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

Abstract

The present invention provides a laser irradiation device, a laser irradiation method and a method for manufacturing a semiconductor device for reducing laser irradiation unevenness. The laser irradiation device includes a laser source (11) and a waveform shaping device (20). The waveform shaping device (20) includes: a first waveform shaping unit (30) that shapes the pulse waveform of the pulsed laser by giving a delay corresponding to the optical path difference to two light beams (L11, L12) obtained by branching the pulsed laser (L1) generated by the laser source (11) through a first beam splitter (31); a wavelength plate (37) that changes the polarization state of the pulsed laser (L13) from the first waveform shaping unit (30); and a second waveform shaping unit (40) that shapes the pulse waveform of the pulsed laser (L14) by giving a delay corresponding to the optical path difference to two light beams (L15, L16) obtained by branching through a second beam splitter (41).

Description

Technical Field

[0001] The present invention relates to a laser irradiation device, a laser irradiation method and a method for manufacturing a semiconductor device. Background Art

[0002] Patent Document 1 discloses a laser annealing device for forming a polycrystalline silicon thin film. Figure 2 2 shows a waveform shaping device for shaping the waveform of a laser pulse.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-15445 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In such a laser irradiation device, it is desired to further reduce laser irradiation unevenness.

[0008] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings.

[0009] Means for solving problems

[0010] According to one embodiment, a laser irradiation device includes: a first waveform shaping unit, which has a first beam splitter that branches a pulsed laser, and shapes the pulse waveform of the pulsed laser by giving a delay corresponding to an optical path difference to two light beams branched by the first beam splitter; a wavelength plate that changes the polarization state of the pulsed laser from the first waveform shaping unit; and a second waveform shaping unit, which has a second beam splitter that branches the pulsed laser from the wavelength plate, and shapes the pulse waveform of the pulsed laser by giving a delay corresponding to the optical path difference to two light beams branched by the second beam splitter.

[0011] According to one embodiment, the laser irradiation device includes: a first waveform shaping unit, which has a first beam splitter that branches a first pulse laser, and shapes the pulse waveform of the first pulse laser by giving a delay corresponding to the optical path difference to two light beams branched by the first beam splitter; a first wavelength plate that changes the polarization state of the first pulse laser from the first waveform shaping unit; a second wavelength plate that changes the polarization state of the second pulse laser; a second waveform shaping unit, which has a second beam splitter that branches the second pulse laser from the second wavelength plate, and shapes the pulse waveform of the second pulse laser by giving a delay corresponding to the optical path difference to two light beams branched by the second beam splitter; and a synthesizer that synthesizes the first pulse laser from the first wavelength plate with the second pulse laser from the second waveform shaping unit.

[0012] According to one embodiment, the laser irradiation method includes the following steps: (B) a step of branching the pulse laser into two light beams by a first beam splitter; (C) a step of shaping a pulse waveform of the pulse laser by giving a delay corresponding to an optical path difference to the two light beams branched by the first beam splitter; (D) a step of changing a polarization state of the pulse laser by using a wavelength plate after step (C); (E) a step of branching the pulse laser from the wavelength plate into two light beams by using a second beam splitter; and (F) a step of shaping a pulse waveform of the pulse laser by giving a delay corresponding to an optical path difference to the two light beams branched by the second beam splitter.

[0013] According to one embodiment, the laser irradiation method includes the following steps: (b) a step of branching the first pulse laser into two light beams by a first beam splitter; (c) a step of shaping the pulse waveform of the first pulse laser by giving a delay corresponding to the optical path difference to the two light beams branched by the first beam splitter; (d) after step (c), a step of changing the polarization state of the first pulse laser by using a first wavelength plate; (e) a step of changing the polarization state of the second pulse laser by using a second wavelength plate; (f) after step (e), a step of branching the second pulse laser into two light beams by using a second beam splitter; and (g) a step of shaping the pulse waveform of the second pulse laser by giving a delay corresponding to the optical path difference to the two light beams branched by the second beam splitter.

[0014] According to one embodiment, a method for manufacturing a semiconductor device includes a step (S2), in which a pulsed laser is irradiated onto the amorphous film to crystallize the amorphous film to form a crystalline film. In the method for manufacturing the semiconductor device, the step (S2) includes the following steps: (SC) a step of shaping a pulse waveform of the pulsed laser by assigning a delay corresponding to an optical path difference to the two light beams branched from the first beam splitter; (SD) a step of changing a polarization state of the pulsed laser by using a wavelength plate after the step (SC); and (SF) a step of shaping a pulse waveform of the pulsed laser by assigning a delay corresponding to an optical path difference to the two light beams branched from the second beam splitter.

[0015] According to one embodiment, a method for manufacturing a semiconductor device includes a step (S2), in which a pulsed laser is irradiated onto the amorphous film to crystallize the amorphous film to form a crystalline film. In the method for manufacturing the semiconductor device, the step (S2) includes the following steps: (sc) a step of shaping the pulse waveform of the first pulsed laser by giving a delay corresponding to the optical path difference to the two light beams branched from the first beam splitter; (sd) after step (sc), a step of changing the polarization state of the first pulsed laser using a first wavelength plate; (se) a step of changing the polarization state of the second pulsed laser using a second wavelength plate; and (sg) a step of shaping the pulse waveform of the second pulsed laser by giving a delay corresponding to the optical path difference to the two light beams branched from the second beam splitter.

[0016] Effects of the Invention

[0017] According to the aforementioned one embodiment, irradiation unevenness can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 is a diagram showing an optical system of the laser annealing apparatus according to the present embodiment.

[0019] Figure 2 This is a diagram showing the optical system of the waveform shaping device according to Embodiment 1.

[0020] Figure 3 It is a diagram showing the pulse waveforms of the P-polarized light component and the S-polarized light component.

[0021] Figure 4 It is a graph showing the pulse waveforms of the P-polarized light component and the S-polarized light component.

[0022] Figure 5 This is a graph showing the evaluation results of laser irradiation unevenness evaluated by changing the irradiation energy density.

[0023] Figure 6 This is a diagram showing the optical system of the waveform shaping device according to the second embodiment.

[0024] Figure 7 It is a cross-sectional view showing a simplified structure of an organic EL display.

[0025] Figure 8 The following are cross-sectional views showing the steps of the method for manufacturing the semiconductor device according to the present embodiment.

[0026] Fig. 9 The following are cross-sectional views showing the steps of the method for manufacturing the semiconductor device according to the present embodiment.

[0027] Fig.10 The following are cross-sectional views showing the steps of the method for manufacturing the semiconductor device according to the present embodiment.

[0028] Fig.11 The following are cross-sectional views showing the steps of the method for manufacturing the semiconductor device according to the present embodiment.

[0029] Fig.12 The following are cross-sectional views showing the steps of the method for manufacturing the semiconductor device according to the present embodiment.

[0030] Fig.13 The following are cross-sectional views showing the steps of the method for manufacturing the semiconductor device according to the present embodiment.

[0031] Fig.14 The following are cross-sectional views showing the steps of the method for manufacturing the semiconductor device according to the present embodiment.

[0032] Fig.15 The following are cross-sectional views showing the steps of the method for manufacturing the semiconductor device according to the present embodiment. DETAILED DESCRIPTION

[0033] Implementation method 1.

[0034] The laser irradiation device of the present embodiment is, for example, an excimer laser annealing (ELA) device for forming a low temperature polysilicon (LTPS) film. Hereinafter, the laser irradiation device, laser irradiation method, and manufacturing method of the present embodiment will be described with reference to the drawings.

[0035] (Optical system of ELA device)

[0036] use Figure 1 The configuration of the ELA apparatus 1 according to the present embodiment will be described. Figure 11 is a diagram schematically showing an optical system of an ELA device 1. The ELA device 1 irradiates a silicon film 101 formed on a substrate 100 with a laser L2. Thus, an amorphous silicon film (amorphous silicon film: a-Si film) 101 can be converted into a polycrystalline silicon film (polycrystalline silicon film: p-Si film) 101. The substrate 100 is, for example, a transparent substrate such as a glass substrate.

