Laser irradiation device, laser irradiation method, and method for manufacturing semiconductor device

Abstract

A laser irradiation device according to the present embodiment includes: a laser light source that generates laser light; an optical system that irradiates a substrate with laser light; a transfer mechanism that transfers the substrate; and a drive unit that drives the transfer mechanism. The drive unit comprises: a first motor and a second motor that move the transfer mechanism; a PWM driver that PWM-drives the first motor; an analog driver that linearly drives the second motor; and a control unit that controls the analog driver and the PWM driver.

Description

Laser irradiation device, laser irradiation method, and semiconductor device manufacturing method

[0001] The present disclosure relates to a laser irradiation apparatus, a laser irradiation method, and a method for manufacturing a semiconductor device.

[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 mechanism transports the substrate. Furthermore, the levitation unit has a common loading and unloading position for the substrate. The transport mechanism transports the substrate along each side of the levitation unit. The substrate then circulates twice above the levitation unit, and laser light is irradiated onto almost the entire surface of the substrate.

[0004] JP 2018-64048 A

[0005] In such a laser irradiation apparatus, it is desirable to perform the laser irradiation process 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, a laser irradiation device includes a laser light source that generates laser light, an optical system that irradiates a substrate with the laser light, a transport mechanism that transports the substrate, and a drive unit that drives the transport mechanism, and the drive unit includes a first motor and a second motor that move the transport mechanism, a PWM driver that PWM-drives the first motor, an analog driver that linearly drives the second motor, and a control unit that controls the analog driver and the PWM driver.

[0008] According to one embodiment, a laser irradiation method includes: (A1) generating laser light; (A2) irradiating a substrate with the laser light; and (A3) transporting the substrate by a transport mechanism, wherein the transport mechanism includes a drive unit provided for transporting the substrate, and the drive unit includes a first motor and a second motor for moving the transport mechanism, a PWM driver for PWM driving the first motor, an analog driver for linearly driving the second motor, and a control unit for controlling the analog driver and the PWM driver.

[0009] According to one embodiment, a method for manufacturing a semiconductor device includes the steps of (S1) generating laser light, (S2) irradiating a substrate with the laser light, and (S3) transporting the substrate by a transport mechanism, wherein the transport mechanism includes a drive unit provided for transporting the substrate, and the drive unit includes a first motor for moving the transport mechanism, a second motor for moving the transport mechanism, a PWM driver for PWM driving the first motor, an analog driver for linearly driving the second motor, and a control unit for controlling the analog driver and the PWM driver.

[0010] According to the embodiment, the laser irradiation process can be carried out quickly and stably.

[0011] 1 is a perspective view showing the overall configuration of a conveying device; FIG. 2 is an xy plan view schematically showing the configuration of the conveying device; FIG. 3 is an xy sectional view schematically showing the configuration of the laser irradiation device; FIG. 4 is a yy sectional view schematically showing the configuration of the laser irradiation device; FIG. 5 is an xy plan view for explaining the conveying operation of the conveying device; FIG. 6 is an xy plan view for explaining the conveying operation of the conveying device; FIG. 7 is an xy plan view for explaining the conveying operation of the conveying device; FIG. 8 is a perspective view schematically showing the configuration of a conveying mechanism and its drive unit; FIG. 9 is a perspective view schematically showing the configuration of the conveying mechanism; FIG. 10 is a view for explaining the operation of a PWM driver; FIG. 11 is a view for explaining the operation of an analog driver; FIG. 12 is a graph for explaining operation examples 1 and 2 of the conveying mechanism; FIG. 13 is an xy plan view showing the irradiation start position and the irradiation end position of laser light; FIG. 14 is a graph for explaining operation example 3 of the conveying mechanism; FIG. 15 is a perspective view showing the configuration of a conveying mechanism in embodiment 2; FIG. 16 is a perspective view showing the configuration of a conveying mechanism in embodiment 2; FIG. 17 is a perspective view showing the configuration of a conveying mechanism in embodiment 2;

[0012] Hereinafter, a laser irradiation apparatus, a laser irradiation method, and a semiconductor device manufacturing method according to the present embodiment will be described with reference to the drawings. The laser irradiation apparatus includes a transport device for transporting a substrate. In the following description, the object to be processed, which is irradiated with the laser, will be described as a glass substrate with an amorphous silicon film, but the object to be processed is not particularly limited.

[0013] An example of a laser irradiation device is an excimer laser annealing device that irradiates an amorphous silicon film formed on a substrate with laser light to form a polysilicon film. Therefore, laser irradiation devices are used to manufacture TFT (Thin Film Transistor) array substrates in the manufacturing process of liquid crystal display panels and organic EL (ElectroLuminescence) display panels. In other words, laser irradiation devices are used in the manufacturing process of semiconductor devices such as TFT array substrates.

[0014] Embodiment 1 (Basic Configuration of Laser Irradiation Apparatus) First, the basic configuration of the laser irradiation apparatus 1 and the transport device 6 will be described with reference to Figs. 1 to 4. Fig. 1 is a perspective view for explaining the basic configuration of the transport device 6. Fig. 2 is a top view of the transport device 6. Fig. 3 is a side view showing the configuration of the laser irradiation apparatus 1 equipped with the transport device 6. Fig. 4 is a side view showing the configuration of the laser irradiation apparatus 1 equipped with the transport device 6. Each figure has been appropriately simplified.

[0015] 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 laser spot, which is perpendicular to the line direction. The laser irradiation device 1 irradiates the substrate 100 with linear laser light along the y direction while transporting (scanning) the substrate 100. The x and y directions are directions along the edges of the rectangular substrate 100.

[0016] The levitation unit 60 is configured to eject gas from the surface of the levitation unit 60, and the gas ejected from the surface of the levitation unit 60 is sprayed onto the underside of the substrate 100, thereby causing the substrate 100 to levitate. The levitation unit 60 is disposed on a stand 640.

[0017] Furthermore, the rectangular levitation unit 60 is divided into six regions 60a to 60f in the xy plane. Specifically, the levitation unit 60 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 rectangular region including corners on the -x and +y sides (the lower left corner in FIG. 2). The second region 60b is a rectangular region including corners on the +x and +y sides (the upper left corner in FIG. 2). The third region 60c is a rectangular region including corners on the +x and -y sides (the upper right corner in FIG. 2). The fourth region 60d is a rectangular region including corners on the -x and -y sides (the lower right corner in FIG. 2). Of course, the regions 60a to 60f are not limited to being rectangular. For example, in the xy plane, the regions 60a to 60f may be trapezoidal or other shapes.

[0018] The process area 60e is located between the first area 60a and the second area 60b. The process area 60e is an area irradiated with laser light. That is, the process area 60e includes an irradiation position 65 of the laser light 15. The passage area 60f is located between the third area 60c and the fourth area 60d. Therefore, the +y-side half of the levitation unit 60 (the left half of FIG. 2) is made up of the first area 60a, the process area 60e, and the second area 60b, in order from the -x side (the lower side of FIG. 2). The -y-side half of the levitation unit 60 (the right half of FIG. 2) is made up of the third area 60c, the passage area 60f, and the fourth area 60d, in order from the +x side. As shown in Patent Document 1, the transport device 6 circulates and transports the substrate 100 above the levitation unit 60. In FIG. 2, the two substrates 100 floating above the floating unit 60 are shown as substrates 100a and 100b.

