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WO2019198513A1 - Dispositif, système et procédé de traitement au laser - Google Patents

Dispositif, système et procédé de traitement au laser Download PDF

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Publication number
WO2019198513A1
WO2019198513A1 PCT/JP2019/013293 JP2019013293W WO2019198513A1 WO 2019198513 A1 WO2019198513 A1 WO 2019198513A1 JP 2019013293 W JP2019013293 W JP 2019013293W WO 2019198513 A1 WO2019198513 A1 WO 2019198513A1
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WO
WIPO (PCT)
Prior art keywords
substrate
processing
unit
laser beam
measurement
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2019/013293
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English (en)
Japanese (ja)
Inventor
弘明 森
義広 川口
隼斗 田之上
和哉 久野
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tokyo Electron Ltd
Original Assignee
Tokyo Electron Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
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Publication of WO2019198513A1 publication Critical patent/WO2019198513A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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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
    • B23K26/03—Observing, e.g. monitoring, the workpiece
    • 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
    • B23K26/36—Removing material
    • B23K26/362—Laser etching
    • B23K26/364—Laser etching for making a groove or trench, e.g. for scribing a break initiation groove
    • 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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques

Definitions

  • the present disclosure relates to a laser processing apparatus, a laser processing system, and a laser processing method.
  • the main surface of a substrate such as a semiconductor wafer is partitioned by a plurality of streets formed in a lattice shape, and devices such as elements, circuits, and terminals are formed in advance in each partitioned region.
  • a chip is obtained by dividing the substrate along a plurality of streets formed in a lattice shape.
  • a laser processing apparatus is used for dividing the substrate.
  • the laser processing apparatus of Patent Document 1 includes a condensing point position adjusting unit that displaces a condensing point position of a processing laser beam for processing a substrate, a height position detecting unit that detects an upper surface height position of the substrate, And a control means for controlling the condensing point position adjusting means based on a detection signal from the height position detecting means.
  • the modified layer can be formed at a uniform predetermined depth position from the upper surface of the substrate.
  • the height position detecting means of Patent Document 1 has a laser displacement meter that measures the upper surface height of the substrate by irradiating the upper surface of the substrate with a measurement laser beam and receiving the reflected light.
  • the measurement laser beam has a wavelength different from that of the processing laser beam and has the same path as the processing laser beam from a dichroic mirror (Dichroic mirror) provided in the middle of the processing laser beam path to the upper surface of the substrate.
  • Dichroic mirror dichroic mirror
  • the dichroic mirror transmits a laser beam having a specific wavelength (for example, a processing laser beam) and reflects a laser beam having another specific wavelength (for example, a measuring laser beam). Thereby, the laser beam for processing and the laser beam for measurement can be simultaneously irradiated to one point on the upper surface of the substrate.
  • a specific wavelength for example, a processing laser beam
  • a laser beam having another specific wavelength for example, a measuring laser beam
  • One aspect of the embodiment provides a technique in which the vertical position of the irradiation point of the processing laser beam on the upper surface of the substrate can be measured with a small laser displacement meter.
  • a laser processing apparatus includes: A substrate holding part for horizontally holding the substrate from below; A processing laser oscillation section for oscillating a processing laser beam for processing the substrate; An irradiation point moving unit for moving the irradiation point of the processing laser beam on the upper surface of the substrate held by the substrate holding unit; A height measuring unit for measuring the vertical position of the irradiation point; A condensing part that condenses the laser beam for processing from above to below the irradiation point; A light collecting unit moving unit for moving the light collecting unit in a vertical direction; A control unit that controls the vertical position of the light collecting unit based on the vertical position of the irradiation point while moving the irradiation point on a plurality of division lines on the upper surface of the substrate; The height measurement unit includes a measurement laser oscillation unit that oscillates a measurement laser beam having a wavelength different from that of the processing laser beam, and the measurement laser beam irradiated to the upper surface of the substrate from the middle along the
  • the vertical position of the irradiation point of the processing laser beam on the upper surface of the substrate can be measured with a small laser displacement meter.
  • FIG. 1 is a perspective view showing a substrate before processing by the substrate processing system according to the first embodiment.
  • FIG. 2 is a plan view showing the substrate processing system according to the first embodiment.
  • FIG. 3 is a flowchart showing the substrate processing method according to the first embodiment.
  • FIG. 4 is a plan view showing the laser processing unit according to the first embodiment.
  • FIG. 5 is a front view showing the laser processing unit according to the first embodiment.
  • FIG. 6 is a side view showing the processing head unit and the substrate holding unit according to the first embodiment.
  • FIG. 7 is a plan view showing the moving path of the irradiation point of the processing laser beam on the upper surface of the substrate according to the first embodiment and an extended surface obtained by horizontally extending the upper surface.
  • FIG. 1 is a perspective view showing a substrate before processing by the substrate processing system according to the first embodiment.
  • FIG. 2 is a plan view showing the substrate processing system according to the first embodiment.
  • FIG. 3 is a flowchart showing the substrate processing method according
  • FIG. 8 is a diagram showing the path of the processing laser beam and the path of the measurement laser beam according to the first embodiment.
  • FIG. 9 is a diagram showing the relationship between the vertical position of the measurement laser beam irradiation point on the upper surface of the substrate and the size of the measurement laser beam irradiation point on the upper surface of the substrate according to the first embodiment.
  • FIG. 10 is a diagram schematically showing the relationship between the material and film thickness of the film forming the upper surface of the substrate according to the first embodiment and the reflectance of the measurement laser beam on the upper surface of the substrate.
  • FIG. 11 schematically shows the relationship between the output of the measurement laser oscillator according to the first embodiment, the reflectance of the measurement laser beam on the upper surface of the substrate, and the intensity of the reflected light received by the second light receiving element.
  • FIG. 12 is a flowchart illustrating a first example of processing by the control unit according to the first embodiment.
  • FIG. 13 is a flowchart illustrating a second example of processing by the control unit according to the first embodiment.
  • FIG. 14 is a front view showing a laser processing unit according to the second embodiment.
  • FIG. 15 is a flowchart illustrating processing of the control unit according to the second embodiment.
  • FIG. 16 is a diagram illustrating functional elements of the control unit according to the third embodiment.
  • FIG. 17 is a flowchart illustrating processing of the control unit according to the third embodiment.
  • the same or corresponding components may be denoted by the same or corresponding reference numerals and description thereof may be omitted.
  • the X axis direction, the Y axis direction, and the Z axis direction are directions perpendicular to each other
  • the X axis direction and the Y axis direction are horizontal directions
  • the Z axis direction is a vertical direction.
  • the rotation direction with the vertical axis as the center of rotation is also called the ⁇ direction.
  • “lower” means the lower side in the vertical direction
  • “upper” means the upper side in the vertical direction.
  • FIG. 1 is a perspective view showing a substrate before processing by the substrate processing system according to the first embodiment.
  • the substrate 10 is, for example, a semiconductor substrate or a sapphire substrate.
  • the first main surface 11 of the substrate 10 is partitioned by a plurality of streets formed in a lattice shape, and devices such as elements, circuits, and terminals are formed in advance in each partitioned region.
  • a chip is obtained by dividing the substrate 10 along a plurality of streets formed in a lattice shape.
  • the planned dividing line 13 is set on the street.
  • a protective tape 14 (see FIG. 6) is bonded to the first main surface 11 of the substrate 10.
  • the protective tape 14 protects the first main surface 11 of the substrate 10 and protects a device formed in advance on the first main surface 11 during laser processing.
  • the protective tape 14 covers the entire first main surface 11 of the substrate 10.
  • the protective tape 14 includes a sheet base material and an adhesive applied to the surface of the sheet base material.
  • the pressure-sensitive adhesive may be cured by irradiating with ultraviolet rays to reduce the adhesive strength. After the adhesive force is reduced, the protective tape 14 can be easily peeled from the substrate 10 by a peeling operation.
  • the protective tape 14 may be attached to the frame so as to cover the opening of the ring-shaped frame, and may be bonded to the substrate 10 at the opening of the frame. In this case, the substrate 10 can be transported while holding the frame, and the handling property of the substrate 10 can be improved.
