Laser processing device and laser processing method

Abstract

To provide a detection device that checks by XY coordinates the state of organic particulates such as dust sticking to the processing face of a workpiece and verifies whether or not processing to be carried out by emitting a laser beam is obstructed.SOLUTION: The detection device includes a chuck table 35 for holding a workpiece 10, with an XY plane specified by XY coordinates taken as a holding face; laser beam irradiation means 7 for irradiating the workpiece 10 with a laser beam LB; and control means 100. The laser beam irradiation means comprises an oscillator 73 for the laser beam, a fθ lens 72 for focusing the oscillated laser beam upon the held workpiece, a scanner 76 for performing scanning with the oscillated laser beam in X-axis and Y-axis directions and disposed between the oscillator and the fθ lens, a branch unit 75 for branching fluorescent light induced from the workpiece and disposed between the oscillator and the scanner, and an optical detector 79 for detecting the light. The control means creates a coordinate value map of XY coordinates when the optical detector detects the induced fluorescent light.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a detection device that detects light induced by fluorescence from a workpiece. [Background technology]

[0002] Wafers, which are to be processed into workpieces and have multiple devices such as ICs and LSIs formed on their surfaces along planned dividing lines, are then divided into individual device chips using a dicing machine or laser processing machine, and are used in electrical devices such as mobile phones and personal computers.

[0003] A dicing device is configured to cut a dividing line on a wafer held on a chuck table using a cutting means equipped with a rotatable cutting blade having a cutting edge on the outer periphery, thereby dividing the wafer into individual device chips (see, for example, Patent Document 1), and a laser processing device is configured to irradiate a laser beam onto the dividing line, which is the processing surface of a wafer held on a chuck table, to form a processing groove, thereby dividing the wafer into individual device chips (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2010-050214 [Patent Document 1] Patent Publication No. 2014-221483 Summary of the Invention [Problem to be solved by the invention]

[0005] When dividing a wafer into individual device chips using the above-mentioned dicing apparatus, even if a small amount of organic fine particles such as dust adheres to the processing surface of the wafer, it is possible to divide the wafer into individual device chips with almost no effect. On the other hand, when dividing the wafer into individual device chips by irradiating a laser beam onto the processing surface of the wafer, for example, along the planned division lines, if organic fine particles such as dust adhere to the planned division lines, the organic fine particles will absorb the laser beam or scatter the laser beam when irradiated onto the fine particles, thereby interfering with the processing of the wafer by the laser beam and preventing the wafer from being properly divided into individual device chips.

[0006] The present invention has been made in consideration of the above facts, and its main technical objective is to provide a detection device that can confirm the state of organic fine particles such as dust adhering to the machining surface of a workpiece using XY coordinates and verify whether or not they will interfere with machining performed by irradiating a laser beam. [Means for solving the problem]

[0007] In order to solve the above-mentioned main technical problem, according to the present invention, there is provided a laser processing apparatus including a detection device, which includes holding means for holding a workpiece using an XY plane specified by X and Y coordinates as a holding surface, laser beam application means for irradiating a laser beam onto the workpiece held by the holding means, and control means, wherein the laser beam application means includes an oscillator for oscillating a laser beam, an fθ lens for focusing the laser beam oscillated by the oscillator onto the workpiece held by the holding means, a scanner disposed between the oscillator and the fθ lens for scanning the laser beam oscillated by the oscillator in the X-axis direction and the Y-axis direction, and a control means disposed between the oscillator and the scanner for controlling the laser beam oscillating on the workpiece during laser processing. By having multiple in a certain areaThe laser processing device includes at least a branching device that branches light induced by fluorescence in response to an obstructing particle, and a photodetector that detects the light guided by the branching device, and the control means, when the photodetector detects the light induced by fluorescence, calculates the coordinate values ​​of the X and Y coordinates scanned by the scanner as the coordinates of the laser beam in the laser processing. Applicable The coordinate value of the light induced by fluorescence in response to the interfering particles Adhesion position of the fine particles year and remember, A map is created to determine whether the particles will interfere with laser processing by the laser processing device, and based on the map, Based on the number of particles detected on the planned dividing line of the workpiece or the number of particles per predetermined area on the surface of the workpiece, The laser processing device performs laser processing on the workpiece when it is determined that the fine particles will not interfere with laser processing. Preferably, the device is configured to be able to clean the workpiece when it is determined that the fine particles will interfere with laser processing based on the map created by the detection device.

