laser light is irradiated onto approximately one-third of the substrate 100. In the area irradiated with the laser light, the amorphous silicon film is crystallized to form a polysilicon film. Then, by performing three irradiation processes, the polysilicon film can be formed over almost the entire substrate 100.

[0120] In the first irradiation process, the laser light is irradiated onto approximately ⅓ of the area of ​​the substrate 100. The laser light is irradiated onto a rectangular area of ​​⅓ on one end side of the substrate 100. In other words, the laser light is irradiated onto the area that will become the display panel P1. In the first irradiation process, the substrate 100 is transported in the x direction while the holding mechanism 12 (not shown in FIG. 25) holds the area that will become one or more of the display panels P1 and P2.

[0121] After the first irradiation process, the substrate 100 is transported in the -y direction. In the second irradiation process, the laser light is irradiated onto approximately one-third of the central area of ​​the substrate 100. In the second irradiation process, the laser light is irradiated onto one-third of a rectangular area including the center of the substrate 100. The laser light is irradiated onto the area that will become display panel P2. In the third irradiation process, the substrate 100 is transported in the x direction while the holding mechanism 12 holds the area that will become one or more of the display panels P1 and P3. Through the two irradiation processes, the laser light is irradiated onto approximately two-thirds of the substrate 100.

[0122] After the second irradiation process, the substrate 100 is rotated 180° around the z-axis and transported in the y-direction. In the third irradiation process, the laser light is irradiated onto a rectangular area of ​​1 / 3 of the other end of the substrate 100. The laser light is irradiated onto the area that will become display panel P3. In the third irradiation process, the substrate 100 is transported in the x-direction while the holding mechanism 12 holds the area that will become one or more of the display panels P1 and P2. Through the three irradiation processes, the laser light is irradiated onto almost the entire substrate 100.

[0123] The order of the laser light irradiation process is not particularly limited. For example, the laser light may be irradiated onto the areas that will become display panels P5 and P6, and then onto the areas that will become display panels P3 and P4. Alternatively, the laser light may be irradiated onto the areas that will become display panels P3 and P4 in the first irradiation process.

[0124] In Examples 2 and 3, the laser light is irradiated onto approximately 1 / 3 of the area of ​​the substrate 100 in one irradiation process. Therefore, the holding mechanism 12 holds the substrate 100 at a position approximately 1 / 3 of the substrate size from the edge of the substrate 100. That is, in the y direction, the second levitation unit 10B has a width approximately 1 / 3 of the substrate size of the substrate 100. Of course, the width of the second levitation unit 10B is not limited to 1 / 3 of the substrate size. The number of processes can be determined depending on the substrate size, the number of chamfers on the panel, and the size of the laser light irradiation area 15a, and the size of the second levitation unit 10B may be determined accordingly. For example, the first levitation unit 10A and the second levitation unit 10B may each be 1 / 4 or more of the substrate size.

[0125] The configuration of this embodiment allows large substrates 100 to be transported appropriately. Even if a rotational force is applied to the substrate 100, the moment of inertia can prevent the substrate 100 from being released from suction. Furthermore, since the substrate 100 can be reliably held with a small suction area, an increase in the amount of charge can be prevented. Therefore, the substrate 100 can come into contact with the first levitation unit 10A or the second levitation unit 10B due to Coulomb force.

[0126] The configuration of the third embodiment can be appropriately combined with the configurations of the first and second embodiments. For example, in the configuration of the third embodiment, the transport direction of the substrate 100 may be inclined from the longitudinal direction of the irradiation region 15a.

[0127] (OLED display) The semiconductor device having the polysilicon film is suitable for a TFT (Thin Film Transistor) array substrate for an organic EL (ElectroLuminescence) display. That is, the polysilicon film is used as a semiconductor layer having a source region, a channel region, and a drain region of the TFT.

[0128] The following describes a configuration in which the semiconductor device according to this embodiment is applied to an organic EL display. Fig. 26 is a cross-sectional view showing a simplified pixel circuit of an organic EL display. The organic EL display 300 shown in Fig. 26 is an active matrix display device in which a TFT is arranged in each pixel PX.

[0129] The organic EL display 300 includes a substrate 310, a TFT layer 311, an organic layer 312, a color filter layer 313, and a sealing substrate 314. FIG. 26 shows a top-emission organic EL display in which the sealing substrate 314 side is the viewing side. Note that the following description shows one example of the configuration of an organic EL display, and the present embodiment is not limited to the configuration described below. For example, the semiconductor device according to the present embodiment may be used in a bottom-emission organic EL display.

[0130] The substrate 310 is a glass substrate or a metal substrate. A TFT layer 311 is provided on the substrate 310. The TFT layer 311 has a TFT 311a arranged in each pixel PX. The TFT layer 311 further has wiring (not shown) connected to the TFT 311a. The TFT 311a and the wiring constitute a pixel circuit.

[0131] An organic layer 312 is provided on the TFT layer 311. The organic layer 312 has an organic EL light emitting element 312a arranged for each pixel PX. Furthermore, the organic layer 312 is provided with partition walls 312b between the pixels PX to separate the organic EL light emitting elements 312a.