[0019] In the xy-plane view, the first region 60a to the fourth region 60d may have approximately the same area. Of course, the first region 60a to the fourth region 60d may have different sizes or shapes. In the xy-plane view, the process region 60e and the passage region 60f may have a rectangular shape with approximately the same area. In this case, the first region 60a and the fourth region 60d are arranged side by side in the y-direction. The second region 60b and the fourth region 60d are arranged side by side in the y-direction. The process region 60e and the passage region 60f are arranged side by side in the y-direction.

[0020] Of course, the process area 60e and the passing area 60f may have different sizes or shapes. The process area 60e and the passing area 60f are not limited to being rectangular. For example, in the xy plane view, the process area 60e and the passing area 60f may have other shapes, such as a trapezoid. Also, for the sake of simplicity, the levitation unit 60 is divided into six areas 60a to 60f here, but it may also be divided into smaller levitation unit cells.

[0021] 2, an end levitation unit 67 is provided outside the levitation unit 60 (note that a part of the end levitation unit 67 is omitted in FIG. 1). A rotation mechanism 68 is provided in the fourth region 60d. A rotation mechanism 69 is provided in the third region 60c. The rotation mechanism 68, the rotation mechanism 69, and the end levitation unit 67 will be described later. The transport device 6 includes a chamber 601 that houses the levitation unit 60, the end levitation unit 67, etc. Note that a circular opening may be formed in the levitation unit cell in order to provide the rotation mechanisms 68 and 69 in the levitation unit 60.

[0022] As shown in FIG. 1, the substrate 100 is transported sequentially through the first to fourth regions 60a to 60d. That is, the substrate 100 is transported from the first region 60a in the +x direction, passes through the process region 60e, and moves to the second region 60b. The transport direction of the substrate 100 during laser irradiation may be parallel to the x direction or tilted from the x direction. The substrate 100 is irradiated with laser light as it passes through the process region 60e. The substrate 100 is transported from the second region 60b in the -y direction, and moves to the third region 60c.

[0023] When the substrate 100 is transported from the third region 60c in the -x direction, it passes through the passage region 60f and moves to the fourth region 60d. In the passage region 60f, the unevenness of the laser light irradiation is monitored. For example, in the passage region 60f, the unevenness of the irradiation is monitored by a camera (not shown). When the substrate 100 is transported from the fourth region 60d in the +y direction, it moves to the first region 60a.

[0024] In this way, the substrate 100 is transported in a direction that changes from the +x direction to the -y direction, the -x direction, and then back to the +y direction. In other words, the substrate 100 is transported in a circulating manner through the first region 60a to the fourth region 60d. Strictly speaking, the fourth region 60d is the position where the substrate 100 is carried in and out, so the substrate 100 is transported in the order of the fourth region 60d, the first region 60a, the second region 60b, and the third region 60c. Of course, the position where the substrate 100 is carried in and out is not limited to the fourth region 60d.

[0025] Furthermore, the substrate 100 may be circulated in the opposite direction. For example, the substrate 100 may be transported in the order of the fourth region 60d, the third region 60c, the second region 60b, and the first region 60a. That is, in the plan view of FIG. 2 , the transport direction may be clockwise or counterclockwise. The transport direction may be switched as appropriate depending on the processing of the laser irradiation device 1.

[0026] As described above, the laser irradiation device 1 includes four transport mechanisms 61_1 to 61_4 to circulate and transport the substrate 100. The transport mechanisms 61_1 to 61_4 are provided outside the levitation unit 60, near each side of the levitation unit 60.

[0027] The levitation unit 60 has a rectangular shape when viewed in the xy plane, and each of the transport mechanisms 61_1 to 61_4 is provided to transport the substrate 100 along each side of the levitation unit 60. Note that although each of the transport mechanisms 61_1 to 61_4 is provided outside each side of the levitation unit 60, they may also be provided inside the levitation unit 60.

[0028] Each of the transport mechanisms 61_1 to 61_4 moves the substrate 100 linearly. The transport mechanism 61_1 moves the substrate 100 in the +x direction. More specifically, the transport mechanism 61_1 transports the substrate 100 in an oblique direction inclined from the +x direction. In other words, the transport mechanism 61_1 moves the substrate 100 in the +x direction and the -y direction. This moves the substrate 100 from the first region 60a to the second region 60b.

[0029] The transport mechanism 61_2 moves the substrate 100 in the -y direction. As a result, the substrate 100 moves from the second region 60b to the third region 60c. The transport mechanism 61_3 moves the substrate 100 in the -x direction. As a result, the substrate 100 moves from the third region 60c to the fourth region 60d. The transport mechanism 61_4 moves the substrate 100 in the +y direction. As a result, the substrate 100 moves from the fourth region 60d to the first region 60a.

[0030] Specifically, the transport mechanism 61_1 is provided on the side of the floating unit 60 on the +y direction side and includes a holding mechanism 62_1 and a moving mechanism 63_1 (see FIG. 4 ). The holding mechanism 62_1 suction-holds the substrate 100. The holding mechanism 62_1 can be configured using a vacuum suction mechanism equipped with a porous body. Note that the holding mechanism 62_1 is not limited to being made of a porous material, and may be made of resin, aluminum, or other alloys. The holding mechanism 62_1 (vacuum suction mechanism) is connected to an exhaust port (not shown), which is connected to an ejector, vacuum pump, or the like. Therefore, a negative pressure for sucking gas acts on the holding mechanism 62_1, allowing the holding mechanism 62_1 to hold the substrate 100.

[0031] The holding mechanism 62_1 also includes a lifting mechanism (not shown in FIGS. 1 to 4) 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 62_1 lifts up to the suction position and picks up the substrate 100. The holding mechanism 62_1 also lowers to the standby position when the suction is released.

[0032] 4, in this embodiment, holding mechanism 62_1 holds substrate 100 by sucking the surface (lower surface) of substrate 100 opposite to the surface (upper surface) irradiated with laser light, that is, the surface of substrate 100 facing levitation unit 60. Furthermore, holding mechanism 62_1 holds the end of substrate 100 in the +y direction (that is, the end in the direction perpendicular to the transport direction of substrate 100).

[0033] The moving mechanism 63_1 included in the transport mechanism 61_1 is connected to the holding mechanism 62_1. The moving mechanism 63_1 is configured to be able to move the holding mechanism 62_1 in the transport direction. The transport mechanism 61_1 (holding mechanism 62_1 and moving mechanism 63_1) is provided on the end side of the levitation unit 60 in the +y direction, and the substrate 100 is transported by the moving mechanism 63_1 moving in the transport direction while the holding mechanism 62_1 holds the substrate 100.

