WO2024057780A1 - Dispositif de traitement laser et procédé de traitement laser - Google Patents

Dispositif de traitement laser et procédé de traitement laser Download PDF

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Publication number
WO2024057780A1
WO2024057780A1 PCT/JP2023/028946 JP2023028946W WO2024057780A1 WO 2024057780 A1 WO2024057780 A1 WO 2024057780A1 JP 2023028946 W JP2023028946 W JP 2023028946W WO 2024057780 A1 WO2024057780 A1 WO 2024057780A1
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Prior art keywords
line
laser
laser processing
extension part
spatial light
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PCT/JP2023/028946
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English (en)
Japanese (ja)
Inventor
剛志 坂本
孝文 荻原
雅輝 小柳津
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浜松ホトニクス株式会社
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Publication of WO2024057780A1 publication Critical patent/WO2024057780A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/073—Shaping the laser spot
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/50—Working by transmitting the laser beam through or within the workpiece
    • B23K26/53—Working by transmitting the laser beam through or within the workpiece for modifying or reforming the material inside the workpiece, e.g. for producing break initiation cracks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26

Definitions

  • the present disclosure relates to a laser processing device and a laser processing method.
  • a support part that supports a target object, a light source that emits laser light, a spatial light modulator that modulates the laser light emitted from the light source, and a laser light modulated by the spatial light modulator that focuses the laser light on the target object.
  • a laser processing apparatus includes a condensing section and an image transfer section that transfers an image of a laser beam in a spatial light modulator onto an entrance pupil plane of the condensing section (see, for example, Patent Document 1).
  • a laser processing device such as that described above can form modified regions and cracks in a target object. Formation of such modified regions and cracks can be applied to various processes, such as dicing to divide an object into a plurality of chips, trimming to remove unnecessary parts from the object, and the like.
  • An object of the present disclosure is to provide a laser processing device and a laser processing method that can form appropriate modified regions and cracks in a target object depending on the processing.
  • a laser processing apparatus includes [1] "a support section that supports a target object, a light source that emits laser light, and a modulation pattern that displays the laser beam emitted from the light source.” a spatial light modulator that modulates the laser beam, a focusing section that focuses the laser beam modulated by the spatial light modulator on the object, and a driving section that drives at least one of the support section and the focusing section. , a control unit that controls at least the spatial light modulator and the drive unit, and the control unit is configured such that the beam shape of the laser beam at the focused spot of the laser beam is radial from the center and the center.
  • a modulation pattern including a trefoil aberration pattern is formed in the space so that the beam shape includes a first extension part, a second extension part, and a third extension part extending in the space and has the highest intensity in the center part.
  • the focused spot moves relatively along a line set on the object while the modulation pattern including the trefoil aberration pattern is displayed on the spatial light modulator.
  • a laser processing apparatus in which at least one of the supporting section and the light condensing section is driven by the driving section.
  • the beam shape of the laser beam at the focused spot is formed into a central portion, a first extending portion, a second extending portion, and a third extending portion extending radially from the central portion.
  • the focused spot is relatively moved along a line set on the object, with the focus having the highest intensity at the center.
  • the state of at least one of the modified region and the cracks formed in the object can be adjusted. Therefore, according to the laser processing apparatus described in [1] above, appropriate modified regions and cracks can be formed in the object according to the processing.
  • a laser processing apparatus includes [2] "forming a modified region in the target object along the line, and from the modified region in the incident direction of the laser beam and in the extending direction of the line.
  • [2] "forming a crack in the object along a first surface parallel to both directions of Displaying the modulation pattern including the trefoil aberration pattern on the spatial light modulator such that the second extension part is located at and the third extension part is located on the other side with respect to the line.
  • the laser processing apparatus described in [1] above.
  • the width of the crack in the laser beam incident direction can be made smaller than, for example, when the modulation pattern does not include a trefoil aberration pattern.
  • the laser processing device may be the laser processing device described in [2] above, [3] "wherein the control unit causes the spatial light modulator to display the modulation pattern including the trefoil aberration pattern such that the first extension portion is located in front of the direction in which the focused spot moves relatively along the line, and the second extension portion and the third extension portion are located in the rear of the direction.”
  • the control unit causes the spatial light modulator to display the modulation pattern including the trefoil aberration pattern such that the first extension portion is located in front of the direction in which the focused spot moves relatively along the line, and the second extension portion and the third extension portion are located in the rear of the direction.
  • the laser processing device includes [4] “In the case where the focused spot is relatively moved along each of a first line and a second line set on the object as the line, When the direction in which the focused spot is relatively moved along the first line is different from the direction in which the focused spot is relatively moved along the second line, the control unit The first extension part is located on the front side in the direction in which the focused spot moves relatively along each of the first line and the second line, and the second extension part and the The laser processing apparatus according to [3] above may change the direction of the modulation pattern including the trefoil aberration pattern so that the third extension portion is located.
  • the direction in which the focused spot is relatively moved along the first line and the direction in which the focused spot is relatively moved along the second line are different. Even when different, the first extension part is located on the front side in the direction in which the focused spot moves relatively along each of the first line and the second line, and the second extension part is located on the rear side in the direction. The state in which the third extension portion is located can be easily and reliably realized.
  • the laser processing device provides [5] “When the control unit sets a width of at least one of the modified region and the crack in the incident direction of the laser beam as a first width, If the modulation pattern including the trefoil aberration pattern having a first trefoil aberration intensity is displayed on the spatial light modulator, and the width of at least one of the patterns is a second width smaller than the first width, The laser processing device according to any one of [2] to [4] above, wherein the modulation pattern including the trefoil aberration pattern having a second trefoil aberration intensity stronger than the trefoil aberration intensity is displayed on the spatial light modulator. ”. According to the laser processing apparatus described in [5], the width of at least one of the modified region and the crack in the incident direction of the laser beam can be set to an appropriate width depending on the processing.
  • the laser processing apparatus includes [6] "forming a modified region in the object along the line, and from the modified region in the incident direction of the laser beam and in the extending direction of the line.
  • a crack is formed in the object along a second surface that is inclined with respect to a first surface that is parallel to both directions, a region on the opposite side to the incident side of the laser beam is perpendicular to the first surface.
  • the control section is configured such that the first extending section is located on the one side with respect to the line and the second surface is inclined with respect to the line.
  • the modulation pattern including the trefoil aberration pattern is displayed on the spatial light modulator so that the second extension part and the third extension part are located on the other side. It may also be a "laser processing device". According to the laser processing apparatus described in [6], the crack extending from the modified region can be inclined to a desired side.
  • the laser processing device includes [7] “In the case where the focused spot is relatively moved along each of a first line and a second line set on the object as the line, When the direction in which the focused spot is relatively moved along the first line is different from the direction in which the focused spot is relatively moved along the second line, the control unit The first extending portion is located on the one side with respect to each of the first line and the second line, and the second extending portion is located on the other side with respect to each of the first line and the second line.