[0008] The scanner preferably comprises an X-axis galvanometer scanner that scans the laser beam in the X-axis direction and a Y-axis galvanometer scanner that scans the laser beam in the Y-axis direction. The holding means preferably comprises an X-axis moving means that moves the holding means in the X-axis direction and a Y-axis moving means that moves the holding means in the Y-axis direction. Furthermore, the configuration preferably comprises an induced fluorescence filter that is disposed between the splitter and the photodetector and transmits only light of a specific wavelength. The laser beam emitted by the oscillator is preferably ultraviolet light, and the energy density of the laser beam is preferably such that the workpiece held by the holding means is not machined, but that fine particles such as dust adhering to the workpiece are irradiated with the laser beam to produce induced fluorescence.

[0009] Further, in order to solve the above-mentioned main technical problem, according to the present invention, a laser beam irradiation means includes a holding means for holding a workpiece using an XY plane specified by X and Y coordinates as a holding surface, a laser beam irradiation means for irradiating a laser beam onto the workpiece held by the holding means, and a control means, wherein the laser beam irradiation means includes an oscillator for oscillating a laser beam, an fθ lens for focusing the laser beam oscillated by the oscillator onto the workpiece held by the holding means, a scanner disposed between the oscillator and the fθ lens for scanning the laser beam oscillated by the oscillator in the X-axis direction and the Y-axis direction, and a control means disposed between the oscillator and the scanner for controlling the laser beam irradiated on the workpiece. Multiple defects in a certain area can cause problems during laser processing.A laser processing method that can be carried out by a laser processing device that includes at least a branching device that branches light induced to fluoresce in response to a fine particle, and a photodetector that detects the light guided by the branching device, and when the photodetector detects the light induced to fluoresce, the coordinate values ​​of the X coordinate and the Y coordinate scanned by the scanner are calculated by the laser beam in the laser processing. Applicable The coordinate value of the light induced by fluorescence in response to the interfering particles Adhesion position of the fine particles year and remember, A map is created to determine whether or not the laser processing by the laser processing device is affected, and based on the map, Based on the number of particles detected on the planned dividing line of the workpiece or the number of particles per predetermined area on the surface of the workpiece, The laser processing method includes performing laser processing on the workpiece using the laser processing device when it is determined that the laser processing will not be hindered. Preferably, the method also includes cleaning the workpiece when it is determined based on the map that the laser processing will be hindered. [Effects of the Invention]

[0010] The detection device of the present invention includes a holding means for holding a workpiece using an XY plane specified by X and Y coordinates as a holding surface, a laser beam application means for applying a laser beam to the workpiece held by the holding means, and a control means, and the laser beam application means includes an oscillator for emitting a laser beam, an fθ lens for focusing the laser beam emitted by the oscillator on the workpiece held by the holding means, a scanner disposed between the oscillator and the fθ lens for scanning the laser beam emitted by the oscillator in the X-axis direction and the Y-axis direction, and a scanning lens disposed between the oscillator and the scanner for detecting induced fluorescence in the workpiece. The control means comprises at least a branching device that branches the light guided by the branching device, and a photodetector that detects the light guided by the branching device. When the photodetector detects light generated by induced fluorescence, the control means creates a map using the coordinate values ​​of the X and Y coordinates scanned by the scanner as the coordinate values ​​of the light generated by induced fluorescence. This makes it possible to check the state of fine particles such as dust adhering to the processing surface of the workpiece using the coordinate values ​​of the X and Y coordinates, verify whether the fine particles will interfere with laser processing, and clean the workpiece as necessary, thereby eliminating the problem of the fine particles interfering with processing of the workpiece. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an overall perspective view of a detection device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a block diagram showing an optical system of the detection device shown in FIG. 1. [Figure 3] FIG. 10A is a perspective view showing a mode in which position information of a workpiece is detected by a positioning means, and FIG. 10B is a conceptual diagram showing the position information of the workpiece detected in FIG. 10A together with the X and Y coordinates on a display means. [Figure 4] FIG. 2(a) is a perspective view showing how a laser beam is applied to a workpiece by the laser beam application means of the detection device shown in FIG. 1; FIG. 2(b) is a conceptual diagram of a map created by operating the laser beam application means shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a detection device configured based on the present invention will be described in detail with reference to the accompanying drawings.