[0037] It should be noted that in Figure 1 In order to make the description clear, an XYZ three-dimensional orthogonal coordinate system is shown. The Z direction is the vertical direction, which is the direction perpendicular to the substrate 100. The XY plane is a plane parallel to the surface formed by the silicon film 101 of the substrate 100. The X direction is the length direction of the rectangular substrate 100, and the Y direction is the width direction of the substrate 100. In addition, in the ELA device 1, while the substrate 100 is transported in the +X direction by a transport mechanism such as a workbench (not shown), the laser L2 is irradiated onto the silicon film 101. It should be noted that in Figure 1 In the figure, in the silicon film 101, the silicon film 101 before being irradiated with the laser light L2 is represented as an amorphous silicon film 101a, and the silicon film 101 after being irradiated with the laser light L2 is represented as a polycrystalline silicon film 101b.

[0038] The ELA apparatus 1 includes an annealing optical system 10. The annealing optical system 10 is an optical system for irradiating the silicon film 101 with the laser light L2 for crystallizing the amorphous silicon film 101a.

[0039] Specifically, the annealing optical system 10 includes a laser source 11 , a reflection mirror 12 , a condenser lens 13 , and a waveform shaping device 20 .

[0040] The annealing optical system 10 is arranged on the upper side (+Z side) of the substrate 100. The laser source 11 is a pulse laser source, and generates pulse laser light. The laser source 11 is, for example, an excimer laser source that radiates an excimer laser light having a central wavelength of 308 nm. In addition, the laser source 11 radiates a pulsed laser light L1. The laser source 11 emits the laser light L1 toward the waveform shaping device 20.

[0041] The laser light L1 is incident on the waveform shaping device 20. The waveform shaping device 20 shapes a pulse waveform on the time axis. More specifically, the waveform shaping device 20 extends the pulse width of the laser light L1. The structure of the waveform shaping device 20 will be described later. The laser light L1 shaped by the waveform shaping device 20 is referred to as the laser light L2. The laser light L2 from the waveform shaping device 20 is incident on the reflector 12.

[0042] A reflecting mirror 12 and a condensing lens 13 are disposed on the substrate 100. The reflecting mirror 12 is, for example, a dichroic mirror that selectively transmits light according to wavelength. The reflecting mirror 12 reflects the laser light L2.

[0043] The laser light L2 is reflected by the reflection mirror 12 and enters the condenser lens 13. The condenser lens 13 has a plurality of lenses for projecting the laser light L2 onto the substrate 100, that is, onto the silicon film 101.

[0044] The condenser lens 13 converges the laser light L2 onto the substrate 100. The laser light L2 forms a linear irradiation area on the substrate 100. That is, on the substrate 100, the laser light L2 becomes a linear beam along the Y direction. In other words, the laser light L2 converged onto the substrate 100 forms a linear illumination area with the Y direction as the length direction (long axis direction) and the X direction as the width direction (short axis direction). In addition, the laser light L2 is irradiated onto the silicon film 101 while the substrate 100 is transported in the +X direction. Thus, the laser light L2 can be irradiated onto a strip-shaped area with the length of the irradiation area in the Y direction as the width.

[0045] The amorphous silicon film 101a is crystallized by irradiation with the laser L2. The laser L2 is irradiated to the silicon film 101 while changing the irradiation position of the laser L2 relative to the substrate 100. The substrate 100 is transported in the +X direction by a transport mechanism (not shown), thereby forming a uniform polycrystalline silicon film 101b on the substrate 100. It goes without saying that the optical system such as a focusing lens may be moved instead of the substrate 100 being transported. In other words, the irradiation area of ​​the laser L2 can be scanned by moving the substrate and the optical system relative to each other.

[0046] (Waveform forming device 20)

[0047] Next, use Figure 2 The waveform shaping device 20 will be described. Figure 2 1 is a diagram showing an optical system of the waveform shaping device 20. The waveform shaping device 20 includes a first waveform shaping portion 30, a 1 / 2 wavelength plate 37, and a second waveform shaping portion 40. The first waveform shaping portion 30, the 1 / 2 wavelength plate 37, and the second waveform shaping portion 40 are arranged in order from the laser source 11 side. The waveform shaping device 20 has a two-stage structure in which the first waveform shaping portion 30 and the second waveform shaping portion 40 are arranged in series.

[0048] The first waveform shaping section 30 and the second waveform shaping section 40 are pulse stretchers for extending the pulse width. The first waveform shaping section 30 includes a first beam splitter 31 and reflectors 32 to 35. Similarly, the second waveform shaping section 40 includes a second beam splitter 41 and reflectors 42 to 45. A 1 / 2 wavelength plate 37 is arranged on the optical path between the first waveform shaping section 30 and the second waveform shaping section 40.

[0049] The laser light L1 from the laser source 11 has a specific polarization ratio. That is, the laser light L1 has a first polarization component and a second polarization component. The first polarization component and the second polarization component are polarization components that are orthogonal to each other. That is, if the directions that are orthogonal to each other in a plane orthogonal to the optical axis are set as the first direction and the second direction, the first polarization component is a linear polarization component parallel to the first direction, and the second polarization component is a linear polarization component parallel to the second direction. The electric field vector of the first polarization component vibrates along the first direction, and the electric field vector of the second polarization component vibrates along the second direction.

[0050] The first polarized light component becomes an S polarized light component with respect to the substrate 100, and the second polarized light component becomes a P polarized light component with respect to the substrate 100. In addition, the length direction of the linear beam is parallel to the first direction, and the width direction is the second direction. Therefore, the S polarized light is parallel to the length direction of the linear beam, and the P polarized light is parallel to the width direction of the linear beam.

[0051] In laser L1, the intensity of the second polarized light component is greater than the intensity of the first polarized light component. For example, the proportion of the first polarized light component in laser L1 is 30% to 40%, and the proportion of the second polarized light component is 60% to 70%. The ratio of the first polarized light component relative to the entire pulse light is set as the polarization ratio, which is expressed as (first polarized light component) / (first polarized light component+second polarized light component). The polarization ratio in laser L1 is (first polarized light component) / (first polarized light component+second polarized light component)=30% to 40%.

[0052] The laser light L1 is first incident on the first beam splitter 31 of the first waveform forming part 30. The first beam splitter 31 is, for example, a plate-type beam splitter, and is arranged at an angle of 45 degrees relative to the optical axis of the laser light L1. The first beam splitter 31 branches the laser light L1 into two light beams L11 and L12 by transmitting a part of the incident light and reflecting a part of the incident light. The light beam transmitted from the first beam splitter 31 is set as the light beam L11, and the light beam reflected by the beam splitter is set as the light beam L12. The first beam splitter 31 is a half-reflecting mirror, and its transmittance with respect to non-polarized light is 50% and its reflectance is 50%. The first beam splitter 31 is not limited to a plate-type, and may also be a box-type.

[0053] The first beam splitter 31 transmits a part of the first polarized light component and reflects a part thereof. Similarly, the first beam splitter 31 transmits a part of the second polarized light component and reflects a part thereof. The first beam splitter 31 is, for example, a non-polarizing beam splitter, and has a predetermined polarization characteristic. In the first beam splitter 31, the branching ratio with respect to the first polarized light component is different from the branching ratio with respect to the second polarized light component. It should be noted that the branching ratio of the beam splitter is the intensity ratio of the reflected light to the transmitted light in the beam splitter. In other words, in the first beam splitter 31, the transmittance with respect to the first polarized light component is different from the transmittance with respect to the second polarized light component. In the first beam splitter 31, the reflectance with respect to the first polarized light component is different from the reflectance with respect to the second polarized light component.

[0054] Therefore, the polarization ratio in the light beam L11 is different from the polarization ratio of the light beam L12. For example, in the first beam splitter 31, the reflectivity with respect to the second polarization component is higher than the reflectivity with respect to the first polarization component. In the first beam splitter 31, the transmittance with respect to the second polarization component is lower than the transmittance with respect to the first polarization component. Therefore, if the laser light L1 is reflected by the first beam splitter 31, the second polarization component is relatively high in the reflected light beam L12. If the laser light L1 is transmitted from the first beam splitter 31, the first polarization component is relatively high in the light beam L11. The polarization ratio is expressed as (first polarization component) / (first polarization ratio+second polarization component), and therefore, the polarization ratio of the light beam L11 is greater than the polarization ratio of the light beam L12.

[0055] The first beam splitter 31 reflects the light beam L12 toward the reflector 32. The reflectors 32 to 35 are total reflection mirrors that reflect almost all of the incident light and are arranged at an angle of 45° relative to the optical axis. The light beam L12 reflected by the first beam splitter 31 is reflected by the reflector 32, the reflector 33, the reflector 34, and the reflector 35 in sequence. The light beam L12 reflected by the reflector 35 enters the first beam splitter 31. Since the first beam splitter 31 has a predetermined polarization characteristic as described above, it transmits a portion of the light beam L12 and reflects a portion of it.