  • the laser processing apparatus may change the direction of the modulation pattern including the trefoil aberration pattern so that the trefoil aberration pattern and the third extension portion are located.
  • the direction in which the focused spot is relatively moved along the first line and the direction in which the focused spot is relatively moved along the second line are different. Even in different cases, the first extension part is located on one side with respect to each of the first line and the second line, and the second extension part is located on the other side with respect to each of the first line and the second line. It is possible to easily and reliably realize the state in which the third extension part and the third extension part are located.
  • the laser processing device includes [8] “When the angle between the first surface and the second surface is the first angle, the control unit controls the first trefoil aberration intensity.
  • the modulation pattern including the trefoil aberration pattern is displayed on the spatial light modulator and the angle is a second angle larger than the first angle, a second trefoil aberration intensity stronger than the first trefoil aberration intensity is used.
  • the laser processing apparatus may display the modulation pattern including the trefoil aberration pattern of aberration intensity on the spatial light modulator. According to the laser processing apparatus described in [8], the angle at which the crack extending from the modified region is inclined can be set to an appropriate angle depending on the processing.
  • a laser processing method includes [9] "a supporting part that supports a target object, a light source that emits a laser beam, and a modulation pattern that is displayed, so that the laser beam that is emitted from the light source is a spatial light modulator that modulates the laser beam, a focusing section that focuses the laser beam modulated by the spatial light modulator on the object, and a driving section that drives at least one of the support section and the focusing section.
  • a laser processing method carried out in a laser processing apparatus comprising: a beam shape of the laser light at a focused spot of the laser light includes a center portion and a first extension portion extending radially from the center portion; , displaying a modulation pattern including a trefoil aberration pattern on the spatial light modulator so as to have a beam shape that includes a second extension part and a third extension part and has the highest intensity at the center; The supporting portion and a step of causing the driving section to drive at least one of the light condensing sections.
  • the beam shape of the laser beam at the condensed spot includes a central portion, a first extending portion, a second extending portion, and a third extending portion extending radially from the central portion.
  • the focused spot is relatively moved along a line set on the object, with the focus having the highest intensity at the center.
  • the state of at least one of the modified region and the cracks formed in the object can be adjusted. Therefore, according to the laser processing method described in [9] above, appropriate modified regions and cracks can be formed in the object depending on the processing.
  • FIG. 1 is a diagram showing the configuration of a laser processing apparatus according to an embodiment.
  • FIG. 2 is a diagram showing the configuration of the irradiation section shown in FIG. 1.
  • FIG. 3 is a diagram showing the 4f lens unit shown in FIG. 2.
  • FIG. 4 is a diagram showing the spatial light modulator shown in FIG. 2.
  • FIG. 5 is a diagram showing an example of a trefoil aberration pattern.
  • FIG. 6 is a diagram showing an example of a focused state of laser light and an example of a beam shape of the laser light at the focused spot.
  • FIG. 7 is a diagram showing an example of a beam shape of a laser beam for each trefoil aberration intensity.
  • FIG. 1 is a diagram showing the configuration of a laser processing apparatus according to an embodiment.
  • FIG. 2 is a diagram showing the configuration of the irradiation section shown in FIG. 1.
  • FIG. 3 is a diagram showing the 4f lens unit shown in FIG. 2.
  • FIG. 4 is
  • FIG. 8 is a diagram showing an example of a beam shape of laser light modulated by a trefoil aberration pattern.
  • FIG. 9 is a diagram showing an example of a beam shape of a laser beam modulated by a trefoil aberration pattern and an astigmatism pattern.
  • FIG. 10 is a diagram showing an example of a beam shape of laser light modulated by a trefoil aberration pattern, an astigmatism pattern, and a spherical aberration pattern.
  • FIG. 11 is a diagram showing an example of a beam shape of laser light modulated by a trefoil aberration pattern.
  • FIG. 12 is a diagram illustrating an example of a focused state of laser light and an example of damage caused by light leakage of laser light.
  • FIG. 13 is a diagram showing a first example of a cut surface of a target object for each laser processing condition.
  • FIG. 14 is a diagram showing a first example of a cut surface of a target object for each laser processing condition.
  • FIG. 15 is a diagram showing the relationship between the trefoil aberration intensity and the respective widths of the modified region and crack.
  • FIG. 16 is a diagram showing a second example of the cut surface of the object for each laser processing condition.
  • FIG. 17 is a diagram showing a second example of the cut surface of the object for each laser processing condition.
  • FIG. 18 is a diagram showing the relationship between the trefoil aberration intensity and the angle at which the crack is inclined.
  • FIG. 19 is a diagram showing the relationship between the trefoil aberration intensity and the angle at which the crack is inclined.
  • FIG. 20 is a diagram showing an object to which the first example of the laser processing method is applied.
  • FIG. 21 is a diagram showing one step of the first example of the laser processing method.
  • FIG. 22 is a diagram illustrating an example of a cut surface of an object subjected to light damage suppression processing.
  • FIG. 23 is a diagram showing an object to which the second example of the laser processing method is applied.
  • FIG. 24 is a diagram showing one step of the second example of the laser processing method.
  • the laser processing device 1 includes a support section 2, an irradiation section 3, drive sections 4 and 5, and a control section 6.
  • the laser processing apparatus 1 forms a modified region 12 on the object 11 by irradiating the object 11 with a laser beam L.
  • the support section 2 supports the object 11 by holding a film attached to the object 11, for example.
  • the support part 2 is movable in each of the X direction and the Y direction, and is rotatable about an axis parallel to the Z direction as a rotation axis.
  • the X direction and the Y direction are a first horizontal direction and a second horizontal direction that are perpendicular to each other, and the Z direction is a vertical direction.
  • the irradiation unit 3 focuses a laser beam L that is transparent to the object 11 and irradiates the object 11 with the laser beam L.
  • the irradiation unit 3 is movable in the Z direction.
  • the laser beam L is particularly absorbed in the part corresponding to the focused spot C of the laser beam L, and the laser beam L is absorbed inside the object 11.
  • a modified region 12 is formed.
  • the focused spot C is also referred to as a focused area or a focused point.
  • the modified region 12 is a region whose density, refractive index, mechanical strength, and other physical properties are different from those of the surrounding unmodified region.
  • Examples of the modified region 12 include a melt-treated region, a crack region, a dielectric breakdown region, and a refractive index change region. From the modified region 12, cracks are formed on the incident side of the laser beam L and on the opposite side. Such modified regions 12 and cracks are used to cut the object 11.
  • a plurality of modified spots 12s are lined up in a line along the line A. is formed.
  • One modification spot 12s is formed by irradiation with one pulse of laser light L.