[0132] A color filter layer 313 is provided on the organic layer 312. The color filter layer 313 is provided with a color filter 313a for color display. That is, a resin layer colored in R (red), G (green), or B (blue) is provided in each pixel PX as the color filter 313a.

[0133] A sealing substrate 314 is provided on the color filter layer 313. The sealing substrate 314 is a transparent substrate such as a glass substrate, and is provided to prevent the organic EL light emitting elements of the organic layer 312 from deteriorating.

[0134] The current flowing through the organic EL element 312a of the organic layer 312 varies depending on the display signal supplied to the pixel circuit. Therefore, by supplying a display signal corresponding to the display image to each pixel PX, the amount of light emitted by each pixel PX can be controlled. This allows the desired image to be displayed.

[0135] In an active matrix display device such as an organic EL display, one pixel PX is provided with one or more TFTs (for example, a switching TFT or a driving TFT). The TFT of each pixel PX is provided with a semiconductor layer having a source region, a channel region, and a drain region. The polysilicon film according to this embodiment is suitable for the semiconductor layer of the TFT. That is, by using the polysilicon film manufactured by the above manufacturing method as the semiconductor layer of the TFT array substrate, it is possible to suppress in-plane variations in TFT characteristics. Therefore, it is possible to manufacture display devices with excellent display characteristics with high productivity.

[0136] (Method of manufacturing a semiconductor device) The method for manufacturing a semiconductor device using the laser irradiation apparatus according to this embodiment is suitable for manufacturing a TFT array substrate. The method for manufacturing a semiconductor device having TFTs will be described with reference to Figs. 27 and 28. Figs. 27 and 28 are cross-sectional views showing the manufacturing process of a semiconductor device. In the following description, a method for manufacturing a semiconductor device having inverted staggered TFTs will be described. Figs. 27 and 28 show the step of forming a polysilicon film in the semiconductor manufacturing method. Note that, as known techniques can be used for the other manufacturing steps, their description will be omitted.

[0137] As shown in Fig. 27, a gate electrode 402 is formed on a glass substrate 401. A gate insulating film 403 is formed on the gate electrode 402. An amorphous silicon film 404 is formed on the gate insulating film 403. The amorphous silicon film 404 is disposed so as to overlap the gate electrode 402 with the gate insulating film 403 interposed therebetween. For example, the gate insulating film 403 and the amorphous silicon film 404 are successively formed by a CVD (Chemical Vapor Deposition) method.

[0138] Then, by irradiating the amorphous silicon film 404 with laser light L1, a polysilicon film 405 is formed as shown in Fig. 28. That is, the amorphous silicon film 404 is crystallized by the laser irradiation apparatus 1 shown in Fig. 1 etc. As a result, a polysilicon film 405 made of crystallized silicon is formed on the gate insulating film 403. The polysilicon film 405 corresponds to the polysilicon film described above.

[0139] Furthermore, in the above description, the laser annealing apparatus according to the present embodiment has been described as irradiating an amorphous silicon film with laser light to form a polysilicon film, but it may also be irradiating an amorphous silicon film with laser light to form a microcrystalline silicon film. Furthermore, the laser light used for annealing is not limited to an Nd:YAG laser. The method according to the present embodiment can also be applied to a laser annealing apparatus that crystallizes a thin film other than a silicon film. That is, the method according to the present embodiment can be applied to any laser annealing apparatus that irradiates an amorphous film with laser light to form a crystallized film. The laser annealing apparatus according to the present embodiment can appropriately modify a substrate with a crystallized film.

[0140] Variation 1 Next, a laser irradiation device using a transport device according to Modification 1 will be described with reference to Fig. 29. Fig. 29 is a top view schematically showing the laser irradiation device 1. Note that the basic configurations of the transport device and the laser irradiation device 1 are the same as those in Embodiment 1, and therefore, the description will be omitted as appropriate.

[0141] In this modification, the angle of the object 16 to be processed is different from that in the first embodiment when viewed from above. Specifically, the edge 161 on the -y side of the object 16 to be processed is inclined with respect to the transport direction. In other words, the transport direction and the edge 161 are not parallel. In FIG. 29, the object 16 to be processed is rotated around the Z axis compared to the configuration in FIG. 1. The angle between the y direction and the edge 161 of the object 16 to be processed is φ. The angle between the x direction and the transport direction is θ. Here, φ is greater than θ, but φ may be less than θ.

[0142] φ is preferably greater than 0° and equal to or less than 5°. Furthermore, θ is preferably greater than 0° and equal to or less than 5°. φ can be adjusted according to the specifications of the laser irradiation process. For example, in the transfer device 600 shown in FIGS. 6 to 14 in the second embodiment, the alignment mechanism 69a can change the angle of the substrate 100 to a desired angle. That is, as shown in FIG. 9, the alignment mechanism 69a functions as a drive mechanism that rotates around the Z axis. The alignment mechanism 69a sets the angle of the edge of the substrate 100 to an angle different from the transfer direction. This allows the substrate 100 to rotate around the Z axis before irradiation with laser light. The transfer device 600 can transfer the substrate 100 in a state inclined at a desired angle with respect to the linear laser light. After irradiation with laser light, the alignment mechanism 69b rotates the substrate 100 on the levitation unit 10, as shown in FIG. 11. This makes the X direction and the edge of the substrate 100 parallel, as shown in FIG. 12.

