Laser processing device and laser processing method

Abstract

The laser processing device of the present invention irradiates an object with a portion of a focusing region by aligning the object with the laser beam, thereby forming a modified region within the object along an imaginary surface. The laser processing device comprises: a support portion that supports the object; an irradiation portion that irradiates the object with laser beam; a movement mechanism that moves at least one of the support portion and the irradiation portion so that the portion of the focusing region moves along the imaginary surface within the object; and a control portion that controls the support portion, the irradiation portion, and the movement mechanism. The irradiation portion includes a shaping portion that shapes the laser beam so that the portion of the focusing region, within a plane perpendicular to the optical axis of the laser beam, has a longitudinal direction. The longitudinal direction is a direction intersecting the direction of movement of the portion of the focusing region.

Description

Technical Field

[0001] One aspect of the present invention relates to a laser processing apparatus and a laser processing method. Background Art

[0002] Patent Document 1 describes a laser processing device comprising: a holding mechanism for holding a workpiece; and a laser irradiation mechanism for irradiating the workpiece held by the holding mechanism with laser light. In the laser processing device described in Patent Document 1, the laser irradiation mechanism, which includes a condensing lens, is fixed to a base, and the holding mechanism moves the workpiece in a direction perpendicular to the optical axis of the condensing lens.

[0003] [Prior art literature]

[0004] [Patent Document]

[0005] Patent Document 1: Japanese Patent No. 5456510 Summary of the Invention

[0006] [Problems to be Solved by the Invention]

[0007] However, in laser processing devices such as those described above, laser irradiation can sometimes form a modified region within an object along an imaginary surface. In this case, a portion of the object is peeled off, separated by the modified region spanning the imaginary surface and the cracks extending from the modified region. In recent years, with the increasing prevalence of peeling processes such as these, there has been a desire for improved smoothness (shortening of processing time).

[0008] Therefore, one aspect of the present invention is to provide a laser processing apparatus and a laser processing method that can improve the smoothness when forming a modified region along a virtual surface inside an object.

[0009] [Means for solving the problem]

[0010] A laser processing device according to one embodiment of the present invention is a laser processing device for irradiating a part of a focusing area with a target object by aligning the laser beam, thereby forming a modified area along an imaginary surface inside the target object. The device comprises: a support portion for supporting the target object; an irradiation portion for irradiating the target object with laser beam; a moving mechanism for moving at least one of the support portion and the irradiation portion in such a manner that the part of the focusing area moves along the imaginary surface inside the target object; and a control portion for controlling the support portion, the irradiation portion and the moving mechanism, wherein the irradiation portion has a forming portion for forming the laser beam in such a manner that the shape of the part of the focusing area within the surface along the imaginary surface has a long side direction, and the long side direction is a direction intersecting with the moving direction of the part of the focusing area.

[0011] The inventors of the present invention have repeatedly devoted themselves to research and found that when a modified area is formed along an imaginary surface, when the shape of a part of the focusing area of ​​the laser in the plane along the imaginary surface has a long side direction, the cracks extending from the modified area along the imaginary surface tend to extend in the long side direction. For this reason, in a laser processing device related to one form of the present invention, a direction intersecting with the moving direction of a part of the focusing area (hereinafter also referred to as the "processing travel direction") is set as the long side direction, thereby making it easy for cracks to extend in the direction intersecting with the processing travel direction, which can promote the progress of cracks along the imaginary surface. Therefore, for example, even if the interval between the modified points of the modified area in the direction intersecting with the processing travel direction is increased, the cracks can still be fully progressed along the imaginary surface. As a result, improved smoothness can be achieved.

[0012] In the laser processing apparatus according to one aspect of the present invention, the longitudinal direction may be inclined at 45° or more relative to the movement direction of a portion of the focusing area. In this case, the development of the crack along the imaginary surface can be further promoted.

[0013] In the laser processing apparatus according to one aspect of the present invention, the longitudinal direction may be a direction perpendicular to the moving direction of a portion of the focusing region. In this case, the development of the crack along the imaginary surface can be further promoted.

[0014] In the laser processing apparatus according to one aspect of the present invention, the shape of a portion of the focusing region may have an ellipticity of 0.88 to 0.95. In this case, the development of the crack along the imaginary surface can be further promoted.

[0015] In one aspect of the laser processing apparatus of the present invention, the control unit may relatively move a portion of the focused region along a processing line extending spirally inward from the periphery of the object, thereby forming a modified region within the object. This allows a portion of the object to be precisely exfoliated, with the modified region spanning an imaginary surface and a crack extending from the modified region serving as a boundary.

[0016] A laser processing apparatus according to one aspect of the present invention includes an input unit capable of receiving input from a user of at least one of information regarding the shape of a portion of a light-collecting region; information regarding the tilt relative to the direction of movement of the portion of the light-collecting region; and information regarding the settings of a forming unit. The control unit may also control the support unit, the irradiation unit, and the moving mechanism based on the input from the input unit. Thus, when forming a modified region along a virtual surface, at least one of the information regarding the shape of the portion of the light-collecting region; information regarding the tilt relative to the direction of movement of the portion of the light-collecting region; and information regarding the settings of the forming unit can be set as desired.

[0017] A laser processing method according to one form of the present invention is a laser processing method in which a part of a focusing area is aligned with an object and irradiated with laser light, thereby forming a modified area along an imaginary surface inside the object. The method comprises: an irradiation step of irradiating the object with laser light, and a moving step of moving a support portion supporting the object and at least one of the irradiation portions irradiated with laser light in a manner that a part of the focusing area moves along the imaginary surface inside the object. The irradiation step comprises a forming step of forming the laser light in a manner that a shape of a part of the focusing area in a plane perpendicular to the optical axis of the laser light has a long side direction, and the long side direction is a direction intersecting with the moving direction of the part of the focusing area.

[0018] The laser processing method also uses the direction intersecting the processing direction as the longitudinal direction to facilitate the extension of cracks in the direction intersecting the processing direction, thereby promoting the development of cracks along the virtual surface. As a result, the smoothness can be improved.

[0019] [Effects of the Invention]

[0020] According to one aspect of the present invention, a laser processing apparatus and a laser processing method can be provided that can improve the smoothness when forming a modified region along a virtual surface inside an object. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] [ Figure 1 ] Figure 1 It is a perspective view of a laser processing device according to an embodiment.

[0022] [ Figure 2 ] Figure 2 for Figure 1 A front view showing a portion of a laser processing device.

[0023] [ Figure 3 ] Figure 3 for Figure 1 A front view of a laser processing head of a laser processing device is shown.

[0024] [ Figure 4 ] Figure 4 for Figure 3 Figure 4 shows a side view of the laser processing head.

[0025] [ Figure 5 ] Figure 5 for Figure 3 A diagram showing the structure of the optical system of the laser processing head.

[0026] [ Figure 6 ] Figure 6 This is a diagram showing the configuration of the optical system of a laser processing head according to a modified example.

[0027] [ Figure 7 ] Figure 7This is a front view of a portion of a laser processing device according to a modified example.

[0028] [ Figure 8 ] Figure 8 A perspective view of a laser processing device according to a modified example.

[0029] [ Figure 9 ] Figure 9 It is a plan view showing a schematic configuration of a laser processing apparatus according to the first embodiment.

[0030] [ Figure 10 ] Figure 10 (a) is a plan view showing an example of an object. Figure 10 (b) Figure 10 (a) shows a side view of the object.

[0031] [ Figure 11 ] Figure 11 (a) is a side view for explaining an object to be laser-processed according to an embodiment. Figure 11 (b) Next Figure 11 (a) is a plan view of the object represented. Figure 11 (c) Figure 11 (b) shows a side view of the object.

[0032] [ Figure 12 ] Figure 12 (a) To continue Figure 11 (b) shows a side view of the object. Figure 12 (b) Next Figure 12 (a) is a plan view of the object represented.

[0033] [ Figure 13 ] Figure 13 (a) for the next Figure 12 (b) is a plan view of the object represented. Figure 13 (b) Figure 13 (a) shows a side view of the object. Figure 13 (c) is followed by Figure 13 (b) shows a side view of the object.

[0034] [ Figure 14 ] Figure 14 (a) To continue Figure 13 (c) is a plan view of the object represented. Figure 14 (b) Figure 14 (a) shows a side view of the object. Figure 14 (c) is followed by Figure 14 (a) shows a side view of the object. Figure 14 (d) Next Figure 14 (c) shows a side view of the object.

[0035] [ Figure 15 ] Figure 15 It is a plan view of an object for explaining the peeling process.

[0036] [ Figure 16 ] Figure 16 (a) is a diagram showing the shape of a light beam according to this embodiment. Figure 16 (b) is a diagram showing a beam shape according to a modified example.

[0037] [ Figure 17 ] Figure 17 (a) is a planar cross-sectional view of an object for explaining the results of a lift-off process in a comparative example using a laser beam having a circular beam shape. Figure 17 (b) is a planar cross-sectional view of an object for explaining the results of the lift-off processing according to the present embodiment using a laser beam having an elliptical beam shape and a beam rotation angle of 90°.

[0038] [ Figure 18 ] Figure 18 This is a plan view of an object for explaining the branch distance X and the branch distance Y.

[0039] [ Figure 19 ] Figure 19 (a) is a graph showing the relationship between ellipticity and beam shape. Figure 19 (b) is a graph showing the relationship between the ellipticity and the beam rotation angle and the occurrence rate of the fully cut state of the slice.

[0040] [ Figure 20 ] Figure 20 This is a diagram showing a case where the beam rotation angle is 0° and the beam shape is an elliptical beam.

[0041] [ Figure 21 ] Figure 21 This is a diagram showing an elliptical beam shape when the beam rotation angle is 60°.

[0042] [ Figure 22 ] Figure 22 This is a diagram showing an example of a setting screen displayed on the touch panel of the GUI.

[0043] [ Figure 23 ] Figure 23 This is a diagram showing another example of a setting screen displayed on the touch panel of the GUI. DETAILED DESCRIPTION

[0044] Hereinafter, the embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are given the same reference numerals, and repeated descriptions are omitted.

[0045] First, the basic structure, function, effect, and modification examples of laser processing are described.

