JP2013091069A - Apparatus and method for laser machining - Google Patents

Abstract

A laser processing apparatus and a laser processing method that can be easily realized without requiring a separate space for removing debris.
A laser processing apparatus according to the present invention includes a light source that emits laser light for processing a surface of a workpiece, a transport unit that transports the workpiece, and a surface of the workpiece that has been transported by laser light. In order to capture substances scattered from the workpiece by irradiation, a liquid supply unit that supplies liquid to the surface of the workpiece and a substance that is scattered from the workpiece and captured in the liquid are collected. And a flying object collecting part.
[Selection] Figure 1

Description

  The present invention relates to a laser processing apparatus and a laser processing method, and more particularly to a laser processing apparatus and a laser processing method for processing the surface of a workpiece.

  Conventionally, a technique for processing the surface of a workpiece with laser light is known. As an example, there is laser ablation in which laser light is irradiated to raise the temperature of the surface of the workpiece and sublimate and evaporate. By this laser ablation, for example, a recess can be formed on the surface of the substrate, and the surface of the substrate can be patterned. However, in laser ablation, it is extremely rare that a portion irradiated with laser light is completely sublimated and evaporated.

  Since the energy of the laser beam is reduced inside the substrate from the outermost surface of the substrate to which the laser beam first hits, the substrate constituent material in the irradiated portion is not vaporized and scattered as a high temperature droplet or solid. . These high temperature droplets and solids are not vaporized and fall around the laser light irradiated portion. Dropped droplets and solids cool and stick to the substrate as debris. This debris is difficult to remove in a later process.

  Therefore, even when a desired pattern can be formed by laser light, the debris becomes a foreign substance, and there is a problem that the substrate on which the pattern is formed cannot exhibit a desired function.

  Another example of the surface processing technique using laser light is laser annealing. By laser annealing, for example, amorphous silicon formed on the surface of the substrate can be crystallized. Laser annealing is intended to melt or crystallize the irradiated portion of the laser beam, and is not intended to sublimate and evaporate the irradiated portion. However, in practice, when the surface of the substrate is annealed, the material in the portion irradiated with the laser light may be scattered as a high temperature droplet or solid. Also in this case, these high temperature droplets or solids become debris and adhere to the substrate.

  As a method for removing the debris adhered to the substrate, trapping or ablation of foreign matter by laser light is known (for example, Patent Document 1). Patent Document 1 describes a configuration in which a liquid is dropped onto a foreign object during trapping to be immersed in the liquid and assists the trapping force by buoyancy, and a configuration in which the foreign object is sublimated by ablation. The liquid is dropped when trapping with laser light, and is not dropped when laser ablating.

  As a method for preventing debris from adhering to the substrate, a method is known in which the entire workpiece is submerged in a solution and laser processing is performed in the solution (for example, Patent Document 2). Patent Document 2 describes a laser processing method in which the entire workpiece is submerged in a container filled with a solution and the entire workpiece is held in the solution. The container is provided with an inlet and an outlet for the solution protruding outside the container, and the solution circulates in the container. Scatter produced by laser ablation dissolves in the solution.

JP 2009-271274 A JP-A-6-684

  However, in the method described in Patent Document 1, it is necessary to separately irradiate a laser beam in order to remove the debris adhered to the substrate, and the work process becomes complicated.

  Further, in the method described in Patent Document 2, a container that is provided with an inlet and an outlet projecting outward and filled with a solution is separately required. When the workpiece is transported for positioning, the workpiece is held in the container and the workpiece is transported together with the container. The container needs to be formed larger than the workpiece so that the entire workpiece can be held in the solution, and in addition, since the inlet and the outlet are provided to protrude outward, In order to hold and convey the workpiece in the container, it is necessary to secure a wider space in the conveyance path of the laser processing apparatus than to convey only the workpiece, which is substantially impossible. It is.

  Further, in the method described in Patent Document 2, since the entire workpiece is submerged in the solution in the container, when the workpiece is held and transported in the solution, the workpiece moves in the container. There is a possibility that. In this case, it becomes difficult to accurately position the irradiated portion of the laser beam with respect to the workpiece. Further, if the workpiece is fixed in the container so that the workpiece does not move in the container, it is necessary to provide a fixing portion in the container, which causes a problem that the apparatus is further complicated. is there. Further, when the object is a glass substrate of several m square, it is very difficult to sink the whole in water or to carry it.

  Accordingly, an object of the present invention is to provide a laser processing apparatus that can save space compared to the above-described conventional technique and has a simple configuration in order to remove debris generated during laser processing. It is another object of the present invention to provide a laser processing method including a process that can easily realize debris removal without requiring a separate space for removing debris generated during laser processing.