  • FIG. 2 is a plan view showing the substrate processing system according to the first embodiment.
  • the carry-in cassette 35 and the carry-out cassette 45 are broken, and the inside of the carry-in cassette 35 and the inside of the carry-out cassette 45 are illustrated.
  • the substrate processing system 1 is a laser processing system that performs laser processing of the substrate 10.
  • the substrate processing system 1 includes a control unit 20, a carry-in unit 30, a carry-out unit 40, a conveyance path 50, a conveyance unit 58, and various processing units. Although it does not specifically limit as a process part, For example, the alignment part 60 and the laser processing part 100 are provided.
  • the transport unit 58 corresponds to the transport device described in the claims
  • the alignment unit 60 corresponds to the alignment device described in the claims
  • the control unit 20 is configured by a computer, for example, and includes a CPU (Central Processing Unit) 21, a storage medium 22 such as a memory, an input interface 23, and an output interface 24 as shown in FIG.
  • the control unit 20 performs various controls by causing the CPU 21 to execute a program stored in the storage medium 22. Further, the control unit 20 receives a signal from the outside through the input interface 23 and transmits the signal through the output interface 24 to the outside.
  • a CPU Central Processing Unit
  • the program of the control unit 20 is stored in the information storage medium and installed from the information storage medium.
  • Examples of the information storage medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical desk (MO), and a memory card.
  • the program may be downloaded from a server via the Internet and installed.
  • the carry-in unit 30 is for carrying the carry-in cassette 35 from the outside.
  • the carry-in unit 30 includes a placement plate 31 on which the carry-in cassette 35 is placed.
  • a plurality of mounting plates 31 are provided in a row in the Y-axis direction. The number of mounting plates 31 is not limited to that shown in the figure.
  • the carry-in cassette 35 stores a plurality of substrates 10 before processing at intervals in the Z-axis direction.
  • the carry-in cassette 35 may store the substrate 10 horizontally with the protective tape 14 facing upward in order to suppress deformation of the protective tape 14 such as a sag.
  • the substrate 10 taken out from the carry-in cassette 35 is turned upside down and transferred to a processing unit such as the alignment unit 60.
  • the unloading unit 40 is for the unloading cassette 45 to be unloaded.
  • the carry-out unit 40 includes a placement plate 41 on which the carry-out cassette 45 is placed.
  • a plurality of mounting plates 41 are provided in a row in the Y-axis direction. The number of mounting plates 41 is not limited to that shown in the figure.
  • the carry-out cassette 45 stores a plurality of processed substrates 10 at intervals in the Z-axis direction.
  • the transport path 50 is a path through which the transport unit 58 transports the substrate 10 and extends, for example, in the Y-axis direction.
  • the transport path 50 is provided with a Y-axis guide 51 extending in the Y-axis direction, and the Y-axis slider 52 is movable along the Y-axis guide 51.
  • the transfer unit 58 holds the substrate 10 and moves along the transfer path 50 to transfer the substrate 10.
  • the transport unit 58 may hold the substrate 10 via a frame.
  • the transport unit 58 vacuum-sucks the substrate 10, but may electrostatically suction the substrate 10.
  • the transport unit 58 includes a Y-axis slider 52 as a transport base and moves along the Y-axis direction.
  • the conveyance unit 58 is movable not only in the Y-axis direction but also in the X-axis direction, the Z-axis direction, and the ⁇ direction. Further, the transport unit 58 has a reversing mechanism that flips the substrate 10 upside down.
  • the transport unit 58 may include a plurality of holding units that hold the substrate 10.
  • the plurality of holding portions are provided side by side in the Z-axis direction at intervals.
  • the plurality of holding units may be used properly according to the processing stage of the substrate 10.
  • the carry-in unit 30, the carry-out unit 40, the alignment unit 60, and the laser processing unit 100 are provided adjacent to the conveyance path 50 as viewed in the vertical direction.
  • the longitudinal direction of the transport path 50 is the Y-axis direction.
  • a carry-in unit 30 and a carry-out unit 40 are provided on the negative side of the conveyance path 50 in the X-axis direction.
  • an alignment unit 60 and a laser processing unit 100 are provided on the X axis positive direction side of the conveyance path 50.
  • the arrangement and number of processing units such as the alignment unit 60 and the laser processing unit 100 are not limited to the arrangement and number shown in FIG. 2 and can be arbitrarily selected.
  • the plurality of processing units may be distributed or integrated in an arbitrary unit. Hereinafter, each processing unit will be described.
  • the alignment unit 60 measures the center position of the substrate 10 and the crystal orientation of the substrate 10 (for example, the direction of the notch 19). For example, the alignment unit 60 moves the substrate holding unit that holds the substrate 10 from below, the imaging unit that images the substrate 10 held by the substrate holding unit, and the imaging position of the substrate 10 by the imaging unit. Part. Note that the crystal orientation of the substrate 10 may be represented by an orientation flat instead of the notch 19.
  • the laser processing unit 100 performs laser processing of the substrate 10. For example, the laser processing unit 100 performs laser processing (so-called laser dicing) for dividing the substrate 10 into a plurality of chips.
  • the laser processing unit 100 irradiates one point of the planned dividing line 13 (see FIG. 1) with the processing laser beam LB1 (see FIG. 6), and moves the irradiation point on the planned dividing line 13 to thereby laser the substrate 10. Processing.
  • FIG. 3 is a flowchart showing the substrate processing method according to the first embodiment.
  • the substrate processing method includes a carry-in process S101, an alignment process S102, a laser processing process S103, and a carry-out process S104. These steps are performed under the control of the control unit 20.
  • the transport unit 58 takes out the substrate 10 from the carry-in cassette 35 placed in the carry-in unit 30, and then transports the taken-out substrate 10 upside down to the alignment unit 60.
  • the alignment unit 60 measures the center position of the substrate 10 and the crystal orientation of the substrate 10 (for example, the direction of the notch 19). Based on the measurement result, alignment of the substrate 10 in the X-axis direction, the Y-axis direction, and the ⁇ direction is performed.
  • the aligned substrate 10 is transported from the alignment unit 60 to the laser processing unit 100 by the transport unit 58.
  • the laser processing unit 100 performs laser processing of the substrate 10.
  • the laser processing unit 100 irradiates one point of the planned dividing line 13 (see FIG. 1) with the processing laser beam LB1 (see FIG. 6), and moves the irradiation point on the planned dividing line 13 to make a plurality of substrates 10. Laser processing to divide into chips.
  • the transport unit 58 transports the substrate 10 from the laser processing unit 100 to the unloading unit 40, and stores the substrate 10 in the unloading cassette 45 in the unloading unit 40.
  • the carry-out cassette 45 is carried out from the carry-out unit 40 to the outside.
  • FIG. 4 is a plan view showing the laser processing unit according to the first embodiment.
  • Fig.4 (a) is a top view which shows the state at the time of the alignment process of a laser processing part.
  • FIG. 4B is a plan view showing a state during laser processing of the laser processing unit.
  • FIG. 5 is a front view showing the laser processing unit according to the first embodiment.
  • FIG. 6 is a side view showing the processing head unit and the substrate holding unit according to the first embodiment.
  • the laser processing unit 100 includes a substrate holding unit 110, an alignment unit 120, a processing head unit 130, a processing head lifting / lowering unit 135, a substrate moving unit 140, and a control unit 20.
  • the control unit 20 is provided separately from the laser processing unit 100 in FIG. 2, but may be provided as a part of the laser processing unit 100.
  • the substrate holding unit 110 holds the substrate 10 horizontally from below. As shown in FIG. 6, the substrate 10 is placed on the upper surface of the substrate holding unit 110 with the first main surface 11 protected by the protective tape 14 facing down.
  • the substrate holding unit 110 holds the substrate 10 via the protective tape 14.
  • a vacuum chuck is used as the substrate holding unit 110, but an electrostatic chuck or the like may be used.
  • the alignment unit 120 detects the division line 13 (see FIG. 1) of the substrate 10 held by the substrate holding unit 110.
  • the division lines 13 of the substrate 10 are set on a plurality of streets that are formed in advance on the first main surface 11 of the substrate 10 in a lattice shape.