[0143] Variation 2 The laser irradiation device according to the second modification will be described with reference to Fig. 30. The laser irradiation device 1 according to the second modification has a slit mechanism 30.

[0144] 30, in a rectangular object to be processed 16, the end side on the +x side is end side 162, the end side on the -x side is end side 163, and the end side on the +y side is end side 164. In Irradiation Example 1, similar to FIG. 29, the transport direction is inclined from the end sides 161 and 164 of the object to be processed 16.

[0145] An example of irradiation in which the entire surface of the object 16 to be processed is irradiated with laser in two separate steps will be described below. On the object 16 to be processed, regions 168 and 169 are irradiated with laser light in turn. Specifically, during the first transfer, region 168, which is half of the object 16 to be processed, is irradiated with laser light. Region 168 is an area surrounded by end sides 162, 163, 161, and boundary line 165. Boundary line 165 is a straight line parallel to the transfer direction.

[0146] Next, the workpiece 16 is rotated 180° around the Z axis and then transported a second time. As a result, the remaining half of the region 169 is irradiated with laser light. That is, a polysilicon film is formed in the region 168 by the first laser irradiation, and a polysilicon film is formed in the region 169 by the second laser irradiation. The region 169 is an area surrounded by the end sides 162, 163, 164, and the boundary line 165. The regions 168 and 169 may partially overlap. In this case, the workpiece 16 is irradiated twice with laser light near the boundary line 165. Alternatively, a gap may be provided between the region 168 irradiated with laser light in the first irradiation and the region 169 irradiated with laser light in the second irradiation. In this case, a region not irradiated with laser light exists between the region 168 irradiated with laser light in the first irradiation and the region 169 irradiated with laser light in the second irradiation. The gap between the region 168 and the region 169 may be as narrow as possible. The boundary line defining the region 168 that will be irradiated by the first irradiation does not match the boundary line defining the region 169 that will be irradiated by the second irradiation.

[0147] The slit mechanism 30 can adjust the length of the irradiation area 15a of the laser light on the workpiece 16. In other words, the slit mechanism 30 is a variable-length slit whose slit length is variable. This allows the sizes of the areas 168 and 169 irradiated by the first and second laser irradiations to be freely changed. Specifically, the slit mechanism 30 can change the length of the linear irradiation area 15a in the y direction by adjusting the slit length. For example, the slit mechanism 30 is installed in the optical system of the laser irradiation unit 14 shown in FIG. 2.

[0148] The slit mechanism 30 includes a light-shielding portion 32 and a light-shielding portion 33. The light-shielding portion 33 and the light-shielding portion 32 each have a light-shielding plate or the like that is provided so as to be movable along the y direction. The light-shielding portion 33 and the light-shielding portion 32 can shield the ends of the laser light. The light-shielding portion 33 shields the end of the line beam on the -y side. In other words, the light-shielding portion 33 defines the position of the -y side of the linear irradiation area 15a. The light-shielding portion 32 shields the end of the line beam on the +y side. In other words, the light-shielding portion 32 defines the position of the +y side of the linear irradiation area 15a. Therefore, the position of the light-shielding portion 32 defines the position of the boundary line 165.

[0149] The slit length can be shortened by moving the light-shielding portion 32 and the light-shielding portion 33 in the y direction so that they come closer to each other. The slit length can be lengthened by moving the light-shielding portion 32 and the light-shielding portion 33 in the y direction so that they move apart from each other.

[0150] The light-shielding portion 32 and the light-shielding portion 33 are provided in the laser irradiation portion 14, but in the following explanation, for the sake of simplicity, the positions of the light-shielding portion 32 and the light-shielding portion 33 will be explained as positions when projected onto the object to be processed 16 by an optical system. For example, the explanation will be given assuming that the position of the light-shielding portion 32 corresponds to the end on the +y side of the irradiation region 15a, and the position of the light-shielding portion 33 corresponds to the end on the -y side of the irradiation region 15a.

[0151] The light-shielding portion 33 and the light-shielding portion 32 move independently. This allows the slit mechanism 30 to change the line beam length and the irradiation end position on the object 16 to be processed. Furthermore, the light-shielding portion 33 and the light-shielding portion 32 may move in conjunction with the transport of the object 16 to be processed. In other words, the positions of the light-shielding portion 32 and the light-shielding portion 33 may change in accordance with changes in the transport position of the object 16 to be processed. Note that in FIG. 30, the transport direction is inclined from the edge 161 of the object 16 to be processed, as in FIG. 29, but it may be parallel as shown in FIG. 1.