  • One row of modified regions 12 is a collection of a plurality of modified spots 12s arranged in one row. Adjacent modification spots 12s may be connected to each other or separated from each other depending on the relative moving speed of the focused spot C with respect to the object 11 and the repetition frequency of the laser beam L.
  • the drive section 4 supports the support section 2 and drives the support section 2.
  • the drive unit 4 moves the support unit 2 in each of the X direction and the Y direction, and rotates the support unit 2 using an axis parallel to the Z direction as the rotation axis.
  • the drive section 5 supports the irradiation section 3 and drives the irradiation section 3.
  • the drive section 5 moves the irradiation section 3 in the Z direction.
  • the drive unit 4 rotates the support unit 2 so that the line A is parallel to the X direction, and the drive unit 4 rotates the support unit so that the focused spot C is located on the line A.
  • the drive unit 5 moves the irradiation unit 3 in the Z direction so that the focused spot C is located inside the object 11, and further, the focused spot C is moved relative to the target object 11 along the line A.
  • the drive section 4 moves the support section 2 so as to move the support section 2 as desired.
  • the control unit 6 controls the support unit 2, the irradiation unit 3, and the drive units 4 and 5.
  • the control unit 6 has a processing unit, a memory unit, and an input reception unit (not shown).
  • the processing unit is configured as a computer device including a processor, memory, storage, and a communication device.
  • the processor executes software (programs) loaded into the memory, etc., and controls the reading and writing of data in the memory and storage, as well as communication by the communication device.
  • the memory unit is, for example, a hard disk, and stores various types of data.
  • the input reception unit is an interface unit that displays various types of information and receives input of various types of information from the user.
  • the input reception unit constitutes, for example, a GUI (Graphical User Interface).
  • the irradiation section 3 includes a light source 31, a spatial light modulator 7, a condensing section 33, and a 4f lens unit 34.
  • the light source 31 emits laser light L using, for example, a pulse oscillation method.
  • the spatial light modulator 7 modulates the laser beam L emitted from the light source 31 by displaying a modulation pattern.
  • the condensing unit 33 includes at least one lens, and condenses the laser beam L modulated by the spatial light modulator 7 onto the object 11 .
  • the 4f lens unit 34 transfers the image of the laser beam L on the modulation surface of the spatial light modulator 7 to the entrance pupil surface of the condenser 33 .
  • the light source 31 may be provided outside the irradiation section 3 and the laser light L emitted from the light source 31 may be guided to the irradiation section 3.
  • the irradiation unit 3 may include other optical systems.
  • the irradiation unit 3 may include an optical system (for example, an attenuator, a beam expander, etc.) arranged on the optical path between the light source 31 and the spatial light modulator 7.
  • the 4f lens unit 34 has a pair of lenses 34A and 34B.
  • the pair of lenses 34A and 34B are arranged on the optical path of the laser beam L traveling from the spatial light modulator 7 to the condensing section 33.
  • the pair of lenses 34A and 34B constitute a double-sided telecentric optical system in which the modulation surface 7a of the spatial light modulator 7 and the entrance pupil surface 33a of the condenser 33 are in an imaging relationship.
  • the image of the laser beam L on the modulation surface 7a of the spatial light modulator 7 (the image of the laser beam L modulated in the spatial light modulator 7) is transferred (formed) onto the entrance pupil plane 33a of the condenser 33. image) to be done.
  • f1 and f2 indicate the focal lengths of the lenses 34A and 34B, respectively, and Fs indicates the Fourier plane.
  • the spatial light modulator 7 is a reflective liquid crystal (LCOS) spatial light modulator (SLM).
  • LCOS reflective liquid crystal
  • SLM spatial light modulator
  • a drive circuit layer 72, a pixel electrode layer 73, a reflective film 74, an alignment film 75, a liquid crystal layer 76, an alignment film 77, a transparent conductive film 78, and a transparent substrate 79 are arranged on a semiconductor substrate 71 in this order. It is constructed by laminating layers.
  • the semiconductor substrate 71 is, for example, a silicon substrate.
  • the drive circuit layer 72 constitutes an active matrix circuit on the semiconductor substrate 71.
  • the pixel electrode layer 73 includes a plurality of pixel electrodes 73a arranged in a matrix along the surface of the semiconductor substrate 71.
  • Each pixel electrode 73a is made of, for example, a metal material such as aluminum. A voltage is applied to each pixel electrode 73a by the drive circuit layer 72.
  • the reflective film 74 is, for example, a dielectric multilayer film.
  • the alignment film 75 is provided on the surface of the liquid crystal layer 76 on the reflective film 74 side, and the alignment film 77 is provided on the surface of the liquid crystal layer 76 on the opposite side to the reflective film 74.
  • Each of the alignment films 75 and 77 is made of, for example, a polymeric material such as polyimide, and the contact surface of each of the alignment films 75 and 77 with the liquid crystal layer 76 is subjected to, for example, a rubbing treatment.
  • the alignment films 75 and 77 align liquid crystal molecules 76a included in the liquid crystal layer 76 in a certain direction.
  • the transparent conductive film 78 is provided on the surface of the transparent substrate 79 on the alignment film 77 side, and faces the pixel electrode layer 73 with the liquid crystal layer 76 and the like interposed therebetween.
  • the transparent substrate 79 is, for example, a glass substrate.
  • the transparent conductive film 78 is made of a light-transmissive and conductive material such as ITO, for example.
  • the transparent substrate 79 and the transparent conductive film 78 transmit the laser beam L.
  • the spatial light modulator 7 configured as described above, when a signal indicating a modulation pattern is input from the control unit 6 to the drive circuit layer 72, a voltage corresponding to the signal is applied to each pixel electrode 73a, and each An electric field is formed between the pixel electrode 73a and the transparent conductive film 78.
  • the electric field is formed, in the liquid crystal layer 76, the alignment direction of the liquid crystal molecules 76a changes for each region corresponding to each pixel electrode 73a, and the refractive index changes for each region corresponding to each pixel electrode 73a. This state is the state in which the spatial light modulator 7 displays a modulation pattern.
  • the laser beam L enters the liquid crystal layer 76 from the outside via the transparent substrate 79 and the transparent conductive film 78, is reflected by the reflective film 74, and the laser beam L enters the liquid crystal layer 76 from the outside through the transparent substrate 79 and the transparent conductive film 78.
  • the intensity, amplitude, phase, polarization, etc. of the laser beam L are modulated according to the modulation pattern displayed on the liquid crystal layer 76.
  • the modulation surface 7a shown in FIG. 3 corresponds to the liquid crystal layer 76.
  • the control unit 6 can cause the spatial light modulator 7 to display a modulation pattern including a trefoil aberration pattern.
  • FIG. 5 is a diagram showing an example of a trefoil aberration pattern.