  • the alignment unit 120 includes an imaging unit 121 that captures an image of the substrate 10 held by the substrate holding unit 110, for example.
  • the imaging unit 121 is immovable in the horizontal direction with respect to the fixed base 101, but may be movable in the horizontal direction with respect to the fixed base 101.
  • the imaging unit 121 may be movable in the vertical direction with respect to the fixed base 101 in order to adjust the focus height of the imaging unit 121.
  • the imaging unit 121 is provided above the substrate holding unit 110 and images a street previously formed on the lower surface (for example, the first main surface 11) of the substrate 10 from above the substrate 10 held by the substrate holding unit 110.
  • an infrared camera that captures an infrared image that passes through the substrate 10 may be used as the imaging unit 121.
  • the imaging unit 121 converts the captured image of the substrate 10 into an electrical signal and transmits the electrical signal to the control unit 20.
  • the control unit 20 detects the position of the planned dividing line 13 of the substrate 10 by performing image processing on the image of the substrate 10 before laser processing captured by the imaging unit 121.
  • a detection method thereof a method of matching a street pattern previously formed in a grid pattern on the first main surface 11 of the substrate 10 with a reference pattern, a center point of the substrate 10 from a plurality of points on the outer periphery of the substrate 10
  • a known method such as a method for obtaining the orientation of the substrate 10 is used.
  • the orientation of the substrate 10 is detected from the position of a notch 19 (see FIG. 1) formed on the outer periphery of the substrate 10.
  • an orientation flat may be used.
  • the control unit 20 can grasp the position of the division line 13 of the substrate 10 in the coordinate system fixed to the substrate holding unit 110.
  • the image processing may be performed in parallel with the image capturing, or may be performed after the image capturing.
  • Alignment unit 120 may also serve as an inspection unit that detects the result of laser processing of substrate 10 in order to reduce cost and installation area.
  • the result of laser processing is the presence or absence of abnormalities in laser processing. Examples of the presence / absence of abnormality in laser processing include the presence / absence of deviation between the processing trace of the substrate 10 due to irradiation of the processing laser beam LB1 (see FIG. 6) and the planned dividing line 13 and the presence / absence of chipping.
  • the imaging unit 121 images the processing trace of the substrate 10 by irradiation with the processing laser beam LB1 (see FIG. 6).
  • an infrared camera that captures an infrared image that passes through the substrate 10 may be used as the imaging unit 121.
  • the imaging unit 121 converts the captured image of the substrate 10 into an electrical signal and transmits the electrical signal to the control unit 20.
  • the control unit 20 detects the result of laser processing of the substrate 10 by performing image processing on the image of the substrate 10 after laser processing captured by the imaging unit 121.
  • the image processing may be performed in parallel with image capturing or may be performed after image capturing.
  • the alignment unit 120 also serves as an inspection unit in the present embodiment, but may not serve as an inspection unit. That is, the alignment unit 120 and the inspection unit may be provided separately. In that case, the inspection unit may be provided as a part of the laser processing unit 100 or may be provided outside the laser processing unit 100.
  • the processing head unit 130 includes a housing 131 that houses an optical system that irradiates the processing laser beam LB1 from above toward the upper surface (for example, the second main surface 12) of the substrate 10.
  • the machining head unit 130 is not movable in the horizontal direction with respect to the fixed base 101, but may be movable in the horizontal direction with respect to the fixed base 101.
  • the processing laser beam LB1 forms a modified layer 15 serving as a starting point of fracture inside the substrate 10 as shown in FIG.
  • a laser beam having transparency to the substrate 10 is used.
  • the modified layer 15 is formed, for example, by locally melting and solidifying the inside of the substrate 10.
  • the processing laser beam LB1 forms the modified layer 15 serving as a starting point of breakage in the substrate 10, but a laser processing groove may be formed on the upper surface of the substrate 10.
  • the laser processing groove may or may not penetrate the substrate 10 in the thickness direction. In this case, a laser beam having absorptivity with respect to the substrate 10 is used.
  • the processing head lifting / lowering unit 135 moves the processing head unit 130 in the vertical direction with respect to the fixed base 101 in order to adjust the distance between the processing head unit 130 and the substrate 10.
  • the processing head lifting / lowering unit 135 includes, for example, a servo motor and a ball screw that converts the rotational motion of the servo motor into a linear motion.
  • the substrate moving unit 140 moves the substrate holding unit 110 relative to the fixed base 101 as viewed in the Z-axis direction.
  • the substrate moving unit 140 moves the substrate holding unit 110 in the X axis direction, the Y axis direction, and the ⁇ direction.
  • the substrate moving unit 140 may move the substrate holding unit 110 also in the Z-axis direction.
  • the substrate moving unit 140 includes a Y-axis guide 142 extending in the Y-axis direction, and a Y-axis slider 143 that is moved along the Y-axis guide 142.
  • a servo motor or the like is used as a drive source for moving the Y-axis slider 143 in the Y-axis direction.
  • the rotational motion of the servo motor is converted into a linear motion of the Y-axis slider 143 by a motion conversion mechanism such as a ball screw.
  • the substrate moving unit 140 includes an X-axis guide 144 that extends in the X-axis direction, and an X-axis slider 145 that is moved along the X-axis guide 144.
  • a servo motor or the like is used as a drive source for moving the X-axis slider 145 in the X-axis direction.
  • the rotational motion of the servo motor is converted into a linear motion of the X-axis slider 145 by a motion conversion mechanism such as a ball screw.
  • the substrate moving unit 140 includes a turntable 146 (see FIG. 5) that is moved in the ⁇ direction.
  • a servo motor or the like is used as a drive source for moving the rotary table 146 in the ⁇ direction.
  • a Y-axis guide 142 is fixed to the fixed base 101.
  • the Y-axis guide 142 is provided across the alignment unit 120 and the processing head unit 130 as viewed in the Z-axis direction.
  • An X-axis guide 144 is fixed to the Y-axis slider 143 that is moved along the Y-axis guide 142.
  • a rotary table 146 is rotatably provided on the X-axis slider 145 that is moved along the X-axis guide 144.
  • the substrate holder 110 is fixed to the turntable 146.
  • FIG. 7 is a plan view showing the movement path of the irradiation point of the processing laser beam on the upper surface of the substrate according to the first embodiment and an extended surface obtained by extending the upper surface horizontally.
  • the control unit 20 moves the substrate holding unit 110 by the substrate moving unit 140, and processes the laser beam LB1 to one point SP (hereinafter also referred to as “processing start point SP”) detected by the alignment unit 120. Irradiate.
  • control unit 20 moves the substrate holding unit 110 in the X-axis direction to thereby apply an irradiation point P1 of the processing laser beam LB1 on the upper surface of the substrate 10 held by the substrate holding unit 110 (hereinafter referred to as “processing irradiation”). (Also referred to as “point P1”) in the X-axis direction. Thereby, a processing mark extending in the X-axis direction is formed.
  • the position in the Y-axis direction and the position in the ⁇ direction of the substrate holding unit 110 are controlled in advance so that the processing trace and the planned dividing line 13 coincide.
  • control unit 20 repeatedly moves the substrate holding unit 110 in the Y-axis direction and moves the substrate holding unit 110 in the X-axis direction, and sets the processing irradiation point P1 at one point on the planned dividing line 13.
  • Move to EP hereinafter also referred to as “processing end point EP”.
  • processing end point EP a plurality of processing marks extending in the X-axis direction are formed at intervals in the Y-axis direction.
  • the processing trace extending in the X-axis direction may be either a dotted line or a straight line.
  • the dotted line processing mark is formed by using the pulsed laser beam LB1 for processing.
  • the linear processing trace is formed using the processing laser beam LB1 oscillated continuously.
  • control unit 20 rotates the substrate holding unit 110 by 90 ° in the ⁇ direction, and again forms a plurality of processing marks extending in the X-axis direction at intervals in the Y-axis direction. Thereby, a processing trace can be formed along the grid-like division planned lines 13 set on the substrate 10 held by the substrate holding unit 110.
  • machining traces extending in the X-axis direction are formed at intervals in the Y-axis direction.