[0046] [Composition of laser processing equipment]

[0047] like Figure 1 As shown, the laser processing apparatus 1 includes: a plurality of moving mechanisms 5 and 6; a support unit 7; a pair of laser processing heads 10A and 10B; a light source unit 8; and a control unit 9. Hereinafter, the first direction is referred to as the X direction, the second direction perpendicular to the first direction is referred to as the Y direction, and the third direction perpendicular to the first and second directions is referred to as the Z direction. In this embodiment, the X and Y directions are horizontal directions, and the Z direction is the vertical direction.

[0048] The moving mechanism 5 comprises a fixed portion 51, a moving portion 53, and a mounting portion 55. The fixed portion 51 is mounted to the device frame 1a. The moving portion 53 is mounted on a track provided on the fixed portion 51 and is movable in the Y direction. The mounting portion 55 is mounted on a track provided on the moving portion 53 and is movable in the X direction.

[0049] The moving mechanism 6 includes: a fixed portion 61, a pair of moving portions 63, 64, and a pair of mounting portions 65, 66. The fixed portion 61 is mounted on the device outer frame 1a. The pair of moving portions 63, 64 are respectively mounted on the rails provided on the fixed portion 61 and are independently movable along the Y direction. The mounting portion 65 is mounted on the rail provided on the moving portion 63 and is movable along the Z direction. The mounting portion 66 is mounted on the rail provided on the moving portion 64 and is movable along the Z direction. That is, the pair of mounting portions 65, 66 are respectively movable along the Y direction and the Z direction relative to the device outer frame 1a. The moving portions 63, 64 respectively constitute the first and second horizontal moving mechanisms (horizontal moving mechanisms). The mounting portions 65, 66 respectively constitute the first and second vertical moving mechanisms (vertical moving mechanisms).

[0050] The support unit 7 is mounted on a rotating shaft provided on the mounting portion 55 of the moving mechanism 5 and is rotatable about an axis parallel to the Z direction. Specifically, the support unit 7 is movable in both the X and Y directions and rotatable about an axis parallel to the Z direction. The support unit 7 supports an object 100. The object 100 is, for example, a wafer.

[0051] like Figure 1 and Figure 2As shown, the laser processing head 10A is mounted on the mounting portion 65 of the moving mechanism 6. The laser processing head 10A is positioned opposite the support portion 7 in the Z direction and irradiates the object 100 supported by the support portion 7 with a laser beam L1 (also referred to as "first laser beam L1"). The laser processing head 10B is mounted on the mounting portion 66 of the moving mechanism 6. The laser processing head 10B is positioned opposite the support portion 7 in the Z direction and irradiates the object 100 supported by the support portion 7 with a laser beam L2 (also referred to as "second laser beam L2"). The laser processing heads 10A and 10B constitute an irradiation unit.

[0052] The light source 8 includes a pair of light sources 81 and 82. The light source 81 outputs a laser beam L1. The laser beam L1 is emitted from an emission portion 81a of the light source 81 and guided to the laser processing head 10A via an optical fiber 2. The light source 82 outputs a laser beam L2. The laser beam L2 is emitted from an emission portion 82a of the light source 82 and guided to the laser processing head 10B via another optical fiber 2.

[0053] The control unit 9 controls the various components of the laser processing apparatus 1 (the support unit 7, the multiple moving mechanisms 5 and 6, the pair of laser processing heads 10A and 10B, and the light source unit 8). The control unit 9 is configured as a computer device that includes a processor, memory, storage, and a communication device. The processor executes software (programs) read from the memory, etc., and the processor controls the reading and writing of data from the memory and storage, as well as communications with the communication device. This enables the control unit 9 to implement various functions.

[0054] An example of processing performed by the laser processing apparatus 1 configured as above will be described. This example of processing is an example of forming a modified region inside the object 100 along a plurality of lines arranged in a grid pattern in order to cut the object 100 as a wafer into a plurality of chips.

[0055] The moving mechanism 5 moves the support portion 7 in the X and Y directions, respectively, so that the support portion 7 supporting the object 100 faces the pair of laser processing heads 10A and 10B in the Z direction. The moving mechanism 5 then rotates the support shaft 7 about an axis parallel to the Z direction, so that a plurality of lines extending in one direction in the object 100 are aligned along the X direction.

[0056] Next, the moving mechanism 6 moves the laser processing head 10A in the Y direction, positioning the focal point (a portion of the focal area) of the laser beam L1 on a line extending in one direction. Meanwhile, the moving mechanism 6 moves the laser processing head 10B in the Y direction, positioning the focal point of the laser beam L2 on another line extending in one direction. Next, the moving mechanism 6 moves the laser processing head 10A in the Z direction, positioning the focal point of the laser beam L1 inside the object 100. Meanwhile, the moving mechanism 6 moves the laser processing head 10B in the Z direction, positioning the focal point of the laser beam L2 inside the object 100.

[0057] Next, light source 81 outputs laser light L1, causing laser processing head 10A to irradiate object 100 with laser light L1. Light source 82 outputs laser light L2, causing laser processing head 10B to irradiate object 100 with laser light L2. Simultaneously, moving mechanism 5 moves support 7 in the X direction, causing the focal point of laser light L1 to relatively move along a line extending in one direction, and the focal point of laser light L2 to relatively move along another line extending in the same direction. In this way, laser processing apparatus 1 forms modified regions within object 100 along multiple lines extending in one direction.

[0058] Next, the moving mechanism 5 rotates the support portion 7 about the axis parallel to the Z direction as the center line so that a plurality of lines extending in the object 100 in another direction orthogonal to the one direction are along the X direction.

[0059] Next, the moving mechanism 6 moves the laser processing head 10A in the Y direction, positioning the focal point of the laser beam L1 on a line extending in the other direction. Meanwhile, the moving mechanism 6 moves the laser processing head 10B in the Y direction, positioning the focal point of the laser beam L2 on another line extending in the other direction. Next, the moving mechanism 6 moves the laser processing head 10A in the Z direction, positioning the focal point of the laser beam L1 inside the object 100. Meanwhile, the moving mechanism 6 moves the laser processing head 10B in the Z direction, positioning the focal point of the laser beam L2 inside the object 100.

[0060] Next, light source 81 outputs laser light L1, causing laser processing head 10A to irradiate object 100 with laser light L1. Light source 82 outputs laser light L2, causing laser processing head 10B to irradiate object 100 with laser light L2. Simultaneously, moving mechanism 5 moves support 7 in the X direction, causing the focal point of laser light L1 to relatively move along a line extending in another direction, and the focal point of laser light L2 to relatively move along another line extending in another direction. In this way, laser processing device 1 forms modified regions within object 100 along multiple lines extending in a direction perpendicular to the one direction.

[0061] Furthermore, in the above-described processing example, light source 81 outputs penetrating laser light L1 toward object 100, for example, using a pulsed oscillation method, and light source 82 outputs penetrating laser light L2 toward object 100, for example, using a pulsed oscillation method. Once the laser light is focused within object 100, it is specifically absorbed by the portion corresponding to the focal point, forming a modified region within object 100. A modified region is an area whose density, refractive index, mechanical strength, and other physical properties differ from those of the surrounding, unmodified region. Examples of modified regions include melt-processed regions, cracked regions, dielectric breakdown regions, and regions with altered refractive index.

[0062] When a laser beam output in a pulsed oscillation manner is irradiated on an object 100 and the focal point of the laser beam is moved relative to a line set on the object 100, a plurality of modified points arranged in a row along the line are formed. One modified point is formed by irradiation with one pulse of laser beam. A row of modified areas is a collection of the plurality of modified points arranged in a row. Adjacent modified points may be continuous or separated, depending on the relative movement speed of the focal point of the laser beam relative to the object 100 and the repetition frequency of the laser beam. The shape of the set line is not limited to a grid shape, and may also be a ring shape, a straight line, a curve, or a combination of at least one of these shapes.

[0063] [Composition of the laser processing head]

[0064] like Figure 3 and Figure 4 1 , the laser machining head 10A includes a housing 11 , an incident portion 12 , an adjustment portion 13 , and a focusing portion 14 .

[0065] The frame 11 includes a first wall 21 and a second wall 22; a third wall 23 and a fourth wall 24; and a fifth wall 25 and a sixth wall 26. The first wall 21 and the second wall 22 face each other in the X direction. The third wall 23 and the fourth wall 24 face each other in the Y direction. The fifth wall 25 and the sixth wall 26 face each other in the Z direction.

[0066] The distance between the third wall portion 23 and the fourth wall portion 24 is smaller than the distance between the first wall portion 21 and the second wall portion 22. The distance between the first wall portion 21 and the second wall portion 22 is smaller than the distance between the fifth wall portion 25 and the sixth wall portion 26. Furthermore, the distance between the first wall portion 21 and the second wall portion 22 may be equal to the distance between the fifth wall portion 25 and the sixth wall portion 26, or may be larger than the distance between the fifth wall portion 25 and the sixth wall portion 26.

[0067] In the laser processing head 10A, the first wall portion 21 is located on the opposite side to the fixed portion 61 of the moving mechanism 6, the second wall portion 22 is located on the fixed portion 61 side, the third wall portion 23 is located on the mounting portion 65 side of the moving mechanism 6, and the fourth wall portion 24 is located on the opposite side to the mounting portion 65 and on the laser processing head 10B side (see Figure 2 The fifth wall portion 25 is located on the opposite side of the support portion 7 , and the sixth wall portion 26 is located on the support portion 7 side.

[0068] The frame 11 is configured so that the third wall portion 23 is disposed on the mounting portion 65 side of the moving mechanism 6. Specifically, as described below, the mounting portion 65 includes a bottom plate 65a and a mounting plate 65b. The bottom plate 65a is mounted on a rail provided on the moving portion 63 (see FIG. 2 ). Figure 2 The mounting plate 65b is erected at the end portion of the base plate 65a on the side of the laser processing head 10B (see Figure 2 The frame 11 is mounted on the mounting portion 65 by screwing the bolts 28 into the mounting plate 65b via the pedestals 27, with the third wall 23 in contact with the mounting plate 65b. The pedestals 27 are provided on the first wall 21 and the second wall 22, respectively. The frame 11 is removable from the mounting portion 65.

[0069] The incident portion 12 is attached to the fifth wall 25. The incident portion 12 injects the laser light L1 into the housing 11. The incident portion 12 is offset toward the second wall 22 (one wall) in the X direction and toward the fourth wall 24 in the Y direction. Specifically, the distance between the incident portion 12 and the second wall 22 in the X direction is smaller than the distance between the incident portion 12 and the first wall 21 in the X direction, and the distance between the incident portion 12 and the fourth wall 24 in the Y direction is smaller than the distance between the incident portion 12 and the third wall 23 in the X direction.

