Laser annealing device

Abstract

This laser annealing device is provided with a light source for emitting a laser beam, and a multimode optical fiber for transmitting the laser beam and emitting the laser beam from the other end, the laser annealing device being provided with a vibration source having a vibration head, the optical fiber being disposed on a mounting surface of the vibration head, the laser annealing device is provided with a support part which covers a region of the optical fiber disposed on the mounting surface and supports and presses the optical fiber against the mounting surface, and the vibration transmissibility between the optical fiber and the support part in contact with the optical fiber is set to be smaller than the vibration transmissibility between the mounting surface and the optical fiber.

Description

Technical Field

[0001] The invention relates to a laser annealing device. Background Art

[0002] There is known a laser beam homogenization system that transmits laser light via an optical fiber (for example, see Patent Document 1). It is proposed that this system be used for an annealing technique that crystallizes a thin film by irradiating a laser from the front end of an optical fiber. Patent Document 1 discloses the following technology: in order to average out the pattern (hereinafter referred to as a speckle pattern) at the beam point of the laser light caused by the variation of the laser intensity distribution generated by the interference of the laser light in the optical fiber optical path, a rotating polarization canceller is arranged on the exit end face side of the optical fiber. Patent Document 1 discloses that in addition to the above-mentioned polarization canceller, a mechanism that mechanically vibrates the optical fiber is used to further average out the speckle pattern.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2008-112953 Summary of the invention

[0006] Problems to be solved by the present invention

[0007] However, when the optical fiber is mechanically vibrated, there is a problem that the boundary between the portion in contact with the vibration mechanism and the portion not in contact with the vibration mechanism in the optical fiber is broken in a short period of time.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a laser annealing device that can suppress the generation of a speckle pattern and increase the life of an optical fiber.

[0009] Solutions to Solve Problems

[0010] In order to solve the above-mentioned problems and achieve the purpose, the laser annealing device involved in the solution of the present invention includes a light source that emits laser light and a multi-mode optical fiber into which the laser light is incident from one end and emitted from the other end, characterized in that the laser annealing device includes a vibration source having a mounting surface, the optical fiber is arranged along the mounting surface, the optical fiber arranged in a region of the mounting surface is covered with a protective layer having rigidity, and the laser annealing device includes a support portion that presses the optical fiber covered by the protective layer toward the mounting surface.

[0011] As the above aspect, it is preferable that a vibration transmissibility between the protective layer and the support portion is set to be smaller than a vibration transmissibility between the mounting surface and the protective layer.

[0012] As the above aspect, preferably, the protective layer is a cylindrical body made of metal or synthetic resin.

[0013] As the above aspect, preferably, a resin material is filled between the optical fiber and the protective layer.

[0014] As the above aspect, it is preferable that the support portion includes a rubber material portion that contacts the optical fiber and a support plate that presses the rubber material portion toward the optical fiber.

[0015] As the above aspect, it is preferable that the support portion includes a resin material portion that contacts the optical fiber and a support plate that presses the resin material portion toward the optical fiber.

[0016] As the above aspect, it is preferable that the support portion includes an adhesive material portion that contacts the optical fiber and a support plate that presses the adhesive material portion toward the optical fiber.

[0017] As the above aspect, it is preferable that the support portion includes a magnetic adsorbent portion that contacts the optical fiber and a support plate that presses the magnetic adsorbent portion toward the optical fiber.

[0018] As the above aspect, preferably, the support plate is a metal plate or a synthetic resin plate.

[0019] As the above aspect, preferably, the resin material portion is a resin tape.

[0020] As the above aspect, it is preferable that the support portion is set so that the mounting surface is accommodated within the contour of the support portion in a state facing the mounting surface.

[0021] Effects of the Invention

[0022] According to the present invention, it is possible to realize a laser annealing apparatus capable of suppressing the generation of a speckle pattern and extending the life of an optical fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of a laser annealing apparatus according to an embodiment of the present invention.