  The present invention relates to a laser processing apparatus. In order to achieve the above object, a laser processing apparatus according to the present invention includes a light source that emits a laser beam for processing the surface of a workpiece, a conveyance unit that conveys the workpiece, and a workpiece to which the laser beam is conveyed. In order to capture the substances scattered from the workpiece by irradiating the surface of the material, the liquid supply unit that supplies liquid to the surface of the workpiece and the material that is scattered from the workpiece and captured in the liquid And a scattered matter collecting part for collecting the collected substances. A liquid supply part may be comprised so that a liquid may be sprayed on the surface of a workpiece in the shape of a mist.

  Another laser processing apparatus according to the present invention is directed to a light source that emits a laser beam that processes the surface of a workpiece, a conveyance unit that conveys the workpiece, and a surface of the workpiece that is conveyed with the laser beam. In order to capture the material scattered from the workpiece, the steam supply unit that supplies steam to the surface of the workpiece, and the scattering that collects the material scattered from the workpiece and captured in the steam And an object recovery unit.

  As an example, a translucent plate arranged to face the surface of the workpiece is further provided, and the liquid supply unit supplies a liquid between the translucent plate and the surface of the workpiece. As another example, a translucent plate arranged to face the surface of the workpiece is further provided, and the steam supply unit supplies steam between the translucent plate and the surface of the workpiece.

  The liquid supply unit may be configured to supply liquid so as to cover substantially the entire surface of the workpiece to be processed, and the vapor supply unit may cover substantially the entire surface of the workpiece to be processed. The cover may be configured to supply steam. You may further provide the micro lens array which condenses the laser beam irradiated from the laser on the surface of a workpiece.

  As an example, the light source can be controlled to select the wavelength of the laser light, and the liquid supply unit supplies the liquid corresponding to the laser light of the selected wavelength. As another example, the light source can be controlled to select the wavelength of the laser beam, and the vapor supply unit supplies the vapor corresponding to the laser beam having the selected wavelength.

  The laser processing method according to the present invention includes a step of conveying a workpiece, a step of supplying a liquid to the surface of the conveyed workpiece, and after supplying the liquid to the surface of the workpiece via the liquid. A step of irradiating a laser beam; and a step of recovering a substance scattered from the workpiece by the irradiation of the laser beam and captured in the liquid. For example, the step of supplying the liquid includes a step of spraying the liquid onto the surface of the workpiece in the form of a mist.

  Another laser processing method according to the present invention includes a step of transporting a workpiece, a step of supplying steam to the surface of the transported workpiece, and after supplying the steam, A step of irradiating the surface with laser light; and a step of collecting a substance scattered in the vapor by being scattered from the workpiece by the laser light irradiation.

  According to the laser processing apparatus of the present invention, a liquid supply unit that supplies a liquid to the surface of the workpiece, a scattered matter collection unit that collects the substance scattered from the workpiece and captured in the liquid, It is possible to remove substances scattered from the workpiece during laser processing. In this laser processing apparatus, the liquid supply unit is configured to supply liquid to the surface of the workpiece. Therefore, the workpiece is only required to be covered with a liquid on the surface to be laser processed, and the entire workpiece is not submerged in the liquid. As a result, a container for holding the entire workpiece in the liquid becomes unnecessary, and a mechanism for circulating the liquid in the container becomes unnecessary. For this reason, according to the laser processing apparatus according to the present invention, it is possible to save space as compared with the above-described conventional technology, and it is possible to remove debris generated during laser processing with a simple configuration.

  When the liquid supply unit is configured so that the liquid is sprayed onto the surface of the workpiece, the temperature change of the surface of the workpiece due to the supply of the liquid can be reduced.

  In addition, according to another laser processing apparatus according to the present invention, a steam supply unit that supplies steam to the surface of the workpiece, and a flying object that collects the substance scattered from the workpiece by being scattered from the workpiece. By providing the recovery unit, substances scattered from the workpiece during laser processing can be removed. In this laser processing apparatus, the steam supply unit is configured to supply steam to the surface of the workpiece. For this reason, like the laser processing apparatus for supplying liquid described above, the laser processing apparatus according to the present invention can save space compared to the above-described prior art, and can perform the laser processing with a simple configuration. Can be removed. In addition, since the temperature of the steam is easy to adjust, the temperature change applied to the surface of the workpiece can be reduced by adjusting the temperature of the supplied steam.

