Laser processing apparatus, laser processing method, and substrate cutting method using same

Abstract

The invention relates to a laser processing apparatus, a laser processing method, and a substrate cutting method using the same. The laser processing apparatus includes: a stage configured to support a substrate to be processed; a laser light source configured to generate a laser beam; a mode converter configured to convert the laser beam into a cylindrical vector beam; a polarization filter configured to polarize the column vector beam to form a double o-shaped beam in which two beams are arranged adjacent to each other in a first horizontal direction; a condensing lens configured to converge the double o-shaped light beam into a first laser beam and a second laser beam at a first light spot and a second light spot separated in a first horizontal direction on the substrate; and a driving portion configured to relatively move the first laser beam and the second laser beam with respect to the substrate in a second horizontal direction different from the first horizontal direction.

Description

Technical Field

[0001] Various example embodiments are directed to one or more of a laser processing apparatus, a laser processing method, and a substrate cutting method using the same. Background Art

[0002] More specifically, various example embodiments relate to one or more of a laser processing apparatus configured to cut a substrate by irradiating laser into the substrate, a laser processing method using the laser processing apparatus, and a substrate cutting method using the laser processing apparatus.

[0003] In a laser post-grinding (GAL) process, a laser may be irradiated into a wafer such as a silicon wafer to apply localized high-density energy to a focal point to form an invisible cutting layer, and the wafer may be separated or singulated into individual chips by a subsequent tape expansion process. Factors determining productivity in a GAL process may include processing speed and / or the number of scans, and since there is a limit to increasing current acceleration, it may be necessary or desirable to reduce the number of scans to increase productivity. Summary of the invention

[0004] Some example embodiments provide a laser processing apparatus capable of improving productivity.

[0005] Alternatively or additionally, some example embodiments provide a laser processing method using the above-mentioned laser processing apparatus.

[0006] Alternatively or additionally, some example embodiments provide a method of cutting a substrate using the above-mentioned laser processing method.

[0007] According to some example embodiments, a laser processing apparatus includes: a stage configured to support a substrate to be processed; a laser light source configured to generate a laser beam; a mode converter configured to convert the laser beam into a cylindrical vector beam; a polarization filter configured to polarize the cylindrical vector beam to form a double O-shaped beam in which two beams are arranged adjacent to each other in a first horizontal direction; a condensing lens configured to converge the double O-shaped beam into a first laser beam and a second laser beam at a first spot and a second spot separated along the first horizontal direction on the substrate; and a driving portion configured to relatively move the first laser beam and the second laser beam relative to the substrate in a second horizontal direction different from the first horizontal direction.

[0008] Alternatively or additionally, according to an example embodiment, a laser processing apparatus includes: a stage configured to support a substrate to be processed; a laser irradiator configured to converge and irradiate a first laser beam and a second laser beam onto a first spot and a second spot spaced apart along a first horizontal direction on the substrate; and a driving portion configured to move at least one of the stage or the laser irradiator and to move the first laser beam and the second laser beam relative to the substrate in a second horizontal direction different from the first horizontal direction. The laser irradiator includes: a laser light source configured to generate a laser beam; a mode converter configured to convert the laser beam into a cylindrical vector beam; a polarization filter configured to polarize the cylindrical vector beam to form a double O-shaped beam, in which two beams are arranged adjacent to each other in a first horizontal direction; a focusing lens, on an optical path of the double O-shaped beam and configured to converge the double O-shaped beam into a first laser beam and a second laser beam on a substrate; and a refractive index adjuster, on the optical path of the cylindrical vector beam, on the double O-shaped beam, or on both the optical path and the double O-shaped beam, the refractive index adjuster being configured to adjust the spacing distance between the first light spot and the second light spot in the first horizontal direction.

[0009] Alternatively or additionally, according to some example embodiments, in a laser processing method, a substrate as an object to be processed is supported on a stage. A laser beam of a cylindrical vector beam is emitted. The cylindrical vector beam is polarized by a polarization filter to form a double O-shaped beam, in which two beams are arranged adjacent to each other in a first horizontal direction. The double O-shaped beam is converged into a first laser beam and a second laser beam at a first spot and a second spot spaced apart in the first horizontal direction on the substrate by a condenser lens. The first laser beam and the second laser beam are scanned along two cutting lines on the substrate, respectively.

[0010] Alternatively or additionally, according to example embodiments, the laser processing apparatus may include: a laser beam splitter configured to split a laser beam emitted from a laser light source as a single light source into a double O-shaped beam in which two beams are arranged adjacent to each other in a first horizontal direction; and a condenser lens configured to converge the double O-shaped beam into a first laser beam and a second laser beam at a first spot and a second spot spaced apart from each other in the first horizontal direction on a substrate. In addition, the laser processing apparatus may further include a refractive index adjuster configured to adjust a spacing distance between the first spot and the second spot in the first horizontal direction.