[0024] Figure 2 This is a cross-sectional view showing a state in which a support portion in a laser annealing device according to an embodiment of the present invention is cut along a direction perpendicular to the optical fiber.

[0025] Figure 3 yes Figure 2 and Figure 4 III-III section view.

[0026] Figure 4 It is a top view of a support portion in the laser annealing apparatus according to the embodiment of the present invention.

[0027] Figure 5 It is a cross-sectional view of a portion of the optical fiber supported by a supporting portion in the laser annealing device according to the embodiment of the present invention.

[0028] Figure 6 It is a cross-sectional view showing Modification 1 of a portion of the optical fiber supported by a supporting portion in the laser annealing apparatus according to the embodiment of the present invention.

[0029] Figure 7 This is a cross-sectional view showing a second modification in which a resin tape is used as a resin material portion used for a support portion in the laser annealing device of the present embodiment.

[0030] Figure 8 It is a cross-sectional view showing a third modification in which a magnetically attractive material portion is used as a support portion in the laser annealing apparatus according to the present embodiment.

[0031] Fig. 9 It is a cross-sectional view showing a modification 4 in which an adhesive material portion is used as a support portion in the laser annealing apparatus of the present embodiment.

[0032] Fig.10 It is a cross-sectional view showing a modification 5 in which the housing groove of the mounting surface is formed larger and the optical fiber is embedded in the housing groove in the laser annealing device of the present embodiment.

[0033] Fig.11 It is a cross-sectional view showing a modification 6 in which the support portion is formed only of a metal spring plate in the laser annealing apparatus of the present embodiment.

[0034] Fig.12 This is a diagram showing a comparative example in which a vertical stripe pattern appears in an annealing region when the optical fiber is not vibrated in a laser annealing device.

[0035] Fig.13 This is a diagram showing a comparative example in which an optical fiber is broken in a laser annealing apparatus without a protective layer and a supporting portion.

[0036] Fig.14 It is a cross-sectional view showing an example in which the position of the end portion of the protective layer of the laser annealing apparatus according to the embodiment of the present invention is changed.

[0037] Fig.15 It is a cross-sectional view showing a modification 7 in which an adhesive material portion is used as a support portion in the laser annealing apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION

[0038] The laser annealing device according to the embodiment of the present invention is described in detail below with reference to the accompanying drawings. It should be noted that the accompanying drawings are schematic, and the number of components, the size of each component, the ratio of the size, the shape, etc. are different from the actual ones. In addition, the drawings also include parts with different size relationships, ratios, and shapes.

[0039] [Embodiment] (Schematic structure of laser annealing device)

[0040] like Figure 1 As shown, the laser annealing device 1 of this embodiment includes semiconductor lasers LD (LD1 to LD3) as light sources, coupling lenses 2, 3, and 4 corresponding to the semiconductor lasers LD, a plurality of optical fibers 10 corresponding to the coupling lenses 2, 3, and 4, a support portion 20 provided in the middle of the optical fibers 10, a first lens 5, and a second lens 6. Figure 2 As shown, the laser annealing device 1 includes a vibration head (vibration source) 21 that transmits vibration to these optical fibers 10. It should be noted that the number of semiconductor lasers LD, coupling lenses 2, 3, 4 and optical fibers 10 is arbitrary and is not limited to the number of this embodiment. In addition, in this embodiment, a semiconductor laser LD is used as a light source, but of course other laser sources can also be used.

[0041] The coupling lenses 2, 3, and 4 are connected to the emission side of each semiconductor laser LD. One end of an optical fiber 10 serving as a waveguide is connected to each coupling lens 2, 3, and 4. In this embodiment, the optical fiber 10 is a multimode optical fiber. Figure 2 and Figure 5 As shown, the optical fiber 10 is composed of a core layer 10A and a cladding layer 10B formed outside the core layer 10A.