[0070] The incident portion 12 forms the connection end 2a to which the optical fiber 2 is connected. A collimator lens is provided at the connection end 2a of the optical fiber 2 to collimate the laser light L1 emitted from the optical fiber's emission end, but no isolator is provided to suppress backreflected light. The isolator is positioned midway along the optical fiber, closer to the light source 81 than the connection end 2a. This allows for miniaturization of the connection end 2a, and consequently, the incident portion 12. Alternatively, an isolator may be provided at the connection end 2a of the optical fiber 2.

[0071] The adjustment unit 13 is disposed within the housing 11. The adjustment unit 13 adjusts the laser light L1 incident from the incident unit 12. The various components of the adjustment unit 13 are attached to an optical base 29 provided within the housing 11. The optical base 29 is attached to the housing 11 and partitions the area within the housing 11 into an area on the third wall 23 side and an area on the fourth wall 24 side. The optical base 29 is integral with the housing 11. The various components of the adjustment unit 13 are attached to the optical base 29 on the fourth wall 24 side. Details of the various components of the adjustment unit 13 will be described later.

[0072] The light collecting portion 14 is arranged on the sixth wall portion 26. Specifically, the light collecting portion 14 is inserted through the hole 26a formed in the sixth wall portion 26 (see FIG. Figure 5 ) is disposed on the sixth wall portion 26. The focusing portion 14 focuses the laser light L1 adjusted by the adjustment portion 13 while emitting the laser light toward the housing 11. The focusing portion 14 is offset toward the second wall portion 22 (one wall portion) in the X direction and toward the fourth wall portion 24 in the Y direction. That is, the distance between the focusing portion 14 and the second wall portion 22 in the X direction is smaller than the distance between the focusing portion 14 and the first wall portion 21 in the X direction, and the distance between the focusing portion 14 and the fourth wall portion 24 in the Y direction is smaller than the distance between the focusing portion 14 and the third wall portion 23 in the X direction.

[0073] like Figure 5 The adjustment unit 13 includes an attenuator 31, a beam expander 32, and a reflector 33. The incident portion 12 and the attenuator 31, beam expander 32, and reflector 33 of the adjustment unit 13 are arranged on a straight line (first straight line) A1 extending in the Z direction. The attenuator 31 and beam expander 32 are arranged on straight line A1 between the incident portion 12 and the reflector 33. The attenuator 31 adjusts the output of the laser light L1 incident from the incident portion 12. The beam expander 32 increases the diameter of the laser light L1 adjusted by the attenuator 31. The reflector 33 reflects the laser light L1, which has been expanded in diameter by the beam expander 32.

[0074] The adjustment unit 13 further includes a reflective spatial light modulator 34 and an optical imaging system 35. The reflective spatial light modulator 34 and the optical imaging system 35 of the adjustment unit 13, and the focusing unit 14 are arranged on a straight line (second straight line) A2 extending along the Z direction. The reflective spatial light modulator 34 modulates the laser light L1 reflected by the reflector 33. The reflective spatial light modulator 34 is, for example, a spatial light modulator (SLM) of reflective liquid crystal (LCOS: Liquid Crystal on Silicon). The optical imaging system 35 is a telecentric optical system on both sides of which the reflection surface 34a of the reflective spatial light modulator 34 and the entrance pupil surface 14a of the focusing unit 14 are in an imaging relationship. The optical imaging system 35 is composed of three or more lenses.

[0075] The straight line A1 and the straight line A2 are located on a plane perpendicular to the Y direction. The straight line A1 is located on the second wall portion 22 side (the wall side on one side) relative to the straight line A2. In the laser processing head 10A, the laser light L1 is incident on the frame 11 from the incident portion 12, travels on the straight line A1, is reflected in sequence by the reflective mirror 33 and the reflective spatial light modulator 34, travels on the straight line A2, and is emitted from the focusing portion 14 to the outside of the frame 11. In addition, the arrangement order of the attenuator 31 and the beam expander 32 may also be reversed. In addition, the attenuator 31 may also be arranged between the reflective mirror 33 and the reflective spatial light modulator 34. In addition, the adjustment portion 13 may also have other optical components (for example, a steering mirror arranged before the beam expander 32).

[0076] The laser processing head 10A further includes a dichroic mirror 15 , a measuring unit 16 , an observation unit 17 , a driving unit 18 , and a circuit unit 19 .

[0077] The dichroic mirror 15 is disposed on the straight line A2 between the optical imaging system 35 and the focusing unit 14. Specifically, the dichroic mirror 15 is disposed within the housing 11 between the adjustment unit 13 and the focusing unit 14. The dichroic mirror 15 is mounted on the optical base 29 on the side of the fourth wall 24. The dichroic mirror 15 transmits the laser beam L1. To suppress astigmatism, the dichroic mirror 15 may be a stereoscopic mirror or a two-plate mirror disposed in a vortex relationship.

[0078] The measuring unit 16 is disposed within the housing 11 on the first wall 21 side (opposite to the one wall side) relative to the adjusting unit 13. The measuring unit 16 is attached to the optical base 29 on the fourth wall 24 side. The measuring unit 16 outputs measurement light L10 for measuring the distance between the surface of the object 100 (e.g., the surface on which the laser light L1 is incident) and the focusing unit 14. The measuring unit 16 detects the measurement light L10 reflected from the surface of the object 100 via the focusing unit 14. Specifically, the measurement light L10 output from the measuring unit 16 is the measurement light L10 that is irradiated onto the surface of the object 100 via the focusing unit 14 and then detected by the measuring unit 16 via the focusing unit 14.

[0079] More specifically, the measurement light L10 output from the measuring unit 16 is sequentially reflected by the dichroic mirror 20 and the dichroic mirror 15 mounted on the optical base 29 on the side of the fourth wall 24, and is emitted from the focusing unit 14 out of the housing 11. The measurement light L10 reflected by the surface of the object 100 is incident on the housing 11 from the focusing unit 14, and is sequentially reflected by the dichroic mirror 15 and the dichroic mirror 20, and is incident on the measuring unit 16 for detection by the measuring unit 16.

[0080] The observation unit 17 is disposed within the housing 11 on the first wall 21 side (opposite to the one wall side) relative to the adjustment unit 13. The observation unit 17 is attached to the optical base 29 on the fourth wall 24 side. The observation unit 17 outputs observation light L20 for observing the surface of the object 100 (e.g., the surface on which the laser light L1 is incident). The observation unit 17 detects the observation light L20 reflected from the surface of the object 100 via the focusing unit 14. Specifically, the observation light L20 output from the observation unit 17 is irradiated onto the surface of the object 100 via the focusing unit 14, and the observation light L20 reflected from the surface of the object 100 is detected by the observation unit 17 via the focusing unit 14.

[0081] More specifically, observation light L20 output from observation unit 17 passes through beam splitter 20, is reflected by dichroic mirror 15, and is emitted from light collecting unit 14 out of housing 11. Observation light L20 reflected from the surface of object 100 enters housing 11 from light collecting unit 14, is reflected by dichroic mirror 15, passes through beam splitter 20, enters observation unit 17, and is detected by observation unit 17. Furthermore, the wavelengths of laser light L1, measurement light L10, and observation light L20 are different from one another (at least their center wavelengths are offset from one another).

[0082] The driving unit 18 is attached to the optical base 29 on the side of the fourth wall 24. The driving unit 18 moves the light collecting unit 14 disposed on the sixth wall 26 in the Z direction using the driving force of, for example, a piezoelectric element.

[0083] The circuit section 19 is in the housing 11 and is arranged on the side of the third wall section 23 relative to the optical seat 29. That is, the circuit section 19 is in the housing 11 and is arranged on the side of the third wall section 23 relative to the adjustment section 13, the measuring section 16, and the observation section 17. The circuit section 19 is, for example, a plurality of circuit substrates. The circuit section 19 processes the signal output from the measuring section 16 and the signal input to the reflective spatial light modulator 34. The circuit section 19 controls the driving section 18 based on the signal output from the measuring section 16. As an example, the circuit section 19 controls the driving section 18 based on the signal output from the measuring section 16 so that the distance between the surface of the object 100 and the focusing section 14 is maintained constant (that is, the distance between the surface of the object 100 and the focusing point of the laser L1 is maintained constant). In addition, a connector (not shown) is provided in the housing 11 to connect the circuit section 19 to the control section 9 (see Figure 1 ) and other wiring.

[0084] The laser processing head 10B is similar to the laser processing head 10A and includes a housing 11, an incident portion 12, an adjustment portion 13, a focusing portion 14, a dichroic mirror 15, a measuring portion 16, an observation portion 17, a driving portion 18, and a circuit portion 19. However, the components of the laser processing head 10B are as follows. Figure 26. In FIG. 6, the components of the laser processing head 10A are arranged in a plane-symmetrical relationship with respect to an imaginary plane passing through the midpoint between the pair of mounting portions 65 and 66 and perpendicular to the Y direction.

[0085] For example, the frame (first frame) 11 of the laser machining head 10A is mounted on the mounting portion 65 so that the fourth wall portion 24 is located on the laser machining head 10B side relative to the third wall portion 23, and the sixth wall portion 26 is located on the support portion 7 side relative to the fifth wall portion 25. In contrast, the frame (second frame) 11 of the laser machining head 10B is mounted on the mounting portion 66 so that the fourth wall portion 24 is located on the laser machining head 10A side relative to the third wall portion 23, and the sixth wall portion 26 is located on the support portion 7 side relative to the fifth wall portion 25.

[0086] The frame 11 of the laser processing head 10B is configured to be mounted on the mounting portion 66 with the third wall portion 23 positioned on the mounting portion 66. Specifically, the mounting portion 66 comprises a base plate 66a and a mounting plate 66b. The base plate 66a is mounted on a rail provided on the movable portion 63. The mounting plate 66b is provided upright on the end of the base plate 66a on the laser processing head 10A side. The frame 11 of the laser processing head 10B is mounted on the mounting portion 66 with the third wall portion 23 in contact with the mounting plate 66b. The frame 11 of the laser processing head 10B is removable from the mounting portion 66.