[0013] 1 shows an overall perspective view of a detection device 1 of this embodiment. The detection device 1 is disposed on a base 2 and includes at least a holding means 3 for holding a workpiece (described later), a laser beam application means 7 for applying a laser beam to the workpiece held by the holding means 3, and a control means 100.

[0014] The detection device 1 also includes an alignment means 6 that takes an image of the work held by the holding means 3 and performs an alignment process, an X-axis moving means 4a that moves the holding means 3 in the X-axis direction, a Y-axis moving means 4b that moves the holding means 3 in the Y-axis direction, a frame 5 consisting of a vertical wall portion 5a erected on the side of the X-axis moving means 4a and Y-axis moving means 4b on the base 2 and a horizontal wall portion 5b extending horizontally from the upper end of the vertical wall portion 5a, and a display means 8.

[0015] The holding means 3 is a means for holding a workpiece using an XY plane, defined by X and Y coordinates, as a holding surface. More specifically, as shown in FIG. 1 , the holding means 3 includes a rectangular X-axis movable plate 31 mounted on the base 2 so as to be movable in the X-axis direction, a rectangular Y-axis movable plate 32 mounted on the X-axis movable plate 31 so as to be movable in the Y-axis direction, a cylindrical support 33 fixed to the upper surface of the Y-axis movable plate 32, and a rectangular cover plate 34 fixed to the upper end of the support 33. A chuck table 35 is disposed on the cover plate 34 and extends upward through an elongated hole formed in the cover plate 34. The chuck table 35 is rotatable by a rotation drive means (not shown) housed in the support 33. A circular suction chuck 36, made of a porous material with air permeability and having an XY plane, defined by the X and Y coordinates, as a holding surface, is disposed on the upper surface of the chuck table 35. The suction chuck 36 is connected to a suction means (not shown) by a flow path that passes through the support 33, and four clamps 37, which are used to hold a workpiece (described later) on the chuck table 35, are arranged at equal intervals around the suction chuck 36. By operating the suction means, the workpiece can be sucked and held by the suction chuck 36.

[0016] The X-axis moving means 4a converts the rotational motion of the motor 42a into linear motion via a ball screw 42b and transmits it to the X-axis movable plate 31, moving the X-axis movable plate 31 in the X-axis direction along a pair of guide rails 2A, 2A arranged along the X-axis direction on the base 2. The Y-axis moving means 4b converts the rotational motion of the motor 44a into linear motion via a ball screw 44b and transmits it to the Y-axis movable plate 32, moving the Y-axis movable plate 32 in the Y-axis direction along a pair of guide rails 31a, 31a arranged along the Y-axis direction on the X-axis movable plate 31.

[0017] The horizontal wall 5b of the frame 5 houses an optical system that constitutes the laser beam application means 7, and the alignment means 6. A condenser 71 that constitutes part of the laser beam application means 7 and irradiates the workpiece with a laser beam is disposed on the underside of the tip of the horizontal wall 5b. The alignment means 6 is an imaging means that captures an image of the workpiece held by the holding means 3 and detects the position and orientation of the workpiece, the position to be irradiated with the laser beam, etc., and is disposed adjacent to the condenser 71 in the X-axis direction indicated by the arrow X in the figure.