[0056] A portion of the light beam L12 is reflected by the first beam splitter 31 toward the 1 / 2 wavelength plate 37. The light beam L12 reflected again by the first beam splitter 31 is synthesized with the light beam L11 transmitted from the first beam splitter 31. When viewed from above perpendicular to the optical axis, the light beam L12 reflected by the reflector 35 and the first beam splitter 31 overlaps with the light beam L11 transmitted from the first beam splitter 31. If the light beam L12 is reflected again by the first beam splitter 31, it becomes a light beam coaxial with the light beam L11. The light beams L11 and L12 synthesized by the first beam splitter 31 are set as laser light L13.

[0057] The optical path branched by the first beam splitter 31 and incident on the first beam splitter 31 again via the mirrors 32 to 35 is defined as a delay path. The optical path length of the delay path corresponds to, for example, 16 nsec.

[0058] A time delay corresponding to the optical path difference is given to the two light beams L11 and L12 synthesized by the first beam splitter 31. That is, after the light beam L12 is repeatedly reflected by the reflectors 32 to 35, it is synthesized with the light beam L11 by the first beam splitter 31. Compared with the light beam L11, the light beam L12 is delayed by the optical path of the delay path. The pulse width of the laser L13 after shaping is greater than the pulse width of the laser L1 before shaping. The first waveform shaping unit 30 uses the optical path difference between the light beam L11 and the light beam L12 to extend the pulse width of the laser L13.

[0059] In addition, a portion of the light beam L12 that enters the first beam splitter 31 again is transmitted through the first beam splitter 31. The light beam L12 that has passed through the first beam splitter 31 is reflected by the reflectors 32 to 35 and enters the first beam splitter 31 again. In this way, a portion of the light beam L12 repeatedly passes through the delay path and is synthesized with the light beam L11. A portion of the light beam L12 is repeatedly branched by the first beam splitter 31 and passes through the delay path multiple times. The light beam L12 is delayed according to the number of times it passes through the delay path and is synthesized with the light beam L11. For example, the light beam L12 that passes through the delay path once is delayed by 16 nsec relative to the light beam L11, and the light beam L12 that passes through the delay path twice is delayed by 32 nsec relative to the light beam L11. In addition, the light amount of the light beam L12 that passes through the delay path decreases each time it is branched by the first beam splitter 31.

[0060] The first waveform shaping unit 30 includes a first beam splitter 31, which branches the laser light L1 into two light beams L11 and L12 by reflecting a part of the laser light L1 and transmitting a part of the laser light L1. The first waveform shaping unit 30 shapes the pulse waveform by giving a time delay corresponding to the optical path difference to the two light beams L11 and L12. Specifically, the light beam L12 branched by the first beam splitter 31 passes through a delay path that repeatedly passes until it enters the first beam splitter 31 again, thereby extending the pulse width.

[0061] The laser light L13 from the first waveform forming section 30 is transmitted through the 1 / 2 wavelength plate 37. The 1 / 2 wavelength plate 37 is a birefringent element that generates a phase difference between orthogonal polarized light components, and changes the polarization state of the laser light L13. The laser light transmitted through the 1 / 2 wavelength plate 37 is set as the laser light L14. In a plane orthogonal to the optical axis, the optical axis of the 1 / 2 wavelength plate 37 is inclined 45 degrees relative to the first direction. Thus, the 1 / 2 wavelength plate 37 rotates the first and second linear polarized light components by 90 degrees respectively. The 1 / 2 wavelength plate 37 converts the first polarized light component into the second polarized light component, and converts the second polarized light component into the first polarized light component. The polarization ratio of the laser light L14 is reversed. If the polarization ratio in the laser light L13 is 30%, the polarization ratio in the laser light L14 is 70% (=100-30).

[0062] The laser light L14 transmitted through the 1 / 2 wavelength plate 37 enters the second waveform forming section 40. The second waveform forming section 40 has the same configuration as the first waveform forming section 30. The second beam splitter 41 and the reflectors 42 to 45 of the second waveform forming section 40 correspond to the first beam splitter 31 and the reflectors 32 to 35 of the first waveform forming section 30, respectively. For example, the configuration of the second beam splitter 41 and the reflectors 42 to 45 is identical to the configuration of the first beam splitter 31 and the reflectors 32 to 35. The delay path in the first waveform forming section 30 and the delay path in the second waveform forming section 40 have substantially the same optical path length. The reflectors 42 to 45 are total reflection mirrors, which are inclined at 45 degrees relative to the optical axis.

[0063] The second beam splitter 41 can use the same non-polarizing beam splitter as the first beam splitter 31. Thus, the second beam splitter 41 branches the laser light L14 into two light beams L15 and L16 by transmitting a part of the laser light L14 and reflecting a part of the laser light L14. In addition, the light beam L16 reflected by the second beam splitter 41 is reflected by the mirrors 42 to 45 and then enters the second beam splitter 41 again. The second beam splitter 41 combines the light beam L16 reflected by the mirror 45 with the light beam L15 transmitted from the second beam splitter 41. The two light beams L15 and L16 are given a delay time corresponding to the optical path of the delay path of the mirrors 42 to 45.

[0064] In this way, the second waveform shaping unit 40 reflects a part of the laser light L14 and transmits a part thereof, thereby branching into two light beams L15 and L16. The configuration of the second waveform shaping unit 40 is the same as that of the first waveform shaping unit 30, so detailed description is omitted. The second waveform shaping unit 40 shapes the pulse waveform of the pulsed laser light by giving a time delay corresponding to the optical path difference to the two light beams L15 and L16. Specifically, after branching by the second beam splitter 41, the pulse width can be extended by repeatedly passing through the delay path until the second beam splitter 41 is incident again.

[0065] Then, the laser beam from the second corrugated forming section 40 becomes Figure 1 The laser light L2 is incident on the reflecting mirror 12 . The laser light L2 is irradiated onto the silicon film 101 via the focusing lens 13 .

[0066] The first beam splitter 31 and the second beam splitter 41 have the same polarization characteristics. The first beam splitter 31 and the second beam splitter 41 have the same polarization characteristics of transmittance and reflectance. The branching ratio with respect to the first polarized light component is the same between the first beam splitter 31 and the second beam splitter 41. The branching ratio with respect to the second polarized light component is the same between the first beam splitter 31 and the second beam splitter 41. For example, the transmittance of the first beam splitter 31 and the second beam splitter 41 is the same with respect to the first polarized light component. The transmittance of the first beam splitter 31 and the second beam splitter 41 is the same with respect to the second polarized light component. In addition, the optical path of the delay path in the second waveform forming section 40 is the same as the delay path in the first waveform forming section 30.

[0067] Thus, the second waveform shaping section 40 can extend the pulse width in the same manner as the first waveform shaping section 30. In addition, the 1 / 2 wavelength plate 37 is disposed between the first waveform shaping section 30 and the second waveform shaping section 40. Thus, the first polarization component and the second polarization component in the first waveform shaping section 30 are interchanged in the second waveform shaping section 40. That is, the first polarization component in the first waveform shaping section 30 becomes the second polarization component in the second waveform shaping section 40. The second polarization component in the first waveform shaping section 30 becomes the first polarization component in the second waveform shaping section 40.

[0068] The pulse waveform of the laser light L1 is shaped by the first waveform shaping unit 30 and the second waveform shaping unit 40 so as to give the same time delay to the S polarized light component and the P polarized light component with respect to the substrate 100. In the laser light L2 irradiated to the substrate 100, the pulse shape of the S polarized light component is the same as the pulse shape of the P polarized light component. By using the first waveform shaping unit 30, the 1 / 2 wavelength plate 37 and the second waveform shaping unit 40 in this way, it is possible to give the same time delay to the orthogonal polarized light components of the laser light L1.

[0069] Figure 3 Graph showing the pulse waveform shaped by the waveform shaping device 20 in the present embodiment. Figure 4 1 is a graph showing a pulse waveform formed by a waveform shaping device of a comparative example. Figure 2 The waveform shaping device disclosed in Figure 3 , Figure 4 In the figure, the horizontal axis represents time and the vertical axis represents laser intensity. Figure 3 , Figure 4In , W1 represents the P polarized light component, that is, the linear polarized light component parallel to the width direction of the linear beam, and W2 represents the S polarized light component, that is, the linear polarized light component parallel to the length direction of the linear beam. Figure 3 , Figure 4 In the embodiment, the intensity of the S polarized light component and the P polarized light component is standardized by the pulse energy. That is, the light intensity is standardized by multiplying at least one of the S polarized light component and the P polarized light component by a certain coefficient in such a way that the area of ​​the S polarized light component and the P polarized light component in one pulse is consistent.