[0152] (Irradiation example 1) Irradiation example 1 will be described with reference to FIG. 31. FIG. 31 is a top view schematically showing an irradiation area 15a of a laser beam on a processing object 16. In the following figures, the transport unit 11 and the floating unit 10 are omitted as appropriate for the sake of simplicity. In irradiation example 1, similar to FIG. 1, the end sides 161 and 164 of the processing object 16 are parallel to the transport direction. A boundary line 165 between area 169 and area 168 is parallel to the transport direction and end side 161.

[0153] The left side of Fig. 31 shows the configuration at the start of irradiation when the first irradiation starts, and the right side of Fig. 31 shows the configuration at the end of irradiation when the first irradiation ends. The start of irradiation refers to the timing when the irradiation area 15a overlaps with the edge 162 of the object to be processed 16 due to transportation. The end of irradiation refers to the timing when the irradiation area 15a passes the edge 163 on the -x side of the object to be processed 16 due to transportation.

[0154] During the first irradiation, the positions of the light-shielding portion 32 and the light-shielding portion 33 are constant. The slit length and the irradiation edge position are constant from the start of irradiation to the end of irradiation. The position of the light-shielding portion 33 is adjusted so that the edge position on the -y side of the irradiation area 15a coincides with the edge 161. In other words, the light-shielding portion 33 forms a line beam so that one end of the irradiation area 15a coincides with the edge 161.

[0155] As the object 16 is transported, the laser light is irradiated onto the region 168. When the irradiation is completed, a polysilicon film 16a is formed in the region 168. When the laser irradiation onto the region 168 is completed, the object 16 is rotated 180° around the Z axis, and the laser light is irradiated onto the region 168 in the same manner (not shown). This completes the laser irradiation onto the region 169.

[0156] This reduces the amount of laser light irradiated onto areas outside the substrate that are not irradiated with the workpiece 16. For example, in Irradiation Example 1, the laser light is irradiated onto a triangular area 170 as shown in FIG. 31. The area 170 represents the trajectory of the laser light that is not irradiated onto the workpiece 16 as it is transported. For the sake of explanation, in FIG. 31 and other figures, the area 170 represents the trajectory of the area outside the workpiece 16 that is irradiated with the laser light, as it moves with transport. In reality, the laser light is irradiated onto a fixed position on the levitation unit 10 (see the irradiation area 15a in FIG. 1 or FIG. 6). In this case, the laser light irradiation area 15a is formed in the gap between the two precision levitation units 111. By adjusting the position of the light-shielding portion 32, the boundary line 165 between the area 169 and the area 168 can be set to a region on the workpiece 16 where no devices are to be formed. For example, the boundary line 165 can be formed on the cutting line of the workpiece 16. This makes it possible to suppress the occurrence of variations in irradiation within the device.

[0157] (Irradiation example 2) Irradiation Example 2 will be described with reference to FIGS. 32 and 33. FIGS. 32 and 33 are top views schematically showing an irradiation area 15a of the workpiece 16 with laser light. In Irradiation Example 2, the light-shielding portion 32 and the light-shielding portion 33 move in accordance with the transport of the workpiece 16. FIG. 32 shows how the laser light is irradiated onto the edge 162 of the workpiece 16. That is, FIG. 32 shows the operation of the light-shielding portion 33 at the start of irradiation of the workpiece 16. FIG. 33 shows how the laser light is irradiated onto the edge 163 of the workpiece 16. That is, FIG. 33 shows the operation of the light-shielding portion 32 at the end of irradiation of the workpiece 16. In Irradiation Example 2, the edge 161 of the workpiece 16 is parallel to the transport direction.

[0158] First, the operation of the light blocking part 33 at the start of irradiation will be described using Fig. 32. The left side of Fig. 32 shows the position of the light blocking part 33 at the start of its movement, and the right side of Fig. 32 shows the position at the end of its movement. In Fig. 32, the position of the light blocking part 32 is constant.

[0159] The light-shielding part 33 moves in the -y direction to match the position of the end of the +x side of the object to be processed 16. While the object to be processed 16 is being transported, the light-shielding part 33 moves along the edge 162 in a top view. As a result, a polysilicon film 16a is formed on the -x side of the edge 161 over the entire edge 161.

[0160] Specifically, the light-shielding portion 33 moves in the -y direction while the irradiation area 15a crosses the edge 162 of the object 16 to be processed. The light-shielding portion 33 moves to the edge 161 of the object 16 to be processed so that the entire area 168 is irradiated with laser light. In other words, the light-shielding portion 33 gradually moves away from the light-shielding portion 32. Therefore, the irradiation area 15a gradually becomes longer as the light-shielding portion 33 moves. After the light-shielding portion 33 moves to the position at the end of movement in FIG. 32, the position of the light-shielding portion 33 remains constant while the object 16 is being transported.

[0161] Next, the operation of the light blocking part 32 at the end of irradiation will be described using Figure 33. The left side of Figure 33 shows the position of the light blocking part 32 at the start of its movement, and the right side of Figure 33 shows the position of the light blocking part 32 at the end of its movement. In Figure 33, the position of the light blocking part 33 is constant.