[0018] 2 is a block diagram showing an outline of the optical system of the above-mentioned alignment means 6 and laser beam application means 7. The laser beam application means 7 includes at least an oscillator 73 that oscillates a laser beam LB, an fθ lens 72 disposed in a condenser 71 to condense the laser beam LB oscillated by the oscillator 73 onto the workpiece 10 held on the chuck table 35 of the holding means 3, a scanner 76 disposed between the oscillator 73 and the fθ lens 72 and that scans the laser beam LB oscillated by the oscillator 73 in the X-axis and Y-axis directions, a branching unit 75 disposed between the oscillator 73 and the scanner 76 and that branches light induced by fluorescence in the workpiece 10, and a photodetector 79 that detects the light guided by the branching unit 75.

[0019] In addition to the configuration described above, the optical system of the laser beam application means 7 of this embodiment also includes an attenuator 74 that adjusts the output of the laser beam LB oscillated from the oscillator 73 to adjust the energy density at the irradiation position on the workpiece within a predetermined range, a reflecting mirror 77 that redirects the optical path of the laser beam LB irradiated from the scanner 76 toward the condenser 71, and an induced fluorescence filter 78 that is disposed between the splitter 75 and the photodetector 79 and transmits only light of a specified wavelength.

[0020] The branching device 75 may be, for example, a half mirror or a beam splitter. The laser beam LB oscillated by the oscillator 73 may be, for example, ultraviolet light, and a light source that emits light with a wavelength of 266 nm may be used. When the laser beam LB is irradiated onto organic particles adhering to the workpiece, the particles react with the laser beam LB, and the returning light containing induced fluorescence is branched by the branching device 75 toward the photodetector 79, the induced fluorescence filter 78 transmits only light of the wavelength of the induced fluorescence; in this embodiment, a filter that transmits light with a wavelength of 450 nm to 470 nm is selected.

[0021] The above-mentioned scanner 76 is composed of an X-axis galvanometer scanner 761 that scans the laser beam LB emitted from the oscillator 73 in the X-axis direction on the workpiece held by the holding means 3, and a Y-axis galvanometer scanner 762 that scans in the Y-axis direction.

[0022] The control means 100 is configured by a computer and includes a central processing unit (CPU) that performs calculations according to a control program, a read-only memory (ROM) that stores the control program, etc., a readable and writable random access memory (RAM) that temporarily stores detected values, calculation results, etc., an input interface, and an output interface (details not shown). The control means 100 is connected to the alignment means 6, the display means 8, the scanner 76 (X-axis galvanometer scanner 761, Y-axis galvanometer scanner 762), the photodetector 79, the X-axis moving means 4a, the Y-axis moving means 4b, etc., and image data captured by the alignment means 6 and information detected by the photodetector 79 are stored in an appropriate memory and displayed on the display means 8. The control means 100 operates the X-axis galvanometer scanner 761 of the scanner 76, moves the laser beam LB in the X-axis direction indicated by the arrow R1, and irradiates the laser beam LB through the fθ lens 72 shown in Figure 2, thereby making it possible to irradiate any X-coordinate position on the surface 10a of the workpiece 10.Similarly, the Y-axis galvanometer scanner 762 is operated, moves the laser beam LB in the Y-axis direction perpendicular to the drawing in Figure 2, and irradiates the laser beam LB through the fθ lens 72, thereby making it possible to irradiate any Y-coordinate position on the surface 10a of the workpiece 10.

[0023] The detection device 1 of this embodiment has roughly the configuration as described above, and the functions and actions of the detection device 1 will be described below.