  In the case of further comprising a translucent plate arranged opposite to the surface of the workpiece and supplying a liquid between the translucent plate and the surface of the workpiece by the liquid supply unit, the liquid is supplied. Since the liquid is held or flows between the translucent plate and the surface of the workpiece, the thickness of the liquid covering the surface can be made uniform.

  If a translucent plate arranged opposite to the surface of the workpiece is further provided and steam is supplied between the translucent plate and the surface of the workpiece by the vapor supply unit, the supply is provided. Since the vapor is held between the light transmitting plate and the surface of the workpiece, the thickness of the vapor covering the surface can be made uniform.

  When a liquid supply unit that supplies a liquid is provided so as to cover substantially the entire surface of the workpiece to be processed, the liquid supply unit and the laser beam irradiation can be applied because the substantially entire surface can be covered with the liquid. Strict alignment with the part becomes unnecessary.

  When a steam supply unit that supplies steam is provided so as to cover substantially the entire surface of the workpiece to be processed, the steam supply unit and the laser beam irradiation can be provided because substantially the entire surface can be covered with steam. Strict alignment with the part becomes unnecessary.

  In the case of including a microlens array that condenses laser light emitted from a laser onto the surface of the workpiece, the laser light can be emitted to a plurality of locations on the surface of the workpiece. In this case, as described above, by supplying liquid or vapor so as to cover substantially the entire surface to be processed in the workpiece, a plurality of laser beam irradiation parts and liquid supply parts or vapor supply parts are provided. Strict alignment is not necessary.

  When a light source that can be controlled to select the wavelength of the laser beam and a liquid supply unit that supplies a liquid corresponding to the laser beam of the selected wavelength are provided, the wavelength of the laser beam is set according to the material of the workpiece and the processing method. The type of liquid corresponding to the selected wavelength can be selected. The “liquid corresponding to the laser beam having the selected wavelength” is, for example, a liquid having a small absorption coefficient with respect to the wavelength of the selected laser beam.

  When a light source that can be controlled to select the wavelength of the laser beam and a vapor supply unit that supplies vapor corresponding to the laser beam of the selected wavelength are provided, the wavelength of the laser beam is set according to the material and processing method of the workpiece. The type of vapor corresponding to the selected wavelength can be selected. “Vapor corresponding to laser light having a selected wavelength” is, for example, vapor generated from a liquid having a small absorption coefficient with respect to the wavelength of the selected laser light.

  According to the laser processing method of the present invention, the method includes a step of supplying a liquid to the surface of the workpiece, and a step of collecting a substance scattered from the workpiece and captured in the liquid. Substances scattered from the workpiece during processing can be removed. In this laser processing method, a liquid is supplied to the surface of the workpiece. Accordingly, the workpiece is such that the surface to be laser processed is covered with the liquid, and the entire workpiece is not submerged in the liquid. As a result, a container for holding the entire workpiece in the liquid becomes unnecessary, and a mechanism for circulating the liquid in the container becomes unnecessary. Therefore, according to the laser processing method of the present invention, debris generated during laser processing can be easily removed without requiring a separate space for removing the debris.

  When the laser processing method according to the present invention includes a step of spraying liquid onto the surface of the workpiece in the form of a mist, the temperature change applied to the surface of the workpiece can be reduced as described above.

  Further, according to another laser processing method according to the present invention, the method includes a step of supplying steam to the surface of the workpiece, and a step of recovering the substance scattered from the workpiece and captured in the steam. Thus, the material scattered from the workpiece during laser processing can be removed. In this laser processing method, steam is supplied to the surface of the workpiece. For this reason, as with the laser processing method for supplying a liquid described above, according to the laser processing method of the present invention, debris generated during laser processing can be easily and without requiring a separate space for the configuration for removing the debris. Can be removed. In addition, since the temperature of the steam is easy to adjust, the temperature change applied to the surface of the workpiece can be reduced by adjusting the temperature of the supplied steam.

It is a side view of the laser processing apparatus concerning a 1st embodiment. It is a flowchart which shows the laser processing method which concerns on 1st Embodiment. FIG. 2 is an enlarged view of part A of FIG. 1. It is a side view of the laser processing apparatus which concerns on 2nd Embodiment. It is a top view which shows the positional relationship of the some liquid supply port and the several scattered material collection | recovery port in the laser processing apparatus which concerns on 2nd Embodiment. It is a side view of the laser processing apparatus which concerns on 3rd Embodiment. FIG. 7 is an enlarged view of part B of FIG. 6. It is sectional drawing which shows the TFT substrate processing process after annealing with the laser processing apparatus which concerns on 3rd Embodiment. It is a flowchart which shows the laser processing method which concerns on other embodiment.