  • Trefoil aberration is one of Zernike's third-order aberrations. Note that spherical aberration and astigmatism are included in Zernike's second-order aberration, and coma aberration and trefoil aberration are included in Zernike's third-order aberration.
  • the laser beam L modulated by the spatial light modulator 7 displaying the trefoil aberration pattern is focused by the condenser 33, the laser beam L becomes a condensed spot, as shown in FIG. 6(a). It is most narrowed down in C.
  • the beam shape 9 of the laser beam L at the condensed spot C i.e., a surface that is perpendicular to the optical axis of the laser beam L (dotted chain line shown in FIG. 6(a)) and includes the condensed spot C.
  • FIG. 92 and the third extending portion 93 and has the highest strength at the center portion 90.
  • each of the first extending portion 91, the second extending portion 92, and the third extending portion 93 becomes smaller as the distance from the center portion 90 increases.
  • the strength of each of the existing portion 92 and the third extending portion 93 decreases as the distance from the center portion 90 increases.
  • the beam shape 9 of the laser beam L is like a triangle with each side curved inward.
  • the modulation pattern including a trefoil aberration pattern includes not only a modulation pattern including only a trefoil aberration pattern, but also a modulation pattern including a trefoil aberration pattern and other patterns. Even when the modulation pattern includes a pattern other than the trefoil aberration pattern, when the laser beam L modulated by the spatial light modulator 7 displaying the modulation pattern including the trefoil aberration pattern is condensed by the condenser 33. , the beam shape 9 of the laser beam L at the focused spot C includes a center portion 90 and a first extending portion 91, a second extending portion 92, and a third extending portion 93 extending radially from the center portion 90.
  • the beam shape has the highest intensity at the center portion 90.
  • the beam shape 9 of the laser light L at each focused spot C is determined by the center portion 90 and the first extending portions 91, second extending portions 92, and third extending portions extending radially from the center portion 90.
  • the beam shape includes the existing portion 93 and has the highest strength at the center portion 90.
  • FIG. 7 is a diagram showing an example of the beam shape of the laser light L for each trefoil aberration intensity.
  • the absolute value of the trefoil aberration strength indicates the strength of the trefoil aberration, and the larger the absolute value of the trefoil aberration strength, the stronger the trefoil aberration (therefore, "the trefoil aberration strength is strong" means that the absolute value of the trefoil aberration strength is large) (meaning).
  • the positive or negative sign of the trefoil aberration intensity indicates the direction of the trefoil aberration, and the direction of the trefoil aberration differs by 180 degrees between the trefoil aberration having a positive sign and the trefoil aberration having a negative sign.
  • FIG. 7 shows a camera image taken by a camera as the beam shape of the laser light L.
  • the beam shape 9 of the laser beam L at the focused spot C is The beam shape includes the extending portion 91, the second extending portion 92, and the third extending portion 93 and has the highest strength at the center portion 90 (see (b) of FIG. 6).
  • the beam shape of the laser light L at the -20 ⁇ m position and the beam shape of the laser light L at the +20 ⁇ m position also have the same shape and direction as the beam shape 9 of the laser light L at the focused spot C. becomes.
  • the beam shape 9 of the laser light L at the focused spot C is oriented to the opposite side from the beam shape of the laser light L at the -20 ⁇ m position and the beam shape of the laser light L at the +20 ⁇ m position.
  • the "-20 ⁇ m position” is a position 20 ⁇ m away from the condensing spot C toward the condensing unit 33
  • the "+20 ⁇ m position” is 20 ⁇ m away from the condensing spot C on the side opposite to the condensing unit 33. It is a remote location.
  • FIG. 8 is a diagram showing an example of the beam shape of the laser light L modulated by the trefoil aberration pattern.
  • FIG. 9 is a diagram showing an example of a beam shape of laser light L modulated by a trefoil aberration pattern and an astigmatism pattern (that is, a modulation pattern in which they are superimposed).
  • FIG. 10 is a diagram showing an example of a beam shape of laser light L modulated by a trefoil aberration pattern, an astigmatism pattern, and a spherical aberration pattern (that is, a modulation pattern in which they are superimposed).
  • 8, 9, and 10 show a simulation image obtained by simulation and a camera image captured by a camera as the beam shape of the laser light L.
  • the trefoil aberration intensity of the trefoil aberration pattern is -0.6.
  • the beam shape 9 of the laser beam L at the focused spot C is The beam shape includes the first extending portion 91, the second extending portion 92, and the third extending portion 93 and has the highest strength at the center portion 90 (see (b) of FIG. 6).
  • the beam shape of the laser light L at the -20 ⁇ m position and the beam shape of the laser light L at the +20 ⁇ m position also have the same shape and direction as the beam shape 9 of the laser light L at the focused spot C. becomes.
  • the beam shape 9 of the laser light L at the focused spot C is oriented to the opposite side from the beam shape of the laser light L at the -20 ⁇ m position and the beam shape of the laser light L at the +20 ⁇ m position.
  • you include not only the high-intensity parts but also the low-intensity parts you can see that they are facing the same side as the beam shape.
  • FIG. 11 is a diagram showing an example of the beam shape of the laser light L modulated by the trefoil aberration pattern.
  • the trefoil aberration intensity of the trefoil aberration pattern is -0.5.
  • the beam shape of the laser light L at the -100 ⁇ m position and the beam shape of the laser light L at the +100 ⁇ m position are on the opposite side to the beam shape 9 of the laser light L at the focused spot C.
  • the beam shape is oriented.
  • the "-100 ⁇ m position” is a position 100 ⁇ m away from the condensing spot C toward the condensing part 33, and the "+100 ⁇ m position” is 100 ⁇ m away from the condensing spot C on the side opposite to the condensing part 33. It is a remote location.
  • the beam shape of the laser light L at the -20 ⁇ m position and the beam shape of the laser light L at the +20 ⁇ m position are similar to the beam shape 9 of the laser light L at the focused spot C. and a beam shape having a direction (see FIGS. 7, 8, 9, and 10).
  • the beam shape of the laser light L at the ⁇ 20 ⁇ m position clearly shows the beam shape 9 of the laser light L at the focused spot C compared to the beam shape of the laser light L at the +20 ⁇ m position.
  • a metal film 8 is formed on the second surface 11b of the object 11, which is a silicon wafer, and the first surface 11a of the object 11 is used as the incident surface of the laser beam L.
  • the laser beam L is irradiated onto the object 11 by aligning the focused spot C with a position 20 to 30 ⁇ m from the second surface 11b and inside the object 11, the laser beam L is modulated by a modulation pattern including a trefoil aberration pattern.
  • damage having the same shape and direction as the beam shape 9 of the laser beam L at the focused spot C occurs on the metal, as shown in FIG.