[0024] As shown in FIG. 3( a), the workpiece 10 used in the detection device 1 of this embodiment is a semiconductor wafer having a plurality of devices 12 formed on a surface 10a defined by division lines 14. A notch 16 is formed on the periphery of the workpiece 10 to identify the crystal orientation of the workpiece 10, and the devices 12 and division lines 14 are formed based on the notch 16. To process the workpiece 10, as shown in FIG. 3( a), an annular frame F having an opening Fa large enough to accommodate the workpiece 10 is prepared, and the workpiece 10 and frame F are attached together with adhesive tape T. A separate laser processing device (not shown) irradiates the workpiece 10 with a laser beam along the division lines 14 to form grooves, dividing the workpiece 10 into individual device chips. Before laser processing is performed using this laser processing device, the workpiece 10 is transported to the detection device 1 of this embodiment, and the workpiece 10 is inspected for dust or other particles adhering to the processing area irradiated with the processing laser beam to a degree that would prevent proper laser processing, as described below.

[0025] Once the workpiece 10 is held on the chuck table 35 of the holding means 3 of the detection device 1 described with reference to FIG. 1, the X-axis moving means 4a and Y-axis moving means 4b are operated to position the workpiece 10 directly below the alignment means 6, as shown in FIG. 3(a). Next, the alignment means 6 photographs the workpiece 10, and as shown in FIG. 3(b), the center O of the workpiece 10 is aligned with the origin of the X and Y coordinates, and the direction of the predetermined dividing line 14 is aligned with the X-axis direction, and the dividing line 14 perpendicular to the dividing line 14 is aligned with the Y-axis direction, based on the notch 16 of the workpiece 10. Furthermore, position information based on the X and Y coordinates of the device 12 and the dividing line 14 is stored in the control means 100, and the positions of the device 12 and the dividing line 14 on the surface 10a of the workpiece 10 are specified by the X and Y coordinates and displayed on the display means 8.

[0026] Next, the X-axis moving means 4a and the Y-axis moving means 4b are operated to move the workpiece 10 directly below the condenser 71 of the laser beam application means 7, as shown in Figure 4(a). As described above, the condenser 71 is provided with an fθ lens 72, and the laser beam application means 7 is operated by the control means 100 to scan the workpiece 10 so that the laser beam LB is applied to the entire surface 10a of the workpiece 10. When the laser beam LB is applied to the entire surface 10a of the workpiece 10, the X-axis moving means 4a and the Y-axis moving means 4b are operated as appropriate.

[0027] The irradiation conditions of the laser beam in this embodiment are set based on the following irradiation conditions, for example. Wavelength: 266nm Repetition frequency: 200kHz Pulse width: 100fs~100ns Average power: 0.12W~0.628W Spot diameter: φ28μm

[0028] Among the irradiation conditions for the laser beam LB described above, the wavelength of the laser beam LB oscillated by the oscillator 73 is preferably light with a wavelength near ultraviolet light that generates induced fluorescence depending on the material of the particles adhering thereto, and is set, for example, in the wavelength range of 200 nm to 500 nm. Furthermore, since the material of the particles adhering to the workpiece 10 differs depending on the processing environment, the average output is adjusted to an energy density such that particles such as dust adhering to the surface 10a of the workpiece 10 emit induced fluorescence when irradiated with the laser beam LB, and the devices 12 and planned division lines 14 formed on the workpiece 10 are not processed.