[First Embodiment]
Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a side view of the laser processing apparatus according to the first embodiment. The laser processing apparatus 1 includes a light source 3 that irradiates a laser beam 4 to process the workpiece 2, a lens unit 5 that focuses the laser beam 4 on the surface 2 a of the workpiece 2, and the workpiece 2. And a transport unit 6 for transporting to a desired position. Further, the laser processing apparatus 1 includes a liquid supply unit 7 and a scattered matter collection unit 10. The liquid supply unit 7 is configured to supply the liquid 8 to the surface 2a of the workpiece 2 through the liquid supply port 7a. The liquid supply port 7 a is located above the surface 2 a at the end of the workpiece 2. The scattered matter recovery unit 10 includes a scattered matter recovery port 10a, and after the irradiation of the laser beam 4 is finished, sucks the liquid 8 containing the scattered matter scattered from the irradiated portion of the workpiece 2 from the scattered matter recovery port 10a. It is configured as follows. The scattered matter collection port 10 a is located above the surface 2 a at the other end of the workpiece 2.

  The process of the laser processing method using the laser processing apparatus 1 is shown in the flowchart of FIG. The workpiece 2 is conveyed by the conveyance part 6 (step S1). When the workpiece 2 is positioned at a predetermined position with respect to the light source 3, the liquid 8 is poured into the workpiece surface 2a from the supply port 7a of the liquid supply unit 7 (step S2). The liquid 8 discharged from the supply port 7a of the liquid supply unit 7 spreads along the surface 2a from the end portion of the workpiece surface 2a and covers substantially the entire surface of the workpiece surface 2a. The thickness of the layer of the liquid 8 that covers the workpiece surface 2a is desirably 1 mm or less.

  When the workpiece surface 2a is covered with the liquid 8, the laser beam 4 is irradiated from the light source 3 to the workpiece surface 2a in order to perform laser ablation (step S3). The portion irradiated with the laser beam 4 on the workpiece surface 2a is heated to sublimation and evaporated. Thereby, the recessed part 9 is formed in the workpiece surface 2a.

  An enlarged view of portion A in FIG. 1 is shown in FIG. In the process of forming the concave portion 9 with the laser light 4, droplets or solids having a high temperature are scattered from the irradiated portion of the laser light 4. The scattered matter 11 is scattered from the irradiated portion and captured in the liquid 8. Thereafter, the temperature of the flying object 11 decreases, but it does not adhere to the workpiece 2 because it is held in the liquid 8. Even if it is a case where it adheres to the workpiece 2, the adhering force becomes extremely weak.

  When the recess 9 is formed and the irradiation of the laser beam 4 is completed, the scattered matter 11 is sucked together with the liquid 8 by the scattered matter collecting unit 10 through the scattered matter collecting port 10a (step S4). When the liquid 8 is evaporated, the scattered matter collecting unit 10 sucks only the scattered matter 11. Even if the liquid 8 evaporates after laser processing, the scattered matter 11 is once caught in the liquid 8 and cooled. Therefore, as described above, even if the workpiece 2 is not fixed or is fixed to the workpiece 2, the fixing force is extremely weak. For this reason, even if the liquid 8 evaporates, the scattered matter collecting unit 10 can suck and collect the scattered matter 11.

  In the laser processing apparatus 1, the liquid supply unit 7 is configured to supply the liquid 8 to the surface 2 a of the workpiece 2. The workpiece 2 only needs to be covered with the liquid 8 only on the surface 2 a to be laser processed, and the entire workpiece 2 is not submerged in the liquid 8. As a result, a container for holding the workpiece 2 in the liquid becomes unnecessary, and a mechanism for circulating the liquid in the container becomes unnecessary. For this reason, according to the laser processing apparatus 1, it is not necessary to secure a separate space when the workpiece 2 is conveyed. Moreover, by providing the liquid supply unit 7 for supplying the liquid 8 and the scattered matter collection unit 10 to the surface 2a of the workpiece 2, debris generated during laser processing can be removed with a simple configuration.

[Second Embodiment]
FIG. 4 shows a side view of the laser processing apparatus 20 according to the second embodiment. The laser processing apparatus 20 includes a light source 23 that irradiates a laser beam 24 to process the substrate 22, a microlens array 25 that focuses the laser beam 24 at a plurality of locations on the substrate surface 22a, and the substrate 22 at a desired position. And a conveyance unit 26 for conveyance. Further, the laser processing apparatus 20 includes a mask portion 31 and a translucent plate 32 between the microlens array 25 and the substrate surface 22a. The mask part 31 has a light shielding part 31a and a light transmitting part 31b formed in a predetermined pattern on the surface of a transparent substrate made of quartz glass or the like.