[0034] As shown in FIG. 4 , for example, the moving mechanism 63_1 is configured to slide the end of the levitation unit 60 in the +y direction along the transport direction. The moving mechanism 63_1 slides the end of the levitation unit 60 along the transport direction, thereby transporting the substrate 100. At this time, the transport speed of the substrate 100 can be controlled by controlling the moving speed of the moving mechanism 63_1. The moving mechanism 63_1 includes, for example, an actuator and a guide mechanism (not shown). For example, the actuator includes a linear motor or the like. The guide mechanism is a linear guide, an air bearing guide, or the like. The configurations of the moving mechanism 63_1, the transport mechanism 61_1, and the like will be described later.

[0035] As shown in Figures 3 and 4, the substrate 100 is irradiated with laser light 15. In Figures 1 and 2, the position irradiated with laser light 15 is referred to as irradiation position 65. The irradiation position 65 is a straight line extending in the y direction. For example, the laser irradiation device 1 is a laser annealing device, and in this case, an excimer laser or the like can be used for the laser irradiation unit 14. As shown in Figure 3, the laser irradiation unit 14 includes a laser light source 14a and an optical system 14b including a cylindrical lens. The laser light supplied from the laser light source 14a is converted into a line by the optical system 14b having a cylindrical lens. The substrate 100 is irradiated with a line-shaped laser light 15 (line beam) whose focal point extends in the y direction (see Figure 1). In other words, the irradiation position 65 on the substrate 100 extends in the y direction.

[0036] In the transport device 6, the substrate 100 is transported in the transport direction while the substrate 100 is floated using the levitation unit 60 and the lower surface of the substrate 100 is held using the transport mechanism 61_1. At this time, the transport mechanism 61_1 provided in the laser irradiation device 1 transports the substrate 100 while holding the substrate 100 at a position that does not overlap with the irradiation position 65 in a plan view (i.e., when viewed from the z direction). In other words, as shown in FIG. 2 , when the substrate 100 is transported in the transport direction, the position at which the transport mechanism 61_1 holds the substrate 100 (corresponding to the position of the holding mechanism 62_1) does not overlap with the irradiation position 65.

[0037] In this way, the substrate 100 can be transported from the first region 60a to the second region 60b by moving the moving mechanism 63_1 in the +x direction while the holding mechanism 62_1 holds the substrate 100. The substrate 100 passes through the process region 60e during transport by the transport mechanism 61_1. Therefore, the laser light 15 is irradiated onto the substrate 100 when the substrate 100 is transported from the first region 60a to the second region 60b.

[0038] The transport mechanism 61_1 moves the substrate 100 in the x direction so as to change the irradiation position 65 of the laser light 15 on the substrate 100. Note that the transport direction of the transport mechanism 61_1 is inclined with respect to the x direction, but it may be parallel to the x direction. In other words, the transport direction may be inclined with respect to the line direction.

[0039] The transport mechanism 61_2 is provided on the side of the levitation unit 60 on the +x direction side. The transport mechanism 61_3 is provided on the side of the levitation unit 60 on the -y direction side. The transport mechanism 61_4 is provided on the side of the levitation unit 60 on the -x direction side. The transport mechanisms 61_2, 61_3, and 61_4 each include a holding mechanism and a moving mechanism, similar to the transport mechanism 61_1. The holding mechanisms of the transport mechanisms 61_2, 61_3, and 61_4 hold the substrate 100 by vacuum suction. The moving mechanisms of the transport mechanisms 61_2, 61_3, and 61_4 include, for example, an actuator and a guide mechanism (not shown). For example, the actuator includes a linear motor or a servo motor. The guide mechanism is a linear guide, an air bearing guide, or the like.

[0040] In the laser irradiation device 1, the length of the irradiation position 65 in the y direction is approximately half the length of the substrate 100 in the y direction. Therefore, when the substrate 100 passes the irradiation position 65, half of the area of ​​the substrate 100 in the y direction is irradiated with the laser light. Therefore, the substrate 100 is transported so as to circulate twice over the levitation unit 60. In this manner, the laser light is irradiated onto almost the entire surface of the substrate 100. Of course, the length of the irradiation position 65 in the y direction is not limited to half the length of the substrate 100. For example, the length of the irradiation position 65 in the y direction may be longer than half the length of the substrate 100. Furthermore, the length of the irradiation position 65 in the y direction may be the same size as the substrate 100 so that the entire surface of the substrate 100 can be irradiated with the laser light in one circulation. Furthermore, the laser irradiation device 1 may circulate the substrate 100 two or more times to irradiate the substrate 100 with the laser light two or more times.

[0041] When irradiating substantially the entire surface of the substrate 100 with laser light, as shown in FIGS. 1 and 2 , a rotation mechanism 68 is provided in the fourth region 60d of the levitation unit 60. The rotation axis of the rotation mechanism 68 is parallel to the z direction. The rotation mechanism 68 rotates the substrate 100 by 180 degrees while maintaining the horizontal plane (xy plane) of the substrate 100. That is, after the substrate 100 is transported from the first region 60a to the second region 60b using the transport mechanism 61_1 and irradiated with the laser light 15, the substrate 100 is transported using the transport mechanisms 61_2 to 61_4 while the rotation mechanism 68 rotates the substrate 100 by 180 degrees. Then, the substrate 100 is transported again from the region 60a to the region 60b using the transport mechanism 61_1 and irradiated with the laser light 15, thereby irradiating the entire surface of the substrate 100 with the laser light 15.

[0042] 2, an end levitation unit 67 is provided outside the levitation unit 60. The end levitation unit 67 is disposed directly below the end of the substrate 100. Like the levitation unit 60, the end levitation unit 67 ejects gas (air) onto the substrate 100 to levitate the substrate 100.

[0043] For example, while the rotation mechanism 68 is rotating the substrate 100, a portion of the substrate 100 protrudes from the fourth region 60d. During rotation, the end levitation unit 67 ejects gas toward the end of the substrate 100 that protrudes from the fourth region 60d. A levitation force is generated on the portion of the substrate 100 that protrudes from the levitation unit 60. In this manner, the rotation mechanism 68 can rotate the substrate 100 without damaging the substrate 100. The transport mechanism 61_3 moves between the end levitation unit 67 and the levitation unit 60.

[0044] A rotation mechanism 69 is also provided in the third region 60c. The rotation mechanism 69 rotates the substrate 100 around the Z axis, similar to the rotation mechanism 68. By rotating the substrate 100, the rotation mechanism 69 adjusts the angle of the substrate 100 when the substrate 100 moves from the third region 60c to the fourth region 60d. For example, the rotation mechanism 69 rotates the substrate 100 so that the edge of the substrate 100 is parallel to the x direction. An end floating unit 67 may also be provided outside the third region 60c. The rotation mechanism 69 may be omitted.

[0045] Next, the transport operation of the substrate 100 will be described with reference to Figures 5 to 7. Figures 5 to 7 are diagrams for explaining the operation of circulating and transporting the substrate 100, and are xy plan views of the transport device 6 as seen from above. In Figures 5 to 7, the levitation unit 60 simultaneously levitates two substrates 100a and 100b. Figures 5 to 7 also show the configuration of each stage in the circulatory transport. Note that the end levitation unit 67 is omitted from Figures 5 to 7.