[0070] By using the waveform shaping device 20 of the present embodiment, the time variation of the polarization ratio of the laser irradiated to the amorphous silicon film 101a can be reduced. That is, in the pulse waveform, the variation of the polarization ratio of the S polarized light component and the P polarized light component becomes smaller. In the melting and crystallization processes, the influence on the polarized light can be reduced. Thus, the irradiation unevenness can be reduced. For example, while the substrate 100 is moved, the pulsed laser is irradiated to the substrate 100. Therefore, if the polarization ratio differs greatly according to the irradiation position, there is a possibility that the crystalline state will be uneven. In this regard, according to the present embodiment, the crystalline state can be suppressed from being uneven.

[0071] According to this embodiment, the intensity difference between the S-polarized light component and the P-polarized light component (hereinafter referred to as the polarization ratio difference) can be always set to 12% or less. Figure 3 The maximum polarization ratio difference is 10%. Figure 3 In the embodiment, at any timing of the pulse, the intensity difference between the S-polarized light component and the P-polarized light component is less than 10%. Figure 4 As described above, the intensity difference between the S-polarized light component and the P-polarized light component in the laser pulse, that is, the polarization ratio difference, can be reduced.

[0072] Figure 5 It is shown Figure 3 and Figure 4 This figure shows the evaluation results of irradiation unevenness in the pulse waveform of . Figure 3 The evaluation result of the pulse waveform is set as P1, Figure 4 The evaluation result of the pulse waveform is set to P2. Figure 5 The horizontal axis is the laser irradiation energy density, and the vertical axis is the non-uniformity score. The non-uniformity score is a value for evaluating the non-uniformity of the crystallized polysilicon film 101b. The smaller the value, the smaller the non-uniformity. Figure 5 In the figure, the laser irradiation energy density is set at 430 mJ / cm 2 ~455mJ / cm 2 In the range of 5mJ / cm 2 The result of incremental changes.

[0073] As shown in the evaluation result P1, by using the pulsed laser shaped by the waveform shaping device 20, it is possible to 2 ~450mJ / cm 2 In other words, even when the irradiation energy of the pulsed laser changes during the process, the unevenness of the crystal structure of the polysilicon film 101b can be suppressed. On the other hand, in the evaluation result P2, the irradiation energy density at which the unevenness score becomes small is only 435 mJ / cm 2 Therefore, in the comparative example, the process margin with respect to the change in irradiation energy becomes smaller.

[0074] According to this embodiment, the margin for irradiation energy density can be increased in the melting and crystallization process, and a polycrystalline silicon film having a more uniform crystal structure can be formed, thereby contributing to improving the performance of semiconductor devices.

[0075] In addition, in the laser L2, it is preferred that the P polarized light component is higher than the S polarized light component. That is, it is preferred that the polarization ratio in the laser L2 is set to be 50% or more. In addition, the irradiation object of the laser L2 is not limited to the substrate 100 having the amorphous silicon film 101a. That is, the above-mentioned waveform shaping device 20 can be applied to laser irradiation devices other than laser annealing devices.

[0076] Implementation method 2.

[0077] use Figure 6 This embodiment will be described. Figure 6 The structure of the corrugated forming device 20 is shown. It should be noted that the basic structure of the ELA device 1 is the same as that of the first embodiment, so the description is appropriately omitted. In this embodiment, the first corrugated forming part 30 and the second corrugated forming part 40 are arranged side by side. It should be noted that the basic structure of the first corrugated forming part 30 and the second corrugated forming part 40 is the same as that of the first embodiment, so the detailed description is omitted.

[0078] In this embodiment, two laser sources are used. Specifically, the laser source 11 has a first laser source 11a and a second laser source 11b. The first laser source 11a and the second laser source 11b are the same laser oscillators. For example, the first laser source 11a and the second laser source 11b are excimer lasers similar to the first embodiment, and emit pulsed lasers with a wavelength of 308nm. The laser generated by the first laser source 11a is set as laser L100, and the laser generated by the second laser source 11b is set as laser L200. Laser L100 has the same polarization ratio as laser L200.

[0079] The laser light L100 is incident on the synthesizer 70 via the first waveform shaping unit 30 and the half wavelength plate 37. The first waveform shaping unit 30 and the half wavelength plate 37 are configured in the same manner as the first waveform shaping unit 30 and the half wavelength plate 37 of the first embodiment. The first beam splitter 31 branches the laser light L100 into two light beams L111 and L112. The light beam L112 reflected by the first beam splitter 31 is reflected by the reflection mirrors 32 to 35 and is incident on the first beam splitter 31. Thus, the first beam splitter 31 synthesizes the light beam L112 with the light beam L111 transmitted from the first beam splitter 31.

[0080] The light beams L111 and L112 synthesized by the first beam splitter 31 are referred to as laser light L113. The laser light L113 is transmitted through the half-wave plate 37. The laser light L113 transmitted through the half-wave plate 37 is referred to as laser light L114. The laser light L114 is incident on the synthesizer 70.

[0081] The first waveform shaping unit 30 shapes the pulse waveform by giving a time delay corresponding to the optical path difference to the two light beams L111 and L112. Specifically, the light beam L112 branched by the first beam splitter 31 repeatedly passes through the delay path until it enters the first beam splitter 31 again, thereby extending the pulse width.

[0082] The laser light L200 enters the combiner 70 via the half-wave plate 47 and the second waveform shaping section 40 . The half-wave plate 47 is disposed at a front stage of the second waveform shaping section 40 . Figure 6 The configuration of the 1 / 2 wavelength plate 47 and the second corrugated portion 40 is Figure 2 The configurations of the half-wavelength plate 37 and the second corrugated portion 40 are the same.

[0083] The 1 / 2 wavelength plate 47 changes the polarization state of the laser L200. The laser L200 transmitted through the 1 / 2 wavelength plate 47 is set to the laser L210. The 1 / 2 wavelength plate 47 is the same as the 1 / 2 wavelength plate 37. That is, in a plane orthogonal to the optical axis of the laser L200, the optical axis of the 1 / 2 wavelength plate 47 is inclined 45 degrees relative to the first direction. The 1 / 2 wavelength plate 47 converts the first polarization component into the second polarization component, and converts the second polarization component into the first polarization component. The polarization ratio of the laser L200 and the laser L210 is reversed. When the polarization ratio of the laser L100 and the laser L200 is the same, the polarization ratio of the laser L210 = {1-(polarization ratio of the laser L100)}. For example, if the polarization ratio in the laser L100 is 30%, the polarization ratio of the laser L210 is 70%.

[0084] The second beam splitter 41 splits the laser light L210 into two beams L211 and L212. The beam L212 reflected by the second beam splitter 41 is reflected by the mirrors 42 to 45 and enters the second beam splitter 41. Thus, the second beam splitter 41 combines the beam L212 with the beam L211 transmitted through the second beam splitter 41.

[0085] The light beams L211 and L212 synthesized by the second beam splitter 41 are set as laser light L213. The laser light L213 is incident on the synthesizer 70. The second waveform shaping unit 40 shapes the pulse waveform by giving a time delay corresponding to the optical path difference to the two light beams L211 and L212. Specifically, the light beam L212 branched by the second beam splitter 41 repeatedly passes through the delay path until it is incident on the second beam splitter 41 again, so that the pulse width can be extended.

[0086] The synthesizer 70 has a beam splitter and the like to synthesize the laser light L114 and the laser light L213. When viewed from above perpendicular to the optical axis, the laser light L114 and the laser light L213 overlap. The laser light L114 and the laser light L213 overlap in space to form the laser light L2. Specifically, the laser light L114 and the laser light L213 become coaxial laser light L2. The laser light L2 synthesized by the synthesizer 70 is irradiated onto the substrate 100 via the reflector 12 and the focusing lens 13 (see FIG. 1 ). Figure 1 ). It should be noted that the synthesizer 70 synthesizes the lasers L114 and L213 in the front section of the condenser lens 13, but the position where the lasers L114 and L213 are synthesized is not particularly limited. That is, in the substrate 100 as the irradiation object, the irradiation position of the laser L114 and the irradiation position of the laser L213 can overlap.