[0162] The light-shielding part 32 moves in the -y direction to match the position of the end of the -x side of the object 16 to be processed. While the object 16 to be processed is being transported, the light-shielding part 33 moves along the edge 163 in a top view. Specifically, the light-shielding part 32 moves in the -y direction while the irradiation area 15a crosses the edge 163 of the object 16 to be processed. The light-shielding part 32 gradually approaches the light-shielding part 33. Therefore, the irradiation area 15a gradually becomes shorter as the light-shielding part 32 moves.

[0163] In this way, the region 168 is irradiated with the laser light, and thus a polysilicon film 16a is formed over the entire region 168. After the laser irradiation of the region 168 is completed, the object 16 is rotated 180° around the Z axis, and the laser light is irradiated again in the same manner. This completes the laser irradiation of the region 169. In the irradiation example 2, the irradiated area outside the object 16 can be reduced. Therefore, damage to the levitation unit 10 can be suppressed.

[0164] (Irradiation example 3) Irradiation example 3 will be described with reference to FIG. 34. FIG. 34 is a top view schematically showing the irradiation area 15a of the workpiece 16 with laser light. The diagram on the left side of FIG. 34 shows the configuration at the start of irradiation, and the diagram on the right side shows the configuration at the end of irradiation. In irradiation example 3, the position of the light-shielding portion 33 is different from that in irradiation example 1. More specifically, the light-shielding portion 33 is arranged so that one end of the irradiation area 15a is located on the -y side of the edge 161 of the workpiece 16. In irradiation example 3, the transport direction is parallel to the edge 161. The positions of the light-shielding portion 32 and the light-shielding portion 33 are constant.

[0165] In top view, one end of the irradiation region 15a is formed to extend beyond the edge 161 toward the -y side. In Irradiation Example 3, the laser light is also irradiated onto an area 170 extending beyond the object 16 to the -y side. The laser light can be reliably irradiated up to the edge 161 on the -y side of the object 16 to be processed. Therefore, the laser light can be uniformly irradiated even near the edge 161.

[0166] (Irradiation example 4) Irradiation example 4 will be described with reference to Figs. 35 and 36. Figs. 35 and 36 are top views schematically showing the workpiece 16 and the laser light irradiation area 15a. Fig. 35 shows the configuration before the start of irradiation, and Fig. 36 shows the configuration after the end of irradiation. In irradiation example 4, the position of the light-shielding part 32 gradually changes while the workpiece 16 is being transported. Note that in irradiation example 4, the transport direction is tilted from the end side 161.

[0167] First, with reference to Figure 35, the points on the object to be processed 16 and their trajectories are defined as follows: As shown in Figure 35, the intersection of end side 162 and boundary line 165 is defined as point C1. The intersection of end side 163 and boundary line 165 is defined as point C2. The intersection of end side 162 and end side 161 is defined as point C3. The intersection of end side 163 and end side 161 is defined as point C4. Points C3 and C4 correspond to the corners of the rectangular object to be processed 16.

[0168] The trajectories of points C1 to C4 during transportation are designated as trajectories T1 to T4, respectively. For example, when the object 16 to be processed is transported in the transport direction, point C1 moves along trajectory T1. Each of trajectories T1 to T4 is a straight line parallel to the transport direction. In top view, the trajectories are arranged in the order of trajectory T2, trajectory T1, trajectory T4, and trajectory T3 from the +y side. Furthermore, as in Irradiation Example 3, one end of the irradiation area 15a is arranged on the -y side of the edge 161 of the object 16 to be processed. In other words, the position of the light-shielding part 33 is adjusted so that the irradiation area 15a extends beyond the edge 161 on the -y side.

[0169] In Irradiation Example 4, when the workpiece 16 is transported along the transport direction, the state becomes as shown in FIG. 36. In FIG. 36, the laser light is irradiated onto an area 168 on the -y side of the boundary line 165. While the workpiece 16 is being transported, the light-shielding portion 32 moves in accordance with the transport. Specifically, when the transport speed is constant, the light-shielding portion 32 moves at a constant speed. The light-shielding portion 32 gradually moves in the +y direction at a constant moving speed. The light-shielding portion 32 moves so that the line connecting points C1 and C2 becomes the boundary line 165. Therefore, even if the edge 161 is inclined from the transport direction, the boundary line 165 and the edge 161 can be made parallel. In other words, the boundary line 165 becomes a straight line inclined from the transport direction.

[0170] Furthermore, the irradiation area 15a extends beyond the locus T3 on the -y side. Therefore, the laser light is also irradiated onto an area 170 extending beyond the -y side of the object 16 to be processed. In addition, in the irradiation example 4, the light-shielding portion 33 is not moved so that the slit length changes depending on the transport, but it may be moved. In other words, the slit length may be constant or may change.

[0171] (Irradiation example 5) Irradiation Example 5 will be described with reference to Figs. 37 and 38. Figs. 37 and 38 are top views schematically showing the configuration of Irradiation Example 5. Fig. 37 shows the configuration before the start of irradiation, and Fig. 38 shows the configuration after the end of irradiation. In Irradiation Example 5, the light-shielding section 32 and the light-shielding section 33 move in accordance with the transport. In Irradiation Example 5, the light-shielding section 33 moves in the +y direction in accordance with the transport.