[0087] [Function and Effect]

[0088] In the laser processing head 10A, the light source that outputs the laser beam L1 is not housed within the housing 11, thereby enabling a more compact housing 11. Furthermore, in the housing 11, the distance between the third wall 23 and the fourth wall 24 is smaller than the distance between the first wall 21 and the second wall 22, and the light-concentrating portion 14 disposed on the sixth wall 26 is offset toward the fourth wall 24 in the Y direction. Consequently, when the housing 11 is moved perpendicularly to the optical axis of the light-concentrating portion 14, even if another component (e.g., the laser processing head 10B) is located on the fourth wall 24 side, the light-concentrating portion 14 can be brought closer to that other component. Consequently, the laser processing head 10A can also move the light-concentrating portion 14 perpendicularly to its optical axis.

[0089] In the laser processing head 10A, the incident portion 12 is provided on the fifth wall portion 25, offset in the Y direction toward the fourth wall portion 24. This allows other components (e.g., the circuit portion 19) to be arranged in the area within the housing 11 on the third wall portion 23 side relative to the adjustment portion 13, thereby effectively utilizing this area.

[0090] Furthermore, in the laser processing head 10A, the light focusing portion 14 is offset in the X direction toward the second wall portion 22. Thus, when the housing 11 is moved in a direction perpendicular to the optical axis of the light focusing portion 14, for example, even if another structure exists on the second wall portion 22 side, the light focusing portion 14 can be brought closer to the other structure.

[0091] In the laser processing head 10A, the incident portion 12 is provided on the fifth wall portion 25, offset in the X direction toward the second wall portion 22. This allows other components (e.g., the measuring portion 16 and the observation portion 17) to be arranged in the area within the housing 11 on the first wall portion 21 side relative to the adjustment portion 13, thereby effectively utilizing this area.

[0092] Furthermore, in the laser processing head 10A, the measuring unit 16 and the observation unit 17 are located within the area within the housing 11 on the first wall 21 side relative to the adjustment unit 13. The circuit unit 19 is located within the area within the housing 11 on the third wall 23 side relative to the adjustment unit 13. The dichroic mirror 15 is located within the housing 11 between the adjustment unit 13 and the focusing unit 14. This allows for efficient utilization of the area within the housing 11. Furthermore, the laser processing apparatus 1 can perform processing based on the measurement results of the distance between the surface of the object 100 and the focusing unit 14. Furthermore, the laser processing apparatus 1 can perform processing based on the observation results of the surface of the object 100.

[0093] In the laser processing head 10A, the circuit unit 19 controls the driving unit 18 based on the signal output from the measuring unit 16. This allows the position of the focal point of the laser beam L1 to be adjusted based on the distance measurement result between the surface of the object 100 and the focusing unit 14.

[0094] Furthermore, in the laser processing head 10A, the incident portion 12 and the attenuator 31, beam expander 32, and reflector 33 of the adjustment portion 13 are arranged on a straight line A1 extending in the Z direction. The reflective spatial light modulator 34, optical imaging system 35, and light focusing portion 14 of the adjustment portion 13 are also arranged on a straight line A2 extending in the Z direction. This allows for a compact adjustment portion 13 including the attenuator 31, beam expander 32, reflective spatial light modulator 34, and optical imaging system 35.

[0095] Furthermore, in the laser processing head 10A, the straight line A1 is located on the second wall portion 22 side relative to the straight line A2. Consequently, when configuring other optical systems (e.g., the measuring unit 16 and the observing unit 17) using the focusing unit 14 in the region within the housing 11 on the first wall portion 21 side relative to the adjusting unit 13, the degree of freedom in configuring the other optical systems can be increased.

[0096] The above-mentioned functions and effects can also be achieved by the laser processing head 10B.

[0097] Furthermore, in the laser processing apparatus 1, the light focusing section 14 of the laser processing head 10A is located on the side of the housing 11 of the laser processing head 10A that is offset toward the laser processing head 10B, while the light focusing section 14 of the laser processing head 10B is located on the side of the housing 11 of the laser processing head 10B that is offset toward the laser processing head 10A. Consequently, when the pair of laser processing heads 10A and 10B are moved in the Y direction, the light focusing section 14 of the laser processing head 10A and the light focusing section 14 of the laser processing head 10B can be brought closer to each other. Consequently, the laser processing apparatus 1 can efficiently process the object 100.

[0098] Furthermore, in the laser processing apparatus 1 , the pair of mounting portions 65 and 66 are movable in the Y direction and the Z direction, respectively.

[0099] Furthermore, in the laser processing apparatus 1 , the support portion 7 moves in the X and Y directions and rotates about an axis parallel to the Z direction. Therefore, the object 100 can be processed more efficiently.

[0100] [Modification]

[0101] For example, Figure 6 The incident section 12, adjustment section 13, and focusing section 14 can also be arranged on a straight line A extending along the Z direction. This allows the adjustment section 13 to be miniaturized. In this case, the adjustment section 13 does not need to include the reflective spatial light modulator 34 and the optical imaging system 35. Furthermore, the adjustment section 13 can include the attenuator 31 and the beam expander 32. This allows the adjustment section 13, which includes the attenuator 31 and the beam expander 32, to be miniaturized. Furthermore, the order of the attenuator 31 and the beam expander 32 can be reversed.

[0102] Furthermore, the frame 11 can be mounted on the mounting portion 65 (or mounting portion 66) of the laser processing apparatus 1 with at least one of the first wall portion 21, the second wall portion 22, the third wall portion 23, and the fifth wall portion 25 positioned on the mounting portion 65 (or mounting portion 66) side. Furthermore, the focusing portion 14 can be positioned at least in the Y direction toward the fourth wall portion 24. With these configurations, when the frame 11 is moved in the Y direction, for example, even if there are other structures on the fourth wall portion 24 side, the focusing portion 14 can be brought closer to these other structures. Furthermore, when the frame 11 is moved in the Z direction, for example, the focusing portion 14 can be brought closer to the object 100.

[0103] Furthermore, the light-collecting portion 14 can be offset toward the first wall 21 in the X direction. This allows the light-collecting portion 14 to be positioned closer to other components, even if other components are located on the first wall 21 side, when the housing 11 is moved perpendicular to the optical axis of the light-collecting portion 14. In this case, the incident portion 12 can also be offset toward the first wall 21 in the X direction. This allows for efficient utilization of the area within the housing 11 by arranging other components (e.g., the measurement portion 16 and the observation portion 17), such as in the area on the second wall 22 side relative to the adjustment portion 13.

[0104] In addition, at least one of guiding the laser light L1 from the emission portion 81a of the light source unit 8 toward the incident portion 12 of the laser processing head 10A and guiding the laser light L2 from the emission portion 82a of the light source unit 8 toward the incident portion 12 of the laser processing head 10B may be implemented by a reflecting mirror. Figure 7 This is a front view of a portion of the laser processing device 1 in which the laser beam L1 is guided by a reflecting mirror. Figure 7 In the illustrated configuration, the reflecting mirror 3 that reflects the laser light L1 is mounted on the moving portion 63 of the moving mechanism 6 so as to face the emitting portion 81a of the light source unit 8 in the Y direction and the incident portion 12 of the laser machining head 10A in the Z direction.

[0105] Figure 7 In the illustrated configuration, even when the moving portion 63 of the moving mechanism 6 moves in the Y direction, the reflector 3 is maintained facing the emission portion 81a of the light source unit 8 in the Y direction. Furthermore, even when the mounting portion 65 of the moving mechanism 6 moves in the Z direction, the reflector 3 is maintained facing the incident portion 12 of the laser processing head 10A in the Z direction. Therefore, regardless of the position of the laser processing head 10A, the laser light L1 emitted from the emission portion 81a of the light source unit 8 can be reliably directed to the incident portion 12 of the laser processing head 10A. Furthermore, light sources such as high-output long and short pulse lasers, which are difficult to guide using the optical fiber 2, can also be used.

[0106] Figure 7 In the illustrated configuration, the reflector 3 may be mounted on the movable portion 63 of the movable mechanism 6 to enable at least one of angle adjustment and position adjustment. This allows the laser light L1 emitted from the emission portion 81a of the light source unit 8 to be more reliably directed to the incident portion 12 of the laser processing head 10A.

[0107] Alternatively, the light source unit 8 may include a single light source. In this case, the light source 8 may be configured to emit a portion of the laser light outputted from the single light source from the emission portion 81 a and the remainder of the laser light from the emission portion 82 b .

[0108] Alternatively, the laser processing device 1 may include a single laser processing head 10A. In a laser processing device 1 including a single laser processing head 10A, even when the housing 11 moves in the Y direction perpendicular to the optical axis of the light-focusing unit 14, the light-focusing unit 14 can still approach other structures, for example, even if these other structures are located on the fourth wall 24 side. Therefore, a laser processing device 1 including a single laser processing head 10A can still efficiently process the object 100. Furthermore, in a laser device 1 including a single laser processing head 10A, if the mounting portion 65 moves in the Z direction, the object 100 can be processed even more efficiently. Furthermore, in a laser device 1 including a single laser processing head 10A, if the support portion 7 moves in the X direction and rotates about an axis parallel to the Z direction, the object 100 can be processed even more efficiently.

[0109] Furthermore, the laser processing apparatus 1 may include three or more laser processing heads. Figure 8 It is a perspective view showing a laser processing apparatus 1 including two pairs of laser processing heads. Figure 8 The laser processing apparatus 1 shown includes a plurality of moving mechanisms 200 , 300 , and 400 , a support portion 7 , a pair of laser processing heads 10A and 10B, a pair of laser processing heads 10C and 10D, and a light source (not shown).

[0110] The moving mechanism 200 moves the support portion 7 in the X direction, the Y direction, and the Z direction, and rotates the support portion 7 about an axis parallel to the Z direction as a center line.

[0111] The moving mechanism 300 comprises a fixed portion 301 and a pair of mounting portions (a first mounting portion and a second mounting portion) 305 and 306. The fixed portion 301 is mounted on the device frame (not shown). The pair of mounting portions 305 and 306 are each mounted on a rail provided on the fixed portion 301 and are independently movable in the Y direction.

[0112] The moving mechanism 400 comprises a fixed portion 401 and a pair of mounting portions (a first mounting portion and a second mounting portion) 405 and 406. The fixed portion 401 is mounted to the device frame (not shown). The mounting portions 405 and 406 are each mounted on a track provided on the fixed portion 401, and are independently movable in the X direction. Furthermore, the track of the fixed portion 401 is arranged to intersect with the track of the fixed portion 301 in a three-dimensional manner.