[0046] First, as shown in the transport start stage in FIG. 5 , the substrate 100a is in the first region 60a, and the substrate 100b is in the fourth region 60d. The transport mechanism 61_1 transports the substrate 100a in the transport direction, causing the substrate 100a to pass through the process region 60e. This results in the first laser irradiation of the substrate 100a. The transport mechanism 61_4 transports the substrate 100b in the y direction. When the transport by the transport mechanisms 61_1 and 61_4 is completed, the configuration is as shown in the transport completion stage in FIG. 5 . At this stage, the substrate 100a is in the second region 60b, and the substrate 100b is in the first region 60a.

[0047] Next, as shown in the -x movement stage in Figure 6, the transport mechanism 61_1 starts moving in the -x direction. That is, the transport mechanism 61_1 moves in the -x direction without holding the substrates 100a and 100b. At this time, the transport mechanism 61_2 is transporting the substrate 100a in the -y direction. That is, the substrate 100a is moving from the second region 60b toward the third region 60c.

[0048] When the movement of the transport mechanism 61_1 in the -x direction is completed, the transport start stage shown in FIG. 6 is reached. At this time, the substrate 100b is in the first region 60a. Furthermore, since the transport of the substrate 100a by the transport mechanism 61_2 has been completed, the substrate 100a is in the third region 60c. Furthermore, at the transport start stage shown in FIG. 6, the rotation mechanism 69 may rotate the substrate 100a. In other words, the rotation mechanism 69 may rotate the substrate 100a after the transport by the transport mechanism 61_2 has been completed and before the transport by the transport mechanism 61_3.

[0049] Then, the transport mechanism 61_1 transports the substrate 100b in the transport direction, causing the substrate 100b to pass through the process region 60e. This completes the first laser irradiation of the substrate 100b. Furthermore, the transport mechanism 61_3 transports the substrate 100a in the -x direction. When the transport by the transport mechanisms 61_1 and 61_3 is completed, the rotation stage shown in FIG. 7 is reached. Here, the substrate 100a is in the fourth region 60d, and the substrate 100b is in the second region 60b. At this stage, the rotation mechanism 68 rotates the substrate 100a by 180° around the z axis. Furthermore, the transport mechanism 61_2 transports the substrate 100b in the -y direction, causing the substrate 100b to move toward the third region 60c.

[0050] When the rotation of the substrate 100a and the transport by the transport mechanism 61_2 are completed, the transport stage shown in FIG. 7 is reached. Here, the substrate 100a is in the fourth region, and the substrate 100b is in the third region 60c. The transport mechanism 61_4 transports the substrate 100a in the +y direction, and the transport mechanism 61_3 transports the substrate 100b in the -x direction. When the transport by the transport mechanisms 61_4 and 61_3 is completed, the substrate 100a moves to the first region 60a, and the substrate 100b moves to the fourth region 60d. Also, during the transport stage shown in FIG. 7, the rotation mechanism 69 may rotate the substrate 100b. That is, the rotation mechanism 69 may rotate the substrate 100b after the transport by the transport mechanism 61_2 is completed and before the transport by the transport mechanism 61_3.

[0051] Therefore, the process returns to the start of transport in Fig. 5. Then, by performing the same operation, substrates 100a and 100b are transported two times around the levitation unit 60. Between the first and second transport rounds, the rotation mechanism rotates substrates 100a and 100b by 180°. As a result, the entire surfaces of substrates 100a and 100b are irradiated with laser light.

[0052] 2 controls the transport operations of the transport mechanisms 61_1 to 61_4 and the laser irradiation process. Here, the substrate 100 is irradiated with laser light during transport by the transport mechanism 61_1. Therefore, high positional accuracy is required for transport by the transport mechanism 61_1. That is, to make the irradiation intensity of the laser light uniform, the transport speed of the transport mechanism 61_1 needs to be constant at a desired speed. Alternatively, the transport height of the substrate 100 needs to be constant during laser irradiation. On the other hand, the substrate 100 is not irradiated with laser light during transport by the transport mechanisms 61_2, 61_3, and 61_4. High positional accuracy is not required for transport by the transport mechanisms 61_2, 61_3, and 61_4.

[0053] Therefore, in this embodiment, the transport mechanisms 61_2, 61_3, and 61_4 use general-purpose drive units such as linear motors and AC servo motors. On the other hand, the transport mechanism 61_1, which requires high positional accuracy, uses two motors. Specifically, the transport mechanism 61_1 is driven by two types of linear motors. The drive unit 610 of the transport mechanism 61_1 and its control will be described below with reference to FIG. 8. FIG. 8 is a diagram showing the configuration of the transport mechanism 61_1 and its drive unit 610.

[0054] The transport mechanism 61_1 includes a base 611, an x-slide unit 613, a linear motor 621, a linear motor 622, a stator 623, a y-linear motor 631, and a y-slide unit 633.

[0055] The base 611 is fixed on a stand 640. A stator 623 is provided on the base 611 along the x direction. The stator 623 is the stator of the linear motors 621 and 622, and has a plurality of permanent magnets. In the stator 623, north poles and south poles are alternately arranged in the x direction. The stator 623 functions as a guide mechanism that guides the movement of the x slide unit 613 (described later) in the x direction.

[0056] Linear motors 621 and 622 are slidably connected to stator 623. Linear motors 621 and 622 have electromagnets and function as movers of the linear motors. Linear motors 621 and 622 share stator 623 and move linearly in the x direction.

[0057] An x-slide portion 613 is attached to the linear motors 621 and 622. Therefore, the x-slide portion 613 slides in the x direction when the linear motors 621 and 622 are operated. In other words, the linear motors 621 and 622 drive the x-slide portion 613 in the x direction.

[0058] A y linear motor 631 is provided on the x slide portion 613. The y linear motor 631 has a stator and a mover (not shown). The stator is provided along the y direction. The mover slides in the y direction along the stator. A y slide portion 633 is attached to the mover. Therefore, when the y linear motor 631 is driven, the y slide portion 633 moves linearly in the y direction. The y linear motor 631, the y slide portion 633, etc. function as a y movement mechanism 630 that moves the holding mechanism 62_1 in the y direction.

[0059] A holding mechanism 62_1 is provided on the y slide portion 633. The y slide portion 633, the x slide portion 613, and the like function as a moving mechanism 63_1 that moves the holding mechanism 62_1. For example, when the linear motors 621 and 622 move the x slide portion 613 in the x direction, the holding mechanism 62_1 moves in the x direction. When the y linear motor 631 moves the y slide portion 632 in the y direction, the holding mechanism 62_1 moves.

[0060] By adjusting the moving speed in the x direction and the moving speed in the y direction, the holding mechanism 62_1 can be moved in a conveying direction tilted from the x direction. For example, the tilt angle of the conveying direction with respect to the x direction can be greater than 0° and less than or equal to 5°. Of course, the conveying direction is not limited to the above angle range. Furthermore, the conveying direction may be parallel to the x direction.