[0087] The first laser source 11a and the second laser source 11b operate synchronously. That is, the laser light L114 from the first waveform forming unit 30 and the laser light L213 from the second waveform forming unit 40 enter the combiner 70 at the same timing. The laser light L114 and the laser light L213 are irradiated onto the substrate 100 simultaneously.

[0088] According to such a configuration, the polarization ratio difference between the S polarized light component and the P polarized light component can be reduced as in Embodiment 1. Thus, the laser light L2 can be irradiated uniformly, and irradiation unevenness can be reduced. In addition, by using two laser light sources 11a and 11b, the irradiation intensity of the laser light can be increased.

[0089] It should be noted that, in Embodiment 2, two laser sources 11a and 11b are used to generate the laser light L100 and the laser light L200, but the laser light from one laser source 11 may be branched to generate the two laser lights L100 and L200. In this case, a non-polarizing beam splitter may be used that transmits or reflects a beam at a constant branching ratio regardless of the polarization state. For example, a non-polarizing beam splitter may be used that has a branching ratio of 50:50 in both the S polarized light component and the P polarized light component to generate the first and second laser lights. By adopting this method, two laser lights of the same polarization state can be generated.

[0090] In addition, more than three laser sources may be used. Figure 2 The composition and Figure 6 Alternatively, Figure 2 The composition is set to 2 groups. Figure 6 The composition is set to 2 groups.

[0091] In addition, in Embodiment 1 or Embodiment 2, 1 / 2 wavelength plates 37 and 47 are used as wavelength plates for changing the polarization state of the laser, but wavelength plates other than 1 / 2 wavelength plates may also be used. For example, a 1 / 4 wavelength plate may also be used to change the polarization state of the laser. By replacing the 1 / 2 wavelength plate 37 and the 1 / 2 wavelength plate 47 with a 1 / 4 wavelength plate, right-handed circularly polarized light and left-handed circularly polarized light can be delayed in the same manner. In this case, a 1 / 4 wavelength plate for restoring circularly polarized light to linearly polarized light may also be arranged in the optical path of the laser L2. Alternatively, the substrate 100 may be irradiated with laser L2 containing right-handed circularly polarized light and left-handed circularly polarized light.

[0092] In addition, the directions of the first beam splitter 31 and the second beam splitter 41 can be adjusted to omit the half-wave plate 37 and the half-wave plate 47. Figure 2 or Figure 6 In the embodiment, either the first beam splitter 31 or the second beam splitter 41 is rotated 90 degrees around the optical axis. Figure 2 In the embodiment, the first beam splitter 31 directs a portion of the laser light L1 to Figure 5 The second beam splitter 41 reflects a portion of the laser light L14 in the vertical direction within the paper surface. Figure 5 By adopting this method, the polarization ratio of the first and second polarized light components can be changed.

[0093] (Organic EL Display)

[0094] 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 trench region, and a drain region of the TFT.

[0095] Hereinafter, a configuration in which the semiconductor device of this embodiment is applied to an organic EL display will be described. Figure 7 This is a cross-sectional view showing a simplified pixel circuit of an organic EL display.

[0096] Figure 7 The organic EL display 300 shown is an active matrix type display device in which a TFT is arranged in each pixel PX.

[0097] 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. Figure 7 , an organic EL display of a top emission type in which the sealing substrate 314 side becomes the visual recognition side is shown. It should be noted that the following description shows an example of the structure of the organic EL display, and this embodiment is not limited to the structure described below. For example, the semiconductor device of this embodiment can also be used for an organic EL display of a bottom emission type.

[0098] 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. In addition, the TFT layer 311 has wiring (not shown) connected to the TFT 311a. The TFT 311a and the wiring constitute a pixel circuit.

[0099] An organic layer 312 is provided on the TFT layer 311. The organic layer 312 has an organic EL light-emitting element 312a configured for each pixel PX. The organic EL light-emitting element 312a has, for example, a stacked structure in which an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode are stacked. In the case of a top emission method, the anode is a metal electrode, and the cathode is a transparent conductive film such as ITO (Indium Tin Oxide). In addition, in the organic layer 312, a partition wall 312b for separating the organic EL light-emitting element 312a is provided between the pixels PX.

[0100] A color filter layer 313 is provided on the organic layer 312. The color filter layer 313 is provided with a color filter portion 313a for color display. That is, as the color filter portion 313a, a resin layer colored R (red), G (green) or B (blue) is provided in each pixel PX. White light emitted from the organic layer 312 is converted into RGB color light when passing through the color filter portion 313a. It should be noted that in the case of a three-color mode in which the organic layer 312 is provided with an organic EL light-emitting element that emits RGB colors, the color filter layer 313 can also be omitted.

[0101] 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 element of the organic layer 312 from deteriorating.

[0102] The current flowing into the organic EL light emitting element 312a of the organic layer 312 changes according to the display signal supplied to the pixel circuit. Thus, by supplying a display signal corresponding to the display image to each pixel PX, the light emission amount in each pixel PX can be controlled. Thus, the desired image can be displayed.

[0103] In an active matrix display device such as an organic EL display, one pixel PX is provided with one or more TFTs (e.g., a switching TFT or a driving TFT). In addition, the TFT of each pixel PX is provided with a semiconductor layer having a source region, a groove region, and a drain region. The polycrystalline silicon film of this embodiment is suitable for the semiconductor layer of the TFT. That is, by applying the polycrystalline silicon film manufactured using the above-mentioned manufacturing method to the semiconductor layer of the TFT array substrate, the in-plane non-uniformity of the TFT characteristics can be suppressed. As a result, a display device with excellent display characteristics can be manufactured with high productivity.

[0104] (Method for manufacturing semiconductor device)

[0105] The method for manufacturing a semiconductor device using the ELA device of this embodiment is suitable for manufacturing a TFT array substrate. Figure 8 to Figure 15 A method for manufacturing a semiconductor device including a TFT will be described. Figure 8 to Figure 15 1 is a cross-sectional view showing a process of manufacturing a semiconductor device. In the following description, a method of manufacturing a semiconductor device of an inverted staggered TFT is described.

[0106] First, if Figure 8As shown, a gate electrode 402 is formed on a glass substrate 401. It should be noted that the glass substrate 401 is equivalent to the above-mentioned substrate 100. For example, a metal film containing aluminum or the like can be used as the gate electrode 402. The metal film is formed on the glass substrate 401 by a sputtering method or an evaporation method. Then, the metal film is patterned by a photolithography method to form the gate electrode 402. In the photolithography method, processes such as resist coating, exposure, development, etching, and resist stripping are performed. It should be noted that various wirings and the like can also be formed in the same process as the patterning of the gate electrode 402.

[0107] Next, if Fig. 9 As shown in FIG. 4 , a gate insulating film 403 is formed on the gate electrode 402. The gate insulating film 403 is formed in a manner covering the gate electrode 402. Then, as shown in FIG. Fig.10 As shown in FIG. 4 , an amorphous silicon film 404 is formed on the gate insulating film 403. The amorphous silicon film 404 is arranged so as to overlap with the gate electrode 402 with the gate insulating film 403 interposed therebetween.

[0108] The gate insulating film 403 is a silicon nitride film (SiN x ), a silicon oxide film (SiO2 film), or a stacked film of these films, etc. Specifically, the gate insulating film 403 and the amorphous silicon film 404 are continuously formed using a CVD (Chemical Vapor Deposition) method.

[0109] Then, by irradiating the amorphous silicon film 404 with laser light L2, Fig.11 The polysilicon film 405 is formed as shown. Figure 1 The ELA apparatus 1 shown in the examples crystallizes the amorphous silicon film 404. Thus, a polysilicon film 405 formed by crystallizing silicon is formed on the gate insulating film 403. The polysilicon film 405 corresponds to the polysilicon film 101b described above.

[0110] At this time, the inspection method of this embodiment is used to inspect the polysilicon film 405. When the polysilicon film 405 does not reach the predetermined reference, the laser is irradiated again to the polysilicon film 405. Therefore, the characteristics of the polysilicon film 405 can be made more uniform. Since the unevenness within the surface can be suppressed, a display device with excellent display characteristics can be manufactured with high productivity.

[0111] Although not shown in the figure, the polysilicon film 405 is patterned by photolithography. Alternatively, impurities may be introduced into the polysilicon film 405 by ion implantation or the like.

[0112] Afterwards, if Fig.12As shown in FIG. 1 , an interlayer insulating film 406 is formed on the polysilicon film 405. The interlayer insulating film 406 is provided with a contact hole 406a for exposing the polysilicon film 405.