[0042] The first lens 5 and the second lens 6 constitute an imaging optical system that forms an image of a laser beam LB formed by laser light emitted from the optical fiber 10 as a beam spot on the surface of the substrate 7 to be processed.

[0043] The laser annealing apparatus 1 of the present embodiment includes a substrate transport mechanism (not shown) and can transport the substrate 7 to be subjected to laser annealing at an arbitrary speed in the scanning direction.

[0044] The substrate 7 used in this embodiment may be a substrate having a structure in which an amorphous silicon film is formed on the surface of a glass substrate. The laser annealing apparatus 1 of this embodiment irradiates the amorphous silicon film on the surface of the substrate 7 with a laser beam LB, thereby forming a quasi-single crystal silicon film.

[0045] It should be noted that the laser annealing apparatus 1 of the present embodiment is not limited to the annealing of an amorphous silicon film, and can be applied to various annealing processes.

[0046] (Vibration source)

[0047] like Figure 2 and Figure 3 As shown, in the laser annealing device 1 of the present embodiment, a vibration head 21 as a vibration source is arranged in a manner opposite to the support portion 20. The vibration head 21 is integrally provided on an ultrasonic vibrator not shown in the figure, and is composed of, for example, a rectangular metal block. The ultrasonic vibrator converts high-frequency power from an oscillator not shown in the figure into ultrasonic vibrations, and is, for example, an electrostrictive ultrasonic vibrator. It should be noted that in the laser annealing device 1 of the present embodiment, as the frequency of the ultrasonic vibrator, any frequency can be selected, for example, it can be used in the range of 30kHz to 400kHz. It should be noted that in the present embodiment, by adjusting the amplitude of the ultrasonic vibrator, the life of the optical fiber 10 can be improved. It should be noted that the vibration source is not limited to the above-mentioned ultrasonic vibrator.

[0048] like Figure 2 As shown, the front end surface of the vibration head 21 constitutes the mounting surface 22. The storage grooves 23 for storing the optical fibers 10 are formed on the mounting surface 22 at equal intervals in a manner parallel to each other. The cross-sectional shape of the storage groove 23 is a V-shape, and the optical fiber 10 can be positioned by storing the optical fiber 10. It should be noted that the inner surface of the storage groove 23 is a surface that contacts and supports the optical fiber 10, and constitutes a part of the mounting surface 22.

[0049] like Figure 2 As shown, in the present embodiment, the optical fiber 10 arranged on the inner surface of the storage groove 23 constituting the mounting surface 22 is covered by the synthetic resin layer 11 and the protective layer 12 in sequence from the inside. It should be noted that, in the present embodiment, the protective layer 12 is composed of a metal tube made of stainless steel (SUS). The synthetic resin layer 11 is formed by filling and curing between the optical fiber 10 inserted into the protective layer 12 as a metal tube and the protective layer 12. For example, as the synthetic resin layer 11, a thermosetting resin such as epoxy resin is preferably used. Since the protective layer 12 is a metal tube, it has rigidity. In addition, the protective layer 12 is provided integrally with the optical fiber 10 by sandwiching the synthetic resin layer 11.

[0050] In the present embodiment, the synthetic resin layer 11 and the protective layer 12 are formed so as to extend laterally from the edge portions of the vibration head 21 located on both sides in the extending direction of the optical fiber 10 . Figure 3 It is shown that the protection layer 12 extends laterally from the edges at both ends of the vibration head 21 .

[0051] (Structure of the support portion)

[0052] like Figure 2 to Figure 4As shown, the support portion 20 includes: a pair of longitudinal plates 24 arranged on both sides of the vibration head 21 in a direction perpendicular to the extension direction of the optical fiber 10 in a manner of clamping the vibration head 21; a support plate 25 mounted on the upper end of the longitudinal plate 24; and a sheet-like rubber material portion 26. It should be noted that the support plate 25 is fixed to the upper end surface of the longitudinal plate 24 by a clamping screw 27. As the support plate 25, a metal plate or a synthetic resin plate can be applied. As the rubber material portion 26, for example, it is formed of a material such as silicone rubber or polyurethane rubber.