[0061] As described above, the transport mechanism 61_1 has two motors, a linear motor 621 and a linear motor 622. The linear motors 621 and 622 are direct-acting mechanisms that share a common axis. The drive unit 610 of the transport mechanism 61_1 controls the linear motors 621 and 622 to transport the substrate 100. The control of the drive unit 610 will be described below with reference to FIG. 9. FIG. 9 is a block diagram showing a control unit 620 of the drive unit 610. Note that the slide operation in the y direction is omitted in FIG. 9.

[0062] The drive unit 610 includes a linear motor 621, a linear motor 622, a motion controller 625, a PWM (Pulse Width Modulation) driver 626, and an analog driver 627. The PWM driver 626 is a driver for PWM driving the x linear motor. The analog driver 627 is a driver for linearly driving the x linear motor.

[0063] The motion controller 625 is a control circuit for controlling the motors. The motion controller 625 controls the positions of the linear motors 621 and 622, for example. The motion controller 625 outputs command signals to the PWM driver 626 and the analog driver 627. The command signals are signals that indicate, for example, the position, speed, acceleration, torque (thrust), etc. of the linear motors.

[0064] The PWM driver 626 supplies power to the linear motor 621 based on the command signal. Specifically, the PWM driver 626 performs pulse width modulation based on the command signal. The PWM driver 626 outputs a PWM-modulated drive current to the linear motor 621. In other words, the PWM driver 626 controls the linear motor 621 by high-speed switching. Therefore, a pulse current having a pulse width according to the command signal is supplied to the linear motor 621. In this way, the PWM driver 626 PWM-drives the linear motor 621.

[0065] The analog driver 627 supplies power to the linear motor 622 based on the command signal. Specifically, the analog driver 627 linearly controls the power based on the command signal. The analog driver 627 has a linear amplifier that linearly amplifies the current. Therefore, a drive current of a current value according to the command signal is supplied to the linear motor 622. In this way, the analog driver 627 linearly drives the linear motor 622.

[0066] The linear motor 621 or the linear motor 622 drives the holding mechanism 62_1, thereby transporting the substrate 100 in the transport direction. A sensor 629 is provided to detect position information of the holding mechanism 62_1. The sensor 629 is, for example, a linear encoder, and detects the positions of the linear motors 621 and 622. The sensor 629 is not limited to a linear encoder, and may be another position sensor, a speed sensor, or the like.

[0067] The sensor 629 outputs a detection signal indicating position information to the motion controller 625. The motion controller 625 performs feedback control based on the detection signal. For example, the motion controller 625 calculates a difference between the target position and the current position of the holding mechanism 62_1, and outputs a command signal according to the difference. This allows the substrate 100 to be transported with high positional accuracy.

[0068] The operations of the PWM driver 626 and the analog driver 627 will be described with reference to Figures 10 and 11. Figure 10 is a schematic diagram for explaining the operation of the PWM driver 626. Figure 11 is a schematic diagram for explaining the operation of the analog driver 627.

[0069] The host control device 628 is a PC (Personal Computer) or PLC (Programmable Logic Controller), and outputs a command to start movement to the motion controller 625. The motion controller 625 pulse-width modulates each of the three-phase (U-phase, V-phase, and W-phase) sinusoidal drive waveforms. The motion controller 625 outputs a pulse signal with a duty ratio corresponding to the phase of the sinusoidal drive waveform as a command signal. For each phase, the command signal is a positive or negative pulse waveform signal.

[0070] The PWM driver 626 generates a drive voltage based on the positive and negative pulse waveforms and outputs a current corresponding to the drive voltage to the linear motor 621. As a result, a drive current with a pulse waveform is supplied to the U, V, and W phases of the linear motor 621. Because the duty ratio of the pulse waveform changes depending on the phase, the linear motor 621 is driven by a sinusoidal drive waveform. The linear motor 621 feeds back the output current value to the motion controller 625.

[0071] Furthermore, the sensor 629 is a linear encoder and detects the positions of the linear motors 621 and 622. For example, the sensor 629 outputs A-phase and B-phase signals as feedback signals to the motion controller 625. The sensor 629 may be an absolute encoder or the like. The motion controller 625 feedback-controls the positions of the linear motors 621 and 622 based on the feedback signals. The motion controller 625 then outputs feedback-controlled command signals.

[0072] On the other hand, the analog driver 627 has a linear amplifier, and therefore amplifies the sinusoidal drive waveform linearly, as shown in FIG. 11 . Therefore, a current having a sinusoidal drive waveform is supplied. The linear motor 622 is driven by the sinusoidal drive waveform. The linear motor 622 feeds back the output current value to the analog amplifier of the analog driver 627.

[0073] The analog driver 627 linearly controls power and therefore has higher positional accuracy than the PWM driver 626. In other words, the analog driver 627 functions as a high-precision driver with higher accuracy than the PWM driver 626. The positional accuracy of the linear motor 622 driven by the analog driver 627 is higher than the positional accuracy of the linear motor 621 driven by the PWM driver 626.

[0074] On the other hand, the PWM driver 626 controls the on / off of the drive current by high-speed switching, and therefore is capable of operating with higher efficiency, lower power consumption, less heat generation, higher torque (high thrust), and higher acceleration than the analog driver 627. Therefore, the torque (thrust) of the linear motor 622 driven by the analog driver 627 is lower than the torque (thrust) of the linear motor 621 driven by the PWM driver 626. The linear motor 621 has high torque and can therefore operate at high acceleration. Therefore, the linear motor 621 can move the substrate 100 at a higher speed than the linear motor 622.

[0075] The analog driver 627 has the advantage of being able to operate with high precision because it uses an analog amplifier that linearly controls power, but because the analog driver 627 is inefficient, it consumes a lot of power, produces low torque, and generates a lot of heat.

[0076] Therefore, in this embodiment, the analog driver 627 drives the linear motor 622 during laser light irradiation, and the PWM driver 626 drives the linear motor 621 during non-irradiation of laser light. For example, when the holding mechanism 62_1 holds the substrate 100, the analog driver 627 drives the linear motor 622 to move the substrate 100 in the +x direction. As a result, the substrate 100 passes through the process region 60e, and the laser light is irradiated onto the object to be processed. Specifically, the analog driver 627 drives the linear motor 622 during at least a portion of the period from the start to the end of transport shown in FIG. 5 . As a result, the substrate 100a is transported in the transport direction.

[0077] On the other hand, while the laser light is not being irradiated, the PWM driver 626 drives the linear motor 621, thereby moving the substrate 100 in the −x direction. For example, when the holding mechanism 62_1 is not holding the substrate 100, the PWM driver 626 drives the linear motor 621. Specifically, in the −x movement stage in FIG. 6 , the PWM driver 626 drives the linear motor 621. As a result, the holding mechanism 62_1, which is not holding the substrate 100, moves in the −x direction. Since the holding mechanism 62_1 moves to the end of the −x side of the levitation unit 60, the 62_1 can receive the substrate 100b in the first region 60a (see the transfer start stage in FIG. 6 ).

[0078] (Operation Example 1) Next, operation example 1 of the linear motors 621, 622 will be described with reference to Figs. 12 and 13. Fig. 12 is a graph for explaining operation example 1. In Fig. 12, the horizontal axis indicates position and the vertical axis indicates movement speed. Fig. 13 is an xy plan view showing the irradiation start position and the irradiation end position. Note that Figs. 12 and 13 show a configuration in which the conveying device 6 is not provided with a rotation mechanism 69.