[0172] In Irradiation Example 5, the position of the light-shielding portion 33 changes along the edge 161 as the object is transported. Similarly to Irradiation Example 4, the position of the light-shielding portion 32 changes along the boundary line 165 parallel to the edge 161 as the object is transported. Therefore, the light-shielding portions 33 and 32 gradually move in the +y direction at the same moving speed. The slit length of the slit mechanism 30 is constant. The line length of the irradiation region 15a is consistent with the distance in the y direction from the edge 161 to the boundary line 165. This prevents the laser light from irradiating an area extending beyond the -y side of the object 16. Therefore, a polysilicon film 16a is formed in region 168.

[0173] Other embodiments A holding mechanism capable of vacuum suction, regardless of whether a valve is provided, may be used as the holding mechanism 12 for holding the workpiece 16 or the substrate 100. In addition, compressed air or an inert gas such as nitrogen may be used as the gas for floating the workpiece 16 or the substrate 100.

[0174] In the second embodiment, the levitation unit 10 has been described as including the precision levitation unit 111, the semi-precise levitation unit 112, and the rough levitation unit 113. However, the levitation unit 10 does not have to include all of the precision levitation unit 111, the semi-precise levitation unit 112, and the rough levitation unit 113. In other words, the levitation unit 10 may include one or more of the precision levitation unit 111, the semi-precise levitation unit 112, and the rough levitation unit 113. For example, the levitation unit 10 may be composed of two units, the precision levitation unit 111 and the rough levitation unit 113. In this case, the rough levitation unit 113 is disposed adjacent to the precision levitation unit 111.

[0175] 6 to 14, laser light can be continuously irradiated onto multiple substrates. An example in which the transport device 600 simultaneously levitates and transports two substrates 100, 101 will be described using FIGS. 39 to 42. Note that descriptions that overlap with those described in the second embodiment will be omitted where appropriate.

[0176] As shown in Fig. 39, while the first substrate 100 is being irradiated with laser light, the second substrate 101 is carried into the fourth region 60d of the floating unit 10. In Fig. 39, the laser light is irradiated onto the substrate 100 with the edge of the substrate 100 tilted from the Y direction. Then, when the transport unit 11b transports the substrate 100 to the second region 60b, the first laser irradiation of the substrate 100 is completed.

[0177] After the laser irradiation of the substrate 100 is completed, the alignment mechanism 69b rotates the substrate 100 as shown in FIG. 40. This causes the edges of the substrate 100 to be parallel to the X and Y directions. At this time, the transport unit 11a transports the substrate 101 in the +Y direction. Therefore, the substrate 101, which was in the fourth region 60d in FIG. 39, has moved to the first region 60a in FIG. 40. In other words, the transport of the substrate 101 by the transport unit 11a and the transport of the substrate 100 by the transport unit 11b are performed simultaneously.

[0178] Then, after the alignment mechanism 69a rotates the substrate 101, the transport unit 11b transports the substrate 101. As a result, as shown in FIG. 41, the substrate 101 passes through the irradiation region 15a with the edge of the substrate 101 tilted from the Y direction. At this time, the transport unit 11c transports the substrate 100 in the -Y direction. Therefore, the substrate 100, which was in the second region 60b in FIG. 40, has moved to the third region 60c in FIG. 41. In other words, the transport of the substrate 101 by the transport unit 11b and the transport of the substrate 100 by the transport unit 11c are performed simultaneously. Then, when the substrate 101 is transported to the second region 60b, the first laser irradiation of the substrate 101 is completed.

[0179] After the laser irradiation of the substrate 101 is completed, the alignment mechanism 69b rotates the substrate 101. As a result, as shown in FIG. 42, the edges of the substrate 101 become parallel to the X and Y directions. At this time, the transport unit 11d transports the substrate 100 in the -X direction. Therefore, the substrate 101, which was in the third region 60c in FIG. 41, has moved to the fourth region 60d in FIG. 42. In other words, while the alignment mechanism 69b rotates the substrate 101, the transport unit 11d transports the substrate 100.

[0180] Furthermore, in the fourth region 60d, as shown in FIG. 42, the rotation mechanism 68 rotates the substrate 100 by 180°. Then, the above-described process is repeated for the substrates 101 and 100. That is, the substrates 101 and 100 are swapped, and the processes shown in FIGS. 39 to 42 are performed. Therefore, in the second laser irradiation, the laser light is irradiated onto the region that was not irradiated with the laser light in the first laser irradiation. That is, in the first laser irradiation, the laser light is irradiated onto one half of the substrate 100, and in the second laser irradiation, the laser light is irradiated onto the other half of the substrate 100.