  The translucent plate 32 provided between the mask portion 31 and the substrate surface 22a is a transparent substrate made of quartz glass or the like. The translucent plate 32 is formed in a rectangular shape so as to cover substantially the entire substrate surface 22a, and projections (not shown) are formed at the four corners thereof. The translucent plate 32 is disposed on the substrate 22 so that the protrusions are in contact with the substrate surface 22a. Therefore, a space is formed between the substrate surface 22a and the translucent plate 32 by the height of the protrusion. The height of the formed space, that is, the distance from the substrate surface 22a to the back surface of the translucent plate 32 is set to 1 mm or less.

  In the present embodiment, the substrate 22 is fitted in the liquid receiving portion 33. The liquid receiving portion 33 has a predetermined space between a bottom portion 33 a in contact with the bottom surface of the substrate 22, a side wall portion 33 b extending from the bottom portion 33 a along the side surface of the substrate 22 and in contact with the side surface, and a side surface of the substrate 22. The tray part 33c which has is provided. The liquid receiving part 33 collects the liquid spilled from the substrate surface 22a by the receiving part 33c.

  Further, the laser processing apparatus 20 includes a plurality of liquid supply units 27 and a plurality of scattered matter collection units 30. The positional relationship between the liquid supply ports 27a of the plurality of liquid supply units 27 and the scattered matter collection ports 30a of the plurality of scattered matter collection units 30 is shown in FIG. FIG. 5 shows the positional relationship between the liquid supply port 27a and the scattered matter collection port 30a with respect to the substrate 22 on which the translucent plate 32 is arranged, from the plane direction of FIG. The plurality of liquid supply ports 27 a and the plurality of scattered matter collection ports 30 a are each formed in one row along the main transport direction X of the substrate 22. The width of the translucent plate 3 is slightly narrower than the width of the substrate 22, and the two substrate end portions 22 b and 22 c extending along the main transport direction X are exposed outside the translucent plate 32. The plurality of liquid supply ports 27a are located on the exposed substrate end 22b and supply the liquid 28 to a space formed between the light-transmitting plate 3 and the substrate surface 22a. The plurality of scattered matter collection ports 30a are located on the other exposed substrate end 22c and captured in the liquid 28 and the liquid 28 from the space formed between the light transmitting plate 32 and the substrate surface 22a. Aspirate scattered objects.

  A laser processing method using the laser processing apparatus 20 will be described. The substrate 22 is transported by the transport unit 26 and positioned with respect to the irradiation position of the laser light 24. At this time, the position of the substrate 22 or the plurality of liquids so that the plurality of liquid supply ports 27a and the plurality of scattered matter collection ports 30a are arranged along the exposed end portions 22b and 22c of the substrate 22 (see FIG. 5). The positions of the supply port 27a and the plurality of scattered matter collection ports 30a are adjusted. In addition, since the substantially whole surface of the substrate surface 22a is covered with the liquid 28 flowing from the plurality of liquid supply ports 27a, the positioning of the plurality of liquid supply ports 27a and the plurality of scattered matter collection ports 30a with respect to the irradiation position of the laser light 24. There is no need to do exactly.

  When the positioning of the substrate 22, the plurality of liquid supply ports 27a, and the plurality of scattered matter collection ports 30a is completed, the plurality of liquid supply units 27 are connected to the translucent plate 32 and the substrate surface 22a via the liquid supply ports 27a. The liquid 28 is supplied to the space between them. The liquid 28 fills the space and spreads along the substrate surface 22 a and the back surface of the light transmitting plate 32. Since the distance from the substrate surface 22a to the back surface of the translucent plate 32 is set to 1 mm or less, the layer of the liquid 28 covering the substrate surface 22a can be kept at a uniform thickness of 1 mm or less. The liquid spilled from the substrate surface 22a is collected by the liquid receiving part 33.

  When the liquid 28 covers substantially the entire surface of the substrate surface 22a, the substrate surface 22a is irradiated with laser light 24 from the light source 23 in order to pattern the substrate surface 22a by laser ablation. The irradiated laser beam 24 is condensed by the microlens array 25, and the substrate surface 22a is heated through the mask portion 31 to be sublimated and evaporated. As a result, a pattern 29 is formed on the substrate surface 22a. The scattered matter scattered when forming the pattern 29 is caught in the liquid 28 covering the substrate surface 22a. When the irradiation of the laser beam 24 is completed, the scattered matter is sucked together with the liquid 28 by the scattered matter collecting unit 30.