  • the film 8 is formed. Therefore, in order to estimate the beam shape 9 of the laser light L at the focused spot C when the laser light L modulated by the modulation pattern including the trefoil aberration pattern is focused, it is necessary to 8 and observe the damage.
  • 13 and 14 are diagrams showing first examples of cut surfaces of the object 11 for each laser processing condition.
  • 13 and 14 "Two rows of modified regions aligned in the thickness direction of the silicon wafer are formed inside the object 11, which is a silicon wafer, along line A, and then the object 11 is A cut surface of the object 11 when it is cut along line A by expanding is shown.
  • condition A is that the condensed spot C is relatively moved in the "direction indicated by the arrow on line A" (rightward in FIG. 13, leftward in FIG. 14);
  • the beam shape 9 of the laser beam L at the focused spot C is such that (1) the center portion 90 and the first extension portion 91 are located on the line A, and the first side with respect to the line A (FIG. 13
  • the second extending portion 92 is located on the upper side in FIG. 14, and the lower side in FIG. and (2) the first extension part 91 is located on the front side in the direction in which the focused spot C moves relatively along the line A, and the second extension part 91 is located on the rear side in the direction.
  • the laser processing conditions are such that the portion 92 and the third extension portion 93 are located.
  • Extension B is such that the focused spot C is relatively moved in the "direction indicated by the arrow on line A" (leftward in FIG. 13, rightward in FIG. 14), and at that time, the focused spot
  • the beam shape 9 of the laser beam L at C is as follows: 13, the second extending portion 92 is located on the lower side) and the third extending portion 93 is located on the first side (lower side in FIG. 13, upper side in FIG. and (3) "the first extension part 91 is located on the rear side in the direction in which the focused spot C moves relatively along the line A, and the second extension part 92 and the third extension part are located on the front side in the direction These are the laser processing conditions in which the extension portion 93 is positioned.
  • “Standard” in the "Condition A” column is a laser processing condition that differs from “Condition A” only in that the modulation pattern does not include a trefoil aberration pattern.
  • “Standard” in the “Condition B” stage is a laser processing condition that differs from “Condition B” only in that the modulation pattern does not include a trefoil aberration pattern.
  • a modified region 12 is formed in the object 11 along a line A, and the incident direction (Z direction) of the laser beam L from the modified region 12 and the extending direction of the line A are
  • the incident direction (Z direction) of the laser beam L from the modified region 12 and the extending direction of the line A are
  • a first The extension part 91 is located
  • the second extension part 92 is located on one side with respect to line A
  • the third extension part 93 is located on the other side with respect to line A (FIG. 13).
  • a modulation pattern including a trefoil aberration pattern may be displayed on the spatial light modulator 7.
  • the width of the crack in the incident direction of the laser beam L is small because the black streaks extending in the left and right direction are modified in two rows. This can be seen from the fact that it is formed between the dark areas (black band-shaped areas extending in the left-right direction).
  • the reason for this is that when cutting the object 11 by expanding is performed in a state where the cracks extending from each modified region are not connected between the two rows of modified regions when two rows of modified regions are formed. This is because black streaks extending in the left-right direction may be formed.
  • the laser beam L when forming the modified region 12 in the object 11 along the line A and also forming the crack 13 in the object 11 along the first surface P1, the laser beam L When reducing not only the width of the crack 13 in the incident direction of the laser beam L but also the width of the modified region 12 in the incident direction of the laser beam L and suppressing the meandering of the crack 13 with respect to the line A,
  • the first extension part 91 is located on the front side in the direction in which the focused spot C moves relatively along the line, and the second extension part 92 and the third extension part 93 are located on the rear side in the direction.
  • a modulation pattern including a trefoil aberration pattern may be displayed on the spatial light modulator 7.
  • twist hackle the amount of twist hackle (referred to as twist hackle) was decreased in "Condition A” compared to "Standard” and "Condition B".
  • the focused spot C is relatively moved along the first line.
  • the direction in which the focused spot C is moved is different from the direction in which the focused spot C is relatively moved along the second line
  • the focused spot C is relatively moved along each of the first line and the second line.
  • a trefoil aberration pattern is formed in the spatial light modulator 7 so that the first extension part 91 is located on the front side in the direction, and the second extension part 92 and the third extension part 93 are located on the rear side in the direction. What is necessary is to switch the direction of the included modulation pattern.
  • the trefoil with the first trefoil aberration strength is displayed on the spatial light modulator 7 and at least one of the widths is a second width smaller than the first width, the second trefoil aberration intensity is stronger than the first trefoil aberration intensity.
  • the widths of each of the modified region 12 and the crack 13 in the incident direction of the laser beam L are smaller at the second trefoil aberration intensity than at the first trefoil aberration intensity.
  • FIGS. 16 and 17 are diagrams showing second examples of cut surfaces of the object 11 for each laser processing condition. 16 and 17, "Two rows of modified regions lined up in the thickness direction of the silicon wafer are formed inside the object 11, which is a silicon wafer, along line A, and then the object 11 is A cut surface of the object 11 when it is cut along line A by expanding is shown.
  • Extension D is such that the focused spot C is relatively moved in the "direction indicated by the arrow on line A" (leftward in FIG. 16, rightward in FIG. 17), and at that time, the focused spot
  • the beam shape 9 of the laser beam L at C is defined as (5) "The center part 90 is located on line A, and the first part is located on the second side with respect to line A (upper side in FIG. 16, lower side in FIG. A state in which the extension part 91 is located and the second extension part 92 and the third extension part 93 are located on the first side (lower side in FIG. 16, upper side in FIG. 17) with respect to line A. These are laser processing conditions.
  • “Standard” in the "Condition C” column is a laser processing condition that differs from “Condition C” only in that the modulation pattern does not include a trefoil aberration pattern.
  • “Standard” in the “Condition D” stage is a laser processing condition that differs from “Condition D” only in that the modulation pattern does not include a trefoil aberration pattern.
  • a modified region 12 is formed in the object 11 along a line A, and the incident direction (Z direction) of the laser beam L from the modified region 12 and the extending direction of the line A are
  • the incident direction (Z direction) of the laser beam L from the modified region 12 and the extending direction of the line A are
  • the area on the opposite side to the incident side of the laser beam L is
  • the second surface P2 is inclined so as to be located on one side (the left side in FIG.
  • the Trefoil aberration pattern is such that the first extending part 91 is located on the left side) and the second extending part 92 and the third extending part 93 are located on the other side (right side in FIG. 18) with respect to the line A. What is necessary is to display a modulation pattern including the following on the spatial light modulator 7.
  • a modified region 12 is formed in the object 11 along line A, and the incident direction (Z direction) of the laser beam L from the modified region 12 and the extending direction of line A are When forming a crack 13 in the object 11 along the second surface P2 that is inclined with respect to the first surface P1 that is parallel to both directions (X direction), the area on the opposite side to the incident side of the laser beam L is When the second surface P2 is inclined so as to be located on the other side (the right side in FIG.