  • machining traces extending in the Y-axis direction are formed in the X-axis direction. It is also possible to form a plurality at intervals.
  • the substrate moving unit 140 is used as an irradiation point moving unit that moves the processing irradiation point P1, but the technique of the present disclosure is not limited to this.
  • the movement of the processing irradiation point P ⁇ b> 1 can be performed by at least one of the movement of the substrate 10 and the movement of the processing head unit 130.
  • FIG. 8 is a diagram showing the path of the processing laser beam and the path of the measurement laser beam according to the first embodiment.
  • the laser processing unit 100 includes a processing laser oscillation unit 150 that oscillates a processing laser beam LB1 for processing the substrate 10, and a processing laser beam LB1 from above to the processing irradiation point P1. And a condensing part 152 for condensing light.
  • the processing laser oscillation unit 150 is provided, for example, outside the housing 131 of the processing head unit 130 and is fixed to the fixed base 101.
  • the condensing unit 152 is housed inside the housing 131 of the processing head unit 130 and is moved in the vertical direction with respect to the fixed base 101 together with the housing 131.
  • the processing laser oscillation unit 150 oscillates a processing laser beam LB1 having a wavelength that is transparent to the substrate 10, for example.
  • a processing laser oscillation unit 150 for example, a YVO 4- pulse laser oscillator or a YAG pulse laser oscillator is used.
  • the wavelength of the processing laser beam LB1 is, for example, 1064 nm.
  • a plurality of processing laser oscillation units 150 may be prepared and exchanged in order to change the wavelength of the processing laser beam LB1.
  • the processing laser beam LB1 oscillated by the processing laser oscillation unit 150 passes through, for example, the dichroic mirror 154, is then direction-changed by the direction conversion mirror 156, and is guided to the light collecting unit 152.
  • the condensing unit 152 includes a condensing lens.
  • the condensing lens condenses the processing laser beam LB1 oscillated by the processing laser oscillation unit 150, for example, inside the substrate 10. Thereby, the modified layer 15 (see FIG. 6) is formed in the substrate 10.
  • the condensing unit 152 is movable in the vertical direction inside the housing 131 of the processing head unit 130.
  • the laser processing unit 100 includes a condensing unit moving unit 158 that moves the condensing unit 152 in the vertical direction inside the housing 131.
  • the condensing unit moving unit 158 is not particularly limited, but, for example, a high-resolution piezo actuator is used.
  • the piezo actuator includes a piezo element that expands and contracts in the vertical direction according to an applied voltage.
  • the light collecting unit moving unit 158 moves the light collecting unit 152 in the vertical direction, for example, by moving the light collecting unit case 153 that houses the light collecting unit 152 in the vertical direction.
  • the laser processing unit 100 has a height measuring unit 160 that measures the vertical position of the processing irradiation point P1.
  • the height measurement unit 160 transmits a signal indicating the measurement result to the control unit 20.
  • the control unit 20 controls the vertical position of the light collecting unit 152 based on the vertical position of the processing irradiation point P1 while moving the processing irradiation point P1.
  • the modified layer 15 can be formed to a certain depth from the upper surface of the substrate 10.
  • the undulation of the upper surface of the substrate 10 is the undulation caused by the variation in the film thickness of the film 18 in FIG. 6, but may be the undulation caused by the variation in the plate thickness of the substrate body 17.
  • the height measuring unit 160 irradiates the upper surface of the substrate 10 with the measurement laser beam LB2, and receives the reflected light of the measurement laser beam LB2 reflected by the upper surface of the substrate 10, thereby causing the vertical position of the processing irradiation point P1.
  • the measurement laser beam LB2 has a wavelength different from that of the processing laser beam LB1, and has the same path as the processing laser beam LB1 from the dichroic mirror 154 provided in the middle of the path of the processing laser beam LB1 to the upper surface of the substrate 10. That is, on the upper surface of the substrate 10, the processing irradiation point P1 and the irradiation point P2 of the measurement laser beam LB2 (hereinafter also referred to as “measurement irradiation point P2”) overlap.
  • the height measurement unit 160 includes a measurement laser oscillation unit 162.
  • the measurement laser oscillator 162 oscillates a measurement laser beam LB2 having a wavelength that is reflective to the substrate 10.
  • a He—Ne pulse laser oscillator is used as the measurement laser oscillation unit 162 as the measurement laser oscillation unit 162.
  • the wavelength of the measurement laser beam LB2 is, for example, 635 nm.
  • the measurement laser beam LB2 oscillated by the measurement laser oscillation unit 162 passes through, for example, the beam splitter 164, is reflected by the dichroic mirror 154, is converted in direction by the direction conversion mirror 156, and is guided to the condensing unit 152.
  • the dichroic mirror 154 transmits the processing laser beam LB1 and reflects the measurement laser beam LB2, but the reverse may be possible. That is, the dichroic mirror 154 may reflect the processing laser beam LB1 and transmit the measurement laser beam LB2. In any case, the processing irradiation point P1 and the measurement irradiation point P2 may be overlapped on the upper surface of the substrate 10.
  • the measurement laser beam LB2 is reflected on the upper surface of the substrate 10 when irradiated on the upper surface of the substrate 10.
  • the reflected light passes through the condensing unit 152, is changed in direction by the direction changing mirror 156, is reflected by the dichroic mirror 154 and the beam splitter 164, passes through the band pass filter 166, and is guided to the reflected light receiving unit 170.
  • the band pass filter 166 passes only light having the same wavelength (for example, 635 nm) as the measurement laser beam LB2.
  • the reflected light receiving unit 170 includes a beam splitter 171 that splits the reflected light that has passed through the bandpass filter 166 into the first light receiving path 172 and the second light receiving path 175.
  • a condensing lens 173 that condenses 100% of the reflected reflected light
  • a first light receiving element 174 that receives the reflected light collected by the condensing lens 173 are provided.
  • the first light receiving element 174 transmits a voltage signal corresponding to the intensity of the received reflected light to the control unit 20.
  • the light receiving region restricting unit 177 includes, for example, a cylindrical lens 178 that condenses the dispersed reflected light in a one-dimensional manner, and a one-dimensional mask that restricts the reflected light collected in a one-dimensional manner by the cylindrical lens 178 to a unit length. 179.
  • the reflected light that has passed through the one-dimensional mask 179 is received by the second light receiving element 176, and the second light receiving element 176 transmits a voltage signal corresponding to the intensity of the received reflected light to the control unit 20.
  • FIG. 9 is a diagram showing the relationship between the vertical position of the measurement laser beam irradiation point on the upper surface of the substrate and the size of the measurement laser beam irradiation point on the upper surface of the substrate according to the first embodiment.
  • the measurement laser beam LB2 is condensed toward the substrate 10 by the condensing unit 152. Therefore, a measurement irradiation point P ⁇ b> 2 having a size corresponding to the distance L between the light collecting unit 152 and the substrate 10 is formed on the upper surface of the substrate 10.
  • the reflected light reflected at the measurement irradiation point P ⁇ b> 2 is split into the first light receiving path 172 and the second light receiving path 175 by the beam splitter 171.
  • the intensity of the reflected light received by the first light receiving element 174 is constant regardless of the size of the measurement irradiation point P2. Accordingly, the voltage V1 output from the first light receiving element 174 is constant regardless of the vertical position of the measurement irradiation point P2.
  • the reflected light split into the second light receiving path 175 is condensed in one dimension by the cylindrical lens 178.
  • the larger the size of the measurement irradiation point P2 the longer the length of the reflected light condensed in one dimension.
  • the reflected light collected in one dimension is received by the second light receiving element 176 after being regulated to a predetermined unit length by the one-dimensional mask 179. Therefore, the intensity of the reflected light received by the second light receiving element 176 decreases as the size of the measurement irradiation point P2 increases.
  • the intensity of the reflected light received by the second light receiving element 176 changes according to the size of the measurement irradiation point P2. Therefore, the voltage V2 output from the second light receiving element 176 changes according to the vertical position of the measurement irradiation point P2.
  • the control unit 20 determines the vertical position of the measurement irradiation point P2 based on the voltage ratio V1 / V2 between the voltage V1 output from the first light receiving element 174 and the voltage V2 output from the second light receiving element 176. .