[0113] The laser processing head 10A is mounted on the mounting portion 305 of the moving mechanism 300. The laser processing head 10A irradiates the object 100 supported by the support portion 7 with laser light, while facing the support portion 7 in the Z direction. The laser light emitted from the laser processing head 10A is guided from the light source unit (not shown) by the optical fiber 2. The laser processing head 10B is mounted on the mounting portion 306 of the moving mechanism 300. The laser processing head 10B irradiates the object 100 supported by the support portion 7 with laser light, while facing the support portion 7 in the Z direction. The laser light emitted from the laser processing head 10B is guided from the light source unit (not shown) by the optical fiber 2.

[0114] The laser processing head 10C is mounted on the mounting portion 405 of the moving mechanism 400. The laser processing head 10C irradiates the object 100 supported by the support portion 7 with laser light, while facing the support portion 7 in the Z direction. The laser light emitted from the laser processing head 10C is guided from the light source unit (not shown) by the optical fiber 2. The laser processing head 10D is mounted on the mounting portion 406 of the moving mechanism 400. The laser processing head 10D irradiates the object 100 supported by the support portion 7 with laser light, while facing the support portion 7 in the Z direction. The laser light emitted from the laser processing head 10D is guided from the light source unit (not shown) by the optical fiber 2.

[0115] Figure 8 The structure of a pair of laser processing heads 10A and 10B of the laser processing apparatus 1 shown is similar to Figure 1 The pair of laser processing heads 10A and 10B of the laser processing apparatus 1 shown have the same configuration. Figure 8 The structure of a pair of laser processing heads 10C and 10D of the laser processing apparatus 1 shown is the same as Figure 1 The pair of laser machining heads 10A and 10B of the laser machining apparatus 1 shown in FIG. 1 are rotated 90° about an axis parallel to the Z direction. The configurations of the pair of laser machining heads 10A and 10B are the same.

[0116] For example, the housing (first housing) 11 of the laser machining head 10C is mounted on the mounting portion 65 so that the fourth wall 24 is located on the laser machining head 10D side relative to the third wall 23 and the sixth wall 26 is located on the support portion 7 side relative to the fifth wall 25. The focusing portion 14 of the laser machining head 10C is offset in the Y direction toward the fourth wall 24 (i.e., toward the laser machining head 10D).

[0117] The housing (second housing) 11 of the laser machining head 10D is mounted on the mounting portion 66 so that the fourth wall 24 is located on the laser machining head 10C side relative to the third wall 23 and the sixth wall 26 is located on the support portion 7 side relative to the fifth wall 25. The focusing portion 14 of the laser machining head 10D is offset in the Y direction toward the fourth wall 24 (i.e., toward the laser machining head 10C).

[0118] According to the above description, Figure 8 In the laser processing apparatus 1 shown, by moving the pair of laser processing heads 10A and 10B in the Y direction, the light focusing section 14 of the laser processing head 10A and the light focusing section 14 of the laser processing head 10B can be brought closer to each other. Furthermore, by moving the pair of laser processing heads 10C and 10D in the X direction, the light focusing section 14 of the laser processing head 10C and the light focusing section 14 of the laser processing head 10D can be brought closer to each other.

[0119] Furthermore, the laser processing head and the laser processing device are not limited to forming a modified region inside the object 100, but can also be used to perform other laser processing.

[0120] Hereinafter, descriptions overlapping with the above-mentioned embodiments will be omitted.

[0121] Figure 9 The laser processing apparatus 101 shown here is a device that aligns a focusing position (at least a portion of the focusing area, the focusing point) with an object 100 and irradiates the object 100 with a laser beam, thereby forming a modified region on the object 100. The laser processing apparatus 101 performs edge trimming, radial cutting, and lift-off processes on the object 100 to obtain (manufacture) a semiconductor device. Edge trimming is a process used to remove unwanted portions from the object 100. Radial cutting is a process used to separate the unwanted portions removed by edge trimming. Lift-off is a process used to remove portions of the object 100.

[0122] The object 100 is, for example, a semiconductor wafer formed into a circular plate shape. The object is not particularly limited and can be formed from a variety of materials and have a variety of shapes. Functional elements (not shown) are formed on the surface 100a of the object 100. These functional elements include, for example, light-receiving elements such as photodiodes, light-emitting elements such as laser diodes, and circuit elements such as memory.

[0123] like Figure 10 (a) and Figure 10 (b) shows that an effective area R and a removal area E are set in the object 100. The effective area R is a portion corresponding to the obtained semiconductor device. The effective area R is a device area. For example, the effective area R is a disk-shaped portion including the central portion of the object 100 as viewed from the thickness direction. The effective area R is an inner area further inside than the removal area E. The removal area E is an area further outside than the effective area R in the object 100. The removal area E is an outer edge portion of the object 100 other than the effective area R. For example, the removal area E is an annular portion surrounding the effective area R. The removal area E is a peripheral portion (the inclined portion of the outer edge) including the object 100 as viewed from the thickness direction. The removal area E is a radial cutting area that becomes the object of radial cutting processing.

[0124] A virtual surface M1 is set on the object 100 as a predetermined peeling surface. The virtual surface M1 is a surface where a modified area is to be formed by the peeling process. The virtual surface M1 is a surface opposite to the back surface 100b of the laser incident surface of the object 100. The virtual surface M1 is a surface parallel to the back surface 100b, for example, in a circular shape. The virtual surface M1 is a hypothetical area and is not limited to a plane. It can also be a curved surface or even a three-dimensional surface. The setting of the effective area R, the removal area E and the virtual surface M1 can be performed in the control unit 9. The effective area R, the removal area E and the virtual surface M1 can also be specified by coordinates.

[0125] In the object 100, a line (annular line) M2 is set as a predetermined line for trimming. The line M2 is a line that is predetermined to form a modified area by trimming. The line M2 extends in a ring shape inside the outer edge of the object 100. Here, the line M2 extends in a circular ring shape. The line M2 is set at the boundary between the effective area R and the removal area E in the part of the interior of the object 100 that is on the opposite side of the laser incident surface than the imaginary surface M1. The setting of the line M2 can be performed in the control unit 9. Although the line M2 is a hypothetical line, it can also be an actually drawn line. The line M2 can also be specified by coordinates. The description related to the setting of the line M2 is the same as that of the lines M3 to M4 described later.

[0126] Object 100 is defined with a line (linear line) M3 serving as a planned radial cutting line. Line M3 is the line along which the modified region is to be formed by radial cutting. Line M3 extends linearly (radially) along the radial direction of object 100 as viewed from the laser incident surface. Line M3 divides removal region E into a plurality of equal (in this case, four) sections in the circumferential direction as viewed from the laser incident surface. In the illustrated example, line M3 includes lines M3a and M3b extending in one direction, and lines M3c and M3d extending in another direction orthogonal to the one direction, as viewed from the laser incident surface.

[0127] like Figure 9 The laser processing device 101 includes a stage 107, a laser processing head 10A, a first Z-axis rail 106A, a Y-axis rail 108, a photographing unit 110, a GUI (Graphical User Interface) 111, and a control unit 9. The stage 107 is a support unit that supports the object 100. The stage 107 is connected to the support unit 7 (see FIG. Figure 1) is similarly constructed. The object 100 is placed on the supporting surface 107a of the stage 107, with the back surface 100b of the object 100 being the upper side of the laser incident surface (the surface 100a being the lower side of the stage 107). The stage 107 has a rotation axis C set at its center. The rotation axis C is an axis extending in the Z direction along the optical axis direction of the focusing section 14. The stage 107 is rotatable around the rotation axis C. The stage 107 is rotationally driven by the driving force of a well-known driving device such as a motor.

[0128] The laser processing head 10A irradiates the object 100 placed on the stage 107 with a laser beam L1 in the Z direction via the focusing unit 14 (see FIG. Figure 11 (a)) forms a modified region within the object 100. The laser processing head 10A is mounted on the first Z-axis track 106A and the Y-axis track 108. The laser processing head 10A can be linearly moved in the Z direction along the first Z-axis track 106A by the driving force of a known drive device such as a motor. The laser processing head 10A can be linearly moved in the Y direction along the Y-axis track 108 by the driving force of a known drive device such as a motor. The laser processing head 10A constitutes the irradiation unit. The focusing unit 14 includes a focusing lens.

[0129] The laser processing head 10A includes a reflective spatial light modulator 34 and a distance measuring sensor 36. The reflective spatial light modulator 34 forms a shaping unit that shapes the shape of the focused spot (hereinafter also referred to as "beam shape") within a plane perpendicular to the optical axis of the laser light L1. The reflective spatial light modulator 34 shapes the laser light L1 so that the beam shape has a longitudinal direction. For example, the reflective spatial light modulator 34 displays a modulation pattern with an elliptical beam shape on the liquid crystal layer, thereby shaping the beam into an elliptical shape.

[0130] The distance measuring sensor 36 emits a distance measuring laser toward the laser incident surface of the object 100, detects the distance measuring light reflected by the laser incident surface, and obtains displacement data of the laser incident surface of the object 100. As the distance measuring sensor 36, in the case of a sensor not coaxial with the laser L1, a sensor of a triangulation distance measuring method, a laser confocal method, a white confocal method, a spectroscopic interference method, an astigmatism method, etc. can be used. As the distance measuring sensor 36, in the case of a sensor coaxial with the laser L1, a sensor of an astigmatism method, etc. can be used. The circuit unit 19 of the laser processing head 10A (see Figure 3 ) Based on the displacement data acquired by the distance measuring sensor 36, the driving unit 18 drives the focusing unit 14 to follow the laser incident surface. Thus, the focusing unit 14 is moved in the Z direction based on the displacement data to maintain a constant distance between the laser incident surface of the object 100 and the focal point of the laser beam L1. The distance measuring sensor 36 and its control (hereinafter referred to as "following control") described above are similar to those in other laser processing heads.

[0131] The 1st Z-axis rail 106A is a rail extending along the Z direction. The 1st Z-axis rail 106A is mounted on the laser processing head 10A via the mounting portion 65. The 1st Z-axis rail 106A moves the laser processing head 10A along the Z direction in such a manner that the focusing position of the laser L1 moves along the Z direction (the direction intersecting the imaginary plane M1). The Y-axis rail 108 is a rail extending along the Y direction. The Y-axis rail 108 is mounted on the 1st Z-axis rail 106A. The Y-axis rail 108 moves the laser processing head 10A along the Y direction in such a manner that the focusing position of the laser L1 moves along the Y direction (the direction along the imaginary plane M1). The 1st Z-axis 106A and the Y-axis rail 108 correspond to the above-mentioned moving mechanism 6 (see Figure 1 ) or the above-mentioned moving mechanism 300 (see Figure 8 ). The first Z-axis track 106A and the Y-axis track 108 move at least one of the stage 107 and the laser processing head 10A so that the focusing position of the laser beam L1 is moved by the focusing unit 14. Hereinafter, the focusing position of the laser beam L1 by the focusing unit 14 may be simply referred to as the "focusing position."