  • the Trefoil aberration pattern is such that the first extending part 91 is located on the right side) and the second extending part 92 and the third extending part 93 are located on one side (left side in FIG. 19) with respect to the line A. What is necessary is to display a modulation pattern including the following on the spatial light modulator 7.
  • the focused spot C is relatively moved along each of the first line and the second line set on the object 11 as the line A.
  • the first extension portion 91 is placed on one side with respect to each of the first line and the second line.
  • a trefoil aberration pattern is formed such that What is necessary is to switch the direction of the included modulation pattern.
  • the angle between the first surface P1 and the second surface P2 (that is, the acute angle formed by the first surface P1 and the second surface P2) is
  • a modulation pattern including a trefoil aberration pattern with the first trefoil aberration intensity is displayed on the spatial light modulator 7, and when the angle is set as a second angle larger than the first angle, the first trefoil aberration intensity is
  • the spatial light modulator 7 may display a modulation pattern including a trefoil aberration pattern having a second trefoil aberration intensity stronger than the trefoil aberration intensity.
  • FIG. 20 is a diagram showing an object 11 to which the first example of the laser processing method is applied.
  • the object 11 is a semiconductor wafer having a first surface 11a and a second surface 11b.
  • the object 11 includes a silicon wafer and a plurality of functional elements (not shown) formed on the first surface 11a side of the silicon wafer.
  • the plurality of functional elements are arranged in a matrix along the first surface 11a with a notch 11c formed in the object 11 as a reference.
  • Each functional element is, for example, a light receiving element such as a photodiode, a light emitting element such as a laser diode, a circuit element such as a memory, and the like.
  • Each functional element may be configured three-dimensionally by stacking a plurality of layers. Note that an orientation flat may be formed on the object 11 instead of the notch 11c.
  • a first example of the laser processing method is carried out in the laser processing apparatus 1 described above.
  • the object 11 shown in FIG. 20 is cut into functional elements along each of a plurality of processing surfaces P10 extending in a grid pattern.
  • Each processed surface P10 is a plane perpendicular to the first surface 11a and the second surface 11b.
  • two rows of modified regions 12 aligned in the thickness direction of the object 11 are formed inside the object 11 along the line A.
  • a modified region 12 is formed in the object 11 along a line A extending within the processing surface P10, and a crack 13 is formed in the object 11 along the first surface P1.
  • the widths of the modified region 12 and the crack 13 in the direction of incidence of the laser beam L are made small, and the crack 13 is made small with respect to the line A. I want to suppress meandering.
  • the first extension part 91 is located on the line A
  • the second extension part 92 is located on one side with respect to the line A
  • the second extension part 92 is located on the other side with respect to the line A.
  • the first extending part 91 is located in the front side in the direction in which the focused spot C moves relatively along the line A
  • the control unit 6 causes the spatial light modulator 7 to display a modulation pattern including the trefoil aberration pattern so that the second extension part 92 and the third extension part 93 are located on the side.
  • the control unit 6 changes the modulation pattern including the trefoil aberration pattern with stronger trefoil aberration intensity to the spatial light. Displayed on the modulator 7.
  • the control unit 6 controls the support unit 2 so that the focused spot C moves relatively along the line A.
  • the drive section 4 is caused to drive.
  • the laser beam L may be incident on the first surface 11a side of the object 11, or the laser beam L may be incident on the second surface 11b side of the object 11. You can. Furthermore, one row of modified regions 12 may be formed inside the object 11 along line A, or three or more rows of modified regions 12 lined up in the thickness direction of object 11 may be formed along line A. It may be formed inside the object 11. When a plurality of rows of modified regions 12 arranged in the thickness direction of the object 11 are formed inside the object 11 along the line A, the laser beam L is spatially modulated so as to have a plurality of focused spots C.
  • a plurality of rows of modified regions 12 are created inside the object 11 along the line A by one scan of the laser beam L (relative movement of the laser beam L along the line A). may be formed.
  • a dicing tape may be attached to the first surface 11a or the second surface 11b opposite to the surface on which the laser beam L is incident, or the first surface on which the laser beam L is incident.
  • a dicing tape that is transparent to the laser beam L may be attached to the first surface 11a or the second surface 11b.
  • the second surface 11b of the object 11 may be ground to make the object 11 thinner. At that time, the modified region 12 formed in the object 11 may be removed.
  • a modified region 12 (hereinafter referred to as "first modified region") near the surface on the emission side of the laser beam L (second surface 11b in the example shown in FIG. 21)
  • the first modified region is formed so that the cracks 13 do not reach the surface on the emission side of the laser beam L from the first modified region, and the first modified region and the surface on the incidence side of the laser beam L are formed.
  • the first surface 11a when forming the modified region 12 (hereinafter referred to as "second modified region"), the first modified region and the second The cracks 13 may be connected to the modified region, and the cracks 13 may be made to reach the surface on the emission side of the laser beam L from the first modified region (hereinafter referred to as "light leakage damage suppression processing").
  • the first extending portion 91 is located on the line A
  • the second extending portion 92 is located on one side with respect to the line A
  • the first extending portion 91 is located on the line A.
  • the control unit 6 causes the spatial light modulator 7 to display a modulation pattern including a trefoil aberration pattern so that the third extension part 93 is located on the other side with respect to A, thereby forming a second modified region.
  • the control unit 6 transmits a modulation pattern that does not include a trefoil aberration pattern (or a modulation pattern that includes a trefoil aberration pattern having a weaker trefoil aberration intensity than when forming the first modified region) to the spatial light modulator 7.
  • the first extending portion 91 is located on line A
  • the second extending portion 92 is located on one side with respect to line A
  • the first extending part 91 is located in front of the direction in which the focused spot C moves relatively along the line A
  • the third extending part 93 is located on the other side.
  • the above findings are applicable when forming "at least one row of first modified regions" and "at least one row of second modified regions” inside the target object 11 along line A in the thickness direction of the target object 11. Applicable to In this case, the number of rows of the first modified region and the number of rows of the second modified region may be the same or different.
  • the laser beam L is modulated by the spatial light modulator 7 so as to have a plurality of focused spots C, and by one scan of the laser beam L, multiple rows of the first modified region are lined up. It may be formed inside the object 11 along A. Also in this case, the first extension part 91 is located on line A, the second extension part 92 is located on one side with respect to line A, and the third extension part 92 is located on the other side with respect to line A.
  • the control unit 6 causes the spatial light modulator 7 to display a modulation pattern including the trefoil aberration pattern so that the existing portion 93 is located.
  • the first extending part 91 is located on line A
  • the second extending part 92 is located on one side with respect to line A
  • the third extending part 93 is located on the other side with respect to line A.