  • a map showing the relationship between the vertical position of the measurement irradiation point P2 and the voltage ratio V1 / V2 is used. This map is created in advance by a test or the like and stored in the storage medium 22.
  • the vertical position of the processing irradiation point P1 can be obtained by obtaining the vertical position of the measurement irradiation point P2.
  • the reflected light split into the first light receiving path 172 is received by the first light receiving element 174, whereas only a part of the reflected light split into the second light receiving path 175 is the second received light.
  • Light is received by the element 176. Therefore, when the intensity of the reflected light split into the first light receiving path 172 and the intensity of the reflected light split into the second light receiving path 175 are the same, the voltage V2 output from the second light receiving element 176 is the first light receiving element. It is smaller than the voltage V1 output from 174.
  • the upper surface of the substrate 10 that reflects the measurement laser beam LB2 may be formed by a film 18 (see FIG. 6) such as a silicon oxide film or a silicon nitride film.
  • the substrate 10 includes a substrate body 17 such as a silicon wafer and a film 18 formed on the surface of the substrate body 17.
  • the film 18 may have a single layer structure or a multiple layer structure. Since the film 18 is formed unintentionally in the process of forming a device, the film thickness of the film 18 may vary. The variation may occur in one substrate 10 or may occur between a plurality of substrates 10.
  • FIG. 10 is a diagram schematically showing the relationship between the material and film thickness of the film forming the upper surface of the substrate according to the first embodiment and the reflectance of the measurement laser beam on the upper surface of the substrate.
  • the horizontal axis indicates the film thickness of the silicon oxide film that forms the film 18
  • the vertical axis indicates the film thickness of the silicon nitride film that forms the film 18.
  • the film 18 may include both a silicon oxide film and a silicon nitride film, or may include only one of them.
  • the reflectance R of the measurement laser beam LB2 on the upper surface of the substrate 10 becomes stronger or weaker as the thickness of the silicon oxide film becomes larger. repeat.
  • the reflectance R of the measurement laser beam LB2 on the upper surface of the substrate 10 increases or decreases as the thickness of the silicon nitride film increases.
  • the reflectance R of the measurement laser beam LB2 on the upper surface of the substrate 10 varies depending on the material and film thickness of the film 18 that forms the upper surface of the substrate 10, so that the reflected light received by the reflected light receiving unit 170 is reflected.
  • the light intensity varies. Therefore, if the output of the measurement laser oscillation unit 162 is insufficient, the voltage V2 indicating the intensity of the reflected light received by the second light receiving element 176 may be lower than the threshold value V2 0 (eg, 0.3 V).
  • Threshold V2 0 is the lower limit for measuring the vertical position of the measurement irradiation point P2.
  • a confocal laser displacement meter is used as the height measurement unit 160, but the measurement method of the laser displacement meter is not particularly limited.
  • the measurement method of the laser displacement meter may be, for example, any of a confocal method, a triangulation method, a time-of-flight method, and an interference method.
  • the laser displacement meter has a laser oscillator and a light receiving element, the laser beam oscillated by the laser oscillator is reflected by the upper surface of the substrate 10, and the reflected light is received by the light receiving element. . Therefore, if the output of the laser oscillator is insufficient, the intensity of the reflected light received by the light receiving element may be below the lower limit value.
  • FIG. 11 schematically shows the relationship between the output of the measurement laser oscillator according to the first embodiment, the reflectance of the measurement laser beam on the upper surface of the substrate, and the intensity of the reflected light received by the second light receiving element.
  • the voltage V2 representing the intensity of the reflected light received by the second light receiving element 176 is the measurement laser beam LB2 on the upper surface of the substrate 10. It is proportional to the reflectance R of When the reflectance R of the measurement laser beam LB2 on the upper surface of the substrate 10 is constant, the voltage V2 indicating the intensity of the reflected light received by the second light receiving element 176 is applied to the output W of the measurement laser oscillation unit 162. Proportional.
  • the reflectance R (hereinafter, also referred to as "critical reflectance”.) Corresponding to the threshold V2 0 and, inversely proportional to the output W.
  • the limit reflectance is a lower limit value of the reflectance R for measuring the vertical position of the measurement irradiation point P2.
  • the limit reflectance becomes 1/5.
  • the limit reflectance can be lowered by increasing the output W.
  • the control unit 20 of the present embodiment controls the output W based on the voltage V2. Unlike the case where the output W is always fixed to the maximum output, since the output W is changed according to the voltage V2, the power consumption of the measurement laser oscillation unit 162 can be suppressed, and heat generation due to the power consumption can be suppressed. Therefore, it is possible to reduce the size of the cooling mechanism that cools the measurement laser oscillation unit 162. In addition, a cooling mechanism may be unnecessary. Therefore, the vertical position of the measurement irradiation point P2 can be measured using a small laser displacement meter, and the vertical position of the processing irradiation point P1 can be measured.
  • the control unit 20 of the present embodiment is to control the output W based on the voltage V2 so that the voltage V2 does not fall below the threshold V2 0, techniques of the present disclosure is not limited thereto. For example, if the voltage V1 than the voltage V2 smaller, the control unit 20 may control the output W based on the voltage V1 so that the voltage V1 does not fall below the threshold V1 0.
  • Threshold V1 0 is the lower limit for measuring the vertical position of the measurement irradiation point P2 (e.g., 0.3V). The same applies to the processing shown in FIGS. 12 to 13, 15, and 17.
  • FIG. 12 is a flowchart illustrating a first example of processing by the control unit according to the first embodiment.
  • the process shown in FIG. 12 is used when the film 18 (and thus the reflectance) is not uniform in the plane of the single substrate 10.
  • the process shown in FIG. 12 can also be used when the thickness of the film 18 is uniform over the entire surface of one substrate 10 and is not uniform among the plurality of substrates 10.
  • the processes after step S201 shown in FIG. 12 are performed after the planned dividing line 13 is detected by the alignment unit 120.
  • control unit 20 performs vertical alignment of the machining head unit 130 (step S201).
  • the casing 131 of the processing head unit 130 is arranged at a predetermined height from the substrate holding unit 110.
  • control unit 20 starts moving the processing irradiation point P1 (step S202). Specifically, the control unit 20 starts moving the processing irradiation point P1 from the processing start point SP shown in FIG. 7 toward the processing end point EP. The control unit 20 starts forming the machining trace.
  • the control unit 20 controls the vertical position of the condensing unit 152 based on the voltage ratio V1 / V2 that represents the vertical position of the processing irradiation point P1, and the reflected light received by the second light receiving element 176.
  • the output W of the measurement laser oscillation unit 162 is controlled based on the voltage V2 representing the intensity of (step S203).
  • the vertical position of the light collector 152 is controlled so that the modified layer 15 is formed at a certain depth from the upper surface of the substrate 10.
  • the condensing unit 152 is moved in the vertical direction inside the housing 131 of the processing head unit 130.
  • the output W of the measuring laser oscillation unit 162 the voltage V2 is controlled so as not to fall below the threshold V2 0. Thereby, the vertical direction position of the processing irradiation point P1 can be measured.
  • the measurement result is used to control the vertical position of the light collecting unit 152.
  • the control unit 20 ends the movement of the processing irradiation point P1 (step S203), and ends the current process.
  • a plurality of processing marks extending in the X-axis direction are formed at intervals in the Y-axis direction.
  • control unit 20 rotates the substrate holding unit 110 by 90 ° in the ⁇ direction, and again forms a plurality of processing marks extending in the X-axis direction at intervals in the Y-axis direction. Thereby, a processing trace can be formed along the grid-like division planned lines 13 set on the substrate 10.
  • the voltage V2 indicating the intensity of the reflected light received by the second light receiving element 176 is monitored while moving the processing irradiation point P1, and the monitoring result is obtained. Based on this, the output W of the measurement laser oscillator 162 is controlled. Therefore, the film thickness of the film 18 (and thus the reflectance R) is to vary according to the position of the working irradiation point P1, the voltage V2 can be prevented reliably from falling below the threshold V2 0.