[0011] The first laser beam and the second laser beam may be scanned simultaneously along two cutting lines on the substrate. The distance between the first spot position and the second spot position of the first laser beam and the second laser beam may be adjusted according to the size (e.g., width and / or length) of the die to be cut from the substrate. The first laser beam and the second laser beam may be converged by a condenser lens including a single-lens optical system.

[0012] Therefore, the first laser beam and the second laser beam can be scanned simultaneously while tracking the surface height in real time along two adjacent cutting lines without increasing the size of the optical system and / or replacing a new optical system. Therefore, the productivity of the cutting process can be improved. Additionally or alternatively, the distance between the first laser beam and the second laser beam can be easily optically adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Various example embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. Figures 1 to 17 Represents non-limiting example embodiments as described herein.

[0014] Figure 1 is a perspective view illustrating a laser processing apparatus according to some example embodiments.

[0015] Figure 2 It is shown Figure 1 Block diagram of the laser irradiator.

[0016] Figure 3A is a graph showing the shape of a laser beam emitted from a laser light source and the intensity distribution in a radial direction.

[0017] Figure 3B is a graph showing the shape of a converted laser beam converted by a mode converter and the intensity distribution in a radial direction.

[0018] Figure 4 is a cross-sectional view showing a beam expander that expands the diameter of a converted laser beam.

[0019] Figure 5 is a diagram showing the shape and polarization of a filtered beam after a cylindrical incident beam with radial polarization passes through a polarization filter.

[0020] Figure 6 is a diagram showing the shape and polarization of a filtered beam of a cylindrical incident beam with azimuthal polarization after passing through a polarization filter.

[0021] Fig. 7A is a graph showing the shape and wavefront of the filtered light beam after passing through the polarization filter.

[0022] Figure 7B is a graph showing the shape and wavefront of the filtered light beam after passing through the spatial light modulator.

[0023] Figure 7C is a graph showing shapes and wavefronts of the first laser beam and the second laser beam collected by the condenser lens.

[0024] Figure 8is a flow chart illustrating a laser processing method according to some example embodiments.

[0025] Fig. 9 is a cross-sectional view showing a wafer on which a first laser beam and a second laser beam are irradiated.

[0026] Fig.10 is a plan view showing two cutting lines on a wafer, Fig. 9 The first laser beam and the second laser beam are scanned along the cutting line.

[0027] Fig.11 is shown along Fig.10 A perspective view of two cutting lines irradiated by a first laser beam and a second laser beam.

[0028] Fig.12 is a flowchart illustrating a substrate cutting method according to some example embodiments.

[0029] Figures 13 to 17 are views illustrating a substrate cutting method according to some example embodiments. DETAILED DESCRIPTION

[0030] Hereinafter, various example embodiments will be described in detail with reference to the accompanying drawings.

[0031] Figure 1 is a perspective view illustrating a laser processing apparatus according to some example embodiments. Figure 2 It is shown Figure 1 Block diagram of the laser irradiator. Figure 3A is a graph showing the shape of a laser beam emitted from a laser light source and the intensity distribution in a radial direction, Figure 3B is a graph showing the shape of a converted laser beam converted by a mode converter and the intensity distribution in a radial direction. Figure 4 is a cross-sectional view showing a beam expander that expands the diameter of a converted laser beam. Figure 5 is a diagram showing the shape and polarization of a filtered beam after a cylindrical incident beam with radial polarization passes through a polarization filter. Figure 6 is a diagram showing the shape and polarization of a filtered beam of a cylindrical incident beam with azimuthal polarization after passing through a polarization filter. Fig. 7A is a graph showing the shape and wavefront of a filtered light beam after passing through a polarization filter, Figure 7B is a graph showing the shape and wavefront of the filtered light beam after passing through the spatial light modulator, Figure 7C is a graph showing shapes and wavefronts of the first laser beam and the second laser beam collected by the condenser lens.

[0032] Reference Figures 1 to 7C, the laser processing apparatus 10 may include a stage 20 and a laser irradiator 30. In some example embodiments, the laser processing apparatus 10 may further include a controller 40 connected to the stage 20 and the laser irradiator 30 to control operations thereof.

[0033] In some example embodiments, the controller 40 may be wired to the stage 20 and / or the laser irradiator 30. Alternatively or additionally, the controller 40 may be wirelessly connected to the stage 20 and / or the laser irradiator 30. In some example embodiments, the controller 40 may be or may include a processor, and / or may be or include a laptop computer and / or a desktop computer and / or a tablet computer; example embodiments are not limited thereto.

[0034] In some example embodiments, the laser processing device 10 may irradiate the first laser beam L1 and the second laser beam L2 onto and into a substrate W (such as a wafer) to apply local high-density energy to a first focal position (hereinafter, may also be referred to as a "focus" or "spot" or "spot position") P1 and a second focal position P2, respectively, to form an invisible cutting layer as a modified region. The substrate W may be a 200 mm substrate, or a 300 mm substrate, or a 450 mm substrate; example embodiments are not limited thereto. The laser processing device 10 may simultaneously scan the first laser beam L1 and the second laser beam L2 along two cutting lines on the substrate W. Therefore, a laser-scribed layer as a modified region may be formed in the substrate W along the two cutting lines. The laser-scribed layer (i.e., the scribe area) formed along the two cutting lines may be used as a cutting start area.