[0113] The interlayer insulating film 406 is a silicon nitride film (SiN x ), a silicon oxide film (SiO2 film), or a stacked film of these films, etc. Specifically, the interlayer insulating film 406 is formed by a CVD method. Then, the interlayer insulating film 406 is patterned by a photolithography method to form a contact hole 406a.

[0114] Next, if Fig.13 As shown in FIG. 1 , a source electrode 407a and a drain electrode 407b are formed on the interlayer insulating film 406. The source electrode 407a and the drain electrode 407b are formed so as to cover the contact hole 406a. That is, the source electrode 407a and the drain electrode 407b are formed from the inside of the contact hole 406a to the top of the interlayer insulating film 406. Thus, the source electrode 407a and the drain electrode 407b are electrically connected to the polysilicon film 405 via the contact hole 406a.

[0115] Thus, TFT410 is formed. TFT410 corresponds to the above-mentioned TFT311a. In the polysilicon film 405, the region overlapping with the gate electrode 402 becomes the groove region 405c. In the polysilicon film 405, the source electrode 407a side relative to the groove region 405c becomes the source region 405a, and the drain electrode 407b side becomes the drain region 405b.

[0116] The source electrode 407a and the drain electrode 407b are formed of a metal thin film including aluminum or the like. The metal thin film is formed on the interlayer insulating film 406 by sputtering or evaporation. Then, the metal thin film is patterned by photolithography to form the source electrode 407a and the drain electrode 407b. It should be noted that various wirings may be formed in the same process as the patterning of the source electrode 407a and the drain electrode 407b.

[0117] Then, if Fig.14 As shown in FIG. 1 , a planarization film 408 is formed on the source electrode 407a and the drain electrode 407b. The planarization film 408 is formed to cover the source electrode 407a and the drain electrode 407b. In addition, a contact hole 408a for exposing the drain electrode 407b is provided in the planarization film 408.

[0118] The planarization film 408 is formed of, for example, a photosensitive resin film. The photosensitive resin film is applied on the source electrode 407a and the drain electrode 407b, and then exposed and developed. In this way, the planarization film 408 having the contact hole 408a can be patterned.

[0119] Then, if Fig.15As shown, a pixel electrode 409 is formed on the planarization film 408. The pixel electrode 409 is formed so as to cover the contact hole 408a. That is, the pixel electrode 409 is formed from the contact hole 408a to the planarization film 408. Thus, the pixel electrode 409 is electrically connected to the drain electrode 407b via the contact hole 408a.

[0120] The pixel electrode 409 is formed of a transparent conductive film or a metal thin film containing aluminum or the like. A conductive film (transparent conductive film or metal thin film) is formed on the planarization film 408 by sputtering or the like. Then, the conductive film is patterned by photolithography. Thus, the pixel electrode 409 is formed on the planarization film 408. In the case of a driving TFT of an organic EL display, a conductive film (transparent conductive film or metal thin film) is formed on the pixel electrode 409. Figure 7 31 and 32 show the organic EL light emitting element 312a, the color filter (CF) 313a, etc. It should be noted that, in the case of a top-emitting organic EL display, the pixel electrode 409 is formed of a metal thin film containing aluminum, silver, etc. with high reflectivity. In addition, in the case of a bottom-emitting organic EL display, the pixel electrode 409 is formed of a transparent conductive film such as ITO.

[0121] The above describes the manufacturing process of an inverted staggered TFT, but the manufacturing method of this embodiment can also be applied to the manufacturing of an inverted staggered TFT. It goes without saying that the manufacturing method of a TFT is not limited to the manufacturing of a TFT for an organic EL display, but can also be applied to the manufacturing of a TFT for an LCD (Liquid Crystal Display).

[0122] In addition, in the above description, the laser annealing device of this embodiment irradiates laser light to an amorphous silicon film to form a polycrystalline silicon film, but it is also possible to irradiate laser light to an amorphous silicon film to form a microcrystalline silicon film. In addition, the laser for annealing is not limited to an excimer laser. In addition, the method of this embodiment can also be applied to a laser annealing device that crystallizes a thin film other than a silicon film. That is, as long as it is a laser annealing device that irradiates laser light to an amorphous film to form a crystalline film, the method of this embodiment can be applied. According to the laser annealing device of this embodiment, a substrate with a crystalline film can be properly inspected.

[0123] It should be noted that the present invention is not limited to the above-described embodiments, and can be appropriately modified within a scope not departing from the gist of the invention.

[0124] This application claims the benefit of priority based on Japanese patent application No. 2019-77707, filed on April 16, 2019, the disclosure of which is incorporated herein by reference in its entirety.

[0125] Description of Reference Numerals

[0126] 1 ELA device

[0127] 11. Laser Source

[0128] 11a 1st laser source

[0129] 11b Second laser source

[0130] 12. Reflector

[0131] 13 Condenser lens

[0132] 20 Wave-forming device

[0133] 30 1st wave-shaped part

[0134] 31 1st beam splitter

[0135] 32~35 Reflector

[0136] 37 1 / 2 wavelength plate

[0137] 40 Second wave-shaped portion

[0138] 41 2nd beam splitter

[0139] 42~45 Reflector

[0140] 47 1 / 2 wavelength plate

[0141] 100 substrates

[0142] 101 Silicone membrane

[0143] 101a Amorphous silicon film 101a

[0144] 101b Polysilicon film 101b

[0145] 300 Organic EL Display

[0146] 310 base plate

[0147] 311 TFT layer

[0148] 311a TFT

[0149] 312 Organic layer

[0150] 312a Organic EL light emitting element

[0151] 312b Next Door

[0152] 313 Color Filter Layer

[0153] 313a Color filter (CF)

[0154] 314 sealing substrate

[0155] 401 Glass Substrate

[0156] 402 gate electrode

[0157] 403 Gate insulation film

[0158] 404 Amorphous Silicon Film

[0159] 405 Polysilicon Film

[0160] 406 interlayer insulation film

[0161] 407a Source electrode

[0162] 407b Drain electrode

[0163] 408 planarization film

[0164] 409 pixel electrode

[0165] 410 TFT

[0166] PX Pixel

Claims

1. A laser irradiation device, characterized in that: include: A laser source that generates a pulse laser having a first polarization component and a second polarization component; a first waveform shaping unit including a first beam splitter for branching the pulsed laser light, and shaping the pulse waveform of the pulsed laser light by imparting a delay corresponding to an optical path difference to two beams branched by the first beam splitter; a wavelength plate that changes the polarization state of the pulsed laser light from the first waveform shaping section; as well as a second waveform shaping unit including a second beam splitter for branching the pulsed laser light from the wavelength plate, and shaping the pulse waveform of the pulsed laser light by imparting a delay corresponding to an optical path difference to the two beams branched by the second beam splitter, The first beam splitter is a non-polarizing beam splitter that splits a first polarized light component into two and splits a second polarized light component orthogonal to the first polarized light component into two. The wavelength plate rotates the first polarized light component and the second polarized light component by 90 degrees respectively. The second beam splitter is a non-polarizing beam splitter that splits the first polarized light component into two and splits the second polarized light component that is orthogonal to the first polarized light component into two. In the first beam splitter, a branching ratio for the first polarized light component is different from a branching ratio for the second polarized light component. In the second beam splitter, a branching ratio for the first polarization component is different from a branching ratio for the second polarization component.

2. The laser irradiation device according to claim 1, wherein: The pulse laser light is branched into a first light beam and a second light beam by the first beam splitter reflecting a part of the pulse laser light and transmitting a part of the pulse laser light. The first wave-shaped portion includes a plurality of first reflecting mirrors, and the plurality of first reflecting mirrors reflect the second light beam so that the optical path of the second light beam is longer than the optical path of the first light beam. The first beam splitter combines the second light beam reflected by the plurality of first reflecting mirrors with the first light beam. The second beam splitter reflects a portion of the pulse laser and transmits a portion thereof, thereby branching the pulse laser into a third light beam and a fourth light beam. The second wave-shaped portion includes a plurality of second reflecting mirrors, and the plurality of second reflecting mirrors reflect the fourth light beam so that the optical path of the fourth light beam is longer than the optical path of the third light beam. The second beam splitter combines the fourth light beam reflected by the plurality of second reflecting mirrors with the third light beam.