  • the control unit 20 measures the laser oscillation for measurement while processing the single substrate 10 with the processing laser beam LB1.
  • the output of the unit 162 is changed. This output change is performed based on a voltage V2 representing the intensity of reflected light received by the second light receiving element 176.
  • the voltage V2 is measured while moving the measurement irradiation point P2 on the planned dividing line 13 while processing the substrate 10 with the processing laser beam LB1. Either one of output increase and output decrease may be performed, or both may be performed.
  • the number of output changes may be one or more.
  • the output W may be changed while the one division line 13 is processed, but the output W may be kept constant.
  • Different outputs W may be set when processing one division planned line 13 and when processing one other planned division line 13.
  • the output W is changed according to the voltage V2, so that the power consumption of the measurement laser oscillation unit 162 can be suppressed, and the power Heat generation due to consumption can be suppressed. Therefore, it is possible to reduce the size of the cooling mechanism that cools the measurement laser oscillation unit 162. In addition, a cooling mechanism may be unnecessary. Therefore, the vertical position of the measurement irradiation point P2 can be measured using a small laser displacement meter, and the vertical position of the processing irradiation point P1 can be measured.
  • FIG. 13 is a flowchart illustrating a second example of processing by the control unit according to the first embodiment.
  • the process shown in FIG. 13 is mainly used when the film thickness (and hence the reflectance R) of the film 18 is not uniform within the surface of the single substrate 10.
  • the process shown in FIG. 13 can also be used when the thickness of the film 18 is uniform over the entire surface of one substrate 10 and is not uniform among the plurality of substrates 10.
  • the processes after step S301 shown in FIG. 13 are performed after the planned dividing line 13 is detected by the alignment unit 120.
  • control unit 20 aligns the machining head unit 130 in the vertical direction (step S301). Thereby, as shown in FIG. 6, the casing 131 of the processing head unit 130 is arranged at a predetermined height from the substrate holding unit 110.
  • the controller 20 irradiates the upper surface of the substrate 10 with the measurement laser beam LB2 and moves the measurement irradiation point P2 on the planned dividing line 13 before processing the substrate 10 with the processing laser beam LB1.
  • the voltage V2 representing the intensity of the reflected light received by the second light receiving element 176 is measured (step S302).
  • the upper surface of the substrate 10 is not irradiated with the processing laser beam LB1. That is, no processing trace is formed in step S302.
  • control unit 20 sets the output W of the measurement laser oscillation unit 162 in the following step S305 (step S303).
  • the output W is set so that the voltage V2 does not fall below the threshold V2 0 In the following step S305.
  • control unit 20 starts moving the processing irradiation point P1 of the processing laser beam LB1 (step S304). Specifically, the control unit 20 starts moving the processing irradiation point P1 from the processing start point SP shown in FIG. 7 toward the processing end point EP. The control unit 20 starts forming the machining trace.
  • the control unit 20 controls the vertical position of the light collecting unit 152 based on the voltage ratio V1 / V2 that represents the vertical position of the processing irradiation point P1 (step S305).
  • the vertical position of the light collector 152 is controlled so that the modified layer 15 is formed at a certain depth from the upper surface of the substrate 10.
  • the condensing unit 152 is moved in the vertical direction inside the housing 131 of the processing head unit 130.
  • the output W of the measurement laser oscillation unit 162 is controlled to be the set value set in step S303. This prevents the voltage V2 below the threshold V2 0, can measure the vertical position of the tool irradiation point P1.
  • the measurement result is used to control the vertical position of the light collecting unit 152.
  • the control unit 20 ends the movement of the processing irradiation point P1 (step S306), and ends the current process.
  • a plurality of processing marks extending in the X-axis direction are formed at intervals in the Y-axis direction.
  • control unit 20 rotates the substrate holding unit 110 by 90 ° in the ⁇ direction, and again forms a plurality of processing marks extending in the X-axis direction at intervals in the Y-axis direction. Thereby, a processing trace can be formed along the grid-like division planned lines 13 set on the substrate 10.
  • the voltage V2 representing the intensity of the reflected light received by the second light receiving element 176 when the measurement laser beam LB2 is measured on the upper surface of the substrate 10 before processing is obtained.
  • the output W of the measurement laser oscillation unit 162 when processing the substrate is set.
  • the time of substrate processing is when the processing irradiation point P1 is moved on the planned dividing line 13 of the substrate 10. Since the output W during substrate processing is set before substrate processing, the processing amount of the control unit 20 during substrate processing can be reduced, and the processing load of the control unit 20 during substrate processing can be reduced.
  • the control unit 20 measures the laser oscillation for measurement while processing the single substrate 10 with the processing laser beam LB1.
  • the output of the unit 162 is changed. This output change is performed based on a voltage V2 representing the intensity of reflected light received by the second light receiving element 176.
  • the voltage V2 is measured while moving the measurement irradiation point P2 on the planned dividing line 13 before processing the substrate 10 with the processing laser beam LB1. Either one of output increase and output decrease may be performed, or both may be performed.
  • the number of output changes may be one or more.
  • the output W may be changed while the one division line 13 is processed, but the output W may be kept constant.
  • Different outputs W may be set when processing one division planned line 13 and when processing one other planned division line 13.
  • the output W is changed according to the voltage V2, so that the power consumption of the measurement laser oscillation unit 162 can be suppressed, and the power Heat generation due to consumption can be suppressed. Therefore, it is possible to reduce the size of the cooling mechanism that cools the measurement laser oscillation unit 162. In addition, a cooling mechanism may be unnecessary. Therefore, the vertical position of the measurement irradiation point P2 can be measured using a small laser displacement meter, and the vertical position of the processing irradiation point P1 can be measured.
  • the process shown in FIG. 13 can also be used when the thickness of the film 18 (and thus the reflectance R) is uniform over the entire surface of one substrate 10 and is not uniform among a plurality of substrates 10. It is. In this case, it is not necessary to move the measurement irradiation point P2 on the planned dividing line 13 in step S302. Since the thickness of the film 18 is uniform over the entire surface of the substrate 10, the voltage V ⁇ b> 2 representing the intensity of the reflected light may be measured only at one point within the surface of the substrate 10. The measurement time of the voltage V2 can be shortened.
  • the voltage V ⁇ b> 2 representing the intensity of the reflected light may be measured at a plurality of points within the surface of the substrate 10. It can be reconfirmed that the thickness of the film 18 is uniform.
  • the output W may be changed while the one substrate 10 is processed, but the output W may be kept constant. Different outputs W may be set when processing one substrate 10 and when processing another substrate 10.
  • FIG. 14 is a front view showing a laser processing unit according to the second embodiment.
  • the alignment unit 120 ⁇ / b> A of the present embodiment measures the reflectance of the inspection laser beam LB ⁇ b> 2 ′ reflected from the upper surface (for example, the second main surface 12) of the substrate 10 in addition to the imaging unit 121.
  • a reflectance measuring unit 122 is included. Since the inspection laser beam LB2 ′ has the same wavelength as the measurement laser beam LB2, the reflectance of the inspection laser beam LB2 ′ is equal to the reflectance R of the measurement laser beam LB2.
  • differences between the present embodiment and the first embodiment will be mainly described.
  • the reflectance measuring unit 122 includes a laser oscillator that oscillates the inspection laser beam LB2 ′ and a light receiving element that receives the reflected light of the inspection laser beam LB2 ′ reflected from the upper surface of the substrate 10.
  • the light receiving element transmits a voltage signal corresponding to the intensity (that is, reflectance) of the received reflected light to the control unit 20.
  • the control unit 20 sets the output W of the measurement laser oscillation unit 162 when moving the processing irradiation point P1 on the planned dividing line 13 of the substrate 10. .
  • the output W, the voltage V2 during substrate processing is set so as not to fall below the threshold V2 0, it is set in correspondence with the position of the working irradiation point P1 on the dividing line 13.
  • FIG. 15 is a flowchart showing processing of the control unit according to the second embodiment.
  • the process shown in FIG. 15 is used when the film 18 has a non-uniform film thickness (and hence reflectivity) within the surface of one substrate 10.
  • the process shown in FIG. 15 can also be used when the thickness of the film 18 is uniform over the entire surface of one substrate 10 and is not uniform among the plurality of substrates 10.