  The laser processing apparatus 20 according to the second embodiment has the advantages described above in the first embodiment by including the translucent plate 32 disposed so that a predetermined space is formed between the substrate surface 22a. In addition, there is an advantage that the thickness of the liquid 28 covering the substrate surface 22a can be made uniform. Further, by providing the liquid receiving portion 33, the liquid spilled from the substrate surface 22a can be collected. The amount of the liquid 28 supplied to the substrate surface 22a can be determined in consideration of the area of the substrate surface 22a. Since the liquid receiving portion 33 only needs to be able to receive a small amount of liquid spilling from the substrate surface 22a, the protruding amount of the receiving tray portion 33c to the outside of the substrate 22 is not large. Therefore, even if the liquid receiving portion 33 is provided, it is extremely low to secure a separate space when the substrate 22 is transported.

[Third Embodiment]
FIG. 6 shows a side view of a laser processing apparatus 40 according to the third embodiment. The laser processing apparatus 40 functions as a laser annealing apparatus that anneals an amorphous silicon film on a thin film transistor (hereinafter referred to as “TFT”) substrate in order to form a low-temperature polysilicon thin film transistor substrate.

  The laser processing apparatus 40 includes a light source 43 that irradiates laser light 44 for processing the TFT substrate 42, a microlens array 45 that condenses the laser light 44 at a plurality of locations on the TFT substrate surface 42a, and a TFT substrate 42. And a transporting section 46 that transports to the position. In addition, the laser processing apparatus 40 includes a light transmitting plate 52 between the microlens array 45 and the TFT substrate surface 42a. The translucent plate 52 has the same configuration as the translucent plate 32 described above in the second embodiment, and is disposed on the TFT substrate surface 42a with a space of 1 mm or less between the TFT substrate surface 42a. Has been. The liquid receiving portion 43 in which the TFT substrate 42 is fitted has the same configuration as the liquid receiving portion 33 in the second embodiment.

  Further, the laser processing apparatus 40 includes a plurality of liquid supply units 47 and scattered matter collection units 50. The plurality of liquid supply units 47 and the scattered matter collection unit 50 correspond to the liquid supply unit 27 and the scattered matter collection unit 30 in the second embodiment, and the liquid supply ports 47a and the scattered matter collection unit of the plurality of liquid supply units 47. The positional relationship between the 50 scattered matter recovery ports 50a is the same as the positional relationship between the plurality of liquid supply ports 27a and the scattered matter recovery ports 30a described above with reference to FIG.

  As a difference from the second embodiment, the liquid supply unit 47 is configured to supply the liquid 48 in a mist form.

  A laser processing method using the laser processing apparatus 40 will be described. The TFT substrate 42 is transported by the transport unit 46 and positioned with respect to the irradiation position of the laser light 44. The TFT substrate 42 includes an amorphous silicon film 61, and the TFT substrate surface 42 a is the surface of the amorphous silicon film 61. When the positioning of the substrate 42, the plurality of liquid supply ports 47a, and the plurality of scattered matter collection ports 50a is completed, the plurality of liquid supply units 47 are connected to the translucent plate 52 and the TFT substrate surface 42a via the liquid supply ports 47a. The liquid 48 is sprayed in a mist form in the space between the two. The mist-like liquid 48 fills the space, spreads along the back surface of the substrate surface 42 a and the translucent plate 52, and is held between the TFT substrate surface 42 a and the translucent plate 52. When the liquid 48 covers substantially the entire surface of the TFT substrate surface 42a, the substrate surface 42a is irradiated with laser light 44 from the light source 43 in order to laser anneal the amorphous silicon film 61 of the TFT substrate 42. The B partial enlarged view in FIG. 6 is shown in FIG. 7A and FIG.

  As shown in FIG. 7A, a gate electrode 63 is formed on the glass substrate 62 of the TFT substrate 42, an SiN insulating film 64 is laminated so as to cover the gate electrode 63, and an amorphous silicon film is formed on the SiN insulating film 64. 61 are stacked. The amorphous silicon film 61 constitutes the TFT substrate surface 42a, and the laser light 44 is irradiated to the amorphous silicon film 61 in the TFT formation region for a predetermined time. When the laser beam 44 is irradiated for a predetermined time, as shown in FIG. 7B, the irradiated portion of the amorphous silicon film 61 is melted. While the amorphous silicon film 61 is annealed by irradiating the laser beam 44, a substance having a high temperature may be scattered from the amorphous silicon film 61 in some cases. If the present invention is used, all the scattered material from the melted amorphous silicon is caught in the liquid 48 covering the TFT substrate surface 42a and does not contaminate the glass substrate.