3. The laser irradiation device according to claim 1 or 2, wherein: After shaping by the second waveform shaping unit, in the pulse laser irradiated onto the object, when the intensities of the P polarized light component and the S polarized light component are normalized by pulse energy, the difference in intensity between the P polarized light component and the S polarized light component is 12% or less.

4. The laser irradiation device according to claim 1 or 2, wherein: The device further includes a mechanism for converting the pulse laser beam irradiated onto the object into a line beam after being shaped by the second waveform shaping unit.

5. The laser irradiation device according to claim 1 or 2, wherein: After being shaped by the second waveform shaping portion, the amorphous film is irradiated with pulse laser light while changing the irradiation position of the pulse laser light relative to the object, thereby crystallizing the amorphous film to form a crystalline film.

6. A laser irradiation device, characterized in that: include: a laser source that generates a first pulse laser and a second pulse laser having a first polarization component and a second polarization component, respectively; a first waveform shaping unit including a first beam splitter for branching the first pulsed laser light, and shaping the pulse waveform of the first pulsed laser light by imparting a delay corresponding to an optical path difference to two beams branched by the first beam splitter; a first wave plate that changes the polarization state of the first pulsed laser light from the first waveform shaping portion; a second wavelength plate that changes the polarization state of the second pulsed laser light from the laser source; a second waveform shaping unit including a second beam splitter for branching the second pulsed laser from the second wave plate, and shaping the pulse waveform of the second pulsed laser by imparting a delay corresponding to an optical path difference to the two beams branched by the second beam splitter; as well as a synthesizer that synthesizes the first pulse laser from the first wave plate and the second pulse laser from the second waveform shaping unit into a synthesized pulse laser, The first beam splitter is a non-polarizing beam splitter that splits the first polarized light component of the first pulse laser into two and splits the second polarized light component of the first pulse laser orthogonal to the first polarized light component of the first pulse laser into two. The first wave plate rotates the first polarization component of the first pulse laser and the second polarization component of the first pulse laser by 90 degrees respectively. The second wave plate rotates the first polarization component of the second pulsed laser light and the second polarization component of the second pulsed laser light by 90 degrees respectively. The second beam splitter is a non-polarizing beam splitter that splits the first polarization component of the second pulse laser into two and splits the second polarization component of the second pulse laser orthogonal to the first polarization component of the second pulse laser into two. In the first beam splitter, a branching ratio for a first polarized light component of the first pulsed laser light is different from a branching ratio for a second polarized light component of the first pulsed laser light. In the second beam splitter, a branching ratio for a first polarization component of the second pulsed laser light is different from a branching ratio for a second polarization component of the second pulsed laser light.

7. The laser irradiation device according to claim 6, wherein: The first pulse laser is branched into a first light beam and a second light beam by causing the first beam splitter to reflect a portion of the first pulse laser and transmit a portion of the first pulse laser. The first wave-shaped portion includes a plurality of first reflecting mirrors, and the plurality of first reflecting mirrors reflect the second light beam so that the optical path of the second light beam is longer than the optical path of the first light beam. The first beam splitter combines the second light beam reflected by the plurality of first reflecting mirrors with the first light beam. The second pulse laser is branched into a third light beam and a fourth light beam by causing the second beam splitter to reflect a portion of the second pulse laser and transmit a portion of the second pulse laser. The second wave-shaped portion includes a plurality of second reflecting mirrors, and the plurality of second reflecting mirrors reflect the fourth light beam so that the optical path of the fourth light beam is longer than the optical path of the third light beam. The second beam splitter combines the fourth light beam reflected by the plurality of second reflecting mirrors with the third light beam.

8. The laser irradiation device according to claim 6 or 7, wherein: In the synthesized pulse laser light irradiated onto the object, when the intensities of the P-polarized light component and the S-polarized light component are normalized by pulse energy, the difference in intensity between the P-polarized light component and the S-polarized light component is 12% or less.

9. The laser irradiation device according to claim 6 or 7, wherein: The device further includes a mechanism for converting the synthesized pulse laser light irradiated onto an object into a line beam.

10. The laser irradiation device according to claim 6 or 7, wherein: By irradiating an amorphous film with the synthetic pulse laser light while changing the irradiation position of the synthetic pulse laser light with respect to an object, the amorphous film is crystallized to form a crystalline film.

11. A laser irradiation method, characterized in that: The steps include: (A) generating a pulse laser having a first polarization component and a second polarization component; (B) a step of branching the pulsed laser into two beams by a first beam splitter; (C) a step of shaping the pulse waveform of the pulse laser by imparting a delay corresponding to the optical path difference to the two light beams branched by the first beam splitter; (D) after step (C), a step of changing the polarization state of the pulsed laser using a wavelength plate; (E) a step of splitting the pulse laser from the wavelength plate into two beams using a second beam splitter; and (F) a step of shaping the pulse waveform of the pulse laser by imparting a delay corresponding to the optical path difference to the two light beams branched by the second beam splitter, The first beam splitter is a non-polarizing beam splitter that splits a first polarized light component into two and splits a second polarized light component orthogonal to the first polarized light component into two. The wavelength plate rotates the first polarized light component and the second polarized light component by 90 degrees respectively. The second beam splitter is a non-polarizing beam splitter that splits the first polarized light component into two and splits the second polarized light component that is orthogonal to the first polarized light component into two. In the first beam splitter, a branching ratio for the first polarized light component is different from a branching ratio for the second polarized light component. In the second beam splitter, a branching ratio for the first polarization component is different from a branching ratio for the second polarization component.

12. The laser irradiation method according to claim 11, wherein: In step (B), The pulse laser light is branched into a first light beam and a second light beam by the first beam splitter reflecting a part of the pulse laser light and transmitting a part of the pulse laser light. In step (C), The second light beam is reflected by a plurality of first reflecting mirrors so that the optical path of the second light beam is longer than the optical path of the first light beam. The first beam splitter combines the second light beam reflected by the plurality of first reflecting mirrors with the first light beam. In step (E), The second beam splitter reflects a portion of the pulse laser and transmits a portion thereof, thereby branching the pulse laser into a third light beam and a fourth light beam. In step (F), The fourth light beam is reflected by a plurality of second reflecting mirrors so that the optical path of the fourth light beam is longer than the optical path of the third light beam. The second beam splitter combines the fourth light beam reflected by the plurality of second reflecting mirrors with the third light beam.

13. The laser irradiation method according to claim 11 or 12, wherein: After the pulse waveform is formed in step (F), in the pulse laser irradiated on the object, when the intensities of the P polarized light component and the S polarized light component are normalized by the pulse energy, the difference in intensity between the P polarized light component and the S polarized light component is less than 12%.

14. The laser irradiation method according to claim 11 or 12, wherein: After the pulse waveform is formed in step (F), the pulse laser light is converted into a line beam and irradiated onto the object.

15. The laser irradiation method according to claim 11 or 12, wherein: By irradiating the amorphous film with pulse laser light while changing the irradiation position of the pulse laser light with respect to the object, the amorphous film is crystallized to form a crystalline film.

16. A laser irradiation method, characterized in that: The steps include: (a) generating a first pulse laser and a second pulse laser having a first polarization component and a second polarization component, respectively; (b) a step of splitting the first pulsed laser into two beams by a first beam splitter; (c) a step of shaping the pulse waveform of the first pulsed laser light by imparting a delay corresponding to the optical path difference to the two light beams branched by the first beam splitter; (d) after step (c), a step of changing the polarization state of the first pulsed laser light by using a first wavelength plate; (e) a step of changing the polarization state of the second pulsed laser light by using a second wavelength plate; (f) after step (e), a step of using a second beam splitter to branch the second pulsed laser into two beams; (g) a step of shaping the pulse waveform of the second pulsed laser light by imparting a delay corresponding to the optical path difference to the two light beams branched by the second beam splitter; and (h) a step of synthesizing the first and second pulse lasers having the pulse waveform into a synthesized pulse laser, The first beam splitter is a non-polarizing beam splitter that splits the first polarized light component of the first pulse laser into two and splits the second polarized light component of the first pulse laser orthogonal to the first polarized light component of the first pulse laser into two. The first wave plate rotates the first polarization component of the first pulse laser and the second polarization component of the first pulse laser by 90 degrees respectively. The second wave plate rotates the first polarization component of the second pulsed laser light and the second polarization component of the second pulsed laser light by 90 degrees respectively. The second beam splitter is a non-polarizing beam splitter that splits the first polarization component of the second pulse laser into two and splits the second polarization component of the second pulse laser orthogonal to the first polarization component of the second pulse laser into two. In the first beam splitter, a branching ratio for a first polarized light component of the first pulsed laser light is different from a branching ratio for a second polarized light component of the first pulsed laser light. In the second beam splitter, a branching ratio for a first polarization component of the second pulsed laser light is different from a branching ratio for a second polarization component of the second pulsed laser light.