  • the process after step S401 shown in FIG. 15 is started when the transport unit 58 places the substrate 10 on the substrate holding unit 110, for example.
  • the control unit 20 measures the reflectance of the inspection laser beam LB2 ′ reflected on the upper surface of the substrate 10 by the reflectance measuring unit 122 (step S401). For example, the control unit 20 moves the irradiation point P2 ′ (hereinafter also referred to as “inspection irradiation point P2 ′”) of the inspection laser beam LB2 ′ on the upper surface of the substrate 10 by the substrate moving unit 140 while moving the inspection laser beam.
  • the reflectance of LB2 ′ is measured by the reflectance measuring unit 122.
  • the inspection irradiation point P2 ′ is moved on the planned division line 13, and the reflectance of the inspection laser beam LB2 ′ is stored in association with the position of the inspection irradiation point P2 ′ on the planned division line 13.
  • the reflectance of the inspection laser beam LB2 ′ is equal to the reflectance R of the measurement laser beam LB2.
  • control unit 20 sets the output W of the measurement laser oscillation unit 162 when processing the substrate based on the reflectance measured by the reflectance measurement unit 122 (step S402).
  • the output W, the voltage V2 during substrate processing is set so as not to fall below the threshold V2 0, it is set in correspondence with the position of the working irradiation point P1 on the dividing line 13.
  • control unit 20 performs vertical alignment of the machining head unit 130 (step S403).
  • the casing 131 of the processing head unit 130 is arranged at a predetermined height from the substrate holding unit 110.
  • control unit 20 starts moving the processing irradiation point P1 (step S404). Specifically, the control unit 20 starts moving the processing irradiation point P1 from the processing start point SP shown in FIG. 7 toward the processing end point EP. The control unit 20 starts forming the machining trace.
  • control unit 20 controls the vertical position of the light collecting unit 152 based on the voltage ratio V1 / V2 that represents the vertical position of the processing irradiation point P1 (step S405).
  • the output W of the measurement laser oscillator 162 is controlled according to the setting in step S402. Therefore, it is possible to prevent the voltage V2 during substrate processing is below a threshold V2 0.
  • the control unit 20 ends the movement of the processing irradiation point P1 (step S406), and ends the current process.
  • a plurality of processing marks extending in the X-axis direction are formed at intervals in the Y-axis direction.
  • control unit 20 rotates the substrate holding unit 110 by 90 ° in the ⁇ direction, and again forms a plurality of processing marks extending in the X-axis direction at intervals in the Y-axis direction. Thereby, a processing trace can be formed along the grid-like division planned lines 13 set on the substrate 10.
  • the reflectance of the inspection laser beam LB2 ′ reflected on the upper surface of the substrate 10 is measured. Since the inspection laser beam LB2 ′ has the same wavelength as the measurement laser beam LB2, the reflectance of the inspection laser beam LB2 ′ is equal to the reflectance R of the measurement laser beam LB2. Based on the measurement result of the reflectance R, the output W of the measurement laser oscillation unit 162 at the time of processing the substrate is set.
  • the output W during substrate processing can be set before substrate processing, the processing amount of the control unit 20 during substrate processing can be reduced, and the processing load of the control unit 20 during substrate processing can be reduced.
  • the control unit 20 measures the laser oscillation for measurement while processing the single substrate 10 with the processing laser beam LB1.
  • the output of the unit 162 is changed. This output change is performed based on the reflectance measured by the reflectance measuring unit 122. Either one of output increase and output decrease may be performed, or both may be performed. The number of output changes may be one or more.
  • the output W may be changed while the one division line 13 is processed, but the output W may be kept constant. Different outputs W may be set when processing one division planned line 13 and when processing one other planned division line 13.
  • the output W is changed according to the voltage V2, so that the power consumption of the measurement laser oscillation unit 162 can be suppressed, and the power Heat generation due to consumption can be suppressed. Therefore, it is possible to reduce the size of the cooling mechanism that cools the measurement laser oscillation unit 162. In addition, a cooling mechanism may be unnecessary. Therefore, the vertical position of the measurement irradiation point P2 can be measured using a small laser displacement meter, and the vertical position of the processing irradiation point P1 can be measured.
  • the control unit 20 uses the plurality of substrates 10 for processing.
  • the output of the measurement laser oscillation unit 162 is changed. This output change is performed based on the reflectance measured by the reflectance measuring unit 122. Either one of output increase and output decrease may be performed, or both may be performed. The number of output changes may be one or more.
  • the output W may be changed while the one substrate 10 is processed, but the output W may be kept constant. Different outputs W may be set when processing one substrate 10 and when processing another substrate 10.
  • the output W is changed according to the voltage V 2, so that the power consumption of the measurement laser oscillator 162 can be suppressed, and the power Heat generation due to consumption can be suppressed. Therefore, it is possible to reduce the size of the cooling mechanism that cools the measurement laser oscillation unit 162. In addition, a cooling mechanism may be unnecessary. Therefore, the vertical position of the measurement irradiation point P2 can be measured using a small laser displacement meter, and the vertical position of the processing irradiation point P1 can be measured.
  • the reflectance measurement unit 122 is provided in the alignment unit 120 that is a part of the laser processing unit 100.
  • the reflectance measurement unit 122 may be provided in the alignment unit 60 provided separately from the laser processing unit 100. May be provided.
  • the measurement of the reflectance R in the alignment unit 60 may be performed in parallel with the detection of the center position of the substrate 10 and the crystal orientation of the substrate 10 in order to improve the throughput.
  • the alignment unit 60 moves the substrate holding unit that holds the substrate 10 from below, the imaging unit that images the substrate 10 held by the substrate holding unit, and the imaging position of the substrate 10 by the imaging unit. And a moving part to be moved. Since the substrate holding unit, the imaging unit, and the moving unit provided in the alignment unit 60 are configured similarly to the substrate holding unit 110, the imaging unit 121, and the substrate moving unit 140 provided in the laser processing unit 100, illustration is omitted. To do.
  • FIG. 16 is a functional block diagram showing the components of the control unit according to the third embodiment.
  • Each functional block illustrated in FIG. 16 is conceptual and does not necessarily need to be physically configured as illustrated. All or a part of each functional block can be configured to be functionally or physically distributed and integrated in arbitrary units.
  • Each processing function performed in each functional block may be realized entirely or arbitrarily by a program executed by the CPU, or may be realized as hardware by wired logic.
  • differences between the present embodiment and the first embodiment will be mainly described.
  • the control unit 20 is connected to the data server 2 via a network such as a LAN (Local Area Network) or an Internet line.
  • the connection may be either a wired connection or a wireless connection.
  • the data server 2 is provided in a factory where the substrate processing system 1 is installed, and transmits various data to the substrate processing system 1. For example, in the data server 2, identification information of the substrate 10, and data on the material and film thickness of the film 18 that forms the upper surface (for example, the second main surface 12) of the substrate 10 (hereinafter, simply
  • the film thickness of the film 18 is measured at least in each of the plurality of planned dividing lines 13, and the measured value is stored in the data server 2.
  • the film thickness of the film 18 can change continuously in each of the plurality of planned dividing lines 13. Therefore, the film thickness of the film 18 is stored in the data server 2 in association with the position in the plane of the substrate 10.
  • the layer thickness of each layer constituting the film 18 is stored in the data server 2 in association with the position in the plane of the substrate 10.
  • the control unit 20 includes a film data acquisition unit 25, a reflectance calculation unit 26, an output setting unit 27, and a processing control unit 28.
  • the film data acquisition unit 25 acquires the film data of the substrate 10 from the data server 2.
  • the reflectance calculation unit 26 calculates the reflectance R of the measurement laser beam LB2 reflected from the upper surface of the substrate 10 based on the film data acquired by the film data acquisition unit 25. For example, the map shown in FIG. 10 is used to calculate the reflectance R.
  • the output setting unit 27 outputs the output W of the measurement laser oscillation unit 162 when moving the processing irradiation point P1 on the planned dividing line 13 of the substrate 10 based on the reflectance R calculated by the reflectance calculation unit 26. Set.