[0079] In Operation Example 1, the analog driver 627 drives the linear motor 622 from the irradiation start position to the irradiation end position (solid arrow in FIG. 12 ). Therefore, the drive unit 610 is in a high-precision mode in which the substrate 100 is transported with high precision. The irradiation start position is the substrate position at the time when one end of the substrate 100 overlaps with the irradiation position 65. The irradiation end position is the substrate position at the time when the other end of the substrate 100 passes the irradiation position 65.

[0080] The PWM driver 626 drives the linear motor 621 except between the irradiation start position and the irradiation end position (dashed arrow in FIG. 12). In other words, while the substrate is not being irradiated with laser light, the PWM driver 626 drives the linear motor 621. Therefore, the substrate 100 enters a high-speed mode in which it is transported at a higher speed than in the high-precision mode. The high-speed mode can also be called a high-torque mode because the linear motor is driven at a higher speed with a higher torque than in the high-precision mode. The high-speed mode can also be called a medium-precision mode because the positional accuracy is lower than in the high-precision mode.

[0081] Specifically, the drive unit 610 is in the medium accuracy mode from the start of transport in Fig. 5 to the irradiation start position in Fig. 13. Also, the drive unit 610 is in the medium accuracy mode from the irradiation end position in Fig. 13 to the end of transport in Fig. 5. Furthermore, while the transport mechanism 61_1 is moving in the -x direction (see -x movement in Fig. 6), the drive unit is in the medium accuracy mode.

[0082] As shown by arrow A in Figure 12, from the start of transport, the linear motor 621 gradually accelerates in the +x direction in medium accuracy mode. Once a constant speed is reached, the linear motor 621 decelerates, and the transport mechanism 61_1 stops just before the irradiation start position (arrow B). After the operation of the linear motor 621 stops, the mode switches to high accuracy mode. As shown by arrow C, the linear motor 622 accelerates in the +x direction to the desired transport speed. Once the linear motor 622 reaches the desired transport speed at the irradiation start position, the linear motor 622 operates at a constant transport speed to the irradiation end position as shown by arrow D in Figure 12.

[0083] When the linear motor 622 reaches the irradiation end position, it starts to decelerate and stops, as indicated by arrow E. After the operation of the linear motor 622 stops, the mode switches to medium accuracy mode. The linear motor 621 gradually accelerates (arrow F). Thereafter, as indicated by arrow G in FIG. 12, the linear motor 621 decelerates and stops at the end of movement on the +x side (the conveyance end position in FIG. 5).

[0084] Next, as shown by arrow H, linear motor 621 starts accelerating in the -x direction. When linear motor 621 reaches a predetermined movement speed, it moves in the -x direction at a constant speed (arrow I in FIG. 12). Then, it starts decelerating so as to stop at the movement limit on the -x side (arrow J in FIG. 12). The movement speed in the -x direction shown by arrow I is faster than the movement speed in the +x direction shown by arrow D.

[0085] In this way, the motion controller 625 switches modes depending on whether or not the substrate 100 is being irradiated with laser light. While the substrate 100 is being irradiated with laser light, the high-precision mode is activated, and the transport mechanism 61_1 moves with high positional accuracy. This allows a stable laser irradiation process to be performed. Meanwhile, while the substrate 100 is not being irradiated with laser light, the medium-precision mode (high-torque mode) is activated, and the transport mechanism 61_1 moves at high speed. This allows the takt time to be shortened, thereby improving productivity.

[0086] (Operation Example 2) In Operation Example 2, both the linear motor 621 and the linear motor 622 are operating in the medium-accuracy mode (high-torque mode). Specifically, during periods other than the period from the irradiation start position to the irradiation end position shown in FIG. 13 , the PWM driver 626 drives the linear motor 621, and the analog driver 627 drives the linear motor 622. This allows the two linear motors 621 and 622 to be driven, resulting in a large torque (thrust). The holding mechanism 62_1 can be moved at a higher speed. This further reduces the takt time, thereby further improving productivity. In particular, since the movement distance is long in the arrow I in FIG. 12 , the two linear motors 621 and 622 are operated during this period. This further reduces the movement time, thereby further shortening the takt time.

[0087] As described above, in Operation Example 2, in the medium accuracy mode (high torque mode), the PWM driver 626 drives the linear motor 621, and the analog driver 627 drives the linear motor 622. While the substrate 100 is being irradiated with laser light, the high accuracy mode is selected, and the transport mechanism 61_1 moves with high positional accuracy. This allows a stable laser irradiation process to be performed. Furthermore, while the substrate 100 is not being irradiated with laser light, the medium accuracy mode (high torque mode) is selected, and the transport mechanism 61_1 moves at high speed. This allows the takt time to be shortened, thereby improving productivity.

[0088] (Operation Example 3) Operation Example 3 will be described with reference to Fig. 14. Fig. 14 is a graph for explaining Operation Example 3. In Fig. 14, the horizontal axis represents position, and the vertical axis represents moving speed. In Operation Example 3, the PWM driver 626 drives the linear motor 621 between the irradiation start position and the irradiation end position. For example, during period K in Fig. 14, the PWM driver 626 drives the linear motor 621.

[0089] While the substrate 100 passes through the process region 60e, the high-precision mode and the medium-precision mode are alternately switched. In other words, the motion controller 625 controls the PWM driver 626 and the analog driver 627 to switch between driving multiple times so that the linear motors 621 and 622 alternately operate. The period K during which the PWM driver 626 is driven and the period during which the analog driver 627 is driven may be registered in advance. Alternatively, the laser light source 14a may be controlled so that the laser light is turned on only in the high-precision mode and turned off in the medium-precision mode.

[0090] Specifically, process stability may not be required in areas of the substrate 100 that are not used as devices. Therefore, even when the laser is irradiated, high-precision transport is not necessary. In areas that are not used as devices, the analog driver 627 may not drive the linear motor 622, and the PWM driver 626 may drive the linear motor 621. It is sufficient that the high-precision mode is in effect for at least a portion of the time that the laser light is irradiated. Of course, as in Operation Example 2, during period K, the PWM driver 626 may drive the linear motor 621, and the analog driver 627 may drive the linear motor 622.

[0091] Embodiment 2 The configuration of a transport mechanism 61_1 in embodiment 2 will be described with reference to FIG. 15. FIG. 15 is a perspective view that schematically shows the configuration of the transport mechanism 61_1. As shown in FIG. 15, embodiment 2 differs from embodiment 1 in that the transport mechanism 61_1 does not include a y-movement mechanism 630. In other words, the transport mechanism 61_1 does not include a y-linear motor 631 or a y-slide unit 633. Note that the basic configuration of the laser irradiation device 1 is the same as that of embodiment 1, and therefore description thereof will be omitted.