[0053] Furthermore, the rubber material portion 26 is set to press the optical fiber 10 including the protective layer 12 and the synthetic resin layer 11 against the inner wall of the storage groove 23 at a predetermined pressure. Here, if the predetermined pressure is too large, there is a possibility that the optical fiber will heat up or deform. When the optical fiber heats up, it will cause a break. In addition, when the optical fiber deforms, it will cause a power loss of light. Therefore, as the predetermined pressure, it is preferably set to a pressure below the level that does not cause a power loss of the ultrasonic vibrator.

[0054] like Figure 3 As shown, the longitudinal plate 24 is set to be longer than the vibration head 21 in the extension direction of the optical fiber 10 in the vibration head 21, and is arranged to extend to both sides of the vibration head 21 in the extension direction of the optical fiber 10. Figure 4 As shown in FIG. 1 , in this embodiment, the support plate 25 is set to be a rectangle larger than the mounting surface 22 so that the mounting surface 22 is accommodated within the contour of the support plate 25 in a state of being opposed to the entire mounting surface 22 of the vibration head 21. It should be noted that in this embodiment, as shown in FIG. Fig.14 As shown, if the optical fiber 10 is not in direct contact with the vibration head 21 due to the thickness of the protective layer 12 , the end of the protective layer 12 may be located inside the end of the vibration head 21 or the support portion 20 .

[0055] In the support portion 20 having the above-mentioned structure, the vibration transmission rate between the protective layer 12 and the rubber material portion 26 as a part of the support portion 20 is set to be smaller than the vibration transmission rate between the mounting surface 22 of the vibration head 21 (including the inner surface of the storage groove 23) and the protective layer 12. Here, the vibration transmission rate is defined by the ratio of the magnitude of the reaction force of the support point to the force input from the vibration source side. That is, it is a parameter that indicates how much the force of the vibration transmitted to the support point on the side receiving the vibration can be reduced.

[0056] (Function of the support part)

[0057] The optical fiber 10 supported by the support portion 20 has a rigid protective layer 12 integrally provided with the optical fiber 10, so that it has a function of preventing the optical fiber 10 from being broken at the edge of the vibration head 21 due to the vibration of the vibration head 21. It should be noted that, Fig.13FIG. 1 shows a comparative example in which the optical fiber 10 not provided with the protective layer 12 or the like is disposed on the vibration head 21 , and shows a state in which a break B occurs at the edge of the vibration head 21 .

[0058] Furthermore, by setting the vibration transmission rate between the protective layer 12 integrally provided on the optical fiber 10 and the synthetic resin layer 11 and the rubber material portion 26 as a part of the support portion 20 to be smaller than the vibration transmission rate between the mounting surface 22 of the vibration head 21 (including the inner surface of the storage groove 23) and the protective layer 12 as described above, the following effects are achieved. That is, the vibration from the vibration head 21 side is reliably transmitted to the optical fiber 10 side, and the vibration is difficult to be transmitted from the optical fiber 10 side to the support portion 20 side, and the reaction force on the optical fiber 10 side from the support portion 20 side is weakened.

[0059] Therefore, in this embodiment, since vibration can be efficiently transmitted to the optical fiber 10, the pattern at the laser beam point caused by the change of laser intensity distribution caused by the interference of laser light in the optical fiber optical path (hereinafter referred to as speckle pattern) can be efficiently averaged. Fig.12 FIG. 2 shows an annealing process region when an amorphous silicon film formed on the surface of a substrate 7 is annealed by a laser annealing device without a vibration head 21. Fig.12 In FIG. 1 , the laser beam LB indicated by the double-dashed line represents the elongated beam spot irradiated onto the substrate 7. The arrow S represents the relative scanning direction of the beam spot. Fig.12 As shown, in the comparative example not including the vibration head 21 , since the speckle pattern is not made uniform, there remains a problem of the generation of the vertical stripe pattern 32 .