  • the output W, the voltage V2 during substrate processing is set so as not to fall below the threshold V2 0.
  • the processing control unit 28 measures the vertical position of the processing irradiation point P1 according to the setting of the output setting unit 27 while moving the processing irradiation point P1 on the planned dividing line 13 of the substrate 10, and based on the measurement result.
  • the vertical position of the light collecting unit 152 is controlled.
  • FIG. 17 is a flowchart showing processing of the control unit according to the third embodiment.
  • the process shown in FIG. 17 is used when the film 18 (and thus the reflectance) is non-uniform in the plane of one substrate 10.
  • the process shown in FIG. 17 can also be used when the thickness of the film 18 is uniform over the entire surface of one substrate 10 and is not uniform among the plurality of substrates 10.
  • the processing after step S501 shown in FIG. 17 is started when the transport unit 58 places the substrate 10 on the substrate holding unit 110, for example.
  • the processing in steps S501 to S503 may be performed in parallel with the alignment processing in which the alignment unit 120 detects the planned dividing line 13 of the substrate 10 in order to improve throughput.
  • the film data acquisition unit 25 acquires identification information (for example, characters, numbers, symbols, graphics, etc.) displayed on the substrate 10 held by the substrate holding unit 110 by the imaging unit 121 and the acquired identification.
  • Film data corresponding to the information is acquired from the external data server 2 (step S501).
  • the graphic representing the identification information include a one-dimensional code and a two-dimensional code.
  • the reflectance calculation unit 26 calculates the reflectance R of the measurement laser beam LB2 reflected from the upper surface of the substrate 10 based on the film data acquired by the film data acquisition unit 25 (step S502).
  • the map shown in FIG. 10 or the like is used for calculating the reflectance R.
  • the reflectance R is stored in association with the position of the processing irradiation point P1 on the planned dividing line 13.
  • the output setting unit 27 sets the output W of the measurement laser oscillation unit 162 when processing the substrate based on the reflectance R calculated by the reflectance calculating unit 26 (step S503).
  • the output W, the voltage V2 during substrate processing is set so as not to fall below the threshold V2 0, it is set in correspondence with the position of the working irradiation point P1 on the dividing line 13.
  • the processing control unit 28 performs vertical alignment of the processing head unit 130 (step S504).
  • the casing 131 of the processing head unit 130 is arranged at a predetermined height from the substrate holding unit 110.
  • the processing control unit 28 starts moving the processing irradiation point P1 (step S505). Specifically, the control unit 20 starts moving the processing irradiation point P1 from the processing start point SP shown in FIG. 7 toward the processing end point EP. The control unit 20 starts forming the machining trace.
  • the processing control unit 28 controls the vertical position of the light collecting unit 152 based on the voltage ratio V1 / V2 that represents the vertical position of the processing irradiation point P1 (step S506).
  • the output W of the measurement laser oscillation unit 162 is controlled according to the setting by the output setting unit 27. Therefore, it is possible to prevent the voltage V2 during substrate processing is below a threshold V2 0.
  • the control unit 20 ends the movement of the processing irradiation point P1 (step S507), and ends the current process.
  • a plurality of processing marks extending in the X-axis direction are formed at intervals in the Y-axis direction.
  • control unit 20 rotates the substrate holding unit 110 by 90 ° in the ⁇ direction, and again forms a plurality of processing marks extending in the X-axis direction at intervals in the Y-axis direction. Thereby, a processing trace can be formed along the grid-like division planned lines 13 set on the substrate 10.
  • the film data of the film 18 forming the upper surface of the substrate 10 is acquired, and the measurement laser beam LB2 reflected on the upper surface of the substrate 10 based on the acquired film data.
  • the reflectance R is calculated. Based on the calculated reflectance R, the output W of the measurement laser oscillation unit 162 during processing of the substrate is set.
  • the output W during substrate processing can be set before substrate processing, the processing amount of the control unit 20 during substrate processing can be reduced, and the processing load of the control unit 20 during substrate processing can be reduced.
  • the control unit 20 measures the laser oscillation for measurement while processing the single substrate 10 with the processing laser beam LB1.
  • the output of the unit 162 is changed. This output change is performed based on the reflectance calculated by the reflectance calculation unit 26. Either one of output increase and output decrease may be performed, or both may be performed. The number of output changes may be one or more.
  • the output W may be changed while the one division line 13 is processed, but the output W may be kept constant. Different outputs W may be set when processing one division planned line 13 and when processing one other planned division line 13.
  • the output W is changed according to the voltage V2, so that the power consumption of the measurement laser oscillation unit 162 can be suppressed, and the power Heat generation due to consumption can be suppressed. Therefore, it is possible to reduce the size of the cooling mechanism that cools the measurement laser oscillation unit 162. In addition, a cooling mechanism may be unnecessary. Therefore, the vertical position of the measurement irradiation point P2 can be measured using a small laser displacement meter, and the vertical position of the processing irradiation point P1 can be measured.
  • the control unit 20 uses the plurality of substrates 10 for processing.
  • the output of the measurement laser oscillation unit 162 is changed. This output change is performed based on the reflectance measured by the reflectance calculator 26. Either one of output increase and output decrease may be performed, or both may be performed. The number of output changes may be one or more.
  • the output W may be changed while the one substrate 10 is processed, but the output W may be kept constant. Different outputs W may be set when processing one substrate 10 and when processing another substrate 10.
  • the output W is changed according to the voltage V 2, so that the power consumption of the measurement laser oscillator 162 can be suppressed, and the power Heat generation due to consumption can be suppressed. Therefore, it is possible to reduce the size of the cooling mechanism that cools the measurement laser oscillation unit 162. In addition, a cooling mechanism may be unnecessary. Therefore, the vertical position of the measurement irradiation point P2 can be measured using a small laser displacement meter, and the vertical position of the processing irradiation point P1 can be measured.
  • control unit 20 combines two or more of the processing shown in FIG. 12, the processing shown in FIG. 13, the processing shown in FIG. 15, and the processing shown in FIG.
  • the output W of the unit 162 may be controlled.
  • the combination is not particularly limited.
  • the output W is associated with the position of the processing irradiation point P1 on the planned dividing line 13 in the above embodiment.
  • the output W may be set for each division line 13. In the latter case, since one output W is set for one division line 13, frequent switching of the output W can be suppressed, and the processing amount of the control unit 20 during substrate processing can be reduced.
  • Substrate processing system (laser processing system) DESCRIPTION OF SYMBOLS 10 Substrate 18 Film

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Optics & Photonics (AREA)
  • Plasma & Fusion (AREA)
  • Mechanical Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Laser Beam Processing (AREA)

Abstract

L'invention concerne un dispositif de traitement au laser comprenant : une unité de mesure de hauteur qui mesure la position de direction verticale d'un point d'exposition à un rayonnement d'un faisceau de lumière laser de traitement sur une surface supérieure d'un substrat ; et une unité de commande qui, tout en provoquant le déplacement du point d'exposition à un rayonnement sur une pluralité de lignes planifiées par division sur la surface supérieure du substrat, commande la position de direction verticale d'une unité de focalisation de lumière sur la base de la position de direction verticale du point d'exposition à un rayonnement. L'unité de mesure de hauteur comprend une unité d'oscillation laser de mesure qui fait osciller un faisceau de lumière laser de mesure ayant une longueur d'onde différente de celle du faisceau de lumière laser de traitement, et une unité de réception de lumière réfléchie qui reçoit la lumière réfléchie du faisceau de lumière laser de mesure, au moyen duquel la surface supérieure du substrat a fait l'objet d'une exposition à un rayonnement, par le même trajet que celui du faisceau de lumière laser de traitement à mi-chemin de ce dernier. L'unité de commande, pendant que l'un dudit substrat est en cours de traitement au moyen du faisceau de lumière laser de traitement, modifie la sortie de l'unité d'oscillation laser de mesure sur la base de l'intensité de la lumière réfléchie reçue par l'unité de réception de lumière réfléchie.
PCT/JP2019/013293 2018-04-09 2019-03-27 Dispositif, système et procédé de traitement au laser Ceased WO2019198513A1 (fr)

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