[0181] In this way, the transport device 600 can transport multiple levitated substrates 100, 101 simultaneously. The transport units 11a to 11d sequentially rotate the substrates 100, 101. As a result, two substrates 100, 101 pass through the irradiation area 15a consecutively. The laser light can be continuously irradiated onto multiple substrates. Furthermore, the waiting time for loading or transporting the substrates into the transport device 600 can be shortened. This can shorten the takt time and improve productivity. Of course, the number of substrates that the transport device 600 can simultaneously levitate is not limited to two, and may be three or more.

[0182] The present invention is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the invention.

[0183] This application claims priority based on Japanese Patent Application No. 2021-12922, filed on January 29, 2021, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0184] 1. Laser irradiation device 10 Levitation Unit 11 Transport unit 12 Retention mechanism 13 Moving mechanism 14 Laser irradiation unit 15 Laser light 15a Irradiation area 16 Object to be treated 60a First Area 60b Second Region 60c Third Realm 60d The Fourth Realm 60e Process Area 60f passing area 670~676 End floating unit 68 Rotation Mechanism 69a, 69b Alignment mechanism 100 boards 161 Edge 162 Edge 163 Edge 164 Edge 165 Borderline 300 OLED display 310 Substrate 311 TFT layer 311a TFT 312 Organic layer 312a Organic EL light emitting device 312b Bulkhead 313 Color filter layer 313a Color filter (CF) 314 Sealing substrate 401 Glass substrate 402 gate electrode 403 Gate insulating film 404 Amorphous silicon film 405 Polysilicon film PX pixels

Claims

1. A conveying device that conveys a substrate in order to irradiate the substrate with a line-shaped laser beam, a substrate levitation unit that levitates the substrate on its upper surface; a holding mechanism for holding the substrate; a moving mechanism that moves the holding mechanism in a direction inclined from a direction perpendicular to a longitudinal direction of the line-shaped laser beam in a top view so as to change an irradiation position of the laser beam on the substrate, A transport device that transports the substrate with the edge of the substrate tilted from the orthogonal direction in a top view, irradiates the substrate with the laser light, and then rotates the substrate on the substrate levitation unit to make the edge of the substrate parallel to the orthogonal direction.

2. the holding mechanism has a plurality of adsorption cells arranged along the conveying direction, the plurality of suction cells suction the lower surface of the substrate, thereby causing the holding mechanism to hold the substrate; 2. The transport device according to claim 1, wherein a valve is provided for each of the adsorption cells.

3. the adsorption cell of the holding mechanism is made of a metal material, 3. The transport device according to claim 1, wherein an adsorption groove is formed on the upper surface of the adsorption cell.

4. 4. The conveying device according to claim 1, wherein an angle formed between the orthogonal direction and the conveying direction is greater than 0° and equal to or less than 5° when viewed from above.

5. the substrate is rectangular; 5. The transport device according to claim 1, wherein the transport direction is inclined from four edge sides of the substrate when viewed from above.

6. 6. The transport device according to claim 1, wherein an angle formed between the orthogonal direction and the edge of the substrate is greater than 0° and equal to or less than 5° when viewed from above.

7. 7. The transport device according to claim 1, further comprising a rotation mechanism that rotates the substrate on the substrate floating unit.

8. 8. The conveying device according to claim 1, further comprising a slit mechanism for adjusting an irradiation position of the laser light in the longitudinal direction.

9. A conveying device that conveys a substrate in order to irradiate the substrate with a line-shaped laser beam, a first substrate levitation unit disposed below the substrate and levitating the substrate, the first substrate levitation unit being disposed from the center of the substrate toward one end of the substrate when viewed from above; a second substrate levitation unit disposed below the substrate and levitating the substrate, the second substrate levitation unit being disposed from the center of the substrate toward the other end of the substrate when viewed from above; a holding mechanism disposed below a central portion of the substrate and configured to hold the substrate by suction; a moving mechanism that moves the holding mechanism along a gap between the first substrate levitation unit and the second substrate levitation unit in order to move the substrate relative to the irradiation position of the laser light, A transport device that transports the substrate with the edge of the substrate tilted from a direction perpendicular to the longitudinal direction of the line-shaped laser light when viewed from above, irradiates the substrate with the laser light, and then rotates the substrate on the first and second substrate levitation units to make the edge of the substrate parallel to the perpendicular direction.

10. A transport method for transporting a substrate in order to irradiate the substrate with a line-shaped laser beam, comprising: (a) a substrate levitation unit levitating the substrate on its upper surface; (b) holding the substrate with a holding mechanism; (c) moving the holding mechanism in a direction inclined from a direction perpendicular to a longitudinal direction of the line-shaped laser beam in a top view so as to change an irradiation position of the laser beam on the substrate; a conveying method in which, when viewed from above, the substrate is conveyed with the edge of the substrate tilted from the orthogonal direction, the substrate is irradiated with the laser light, and then the substrate on the substrate levitation unit is rotated to make the edge of the substrate parallel to the orthogonal direction.

11. the holding mechanism has a plurality of adsorption cells arranged along the conveying direction, the plurality of suction cells suction the lower surface of the substrate, thereby causing the holding mechanism to hold the substrate; The method according to claim 10, wherein a valve is provided for each of the adsorption cells.