[0132] The imaging unit 110 captures the object 100 from a direction parallel to the incident direction of the laser beam L1. The imaging unit 110 includes an alignment camera AC and an imaging unit IR. The alignment camera AC and imaging unit IR are mounted on the mounting portion 65 together with the laser processing head 10A. The alignment camera AC captures, for example, a device pattern using light that penetrates the object 100. The resulting image is used to align the irradiation position of the laser beam L1 on the object 100.

[0133] The imaging unit 1R photographs the object 100 using light that penetrates the object 100. For example, if the object 100 is a silicon wafer, the imaging unit 1R uses light in the near-infrared region. The imaging unit 1R includes a light source, an objective lens, and a light detection unit. The light source outputs penetrating light toward the object 100. The light source is composed of, for example, a halogen lamp and a filter, and outputs, for example, light in the near-infrared region. The light output from the light source is guided by an optical system such as a reflector and passes through the objective lens to illuminate the object 100. The objective lens allows light reflected from the surface opposite to the laser incident surface of the object 100 to pass through. In other words, the objective lens 100 allows light that is transmitted (penetrated) by the object to pass through. The objective lens includes a correction ring. The correction ring corrects aberrations caused by light in the object 100 by, for example, adjusting the distance between the multiple lenses that constitute the objective lens. The light detection unit detects light that has passed through the objective lens. The light detection unit is composed of, for example, an InGaAs camera and detects light in the near-infrared region. The imaging unit 1R can capture at least one of a modified region formed inside the object 100 and a crack extending from the modified region. In the laser processing apparatus 101, the imaging unit IR can be used to non-destructively check the processing status of the laser processing.

[0134] The GUI 111 displays various information. The GUI 111 includes, for example, a touch panel display. Various settings related to processing conditions are input to the GUI 111 by a user's touch operation or the like. The GUI 111 constitutes an input unit that receives input from the user.

[0135] The control unit 9 is a computer device composed of a processor, memory, storage, and a communication device. The processor executes software (programs) stored in the memory, reading and writing data from and to the memory. Furthermore, the processor controls communications with the communication device. The control unit 9 controls various components of the laser processing apparatus 101 to achieve various functions.

[0136] The control unit 9 controls at least: the stage 107, the laser processing head 10A and the above-mentioned moving mechanism 6 (see Figure 1 ) or the above-mentioned moving mechanism 300 (see Figure 1 The control unit 9 controls: the rotation of the stage 107; the irradiation of the laser beam L1 from the laser processing head 10A; and the movement of the focal position of the laser beam L1. The control unit 9 can perform various controls based on rotation information related to the rotation amount of the stage 107 (hereinafter also referred to as "θ information"). The θ information can also be obtained from the drive amount of the driving device of the rotating stage 107, or can be obtained from another sensor, etc. The θ information can be obtained by various well-known methods.

[0137] The control unit 9 controls the start and stop of irradiation of the laser light L1 by the laser processing head 10A based on the θ information while rotating the stage 107 and positioning the focusing position on the line M2 (the periphery of the effective region R) of the object 100, thereby performing edge straightening processing to form a modified region along the periphery of the effective region R. The edge straightening processing is a process performed by the control unit 9 to realize the edge straightening processing.

[0138] The control unit 9 controls the start and stop of irradiation of the laser light L1 by the laser processing head 10A, while the stage 107 is not rotated and the focusing position is positioned on the line M3 of the object 100, thereby moving the focusing position of the laser light L1 along the line M3. This performs a radial milling process to form a modified area in the removal area E along the line M3. The radial milling process is a process performed by the control unit 9 to realize the radial milling process.

[0139] The control unit 9 rotates the stage 107 while irradiating the laser processing head 10A with laser light L1 and controlling the Y-direction movement of the focusing position, thereby executing a peeling process to form a modified region along the imaginary surface M1 within the object 100. The peeling process is performed by the control unit 9 to implement the peeling process. The control unit 9 controls the display of the GUI 111. Edge straightening, radial cutting, and peeling processes are executed based on various settings input through the GUI 111.

[0140] The switching between the formation and stop of the modified region can be achieved as follows. For example, in the laser processing head 10A, the start and stop (ON / OFF) of the irradiation (output) of the laser L1 can be switched to switch the formation of the modified region and the stop of the formation. Specifically, when the laser oscillator is composed of a solid laser, the Q switch (AOM (acousto-optic modulator), EMO (electro-optic modulator), etc.) provided in the resonator is switched ON / OFF, thereby switching the start and stop of the irradiation of the laser L1 at high speed. When the laser oscillator is composed of a fiber laser, the output of the semiconductor laser constituting the seed source laser and the amplification (excitation) laser is switched ON / OFF, thereby switching the start and stop of the irradiation of the laser L1 at high speed. When the laser oscillator uses an external modulation element, the external modulation element (AOM, EOM, etc.) provided outside the resonator is switched ON / OFF, thereby switching the irradiation of the laser L1 at high speed.

[0141] Alternatively, switching between the formation of the modified region and its cessation can be achieved as follows. For example, the optical path of the laser light L1 can be switched by a mechanical mechanism such as a shutter, thereby switching between the formation of the modified region and the cessation of such formation. The laser light L1 can also be switched to CW light (continuous wave) to stop the formation of the modified region. The liquid crystal layer of the reflective spatial light modulator 34 can also be displayed with a pattern that shows the focused state of the laser light L1 as a state that cannot be modified (for example, a pattern resembling pearskin that scatters the laser light) to stop the formation of the modified region. The output adjustment unit such as an attenuator can also be controlled to reduce the output of the laser light L1 so that the modified region cannot be formed, thereby stopping the formation of the modified region. The polarization direction can also be switched to stop the formation of the modified region. The scattering (emission) of the laser light L1 in directions other than the optical axis can also be blocked to stop the formation of the modified region.

[0142] Next, an example of a laser processing method for obtaining (manufacturing) a semiconductor device by performing edge trimming, radial cutting, and lift-off processing on the object 100 using the laser processing apparatus 101 will be described below.

[0143] First, the object 100 is placed on the stage 107 with the back surface 100b facing the laser incident surface. The surface 100a of the object 100 where the functional element is mounted is protected by bonding a supporting substrate or a tape member.

[0144] Next, the edge trimming process is performed. The edge trimming process is performed by the control unit 9 (the first process). The edge trimming process includes the edge trimming process (the first process). Specifically, the edge trimming process is as follows Figure 11 (a) shows that the laser processing head 10A starts and stops irradiating the laser L1 in accordance with the θ information while rotating the stage 107 at a constant rotation speed so that the focusing position P1 is positioned on the line M2. Figure 11 (b) and Figure 11 (c) shows that a modified region 4 is formed along the line M2. The formed modified region 4 includes modified points and cracks extending from the modified points.

[0145] Next, radial cutting is performed. The radial cutting is performed by the control unit 9 (second process). The radial cutting includes a radial cutting step (second process). Specifically, the radial cutting is performed as follows Figure 11 (b) and Figure 12(a) shows that the laser processing head 10A irradiates the laser beam L1 without rotating the stage 107, and the laser processing head 10A is moved along the Y-axis track 108 so that the focusing position P1 moves along the lines M3a and M3b. After the stage 107 is rotated 90 degrees, the laser processing head 10A irradiates the laser beam L1 without rotating the stage 107, and the laser processing head 10A is moved along the Y-axis track 108 so that the focusing position P1 moves along the lines M3c and M3d. As a result, Figure 12 (b) shows that a modified region 4 is formed along line M3. The formed modified region 4 includes a modified point and a crack extending from the modified point. This crack may or may not reach at least one of the surface 100a and the back surface 100b. Figure 13 (a) and Figure 13 (b) shows that the removal area E is cut and removed (eliminated) with the modified area 4 as the boundary, for example, using a tool or air.

[0146] Next, the peeling process is performed. Specifically, Figure 13 (c) shows that while rotating the stage 107 at a constant speed, the laser processing head 10A irradiates the laser L1, and the laser processing head 10A moves along the Y-axis track 108, so that the focusing position P1 moves from the outer edge side of the imaginary surface M1 to the inner side along the Y direction. Figure 13 (a) and Figure 13 (b) shows that a rotation axis C (see FIG. Figure 9 ) is a modified region 4 extending in a spiral shape (involute curve) at the center. The formed modified region 4 includes multiple modified points.

[0147] Then, if Figure 14 (c) indicates that a portion of the object 100 is peeled off, for example, by an adsorption tool, with the modified region 4 across the imaginary surface M1 as the boundary. The peeling of the object 100 can also be carried out on the carrier 107, or it can be moved to a dedicated peeling area. The object 100 can also be peeled off by air jet or tape member. In the case where the object 100 cannot be peeled off by external stress alone, the modified region 4 can also be selectively etched by an etching solution (KOH or TMAH, etc.) that reacts with the object 100. In this way, the object 100 can be easily peeled off. As shown in FIG. Figure 14 (d) shows that the peeling surface 100h of the object 100 is polished by finishing grinding or grinding with a grinding material KM such as a grinding wheel. When the object 100 is peeled by etching, these grinding operations can be simplified. As a result, a semiconductor device 100K is obtained.

[0148] Next, the peeling process will be described.

[0149] In the laser processing apparatus 101 and the laser processing method implemented thereby, a portion of the focusing region is focused on the object 100 and irradiated with laser light, thereby forming a modified region 4 along the imaginary plane M1 within the object 100. As described above, the laser processing apparatus 101 includes a reflective spatial light modulator 34 as a shaping unit for shaping the laser light L1 so that the beam shape has a longitudinal direction.