17. The laser irradiation method according to claim 16, wherein: In step (b), The first pulse laser is branched into a first light beam and a second light beam by causing the first beam splitter to reflect a portion of the first pulse laser and transmit a portion of the first pulse laser. In step (c), The second light beam is reflected by a plurality of first reflecting mirrors so that the optical path of the second light beam is longer than the optical path of the first light beam. The first beam splitter combines the second light beam reflected by the plurality of first reflecting mirrors with the first light beam. In step (f), The second pulse laser is branched into a third light beam and a fourth light beam by causing the second beam splitter to reflect a portion of the second pulse laser and transmit a portion of the second pulse laser. In step (g), The fourth light beam is reflected by a plurality of second reflecting mirrors so that the optical path of the fourth light beam is longer than the optical path of the third light beam. The second beam splitter combines the fourth light beam reflected by the plurality of second reflecting mirrors with the third light beam.

18. The laser irradiation method according to claim 16 or 17, wherein: In the synthesized pulse laser light irradiated onto the object, when the intensities of the P-polarized light component and the S-polarized light component are normalized by pulse energy, the difference in intensity between the P-polarized light component and the S-polarized light component is 12% or less.

19. The laser irradiation method according to claim 16 or 17, wherein: The synthesized pulse laser light is converted into a line beam and irradiated onto an object.

20. The laser irradiation method according to claim 16 or 17, wherein: By irradiating the amorphous film with the synthetic pulse laser light while changing the irradiation position of the synthetic pulse laser light with respect to the object, the amorphous film is crystallized to form a crystalline film.

21. A method for manufacturing a semiconductor device, comprising the following steps: (S1) a step of forming an amorphous film on a substrate; and (S2) irradiating the amorphous film with a pulsed laser having a first polarized light component and a second polarized light component to crystallize the amorphous film to form a crystalline film, In the method for manufacturing a semiconductor device, The step (S2) comprises the following steps: (SA) step of generating pulsed laser; (SB) a step of branching the pulsed laser into two beams by a first beam splitter; (SC) a step of shaping the pulse waveform of the pulse laser by imparting a delay corresponding to the optical path difference to the two light beams branched by the first beam splitter; (SD) after step (SC), a step of changing the polarization state of the pulsed laser using a wavelength plate; (SE) a step of using a second beam splitter to split the pulse laser from the wavelength plate into two beams; (SF) a step of shaping the pulse waveform of the pulse laser by imparting a delay corresponding to the optical path difference to the two light beams branched by the second beam splitter, The first beam splitter is a non-polarizing beam splitter that splits a first polarized light component into two and splits a second polarized light component orthogonal to the first polarized light component into two. The wavelength plate rotates the first polarized light component and the second polarized light component by 90 degrees respectively. The second beam splitter is a non-polarizing beam splitter that splits the first polarized light component into two and splits the second polarized light component that is orthogonal to the first polarized light component into two. In the first beam splitter, a branching ratio for the first polarized light component is different from a branching ratio for the second polarized light component. In the second beam splitter, a branching ratio for the first polarization component is different from a branching ratio for the second polarization component.

22. The method for manufacturing a semiconductor device according to claim 21, wherein: In step (SB), The pulse laser light is branched into a first light beam and a second light beam by the first beam splitter reflecting a part of the pulse laser light and transmitting a part of the pulse laser light. In the (SC) step, The second light beam is reflected by a plurality of first reflecting mirrors so that the optical path of the second light beam is longer than the optical path of the first light beam. The first beam splitter combines the second light beam reflected by the plurality of first reflecting mirrors with the first light beam. In the (SE) step, The second beam splitter reflects a portion of the pulse laser and transmits a portion thereof, thereby branching the pulse laser into a third light beam and a fourth light beam. In the (SF) step, The fourth light beam is reflected by a plurality of second reflecting mirrors so that the optical path of the fourth light beam is longer than the optical path of the third light beam. The second beam splitter combines the fourth light beam reflected by the plurality of second reflecting mirrors with the third light beam.

23. The method for manufacturing a semiconductor device according to claim 21 or 22, wherein: In the pulse laser irradiated onto the amorphous film in step (S2), when the intensities of the P-polarized light component and the S-polarized light component are normalized by pulse energy, the difference in intensity between the P-polarized light component and the S-polarized light component is 12% or less.

24. The method for manufacturing a semiconductor device according to claim 21 or 22, wherein: In step (S2), the pulse laser is converted into a linear beam and irradiated to the amorphous film.

25. The method for manufacturing a semiconductor device according to claim 21 or 22, wherein: In step (S2), the amorphous film is irradiated with pulse laser light while changing the irradiation position of the pulse laser light relative to the object, thereby crystallizing the amorphous film to form a crystalline film.

26. A method for manufacturing a semiconductor device, comprising the following steps: (S1) a step of forming an amorphous film on a substrate; and (S2) irradiating the amorphous film with a pulsed laser having a first polarized light component and a second polarized light component to crystallize the amorphous film to form a crystalline film, In the method for manufacturing a semiconductor device, The (S2) step comprises the following steps: (sa) a step of generating a first pulse laser and a second pulse laser; (sb) a step of branching the first pulsed laser into two beams by a first beam splitter; (sc) a step of shaping the pulse waveform of the first pulsed laser light by imparting a delay corresponding to the optical path difference to the two light beams branched by the first beam splitter; (sd) after step (sc), a step of changing the polarization state of the first pulsed laser light by using a first wavelength plate; (se) a step of changing the polarization state of the second pulsed laser light by using a second wavelength plate; (sf) after step (se), a step of using a second beam splitter to split the second pulsed laser into two beams; (sg) a step of shaping the pulse waveform of the second pulsed laser light by imparting a delay corresponding to the optical path difference to the two light beams branched by the second beam splitter; and (sh) a step of synthesizing the first and second pulse lasers having the pulse waveform into a synthesized pulse laser, The first beam splitter is a non-polarizing beam splitter that splits a first polarized light component into two and splits a second polarized light component orthogonal to the first polarized light component into two. The first wave plate rotates the first polarized light component and the second polarized light component by 90 degrees respectively. The second wave plate rotates the first polarized light component and the second polarized light component by 90 degrees respectively. The second beam splitter is a non-polarizing beam splitter that splits the first polarized light component into two and splits the second polarized light component that is orthogonal to the first polarized light component into two. In the first beam splitter, a branching ratio for the first polarized light component is different from a branching ratio for the second polarized light component. In the second beam splitter, a branching ratio for the first polarization component is different from a branching ratio for the second polarization component.

27. The method for manufacturing a semiconductor device according to claim 26, wherein: In step (sb), The first pulse laser is branched into a first light beam and a second light beam by causing the first beam splitter to reflect a portion of the first pulse laser and transmit a portion of the first pulse laser. In step (sc), The second light beam is reflected by a plurality of first reflecting mirrors so that the optical path of the second light beam is longer than the optical path of the first light beam. The first beam splitter combines the second light beam reflected by the plurality of first reflecting mirrors with the first light beam. In the (sf) step, The second pulse laser is branched into a third light beam and a fourth light beam by causing the second beam splitter to reflect a portion of the second pulse laser and transmit a portion of the second pulse laser. In step (sg), The fourth light beam is reflected by a plurality of second reflecting mirrors so that the optical path of the fourth light beam is longer than the optical path of the third light beam. The second beam splitter combines the fourth light beam reflected by the plurality of second reflecting mirrors with the third light beam.

28. The method for manufacturing a semiconductor device according to claim 26 or 27, wherein: In the synthetic pulse laser light irradiated onto the amorphous film, when the intensities of the P-polarized light component and the S-polarized light component are normalized by pulse energy, a difference in the intensities of the P-polarized light component and the S-polarized light component is 12% or less.

29. The method for manufacturing a semiconductor device according to claim 26 or 27, wherein: The synthesized pulse laser light is converted into a linear beam and irradiated toward the amorphous film.

30. The method for manufacturing a semiconductor device according to claim 26 or 27, wherein: In step (S2), the amorphous film is irradiated with the synthetic pulse laser light while changing the irradiation position of the synthetic pulse laser light relative to the substrate, thereby crystallizing the amorphous film to form a crystalline film.

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