12. the adsorption cell of the holding mechanism is made of a metal material, 12. The transport method according to claim 10, wherein an adsorption groove is formed on the upper surface of the adsorption cell.

13. The conveying method according to any one of claims 10 to 12, wherein an angle formed between the orthogonal direction and the conveying direction is greater than 0° and not greater than 5° when viewed from above.

14. the substrate is rectangular; The transport method according to any one of claims 10 to 13, wherein the transport direction is inclined from the four end sides of the substrate when viewed from above.

15. The transport method according to any one of claims 10 to 14, wherein an angle formed between the orthogonal direction and the edge of the substrate is greater than 0° and equal to or less than 5° when viewed from above.

16. 16. The transfer method according to claim 10, wherein the substrate on the substrate levitation unit is rotated before the irradiation with the laser light.

17. The conveying method according to any one of claims 10 to 16, wherein a slit mechanism provided in an optical system of the laser beam adjusts the irradiation position of the laser beam in the longitudinal direction.

18. A transport method for transporting a substrate in order to irradiate the substrate with a line-shaped laser beam, comprising: (A) using a first substrate levitation unit arranged below the substrate to levitate one end side of the substrate from a center portion of the substrate as viewed from above, and using a second substrate levitation unit arranged below the substrate to levitate the other end side of the substrate from the center portion of the substrate as viewed from above; (B) using a holding mechanism disposed below the center of the substrate to hold the substrate by suction; (C) moving the holding mechanism along a gap between the first substrate levitation unit and the second substrate levitation unit to move the substrate relative to the irradiation position of the laser light; A transport method in which, when viewed from above, the substrate is transported with the edge of the substrate tilted from a direction perpendicular to the longitudinal direction of the line-shaped laser light, and the laser light is irradiated, and then the substrate on the first and second substrate levitation units is rotated to make the edge of the substrate parallel to the perpendicular direction.

19. (s1) forming an amorphous film on a substrate; (s2) irradiating the substrate with a line-shaped laser beam to anneal the amorphous film so as to crystallize the amorphous film and form a crystallized film; The annealing step (s2) includes: (sa) a substrate levitation unit levitating the substrate on its upper surface; (sb) holding the substrate with a holding mechanism; (sc) moving the holding mechanism in a direction inclined from a direction perpendicular to a longitudinal direction of the line-shaped laser beam in a top view so as to change an irradiation position of the laser beam on the substrate; A method for manufacturing a semiconductor device, in which the substrate is transported with an edge of the substrate tilted from the orthogonal direction when viewed from above, the substrate is irradiated with the laser light, and then the substrate on the substrate levitation unit is rotated to make the edge of the substrate parallel to the orthogonal direction.

20. the holding mechanism has a plurality of adsorption cells arranged along the conveying direction, the plurality of suction cells suction the lower surface of the substrate, thereby causing the holding mechanism to hold the substrate; 20. The method for manufacturing a semiconductor device according to claim 19, wherein a valve is provided for each of the adsorption cells.

21. the adsorption cell of the holding mechanism is made of a metal material, 21. The method for manufacturing a semiconductor device according to claim 19, wherein an adsorption groove is formed on the upper surface of the adsorption cell.

22. 22. The method for manufacturing a semiconductor device according to claim 19, wherein an angle formed between the orthogonal direction and the transport direction is greater than 0° and equal to or less than 5° when viewed from above.

23. the substrate is rectangular; 23. The method for manufacturing a semiconductor device according to claim 19, wherein the transport direction is inclined from the four end sides of the substrate when viewed from above.

24. 24. The method for manufacturing a semiconductor device according to claim 19, wherein an angle formed between the orthogonal direction and the edge of the substrate is greater than 0° and equal to or less than 5° when viewed from above.

25. 25. The method for manufacturing a semiconductor device according to claim 19, wherein the substrate on the substrate levitation unit is rotated before the irradiation with the laser light.

26. 26. The method for manufacturing a semiconductor device according to claim 19, wherein a slit mechanism provided in an optical system of the laser beam adjusts the irradiation position of the laser beam in the longitudinal direction.

27. (S1) forming an amorphous film on a substrate; (S2) irradiating the substrate with a line-shaped laser beam to anneal the amorphous film so as to crystallize the amorphous film and form a crystallized film, The annealing step (S2) includes: (SA) using a first substrate levitation unit to levitate one end side of the substrate from a center portion of the substrate when viewed from above, and using a second substrate levitation unit to levitate the other end side of the substrate from the center portion of the substrate when viewed from above; (SB) a step of suction-holding the substrate using a holding mechanism arranged below the center of the substrate; (SC) a step of moving the holding mechanism along a gap between the first substrate levitation unit and the second substrate levitation unit to move the substrate relative to the irradiation position of the laser light, A method for manufacturing a semiconductor device, comprising: transporting the substrate with an edge of the substrate tilted from a direction perpendicular to the longitudinal direction of the line-shaped laser light when viewed from above; irradiating the substrate with the laser light; and then rotating the substrate on the first and second substrate levitation units to make the edge of the substrate parallel to the perpendicular direction.

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