  • the first extension part 91 is located on the front side in the direction in which the focused spot C moves relatively along line A
  • the control unit 6 causes the spatial light modulator 7 to display a modulation pattern including the trefoil aberration pattern so that the third extension portion 93 is located.
  • a plurality of rows of first modified regions may be formed inside the object 11 along the line A by each scan of the laser beam L a plurality of times. Note that even when a plurality of rows of first modified regions are formed inside the object 11 along the line A by one scan of the laser beam L, a plurality of rows of first modified regions are formed by each of the plurality of scans of the laser beam L. Even when each of the first modified regions in the rows is formed inside the object 11 along the line A, it is preferable that the cracks extending from each of the first modified regions in the plurality of rows do not connect to each other.
  • a plurality of focused spots C are formed in order to increase the takt time. Even if the laser beam L is modulated by the spatial light modulator 7 so that a plurality of rows of second modified regions are formed inside the object 11 along the line A by one scan of the laser beam L. good.
  • the plural rows of second modified regions are formed by each of the plurality of scans of the laser beam L.
  • Each of the second modified regions may be formed inside the object 11 along the line A.
  • FIG. 22 is a diagram illustrating an example of a cut surface of the object 11 obtained by processing to suppress damage caused by light leakage.
  • the example of the cut plane shown in FIGS. 22(a) and (b) shows "three rows of first modified regions” and "three rows of second modified regions” arranged in the thickness direction of the object 11. This is obtained by forming it inside the object 11 along line A.
  • three rows of first modified regions are formed inside the object 11 along the line A by one scan of the laser beam L, and then, Three rows of second modified regions were formed inside the object 11 along the line A by one scan of the laser beam L.
  • FIG. 22 is a diagram illustrating an example of a cut surface of the object 11 obtained by processing to suppress damage caused by light leakage.
  • the example of the cut plane shown in FIGS. 22(a) and (b) shows "three rows of first modified regions" and "three rows of second modified regions” arranged in the thickness direction of the object 11. This is obtained by forming it inside the object 11 along line A.
  • FIG. 22(a) when forming three rows of first modified regions, a modulation pattern that does not include a trefoil aberration pattern is displayed on the spatial light modulator 7.
  • the first extending portion 91 is located on line A, and the second extending portion is located on one side with respect to line A.
  • 92 and the third extension part 93 is located on the other side with respect to the line A, and the first extension part 93 is located on the front side in the direction in which the focused spot C moves relatively along the line A.
  • a modulation pattern including a trefoil aberration pattern was displayed on the spatial light modulator 7 such that the existing portion 91 was located and the second extending portion 92 and the third extending portion 93 were located on the rear side in this direction.
  • twist hackles occurred in the region where the three rows of first modified regions were formed, and the way the cracks grew was not stable.
  • FIG. 22(b) the occurrence of twist hackles was suppressed in the region where the three rows of first modified regions were formed, and the growth of cracks was also stabilized.
  • FIGS. 23A and 23B are diagrams showing an object 100 to which the second example of the laser processing method is applied.
  • the object 100 includes an object 11 and an object 11R that is a separate member from the object 11.
  • Each target object 11, 11R is, for example, a silicon wafer.
  • a device layer 110 including a plurality of functional elements (not shown) is formed on the second surface 11b of the object 11.
  • a device layer 110R including a plurality of functional elements (not shown) is formed on one surface of the object 11R.
  • the device layer 110 and the device layer 110R are bonded to each other.
  • a second example of the laser processing method is carried out in the laser processing apparatus 1 described above.
  • the object 11 shown in FIGS. 23A and 23B is cut along each of the processing surface P11, the processing surface P12, and the plurality of processing surfaces P13, and The outer edge portion of the object 11 is removed (trimming process).
  • the processed surface P11 is a cylindrical surface having a center line parallel to the Z direction.
  • the processed surface P12 is a truncated conical tapered surface that expands from the end of the processed surface P11 on the device layer 110 side toward the outer edge of the device layer 110R.
  • the plurality of processing surfaces P13 are planes extending from the processing surface P11 to the outer edge of the object 11.
  • the line A extends circumferentially within the processing surface P12, but when the line A is a curved line, the extending direction of the line A is defined as means the tangential direction.
  • a modified region 12 is formed in the object 11 along the line A extending within the processing surface P12, and a crack 13 is formed in the object 11 along the second surface P2.
  • the second surface P2 is inclined such that the region on the opposite side to the incident side of the laser beam L is located on the outside in the direction perpendicular to the first surface P1 (Y direction). ing.
  • the first extension part 91 is located outside the line A, and the second extension part 92 and the third extension part 93 are located inside the line A.
  • the control unit 6 causes the spatial light modulator 7 to display a modulation pattern including the trefoil aberration pattern.
  • the control unit 6 applies a modulation pattern including a trefoil aberration pattern with a stronger trefoil aberration intensity to the spatial light modulator 7. Display.
  • the control unit 6 controls the support unit 2 so that the focused spot C moves relatively along the line A.
  • the drive section 4 is caused to drive. Subsequently, a plurality of modified regions 12 arranged in the thickness direction of the object 11 are formed along each of the processed surface P11 and the plurality of processed surfaces P13. After the above steps are performed, the outer edge portion of the object 11 is removed, and the first surface 11a of the object 11 is polished to remove the portion where the processed surface P11 was set. [Action and effect]
  • the beam shape 9 of the laser light L at the focused spot C has a center portion 90 and a first extension extending radially from the center portion 90.
  • the focused spot C is located along the line A set on the object 11, including the existing part 91, the second extending part 92, and the third extending part 93, and having the highest intensity in the central part 90. can be moved relative to each other.
  • the state of at least one of the modified region 12 and the crack 13 formed in the object 11 can be adjusted. Therefore, according to the laser processing apparatus 1, appropriate modified regions 12 and cracks 13 can be formed in the object 11 according to the processing.
  • a modified region 12 is formed in the object 11 along the line A, and a first surface parallel to both the incident direction of the laser beam L and the extending direction of the line A is formed from the modified region 12.
  • the control unit 6 determines that the first extension part 91 is located on the line A and the second extension part is located on one side with respect to the line A.
  • a modulation pattern including a trefoil aberration pattern is displayed on the spatial light modulator 7 such that the third extension part 93 is located on the other side with respect to the line A.
  • the width of the crack 13 in the incident direction of the laser beam L can be made smaller than, for example, when the modulation pattern does not include a trefoil aberration pattern.
  • the control unit 6 is configured such that the first extension part 91 is located on the front side in the direction in which the focused spot C moves relatively along the line A, and the second extension part 91 is located on the rear side in the direction in which the focused spot C moves relatively along the line A.