[0150] like Figure 15 and Figure 16 (a) shows that the beam shape 71 formed by the reflective spatial light modulator 34 is an ellipse. The beam shape 71 has an ellipticity of 0.88 to 0.95. The ellipticity is the ratio of the length of the long side of the beam shape 71 to the length of the short side. Furthermore, the beam shape 71 is not limited to an ellipse; it can be an elongated strip. The beam shape can also be a flat circle, an oblong circle, or a racetrack. The beam shape can also be an elongated triangle, a rectangle, or a polygon. For example, the beam shape 71 can also be a shape with a notch in a portion of an ellipse (see 16(b)). The modulation pattern of the reflective spatial light modulator 34 that realizes such a beam shape 71 can also include at least one of a slit pattern and a non-point pattern. In the case where the laser light L1 has multiple focal points due to astigmatism, the focal point on the most upstream side of the optical path of the laser light L1 can also have the beam shape 71 of this embodiment. The long side direction here refers to the long axis direction of the ellipse associated with the beam shape 71, also referred to as the long axis direction of the ellipse.

[0151] The elliptical beam shape 71 only needs to be a portion of the focusing area (the area where light is focused). The beam intensity distribution within the plane of the beam shape 71 is a distribution with strong intensity in the longitudinal direction, and the direction of strong beam intensity is consistent with the longitudinal direction. By adjusting the modulation pattern of the reflective spatial light modulator 34, the position of the beam shape 71 in the Z direction can be controlled as desired. The shaping unit is not limited to the reflective spatial light modulator 34, and can also be a slit optical system (including mechanical slits, etc.) or an astigmatism optical system (including cylindrical lenses, etc.).

[0152] The longitudinal direction of beam shape 71 is tilted at least 45° relative to the processing direction. The processing direction is the direction in which a portion of the focusing area of ​​laser light L1 moves. The processing direction is the direction in which line M4, described below, extends. Hereinafter, the angle at which the longitudinal direction of beam shape 71 is tilted relative to the processing direction is referred to as the "beam rotation angle." In this embodiment, the longitudinal direction of beam shape 71 is perpendicular to the processing direction. In other words, the beam rotation angle is 90°.

[0153] The control unit 9 controls the reflective spatial light modulator 34 to shape the laser light L1 into a beam having the aforementioned longitudinal direction. The control unit 9 relatively moves the focal point along a line (processing line) M4 that spirally extends inward from the periphery of the object 100, thereby forming a modified region 4 within the object 100. The line M4 represents the effective region R defined on the imaginary plane M1. The line M4 spirally extends from the center of the object 100.

[0154] The GUI 111 can receive input from the user of at least one of information regarding the beam shape 71, information regarding the beam rotation angle, and information regarding the settings of the reflective spatial light modulator 34. The control unit 9 controls various operations of the laser processing apparatus 101 based on the inputs from the GUI 111.

[0155] During the peeling process, first, the stage 107 is rotated at a constant rotation speed. The laser processing head 10A irradiates the laser L1 (irradiation process). At the same time, the laser processing head 10A is moved along the Y-axis track 108 so that the focal point of the laser L1 moves from the outer edge side of the imaginary surface M1 to the inner side along the Y direction (movement process). As a result, the focal point of the laser L1 is relatively moved along the line M4. Here, the photographic process is to control the reflective spatial light modulator 34 by the control unit 9 to shape the laser L1 so that the beam shape 71 has a long side direction in which the rotation angle of the beam 1 becomes 90° (forming process). As described above, a modified area 4 is formed along the line M4 on the imaginary surface M1 inside the object 100.

[0156] Figure 17 (a) is a diagram for explaining the results of lift-off processing in a comparative example using a laser beam having a circular beam shape. Figure 17 (b) is a diagram illustrating the results of the lift-off processing according to the present embodiment using the laser light L1 having an elliptical beam shape 71 with a beam rotation angle of 90°. Figure 17 (a) and Figure 17 (b) is a cross-sectional view taken along the imaginary plane M1. The processing index direction is a direction perpendicular to the extending direction of the line M4 as viewed from the laser incident surface. The processing index direction here is the direction from the periphery of the object 100 toward the inside in the Y direction.

[0157] The peeling process results of the comparative example can form a circular modified point S1 with less energy, but Figure 17(a) shows that the crack C1 extending from the modified point S1 along the imaginary plane M1 is difficult to connect. On the other hand, it can be seen that in this embodiment, an elliptical modified point S2 corresponding to the beam shape 71 is formed, and the crack C2 extending from the modified point S2 along the imaginary plane M1 is easily extended in the direction of the long side of the modified point S2 corresponding to the long side of the beam shape 71. Because this long side direction intersects the processing direction, the crack C2 is easily extended in the direction intersecting the processing direction, which promotes the development of the crack along the imaginary plane M1.

[0158] Therefore, according to this embodiment, even if the intervals between the modified points S2 (intervals between the lines M4) in a direction intersecting the machining direction (here, the machining index direction) are wide, the cracks C2 along the imaginary surface M1 can still be sufficiently advanced. As a result, when the modified region 4 is formed along the imaginary surface M1 within the object 100, the smoothness can be improved.

[0159] The following first peeling processing result (see Table 1) is the result of the peeling processing related to the first comparative example and the first embodiment. The first comparative example and the first embodiment use the following conditions as common processing conditions. That is, the laser L1 is branched into two, and the branch distance X is set to 100μm and the branch distance Y is set to 60μm. The branch distance X is the distance in the processing direction of the two beam shapes 71 formed by branching the laser L1 into two, and the branch distance Y is the distance in the processing index direction for the two beam shapes 71 (see Figure 18 Laser L1 has an output of 3.7 W, a pulse energy (calculated using a 20% loss in branching) of 18.5 μJ, a pulse spacing of 6.25 μm, a frequency of 80 kHz, and a pulse width of 700 ns. Object 100 is a wafer having a principal surface with a

[100] orientation. The 0° direction of object 100 corresponds to the 110 plane.

[0160] [Result of the first peeling process]

[0161] [Table 1]

[0162]

[0163] The SFC state represents a fully sliced ​​state. This state is a state in which cracks extending from multiple modified points within the modified region 4 formed along the imaginary plane M1 extend along the imaginary plane M1 and are connected to one another. This state allows the cracks extending from the modified points to extend horizontally, vertically, and vertically in the image obtained by the imaging unit 110, connecting across line M4. This state is a state in which no modified points can be identified in the image obtained by the imaging unit 110 (in which spaces or gaps formed by the cracks are identified).

[0164] According to the above-mentioned first peeling processing result, the beam shape 71 is set to a shape with a long side direction, and the long side direction is set to a direction intersecting the processing direction (for example, the beam shape 71 is set to an elliptical shape, and the beam rotation angle is 90°). Compared with the circular shape, the beam shape 71 can be seen that the cracks are likely to extend in the direction intersecting the processing direction, thereby promoting the progress of the cracks along the imaginary surface M1.

[0165] Figure 19 (a) is a diagram showing the relationship between ellipticity and beam shape 71. Figure 19 (b) is a graph showing the ellipticity and beam rotation angle and the rate of occurrence of the fully cut state of the slice. The "-" in the graph means that it cannot be measured. Figure 19 (a) and Figure 19 (b) shows that when the ellipticity of beam shape 71 is less than 0.88, the probability of fully sliced ​​cutting is extremely low. For example, when the ellipticity of beam shape 71 is 0.59, the probability of fully sliced ​​cutting is 0%. When the ellipticity of beam shape 71 is greater than 0.95, the probability of fully sliced ​​cutting is extremely low. For example, when the ellipticity of beam shape 71 is 1 (a perfect circle), the probability of fully sliced ​​cutting is 40%.

[0166] Therefore, in this embodiment, the shape of a portion of the focusing area has an ellipticity of 0.88 to 0.95. This further promotes the development of cracks along the imaginary plane M1. This makes it easier for cracks to extend along the longitudinal direction of the beam shape 71, thereby increasing the probability of achieving a fully cut state in the slice.

[0167] In addition, if Figure 19 (b) shows that when the beam rotation angle of the elliptical beam shape 71 is 0°, the generation rate of the slice fully cut state is extremely low. When the beam rotation angle of the elliptical beam shape 71 is 90°, the generation rate of the slice fully cut state is improved. In addition, when the beam rotation angle of the elliptical beam shape 71 is 0°, the long side direction of the beam shape 71 is along the processing direction (see Figure 20 ).

[0168] The following second peeling processing result (see Table 2) is the peeling processing result when the beam rotation angle is changed. The common processing conditions for the second peeling processing result are the same as those for the first peeling processing result except that the pulse interval is 10 μm. The ellipticity is 0.95. In addition, in the second peeling processing result, for example, when the beam rotation angle of the elliptical beam shape 71 is 60°, the long side direction of the beam shape 71 may be tilted at an angle of 60° relative to the processing direction (see Table 2). Figure 21 ).

[0169] [Result of the second peeling process]

[0170] [Table 2]

[0171]

[0172] The above-mentioned second peeling process results show that setting the beam rotation angle to 45° or greater facilitates the propagation of cracks in a direction intersecting the processing direction, further promoting the development of cracks along the imaginary plane M1. Furthermore, setting the beam rotation angle to 90° further facilitates the propagation of cracks in a direction intersecting the processing direction, further promoting the development of cracks along the imaginary plane M1.

[0173] Therefore, in this embodiment, the longitudinal direction of the beam shape 71 is tilted at least 45° relative to the machining direction. This further promotes the development of cracks along the imaginary surface M1. In this embodiment, the longitudinal direction of the beam shape 71 is perpendicular to the machining direction. This further promotes the development of cracks along the imaginary surface M1.

[0174] The following third lift-off result (see Tables 3 and 4) shows the lift-off process results when the pulse spacing was varied. The common processing conditions for the third lift-off result were the same as those for the first lift-off result, except for the pulse spacing. The ellipticity was 0.95, and the beam rotation angle was 90°.

[0175] [Result of the third peeling process]

[0176] [Table 3]

[0177]

[0178] [Table 4]

[0179]

[0180] According to the third peeling processing results, it is found that setting the pulse pitch to 6.25 μm to 10 μm facilitates the extension of cracks in a direction intersecting the processing direction, further promoting the development of cracks along the imaginary plane M1.

[0181] The following fourth peeling result (see Tables 5 and 6) shows the peeling process results obtained when the pulse spacing was varied. The common processing conditions for the fourth peeling result were the same as those for the second peeling result, except for the pulse energy. The ellipticity was 0.95.

[0182] [Result of the third peeling process]

[0183] [Table 5]

[0184]

[0185] [Table 6]

[0186]

[0187] According to the fourth peeling processing result, when the pulse energy is set to 18.5 μJ (larger than 16 μJ and smaller than 20 μJ), cracks extending in a direction intersecting the processing direction are more easily extended, further promoting the development of cracks along the imaginary plane M1.