[0029] As described above, when the laser beam application means 7 is operated by the control means 100 to scan the entire surface 10a of the workpiece 10, if fine particles made of organic matter such as dust adhere to the position where the laser beam LB is applied, induced fluorescent light is emitted in response to the laser beam LB. The induced fluorescent light passes through the fθ lens 72 of the condenser 71 and reaches the reflecting mirror 77, scanner 76, and branching device 75 of the optical system shown in Figure 2 as returned light, and is branched to the photodetector 79 side. As described above, in this embodiment, an induced fluorescence filter 78 that transmits only light with wavelengths between 450 nm and 470 nm, which includes the wavelength of induced fluorescence light generated from particles expected to adhere to the surface 10 a of the workpiece 10, is disposed between the splitter 75 of the laser beam application means 7 and the photodetector 79. This filter filters out light with wavelengths other than 450 nm to 470 nm, i.e., light simply reflected from the surface 10 a of the workpiece 10 and other wavelengths, and only the induced fluorescence light generated when the laser beam LB is irradiated onto the particles reaches the photodetector 79, where its light intensity is detected. When the photodetector 79 detects the induced fluorescence light, the control means 100 identifies the position P of the particle based on the X and Y coordinate values ​​of the position irradiated with the laser beam LB by the scanner 76, creates a map as shown in FIG. 4( b), stores it in the memory of the control means 100, and displays it on the display means 8.

[0030] By referring to the map, it is possible to detect to what extent the particles are attached to which positions on the surface 10a of the workpiece 10. For example, by referring to the position information of the devices 12 and the planned division lines 14 of the workpiece 10 detected by the positioning means 6, it is possible to detect how many particles are attached to a predetermined planned division line 14 of the workpiece 10, determine whether the number of attached particles is equal to or greater than a predetermined value, and verify whether the particles will interfere with laser processing. In other words, according to the detection device 1 of the present embodiment described above, it is possible to confirm the state of particles such as dust attached to the processing surface of the workpiece 10 using XY coordinates, and the workpiece 10 can be cleaned as necessary, thereby solving the problem of the particles interfering with processing of the workpiece 10.

[0031] In the above embodiment, the wavelength transmitted by the induced fluorescence filter 78 is set to 450 nm to 470 nm, but the present invention is not limited to this. The wavelength of the induced fluorescence light emitted when the laser beam LB is irradiated onto the particles adhering to the workpiece 10 varies depending on the type of organic matter that makes up the particles. Therefore, the induced fluorescence filter 78 is changed to change the transmitted wavelength range depending on the type of particles expected to adhere to the workpiece 10.

[0032] Furthermore, when the photodetector 79 detects the light generated by induced fluorescence, a map is created using the coordinate values ​​of the X and Y coordinates scanned by the scanner 76 as the coordinate values ​​of the light generated by induced fluorescence, and then it is determined whether or not the particles will interfere with laser processing by verifying the number of particles detected on the planned division line 14, or by verifying the number of particles per predetermined area on the surface 10a of the workpieces 10. Furthermore, among multiple workpieces 10 stored in one cassette, verification may be performed to detect the number of particles using the above-mentioned detection device 1 for some of the workpieces 10, and if adhesion of a predetermined number or more of particles is detected, it may be determined that all of the workpieces 10 stored in the cassette should be cleaned.

[0033] In the above-described embodiment, the detection device 1 is configured as an independent device separate from the laser processing device, but the present invention is not limited to this. For example, a detection device configured based on the present invention may be incorporated into a laser processing device, and if the results of the above-described verification performed on the workpiece 10 are good, laser processing may be performed on the workpiece 10 as is. [Explanation of symbols]

[0034] 1: Detection device 2: Base 3: Holding means 31:X-axis movable plate 32: Y-axis direction movable plate 33: Post 34: Cover plate 35: Chuck table 36: Vacuum chuck 37: Clamp 4a:X-axis movement means 42a: Motor 42b: Ball screw 4b: Y-axis movement means 44a: Motor 44b: Ball screw 5:Frame body 5a: Vertical wall 5b:Horizontal wall part 6: Alignment means 7: Laser beam irradiation means 71: Concentrator 72: fθ lens 73: Oscillator 74: Attenuator 75: Switch 76: Scanner 761: X-axis galvanometer scanner 762: Y-axis galvanometer scanner 77: Reflective mirror 78: Induced fluorescence filter 79: Photodetector 8:Display means 10: Work 12: Device 14: Planned division line 16: Notch 100: Control means