  When the irradiation with the laser beam 44 is completed, the melted amorphous silicon film 61a is rapidly cooled and recrystallized to form a polysilicon film. The scattered matter collection unit 50 sucks the scattered matter and the liquid 48 from the scattered matter collection port 50a and collects the scattered matter.

  As shown in FIG. 8C, the annealed TFT substrate 42 is formed with a resist mask 67 having a predetermined pattern on the polysilicon film 66, and as shown in FIG. The silicon film 66 and the SiN insulating film 64 are etched. Next, as shown in FIG. 8E, by removing the resist mask 67, a TFT substrate in which a polysilicon film 66 having a predetermined pattern is formed on the gate electrode 63 can be obtained. A low-temperature polysilicon TFT substrate can be formed by forming a source electrode and a drain electrode on the polysilicon film 66 of the TFT substrate.

  In the laser annealing, if the temperature of the annealed TFT substrate surface 42a changes during the annealing of the amorphous silicon film 61, the formed crystal varies. The laser processing apparatus 40 according to the third embodiment has a configuration in which the liquid 48 is supplied in the form of a mist, so that in addition to the advantages described in the first embodiment and the second embodiment, the liquid processing can be performed. It has the advantage that the accompanying temperature change of the TFT substrate surface 42a can be reduced.

[Other Embodiments]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention. As an example, the second and third embodiments have a configuration in which a liquid is supplied to the surface of a workpiece, but may be configured to supply a vapor instead of a liquid. . In this case, the liquid supply units 27 and 47 each function as a vapor supply unit. The process of the laser processing method using steam instead of liquid is shown in the flowchart of FIG. Steps S11 to S14 correspond to steps S1 to S4 described with reference to FIG. Since the temperature of the steam is easy to adjust, the temperature change applied to the surface of the workpiece can be reduced by adjusting the temperature of the supplied steam.

  In the first to third embodiments, the liquid supply units 7, 27, 47 and the scattered matter collection units 10, 30, 50 are shown as separate components, but the present invention is not limited to this. A suction function may be added to the liquid supply units 7, 27, and 47, and the liquid supply units 7, 27, and 47 and the scattered matter collection units 10, 30, and 50 may be configured integrally.

  Although the said 2nd Embodiment and 3rd Embodiment are provided with the liquid receiving parts 33 and 43, it is not limited to this, The liquid receiving parts 33 and 43 may not be provided. Moreover, you may make the liquid receptacle parts 33 and 43 function as a scattered matter collection | recovery part. In this case, as an example, the liquid supply units 27 and 47 supply new liquid to the substrate surfaces 22a and 42a after the irradiation of the laser beams 24 and 44 is finished, and wash the substrate surfaces 22a and 42a. The liquids 28 and 48 including the scattered matter are washed away by the newly supplied liquid and flow down from the substrate surfaces 22a and 42a to the liquid receiving portions 33 and 43. Thus, when making the liquid receiving parts 33 and 43 function as a scattered matter collection | recovery part, it is not necessary to provide the scattered matter collection | recovery parts 30 and 50 which have a suction function.

  In the first to third embodiments, the liquids 8, 28, and 48 to be supplied are not limited to a specific type of liquid. It is desirable to select the type of liquid that does not chemically react with the material of the workpiece and does not absorb laser light. In the third embodiment, as an example, when the light source 43 is an excimer laser light source and the laser light 44 having a wavelength of 308 nm or 353 nm is emitted at a repetition period of 50 Hz, water is selected as the liquid 48 to be supplied. can do. This is because water does not affect the material of the amorphous silicon film 61 constituting the TFT substrate surface 42a and has an extremely low absorption coefficient for light having a wavelength of 308 nm or 353 nm.

  Other liquids that do not absorb ultraviolet rays include organic acid, sugar or amino acid solutions, amine solutions, and the like. Therefore, when irradiating a laser beam having a wavelength in the ultraviolet region, such as a laser beam of 308 nm or 353 nm, an organic acid, a solution of sugar or amino acid, an amine solution, or the like is applied in consideration of the material of the workpiece. You may select as a liquid supplied to the surface of a workpiece.