[0060] In the laser annealing device 1 of this embodiment, since the reaction force from the support portion 20 associated with the vibration of the optical fiber 10 is weakened, in addition to the protective effect of the protective layer 12, the generation of undulation on the optical fiber 10 side can be suppressed, thereby preventing damage.

[0061] (Variant 1)

[0062] Figure 6 A modification example 1 in this embodiment is shown. In this modification example 1, a protective layer 12 made of a metal tube is not provided in the region corresponding to the support portion 20 in the optical fiber 10, but only a rigid synthetic resin layer 11 is provided, and the other structures are the same as those in the above-mentioned embodiment. In this modification example 1, since the synthetic resin layer 11 has rigidity, it has the same effect as in the above-mentioned embodiment to protect the optical fiber 10 and suppress the reaction force from the support portion 20 side, and the same effect can be obtained.

[0063] (Variant 2)

[0064] Figure 7 A modification example 2 in this embodiment is shown. This modification example 2 is a structure in which the rubber material part 26 used in the above embodiment is replaced with a resin tape 28 as a resin material part, and the other structures are the same as those in the above embodiment. By adjusting the thickness of the resin tape 28, etc., the same action and effect as in the above embodiment can be obtained.

[0065] (Variant 3)

[0066] Figure 8 A variation example 3 in the present embodiment is shown. This variation example 3 is a structure in which the rubber material portion 26 used in the above-mentioned embodiment is replaced with a magnetic adsorption material portion 29. As the material of the magnetic adsorption material portion 29, for example, a rubber magnet in which magnetic powder is mixed in a rubber material may be used. It should be noted that in this variation example 3, the storage groove 23 formed on the mounting surface 22 of the vibration head 21 is set to a depth that can be stored up to the upper end of the protective layer 12 surrounding the optical fiber 10, and the upper end of the protective layer 12 is set in a manner that contacts the lower surface of the magnetic adsorption material portion 29. In this variation example 3, there are also functions of protecting the optical fiber 10 and suppressing the reaction force from the support portion 20 side, and the same effect as the above-mentioned embodiment can be obtained.

[0067] (Variant 4)

[0068] Fig. 9 Modification 4 of the present embodiment is shown. In this modification 4, the accommodation groove 23 is not formed in the vibration head 21, and the optical fibers 10 are arranged in parallel and fixed by the adhesive material portion 30. The other structures in this modification 4 are the same as those of the above-mentioned embodiment.

[0069] (Variant 5)

[0070] Fig.10 Modification 5 in this embodiment is shown. This modification 5 uses the rubber material portion 26 in the same manner as the above-mentioned embodiment. It should be noted that in this modification 5, the storage groove 23 formed on the mounting surface 22 of the vibration head 21 is set to a depth that can be stored up to the upper end of the protective layer 12 surrounding the optical fiber 10, and the upper end of the protective layer 12 is set in a manner that contacts the lower surface of the rubber material portion 26. Even with such a configuration, it has the effect of protecting the optical fiber 10 and the effect of suppressing the reaction force from the support portion 20 side, and the same effect as the above-mentioned embodiment can be obtained.

[0071] (Variant 6)

[0072] Fig.11Modification 6 of the present embodiment is shown. In this modification 6, the rubber material portion 26 of the above-mentioned embodiment is omitted, and a spring plate 25A is provided in a manner to press the optical fiber 10 having the protective layer 12, and the spring plate 25A has the functions of both the support portion 20 and the rubber material portion 26 of the above-mentioned embodiment. That is, the spring plate 25A applies a predetermined pressure to the protective layer 12, and has a function as a buffer member that reduces the reaction force associated with the vibration of the optical fiber 10 side.