  • a modulation pattern including a trefoil aberration pattern is displayed on the spatial light modulator 7 such that the third extension portion 92 and the third extension portion 93 are located.
  • the control unit 6 moves the focal spot C along the first line and the second line, respectively.
  • Trefoil aberration is created such that the first extension part 91 is located on the front side in the direction in which the light spot C moves relatively, and the second extension part 92 and the third extension part 93 are located on the rear side in the direction. Switch the orientation of modulation patterns including patterns.
  • the first line and The first extension part 91 is located on the front side in the direction in which the focused spot C moves relatively along each of the second lines, and the second extension part 92 and the third extension part are on the rear side in the direction. 93 can be easily and reliably realized.
  • the controller 6 sets a trefoil aberration pattern with a first trefoil aberration intensity.
  • the spatial light modulator 7 displays a modulation pattern including a modulation pattern, and when at least one of the widths is a second width smaller than the first width, a trefoil aberration with a second trefoil aberration intensity stronger than the first trefoil aberration intensity.
  • a modulation pattern including the pattern is displayed on the spatial light modulator 7.
  • a modified region 12 is formed in the object 11 along the line A, and a first surface parallel to both the incident direction of the laser beam L and the extending direction of the line A is formed from the modified region 12.
  • the region opposite to the incident side of the laser beam L is on one side in the direction perpendicular to the first surface P1.
  • the second surface P2 is inclined so as to be located at A modulation pattern including a trefoil aberration pattern is displayed on the spatial light modulator 7 so that the second extension part 92 and the third extension part 93 are located.
  • the cracks 13 extending from the modified region 12 can be inclined to a desired side.
  • the control unit 6 controls one direction for each of the first line and the second line. Trefoil aberration such that the first extending part 91 is located on the side of Switch the orientation of modulation patterns including patterns.
  • the first line and A first extending portion 91 is located on one side with respect to each of the second lines, and a second extending portion 92 and a third extending portion are located on the other side with respect to each of the first line and the second line. 93 can be easily and reliably realized.
  • the control unit 6 when the control unit 6 sets the angle between the first surface P1 and the second surface P2 as the first angle, the control unit 6 spatially modulates the modulation pattern including the trefoil aberration pattern with the first trefoil aberration intensity.
  • a modulation pattern including a trefoil aberration pattern with a second trefoil aberration intensity stronger than the first trefoil aberration intensity is displayed on the spatial light. Displayed on the modulator 7. Thereby, the angle at which the cracks 13 extending from the modified region 12 are inclined can be set to an appropriate angle depending on the processing.
  • the spatial light modulator 7 is not limited to a reflective type, but may be a transmissive type.
  • the optical system that transfers the image of the laser beam L on the modulation surface 7a of the spatial light modulator 7 to the entrance pupil plane 33a of the condenser 33 is limited to the 4f lens unit 34 having a pair of lenses 34A and 34B.
  • the first lens system for example, a cemented lens, three or more lenses, etc.
  • the second lens system for example, a cemented lens, three or more lenses, etc.
  • the drive section 4 drives the support section 2, and the drive section 5 drives the light collecting section 33 by driving the irradiation section 3,
  • the drive section of the present disclosure The section is not limited to such.
  • the drive unit 4 may move the support unit 2 in each of the Z direction, the X direction, and the Y direction, and rotate the support unit 2 using an axis parallel to the Z direction as the rotation axis.
  • the drive section 5 may move the light condensing section 33 in each of the Z direction, the X direction, and the Y direction, and may move the light condensing section 33 with an axis parallel to the Z direction as the center line.
  • the drive unit of the present disclosure may be any drive unit that drives at least one of the support unit and the light condensing unit.
  • control unit 6 controls the support unit 2, the irradiation unit 3, and the drive units 4 and 5, but the control unit of the present disclosure is not limited to such a unit.
  • the control unit of the present disclosure may be any unit as long as it controls at least the spatial light modulator and the drive unit.
  • the Trefoil is arranged such that the first extending portion 91 is located on one side with respect to line A, and the second extending portion 92 and third extending portion 93 are located on the other side with respect to line A.
  • the laser processing method of displaying a modulation pattern including an aberration pattern on the spatial light modulator 7 can also be used when cutting a wafer into a plurality of square pyramid-shaped chips, cutting out a plurality of truncated cone-shaped wafers from a wafer, etc. It is valid.
  • SYMBOLS 1 Laser processing device, 2... Support part, 4, 5... Drive part, 6... Control part, 7... Spatial light modulator, 9... Beam shape, 11... Target object, 12... Modified region, 13... Crack, 31...Light source, 33...Condensing part, 90...Central part, 91...First extension part, 92...Second extension part, 93...Third extension part, A...Line, C...Condensing spot, L ...Laser light, P1...first surface, P2...second surface.

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Abstract

La présente invention concerne un dispositif de traitement laser qui comprend une unité de support pour supporter un objet cible, une source de lumière pour émettre une lumière laser, un modulateur optique spatial pour moduler la lumière laser par affichage d'un motif de modulation, une unité de condensation pour condenser la lumière laser sur l'objet cible, une unité d'entraînement pour entraîner l'unité de support et/ou l'unité de condensation, ainsi qu'une unité de commande. L'unité de commande amène le modulateur optique spatial à afficher un motif de modulation qui comprend un motif d'aberration en trèfle de telle sorte qu'une forme de faisceau de la lumière laser au niveau d'un point focal comprend une partie centrale et une première partie étendue, une deuxième partie étendue et une troisième partie étendue qui s'étendent selon un motif radial à partir de la partie centrale et de telle sorte que l'intensité la plus élevée dans le centre de forme de faisceau se trouve dans la partie centrale. L'unité de commande amène l'unité d'entraînement à entraîner l'unité de support et/ou l'unité de condensation de telle sorte que le point focal se déplace relativement le long d'une ligne.
PCT/JP2023/028946 2022-09-13 2023-08-08 Dispositif de traitement laser et procédé de traitement laser WO2024057780A1 (fr)

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JP2022145550A JP2024040900A (ja) 2022-09-13 2022-09-13 レーザ加工装置及びレーザ加工方法

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021087974A (ja) * 2019-12-04 2021-06-10 浜松ホトニクス株式会社 レーザ加工装置
JP2021090990A (ja) * 2019-12-11 2021-06-17 株式会社ディスコ レーザービームのスポット形状の補正方法
JP2022029227A (ja) * 2020-08-04 2022-02-17 株式会社ディスコ レーザー加工装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021087974A (ja) * 2019-12-04 2021-06-10 浜松ホトニクス株式会社 レーザ加工装置
JP2021090990A (ja) * 2019-12-11 2021-06-17 株式会社ディスコ レーザービームのスポット形状の補正方法
JP2022029227A (ja) * 2020-08-04 2022-02-17 株式会社ディスコ レーザー加工装置

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