  In the first to third embodiments, the liquid supply units 7, 27, 47 may be configured to supply the liquids 8, 28, 48 corresponding to the wavelength of the laser light. For example, the light sources 3, 23, and 43 are configured so that the wavelength of the laser light can be selected. The liquid supply units 7, 27, and 47 are connected to a plurality of liquid tanks (not shown), and different types of liquids are held in the plurality of liquid tanks. As an example, when the light sources 3, 23, and 43 are configured to selectively irradiate laser light having a wavelength of 308 nm or 1064 nm, a liquid that hardly absorbs light having a wavelength of 308 nm is applied to the first liquid tank. The second liquid tank is configured to hold a liquid that hardly absorbs light having a wavelength of 1064 nm. In this case, the liquid supply units 7, 27, and 47 supply the liquid from the first liquid tank when the irradiated laser beam is 308 nm, and the second liquid when the irradiated laser beam is 1064 nm. It is configured to supply liquid from the tank.

  Even when steam is supplied to the surface of the workpiece instead of liquid, the type of steam is not limited as in the case of liquid. When supplying vapor corresponding to the wavelength of the laser beam, for example, the first liquid tank and the second liquid tank are connected to the vapor supply unit via the vapor generation unit, and the laser beam to be irradiated is irradiated. Depending on the wavelength, the liquid may be supplied from the first liquid tank or the second liquid tank to the vapor generating unit.

  In the first to third embodiments, the liquids 8, 28, and 48 are supplied so as to cover substantially the entire surface of the workpiece surface 2a, the substrate surface 22a, and the TFT substrate surface 42a. However, the present invention is not limited to this. For example, a liquid or vapor may be supplied only to a portion to be irradiated with laser light on the workpiece surface.

DESCRIPTION OF SYMBOLS 1,20,40 Laser processing apparatus 2 Work material 2a Work material surface 3,23,43 Light source 4,24,44 Laser light 5 Lens part 6,26,46 Conveyance part 7,27,47 Liquid supply part 8, 28,48 Liquid 10,30,50 Scatter collection part 22 Substrate 22a Substrate surface 25,45 Microlens array 32,52 Translucent plate 42 TFT substrate 42a TFT substrate surface

Claims (13)

A light source that emits laser light to process the surface of the workpiece;
A transport unit for transporting the workpiece;
A liquid supply unit for supplying a liquid to the surface of the workpiece in order to capture a substance scattered from the workpiece by irradiating the surface of the conveyed workpiece with the laser beam; ,
A laser processing apparatus comprising: a scattered matter recovery unit that recovers the substance scattered from the workpiece and captured in the liquid.   The laser processing apparatus according to claim 1, wherein the liquid supply unit is configured to spray the liquid onto the surface of the workpiece in the form of a mist. A light source that emits laser light to process the surface of the workpiece;
A transport unit for transporting the workpiece;
A vapor supply unit for supplying vapor to the surface of the workpiece in order to capture the substance scattered from the workpiece by irradiating the surface of the conveyed workpiece with the laser beam; ,
A laser processing apparatus comprising: a scattered matter recovery unit that recovers the substance that is scattered from the workpiece and captured in the vapor. A translucent plate disposed opposite to the surface of the workpiece;
The laser processing apparatus according to claim 1, wherein the liquid supply unit supplies the liquid between the translucent plate and the surface of the workpiece. A translucent plate disposed opposite to the surface of the workpiece;
The laser processing apparatus according to claim 3, wherein the steam supply unit supplies the steam between the translucent plate and the surface of the workpiece.   The laser processing apparatus according to claim 1, wherein the liquid supply unit supplies the liquid so as to cover substantially the entire surface of the workpiece to be processed. .   The laser processing apparatus according to claim 3, wherein the steam supply unit supplies the steam so as to cover substantially the entire surface to be processed of the workpiece.   The laser processing apparatus according to claim 1, further comprising a microlens array that condenses laser light emitted from the laser onto the surface of the workpiece. The light source can be controlled to select the wavelength of laser light,
The laser processing apparatus according to claim 1, wherein the liquid supply unit supplies a liquid corresponding to the laser beam having the selected wavelength. The light source can be controlled to select the wavelength of laser light,
The laser processing apparatus according to claim 3, wherein the steam supply unit supplies steam corresponding to the laser beam having the selected wavelength. Conveying the workpiece;
Supplying liquid to the surface of the conveyed workpiece;
Irradiating the surface of the workpiece with laser light through the liquid after supplying the liquid;
A step of recovering a substance scattered from the workpiece by the irradiation of the laser light and captured in the liquid.   The laser processing method according to claim 11, wherein the step of supplying the liquid includes a step of spraying the liquid onto the surface of the workpiece in a mist form. Conveying the workpiece;
Supplying steam to the surface of the conveyed workpiece;
Irradiating the surface of the workpiece with laser light through the steam after supplying the steam;
A step of recovering a substance scattered from the workpiece by being irradiated with the laser light and captured in the vapor.

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