[0092] Since the y linear motor 631 and the y slide unit 633 are not provided, the holding mechanism 62_1 is mounted on the x slide unit 613. The holding mechanism 62_1 moves only in the x direction. As in the first embodiment, two linear motors 621 and 622 move the holding mechanism 62_1. Therefore, as in the first embodiment, the laser irradiation process can be stably executed and the takt time can be shortened. Note that the transport direction of the substrate 100 may be parallel to the x direction or may be tilted from the x direction. When the transport direction of the substrate 100 is tilted from the x direction, the stator 623 may be disposed tilted from the x direction.

[0093] Embodiment 3 The configuration of a transport mechanism 61_1 in embodiment 3 will be described with reference to FIG. 16. FIG. 16 is a perspective view that schematically shows the configuration of the transport mechanism 61_1. As shown in FIG. 16, in embodiment 3, two transport mechanisms 61_1a and 61_1b are provided. The transport mechanisms 61_1a and 61_1b are provided at the -y side end of the levitation unit 60 shown in FIG. 1 and the like. Note that the basic configuration of the laser irradiation device 1 is the same as in embodiments 1 and 2, and therefore description thereof will be omitted.

[0094] The transport mechanisms 61_1a and 61_1b are configured to move independently in the x direction. That is, the transport mechanisms 61_1a and 61_1b each have the same configuration as the transport mechanism 61_1 of the second embodiment. The transport mechanism 61_1a includes two linear motors. The transport mechanism 61_1b includes two linear motors. The holding mechanism 62_1a of the transport mechanism 61_1a and the holding mechanism 62_1b of the transport mechanism 61_1b each suction-hold a different substrate 100.

[0095] Two stators 623a and 623b are provided on the base 611. The stator 623a functions as a stator of the linear motor of the transport mechanism 61_1a. The stator 623b functions as a stator of the linear motor of the transport mechanism 61_1b. A mover (not shown) of the linear motor is attached to each of the stators 623a and 623b.

[0096] As in the first embodiment, the transport mechanism 61_1a is operated by two linear motors 621a and 622a. That is, the linear motor 621a is driven by a PWM driver, and the linear motor 622a is driven by an analog driver. The transport mechanism 61_1b is also operated by two linear motors (not shown). This allows the substrate 100 to be transported with high precision. Furthermore, the presence of two transport mechanisms 61_1a and 61_1b reduces the takt time. Note that the transport direction of the substrate 100 may be parallel to the x-direction or may be tilted from the x-direction. When the transport direction of the substrate 100 is tilted from the x-direction, the stators 623a and 623b may be arranged tilted from the x-direction.

[0097] Fourth Embodiment The configuration of a transport mechanism 61_1 according to a fourth embodiment will be described with reference to FIG. 17. FIG. 17 is a perspective view that schematically shows the configuration of the transport mechanism 61_1. In this embodiment, a levitation unit that levitates the substrate 100 is not provided. Specifically, the substrate 100 is placed on a tray 660. In other words, the tray 660 supports almost the entire substrate 100. The tray 660 may also serve as a suction stage that suction-holds the substrate 100.

[0098] A transport mechanism 61_1 is attached on a stage 661. The transport mechanism 61_1 includes two linear motors 621 and 622, as in the embodiment. Furthermore, stators 623 of the linear motors 621 and 622 are arranged along the x direction. The linear motors 621 and 622 hold a tray 660 so that the tray 660 can slide. The tray 660 is moved in the x direction by the two linear motors 621 and 622. Even with this configuration, the substrate 100 can be transported with high precision. Note that the transport direction of the substrate 100 may be tilted from the x direction. In this case, the stators 623a and 623b may be arranged tilted from the x direction.

[0099] (Organic EL 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.

[0100] The following describes a configuration in which the semiconductor device according to this embodiment is applied to an organic EL display. Fig. 18 is a cross-sectional view showing a simplified pixel circuit of the organic EL display. The organic EL display 300 shown in Fig. 18 is an active matrix display device in which a TFT is arranged in each pixel PX.

[0101] 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. 18 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 this embodiment may be used in a bottom-emission organic EL display.

[0102] 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.

[0103] An organic layer 312 is provided on the TFT layer 311. The organic layer 312 has an organic EL element 312a arranged for each pixel PX. Furthermore, the organic layer 312 is provided with partition walls 312b for separating the organic EL elements 312a between the pixels PX.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] In an active matrix display device such as an organic EL display, one pixel PX is provided with one or more TFTs (e.g., switching TFTs or driving TFTs). The TFTs of each pixel PX are 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. In other words, by using the polysilicon film manufactured by the above manufacturing method as the semiconductor layer of a TFT array substrate, it is possible to suppress in-plane variations in TFT characteristics. Therefore, display devices with excellent display characteristics can be manufactured with high productivity.

[0108] (Method for Manufacturing Semiconductor Device) A method for manufacturing a semiconductor device using a laser irradiation apparatus according to this embodiment is suitable for manufacturing a TFT array substrate. A method for manufacturing a semiconductor device having TFTs will be described with reference to FIGS. 19 and 20. FIGS. 19 and 20 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. 19 and 20 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.

[0109] 19 , 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.

[0110] Then, the glass substrate 401 on which the amorphous silicon film 404 has been formed is transported to the transport device 6. The amorphous silicon film 404 is irradiated with laser light L1, thereby forming a polysilicon film 405, as shown in FIG. 20 . That is, the amorphous silicon film 404 is crystallized by the laser irradiation device 1 shown in FIG. 1 etc. As a result, a polysilicon film 405, in which silicon has been crystallized, is formed on the gate insulating film 403. The polysilicon film 405 corresponds to the polysilicon film described above. While the transport device 6 is transporting the glass substrate 401, the glass substrate 401 is irradiated with laser light L1. As a result, the amorphous silicon film 404 is annealed and converted into the polysilicon film 405.

[0111] The method for manufacturing a semiconductor device according to this embodiment includes the steps of (sa1) forming an amorphous film on a substrate, (sa2) transferring the substrate on which the amorphous film has been formed to a transport device 6, and (sa3) irradiating a line-shaped laser beam onto the substrate while transporting the substrate using the transport device 6, thereby annealing the amorphous film to crystallize it and form a crystallized film.

[0112] 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 excimer 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.

[0113] The first to fourth embodiments and their operation examples can be used in any suitable combination. Note that the present invention is not limited to the above-described embodiments, and can be modified as appropriate within the scope of the invention.

[0114] DESCRIPTION OF SYMBOLS 1 Laser irradiation device 14 Laser irradiation section 15 Laser light 60a First region 60b Second region 60c Third region 60d Fourth region 60e Process region 60f Passage region 67 End floating unit 68 Rotation mechanism 100, 100a, 100b Substrate 300 Organic EL display 310 Substrate 311 TFT layer 311a TFT 312 Organic layer 312a Organic EL light emitting element 312b Partition 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 Pixel 610 Drive unit 611 Base 613 x-slide section 620 Control unit 621 Linear motor 622 Linear motor 623 Stator 625 Motion controller 626 PWM driver 627 Analog driver 628 Upper control device 629 Sensor 630 y movement mechanism 631 y linear motor 633 y slide unit 640 Base

Claims

1. A laser irradiation device including: a laser light source that generates laser light; an optical system that irradiates a substrate with the laser light; a transport mechanism that transports the substrate; and a drive unit that drives the transport mechanism, wherein the drive unit includes: a first motor and a second motor that move the transport mechanism; a PWM driver that PWM drives the first motor; an analog driver that linearly drives the second motor; and a control unit that controls the analog driver and the PWM driver.