[0073] (Variant 7)

[0074] Fig.15 A modification example 7 of the present embodiment is shown. In this modification example 7, a plurality of storage grooves 23 are formed in parallel on the vibration head 21, an optical fiber 10 is arranged in each storage groove 23, and a plurality of optical fibers 10 are arranged in parallel, and these optical fibers 10 are fixed by an adhesive material portion 30. The other structures in this modification example 7 are the same as those of the above-mentioned embodiment.

[0075] (Other Embodiments)

[0076] Although the embodiments of the present invention have been described above, it should not be understood that the description and drawings constituting part of the disclosure of the embodiments limit the present invention. The present invention includes various embodiments and alternatives attached hereto.

[0077] For example, in most of the above-mentioned embodiments and modifications, the surface (inner surface) of the housing groove 23 having a V-shaped cross section is used as the mounting surface 22 of the vibration head 21, but the cross section formed by the mounting surface 22 may also be other shapes such as a U-shape or a rectangular shape.

[0078] Explanation of symbols

[0079] LD semiconductor laser (light source)

[0080] 1Laser annealing device

[0081] 2, 3, 4 coupling lens

[0082] 5. First lens

[0083] 6 Second lens

[0084] 7 substrate

[0085] 10. Fiber Optics

[0086] 10A Core

[0087] 10B cladding

[0088] 11 Synthetic resin layer

[0089] 12. Protective layer

[0090] 20 Supporting part

[0091] 21 Vibration head (vibration source)

[0092] 22 Mounting surface

[0093] 23 Storage slots

[0094] 24 Vertical Board

[0095] 25 Support plate

[0096] 25A Spring Plate

[0097] 26 Rubber Materials Department

[0098] 27 Compression screw

[0099] 28 resin belt (resin material part)

[0100] 29 Magnetic Adsorption Materials Department

[0101] 30 Adhesive Materials Department

[0102] 31 Annealing area

[0103] 32 vertical stripe pattern

Claims

1. A laser annealing device comprising a light source for emitting laser light and a multimode optical fiber into which the laser light is incident from one end and from which the laser light is emitted from the other end, It is characterized in that The laser annealing device comprises a vibration source having a mounting surface, The optical fiber is arranged along the mounting surface, The optical fiber disposed in the region of the mounting surface is covered by a rigid protective layer, The laser annealing device includes a support portion that presses the optical fiber covered with the protective layer toward the mounting surface.

2. The laser annealing device according to claim 1, in, The vibration transmissibility between the protective layer and the support portion is set to be smaller than the vibration transmissibility between the mounting surface and the protective layer.

3. The laser annealing device according to claim 1, in, The protective layer is a cylinder made of metal or synthetic resin.

4. The laser annealing device according to claim 1, in, A resin material is filled between the optical fiber and the protective layer.

5. The laser annealing device according to claim 1, in, The support portion includes a rubber material portion that contacts the optical fiber and a support plate that presses the rubber material portion toward the optical fiber.

6. The laser annealing device according to claim 1, in, The support portion includes a resin material portion that contacts the optical fiber and a support plate that presses the resin material portion toward the optical fiber.

7. The laser annealing device according to claim 1, in, The support portion includes an adhesive material portion that contacts the optical fiber and a support plate that presses the adhesive material portion toward the optical fiber.

8. The laser annealing device according to claim 1, in, The support portion includes a magnetic adsorbent portion in contact with the optical fiber and a support plate that presses the magnetic adsorbent portion toward the optical fiber.

9. The laser annealing device according to any one of claims 5 to 8, in, The support plate is a metal plate or a synthetic resin plate.

10. The laser annealing device according to claim 6, in, The resin material portion is a resin belt.

11. The laser annealing device according to claim 1, in, The support portion is set so that the mounting surface is accommodated within the contour of the support portion in a state facing the mounting surface.

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