[0188] In this embodiment, the control unit 9 relatively moves a portion of the light-concentrating region along a line M4 spirally extending inward from the periphery of the object 100, thereby forming a modified region 4 within the object 100. Thus, a portion of the object 100 can be precisely peeled off, with the modified region 4 spanning the imaginary surface M1 and the crack extending from the modified region 4 serving as the boundary.

[0189] This embodiment includes a GUI 111 that accepts user input of at least one of information related to the beam shape 71, information related to the beam rotation angle, and information related to the settings of the reflective spatial light modulator 34. Based on the inputs from the GUI 111, the control unit 9 controls the rotation of the stage 107, the irradiation of the laser beam L1 from the laser processing head 10A, and the movement along the Y-axis track 108 of the laser processing head 10A. This allows the user to set at least one of the predetermined information related to the beam shape 71, the beam rotation angle, and the settings of the reflective spatial light modulator 34 during the lift-off process. This allows for easy adjustment of the beam shape 71, the beam rotation angle, and other information to promote the development of cracks along the imaginary surface M1.

[0190] Figure 22 1 is a diagram showing an example of a setting screen displayed on the touch panel 111a of the GUI 111. The touch panel 111a of the GUI 111 allows various detailed settings to be displayed and input. Figure 22 Examples of settings displayed and inputted via the GUI 111 include, for example, the thickness of the object 100, the X offset of the reflective spatial light modulator 34, the Y offset of the reflective spatial light modulator 34, the beam shape, the beam rotation angle, and processing indicators. Furthermore, examples of settings displayed and inputted via the GUI 111 include, for example, the number of focal spots, the branching distance X, the branching distance Y, the pulse width of the laser light L1, the frequency, the processing depth, the processing speed, the output of the laser light L1, and the focusing correction level.

[0191] The X offset of the reflective spatial light modulator 34 is the distance by which the reference position of the liquid crystal layer is shifted in a predetermined direction when the modulation pattern is displayed on the liquid crystal layer. The Y offset of the reflective spatial light modulator 34 is the distance by which the reference position of the liquid crystal layer is shifted in a direction orthogonal to the predetermined direction when the modulation pattern is displayed on the liquid crystal layer. The processing index is the distance between a pair of adjacent modified points in the processing index direction. The focus correction level is the intensity of aberration correction at the processing position; a larger number results in greater aberration correction. Various inputs are user-specified values, selected by the user through a pull-down menu, or automatically selected.

[0192] The beam shape input allows you to specify or select between an ellipse and a perfect circle, specify or select the ellipticity or the name of the modulation pattern that achieves it, and specify or select the intensity of the modulation pattern. The output can be the total output of laser L1 or the output of each beam branched from laser L1. The branch distances X and Y can also be specified or selected.

[0193] Figure 23 1 is a diagram showing another example of a setting screen displayed on the touch panel 111a of the GUI 111. Figure 23 The example of the setting items displayed and inputted via GUI 111 is relative to Figure 22 The example shown does not include the beam shape and beam rotation angle, but does include a slit. The slit is an item that forms the beam shape 71 in accordance with the laser beam L1 so that it has the shape in the longitudinal direction described above. The slit input is optional, and a predetermined slit width that should produce the desired beam shape 71 can also be input or selected.

[0194] [Modification]

[0195] As mentioned above, one aspect of the present invention is not limited to the above-mentioned embodiment.

[0196] In the above embodiment, the edge trimming and radial cutting processes for forming the modified region 4 are performed before the object 100 is peeled off by glass processing. However, the order of performing the peeling process, edge trimming, and radial cutting processes is different. At least one of the edge trimming and radial cutting processes may not be performed.

[0197] In the above embodiment, a spiral-shaped line M4 is set as the processing line for forming the modified region 4 during the lift-off process. However, the present invention is not limited thereto, and processing lines of various shapes may be set on the object 100. For example, a plurality of straight lines (parallel lines) may be set on the object 100 so as to be arranged in a predetermined direction.

[0198] The above embodiment may include a plurality of laser processing heads as the irradiation unit. In the case where the irradiation unit includes a plurality of laser processing heads, the above laser processing may be performed using at least one of the plurality of laser processing heads.

[0199] While the above embodiment employs a reflective spatial light modulator 34, the spatial light modulator is not limited to a reflective type; a transmissive spatial light modulator may also be employed. In the above embodiment, the type of object 100, the shape of object 100, the size of object 100, the number and directions of crystal orientations in object 100, and the orientation of the principal surface of object 100 are not particularly limited.

[0200] In the above embodiment, the back surface 100b of the object 100 is set as the laser incident surface, but the surface 100a of the object 100 can also be set as the laser incident surface. In the above embodiment, the modified area 4 can be, for example, a crystallized area, a recrystallized area, or an aggregation area formed inside the object 100. The crystallized area is an area that maintains the structure of the object 100 before processing. The recrystallized area is an area that solidifies into a single crystal or polycrystalline when it evaporates, plasmatizes or melts, and then solidifies. The aggregation area is an area that gathers impurities such as heavy metals to exert an aggregation effect of capturing, and can be formed continuously or intermittently. The above embodiment can also be applied to processing such as grinding.

[0201] In the above embodiment, the beam rotation angle is not particularly limited, as long as it is an angle inclined with respect to the processing direction. In the above embodiment, the polarization direction of the laser light L1 irradiated on the object 100 is not limited; for example, the polarization direction may be along the processing direction. The polarization direction of the laser light L1 can be adjusted using various known techniques.

[0202] The components of the above-mentioned embodiments and modifications are not limited to the above-mentioned materials and shapes, and various materials and shapes can be used. Furthermore, the components of the above-mentioned embodiments and modifications can be arbitrarily applied to the components of other embodiments and modifications.

[0203] [Explanation of symbols]

[0204] 1,101:Laser processing equipment

[0205] 4: Modified area

[0206] 6,300: Mobile mechanism

[0207] 9: Control Department

[0208] 10A, 10B: Laser processing head (irradiation part)

[0209] 34: Reflective spatial light modulator (forming unit)

[0210] 71: Beam shape (shape of part of the focusing area)

[0211] 100: Object

[0212] 100a: Surface

[0213] 100b: Back side (laser incident side)

[0214] 107: stage (support part)

[0215] 108: Y-axis track (moving mechanism)

[0216] 111: GUI (input unit)

[0217] L1: Laser (Laser)

[0218] M1: imaginary surface

[0219] M4: Wire (processing wire).

Claims

1. A laser processing device that irradiates an object with laser light by aligning a portion of a focusing region with the object, thereby forming a modified region along an imaginary surface within the object, comprising: a support portion for supporting the object; irradiating the laser beam onto an irradiation portion of the object; a moving mechanism for moving at least one of the support portion and the irradiation portion so that a portion of the light-collecting area moves along the imaginary plane inside the object; and a control unit for controlling the support unit, the irradiation unit, and the moving mechanism; The irradiation unit includes a shaping unit that shapes the laser light so that a portion of the light-collecting region in a plane perpendicular to the optical axis of the laser light has a longitudinal direction. The longitudinal direction is a direction intersecting with a moving direction of a portion of the light-collecting area.

2. The laser processing device according to claim 1, wherein: The longitudinal direction is a direction inclined at 45° or more with respect to the moving direction of a portion of the light-collecting region.

3. The laser processing device according to claim 1, wherein: The long side direction is a direction perpendicular to the moving direction of a portion of the light-collecting area.

4. The laser processing device according to claim 2, wherein: The long side direction is a direction perpendicular to the moving direction of a portion of the light-collecting area.

5. The laser processing device according to any one of claims 1 to 4, wherein: The shape of a portion of the light-collecting region has an ellipticity of 0.88 to 0.95, where the ellipticity is a ratio of a length in a short side direction to a length in a long side direction.

6. The laser processing device according to any one of claims 1 to 4, wherein: The control unit relatively moves a portion of the light-concentrating region along a processing line spirally extending from a periphery toward an inner side of the object, thereby forming the modified region inside the object.

7. The laser processing device according to claim 5, wherein: The control unit relatively moves a portion of the light-concentrating region along a processing line spirally extending from a periphery toward an inner side of the object, thereby forming the modified region inside the object.

8. The laser processing device according to any one of claims 1 to 4, wherein: An input unit is provided, the input unit being capable of receiving from a user at least any one of: information related to the shape of a portion of the light-concentrating area; information related to the inclination relative to the moving direction of the portion of the light-concentrating area; and information related to the setting of the forming portion, The control unit controls the support unit, the irradiation unit, and the moving mechanism according to the input of the input unit.

9. The laser processing apparatus according to claim 5, wherein: An input unit is provided, the input unit being capable of receiving from a user at least any one of: information related to the shape of a portion of the light-concentrating area; information related to the inclination relative to the moving direction of the portion of the light-concentrating area; and information related to the setting of the forming portion, The control unit controls the support unit, the irradiation unit, and the moving mechanism according to the input of the input unit.

10. The laser processing apparatus according to claim 6, wherein: An input unit is provided, the input unit being capable of receiving from a user at least any one of: information related to the shape of a portion of the light-concentrating area; information related to the inclination relative to the moving direction of the portion of the light-concentrating area; and information related to the setting of the forming portion, The control unit controls the support unit, the irradiation unit, and the moving mechanism according to the input of the input unit.

11. The laser processing apparatus according to claim 7, wherein: An input unit is provided, the input unit being capable of receiving from a user at least any one of: information related to the shape of a portion of the light-concentrating area; information related to the inclination relative to the moving direction of the portion of the light-concentrating area; and information related to the setting of the forming portion, The control unit controls the support unit, the irradiation unit, and the moving mechanism according to the input of the input unit.

12. A laser processing method comprising: directing a portion of a focusing region toward an object and irradiating the object with laser light, thereby forming a modified region along an imaginary surface within the object; the method comprising: an irradiation step of irradiating the object with the laser light, and a moving step of moving at least one of a support portion supporting the object and an irradiation portion irradiating the object with the laser light so that a portion of the focusing area moves along the imaginary surface inside the object; The irradiation step includes a shaping step of shaping the laser light so that a portion of the light-collecting region in a plane perpendicular to the optical axis of the laser light has a longitudinal direction. The longitudinal direction is a direction intersecting with a moving direction of a portion of the light-collecting area.

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