Claims

1. A laser processing apparatus including a detection device, The apparatus includes a holding means for holding a workpiece using an XY plane specified by X and Y coordinates as a holding surface, a laser beam application means for applying a laser beam to the workpiece held by the holding means, and a control means, The laser beam application means comprises an oscillator that emits a laser beam, an fθ lens that focuses the laser beam emitted by the oscillator on the workpiece held by the holding means, a scanner that is disposed between the oscillator and the fθ lens and that scans the laser beam emitted by the oscillator in the X-axis direction and the Y-axis direction, a branching device that is disposed between the oscillator and the scanner and that branches light that is induced to fluoresce in response to fine particles that would be a hindrance if multiple particles exist in a certain area of ​​the workpiece during laser processing, and a photodetector that detects the light guided by the branching device. At least When the photodetector detects induced fluorescent light, the control means stores the coordinate values ​​of the X and Y coordinates scanned by the scanner and the coordinate values ​​of the light induced to fluoresce when the laser beam reacts with the particle that will cause a problem in laser processing as the adhesion position of the particle, creates a map for determining whether the particle will cause a problem in laser processing by the laser processing device, and when it determines that the particle will not cause a problem in laser processing based on the map and based on the number of particle detected on the planned dividing line of the workpiece or the number of particle per specified area on the surface of the workpiece, the laser processing device performs laser processing on the workpiece.

2. A laser processing device as described in claim 1, configured to be able to clean the workpiece if it is determined based on the map created by the detection device that the microparticles will interfere with laser processing.

3. A laser processing apparatus as described in claim 1 or 2, wherein the scanner is composed of an X-axis galvanometer scanner that scans the laser beam in the X-axis direction, and a Y-axis galvanometer scanner that scans the laser beam in the Y-axis direction.

4. A detection device described in any one of claims 1 to 3, wherein the holding means is provided with an X-axis moving means for moving the holding means in the X-axis direction and a Y-axis moving means for moving the holding means in the Y-axis direction.

5. A laser processing apparatus as described in any one of claims 1 to 4, which is provided with an induced fluorescence filter arranged between the branching device and the photodetector and which transmits only light of a specific wavelength.

6. A laser processing device described in any one of claims 1 to 5, wherein the laser beam emitted by the oscillator is ultraviolet light.

7. A laser processing apparatus described in any of claims 1 to 6, wherein the energy density of the laser beam is such that the workpiece held by the holding means is not processed, but produces induced fluorescence when the laser beam is irradiated onto fine particles such as dust adhering to the workpiece.

8. A laser processing method that can be carried out by a laser processing device including: holding means for holding a workpiece using an XY plane specified by X and Y coordinates as a holding surface; laser beam application means for applying a laser beam to the workpiece held by the holding means; and control means, wherein the laser beam application means is equipped with at least: an oscillator for emitting a laser beam; an fθ lens for focusing the laser beam oscillated by the oscillator on the workpiece held by the holding means; a scanner disposed between the oscillator and the fθ lens for scanning the laser beam oscillated by the oscillator in the X-axis direction and the Y-axis direction; a branching device disposed between the oscillator and the scanner for branching light induced by fluorescence in response to fine particles on the workpiece that would cause problems if multiple particles exist in a certain area during laser processing; and a photodetector for detecting the light guided by the branching device, When the photodetector detects the induced fluorescent light, the coordinate values ​​of the X and Y coordinates scanned by the scanner are stored as coordinate values ​​of the light induced to fluoresce when the laser beam reacts with the particle that will cause a problem in laser processing, as the adhesion position of the particle, and a map is created for determining whether or not the particle will cause a problem in laser processing by the laser processing device. A laser processing method in which, based on the map, it is determined that there will be no interference with laser processing based on the number of particles detected on the planned dividing line of the workpiece or the number of particles per specified area on the surface of the workpiece, and then laser processing is performed on the workpiece using the laser processing device.

9. A laser processing method in which the workpiece is cleaned if it is determined based on the map that the workpiece will interfere with laser processing.

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