2. A laser irradiation device as described in claim 1, wherein, when the laser light is irradiating the substrate, the analog driver is in a high precision mode to drive the second motor, and when not in the high precision mode, the PWM driver is in a high torque mode to drive the first motor.

3. The laser irradiation device according to claim 1, wherein, when the laser light is irradiating the substrate, a high precision mode is entered in which the analog driver drives the second motor, and when not in the high precision mode, a high torque mode is entered in which the PWM driver drives the first motor and the analog driver drives the second motor.

4. A laser irradiation device as described in any one of claims 1 to 3, wherein the position accuracy of the second motor driven by the analog driver is higher than the position accuracy of the first motor driven by the PWM driver, and the torque of the second motor driven by the analog driver is lower than the torque of the first motor driven by the PWM driver.

5. A laser irradiation device according to any one of claims 1 to 3, further comprising a sensor for detecting the position of the transport mechanism, and the control unit performs feedback control based on the position detected by the sensor.

6. A laser irradiation device as described in any one of claims 1 to 3, further comprising a levitation unit which levitates the substrate on its upper surface, wherein the optical system shapes the laser light into a line shape on the substrate, and the transport mechanism comprises: a holding mechanism which holds the substrate levitated above the levitation unit; and a first moving mechanism which moves the holding mechanism in a first direction, wherein the first moving mechanism is moved by the first motor and the second motor.

7. A laser irradiation device as described in claim 6, further comprising a second moving mechanism that moves the holding mechanism in a second direction inclined from the first direction, wherein the first moving mechanism moves the second moving mechanism and the holding mechanism.

8. The laser irradiation device according to claim 6, wherein the first moving mechanism moves the holding mechanism in a direction inclined from a direction perpendicular to the longitudinal direction of the line-shaped laser light when viewed from above.

9. A laser irradiation device according to any one of claims 1 to 3, wherein the transport mechanism includes a tray on which the substrate is placed, and the first motor and the second motor move the tray.

10. A laser irradiation method comprising: (A1) the step of generating laser light; (A2) the step of irradiating a substrate with the laser light; and (A3) the step of a transport mechanism transporting the substrate, wherein the transport mechanism includes a drive unit provided for transporting the substrate, the drive unit including: a first motor and a second motor for moving the transport mechanism; a PWM driver for PWM driving the first motor; an analog driver for linearly driving the second motor; and a control unit for controlling the analog driver and the PWM driver.

11. A laser irradiation method as described in claim 10, wherein, when the laser light is irradiating the substrate, the analog driver is in a high precision mode to drive the second motor, and when not in the high precision mode, the PWM driver is in a high torque mode to drive the first motor.

12. The laser irradiation method according to claim 10, wherein, when the laser light is irradiating the substrate, a high precision mode is entered in which the analog driver drives the second motor, and, except in the high precision mode, a high torque mode is entered in which the PWM driver drives the first motor and the analog driver drives the second motor.

13. A laser irradiation method according to any one of claims 10 to 12, wherein the position accuracy of the second motor driven by the analog driver is higher than the position accuracy of the first motor driven by the PWM driver, and the torque of the second motor driven by the analog driver is lower than the torque of the first motor driven by the PWM driver.

14. A laser irradiation method according to any one of claims 10 to 12, wherein a position of the transport mechanism is detected by a sensor, and the control unit performs feedback control based on the position detected by the sensor.

15. A laser irradiation method as described in any one of claims 10 to 12, wherein a levitation unit levitates the substrate by its upper surface, and in step (A2), the laser light is shaped into a line on the substrate, and the transport mechanism comprises a holding mechanism that holds the substrate levitated above the levitation unit, and a first moving mechanism that moves the holding mechanism in a first direction, and the first moving mechanism is moved by the first motor and the second motor.

16. A laser irradiation method as described in claim 15, wherein a second moving mechanism moves the holding mechanism in a second direction inclined from the first direction, and the first moving mechanism moves the second moving mechanism and the holding mechanism.

17. A laser irradiation method as described in claim 15, wherein the first moving mechanism moves the holding mechanism in a direction inclined from a direction perpendicular to the longitudinal direction of the line-shaped laser light when viewed from above.

18. A laser irradiation method according to any one of claims 10 to 12, wherein the transport mechanism includes a tray on which the substrate is placed, and the first motor and the second motor move the tray.

19. A method for manufacturing a semiconductor device, comprising: (S1) a step of generating laser light; (S2) a step of irradiating a substrate with the laser light; and (S3) a step of a transport mechanism transporting the substrate, wherein the transport mechanism includes a drive unit provided for transporting the substrate, the drive unit including: a first motor for moving the transport mechanism; a second motor for moving the transport mechanism; a PWM driver for PWM driving the first motor; an analog driver for linearly driving the second motor; and a control unit for controlling the analog driver and the PWM driver.

20. A method for manufacturing a semiconductor device as described in claim 19, wherein, when the laser light is irradiating the substrate, the analog driver is in a high precision mode to drive the second motor, and when not in the high precision mode, the PWM driver is in a high torque mode to drive the first motor.

21. The method for manufacturing a semiconductor device as described in claim 19, wherein, when the laser light is irradiating the substrate, a high precision mode is entered in which the analog driver drives the second motor, and, except in the high precision mode, a high torque mode is entered in which the PWM driver drives the first motor and the analog driver drives the second motor.

22. A method for manufacturing a semiconductor device as described in any one of claims 19 to 21, wherein the position accuracy of the second motor driven by the analog driver is higher than the position accuracy of the first motor driven by the PWM driver, and the torque of the second motor driven by the analog driver is lower than the torque of the first motor driven by the PWM driver.

23. The method for manufacturing a semiconductor device according to any one of claims 19 to 21, wherein a sensor detects the position of the transport mechanism, and the control unit performs feedback control based on the position detected by the sensor.

24. A method for manufacturing a semiconductor device as described in any one of claims 19 to 21, wherein a levitation unit levitates the substrate on its upper surface, and in step (S2), the laser light is shaped into a line on the substrate, and the transport mechanism comprises a holding mechanism that holds the substrate levitated above the levitation unit, and a first moving mechanism that moves the holding mechanism in a first direction, and the first moving mechanism is moved by the first motor and the second motor.

25. A method for manufacturing a semiconductor device as described in claim 24, wherein a second moving mechanism moves the holding mechanism in a second direction inclined from the first direction, and the first moving mechanism moves the second moving mechanism and the holding mechanism.

26. The method for manufacturing a semiconductor device according to claim 24, wherein the first moving mechanism moves the holding mechanism in a direction inclined from a direction perpendicular to the longitudinal direction of the line-shaped laser light when viewed from above.

27. The method for manufacturing a semiconductor device according to any one of claims 19 to 21, wherein the transport mechanism includes a tray on which the substrate is placed, and the first motor and the second motor move the tray.

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