[0035] The laser processing apparatus 10 may further include a driving portion configured to move the first laser beam L1 and the second laser beam L2 relative to the substrate W. The driving portion may include a stage driver 22 configured to move the stage 20 along three orthogonal axes, such as along the X-axis, the Y-axis, and the Z-axis. In some cases, the stage driver 22 may rotate the substrate along an angle; however, example embodiments are not limited thereto.

[0036] In particular, the stage 20 may be or may include or be included in a movable stage that supports the substrate W and is movable in at least one direction. The stage 20 may be mounted to be movable in the X direction and the Y direction on the stage driver 22. The stage driver 22 may include a stage drive mechanism (such as a motor) for moving the stage 20, and the stage driver 22 may move the stage 20 in the X direction and the Y direction in response to a control signal from the controller 40. The moving speed of the stage 20 may be adjustable, for example, by the controller 40.

[0037] In addition, the driving part may further include a laser head driver for moving the laser irradiator 30 in the X-axis, the Y-axis, and the Z-axis. For example, the laser head driver may move the optical system of the laser irradiator 30 in the X-direction, the Y-direction, and the Z-direction. Alternatively or additionally, the laser head driver may move the laser irradiator 30 in the Z-direction, and the stage driver 22 may move the wafer W in the X-direction and the Y-direction and may rotate the stage 20 around the center of the wafer W.

[0038] For example, the substrate W may include a silicon wafer (Si wafer), a silicon carbide wafer (SiC wafer), a gallium arsenide wafer (GaAs wafer), or a silicon single crystal wafer (Si-single crystal wafer). The thickness of the substrate W may be in the range of 50 μm to 850 μm.

[0039] like Figure 2 As shown in , the laser irradiator 30 may include a laser light source 310 for generating a laser beam L00, a laser beam splitter 320 for splitting the laser beam L00 into two laser beams L10 and L20 in a first horizontal direction (X direction), and a condenser lens 340 for converging the two separated laser beams L10 and L20 into the first laser beam L1 and the second laser beam L2 at a first light spot P1 and a second light spot P2 spaced apart in the first horizontal direction (X direction). The laser beam splitter 320 may include a mode converter 322 and a polarization filter 324. The laser irradiator 30 may also include a refractive index adjuster 330 to adjust the spacing distance V1 between the first light spot P1 and the second light spot P2 in the first horizontal direction (X direction). The refractive index adjuster 330 may include at least one of a beam expander 332 and a spatial light modulator 334.

[0040] In particular, the laser light source 310 may emit a laser beam L00 as a single light source. The laser beam L00 may have a wavelength band that is transparent to the substrate W as an object to be processed. The wavelength band may be within a wavelength range of 1080 nm to 1100 nm. The laser light source 310 may emit a pulsed laser beam. However, example embodiments are not limited thereto, and a continuous wave laser beam may be emitted depending on the type of processing operation. The laser beam L00 may be an ultrashort pulse laser beam having a pulse width of 1 μs or less (e.g., picosecond or femtosecond order).

[0041] The laser light source 310 may include a solid medium for passing the laser beam. The properties of the laser beam may vary depending on the solid medium. For example, the solid medium may be or may include at least one of ytterbium yttrium aluminum garnet compound (Yb:YAG), neodymium yttrium aluminum garnet compound (Nd:YAG), neodymium yttrium orthovanadate compound (Nd:YVO4), aluminum gallium arsenide compound, aluminum gallium indium compound (AlGaInP), gallium nitride compound (GaN), neodymium fiber (Nd fiber), sapphire, etc.

[0042] The mode converter 322 can convert the laser beam L00 into a cylindrical vector beam (CVB) L01. The mode converter 322 can be installed inside the laser head or on the optical path of the laser beam L00 after the laser head. The mode converter 322 can convert the laser beam L00 generated by the laser light source 310 into a high-order mode laser beam. The mode converter 322 can only convert the shape of the laser beam into a donut shape (or a single o-shape) without changing the basic characteristics of the laser beam. For example, the mode converter 322 can convert the mode of the laser beam L00 by using birefringence, using a dichroic material, or using an interferometer.

[0043] like Figure 3A and Figure 3B As shown in , the laser beam L00 generated by the laser light source 310 may include a Gaussian beam (or a Gaussian beam with a Gaussian spot), and the cylindrical vector beam L01 converted and emitted by the mode converter 322 may have a ring laser mode (or a single o-shaped laser mode).

[0044] The beam expander 332 may be provided on the optical path of the cylindrical vector beam L01 and may expand the cylindrical vector beam L01. The expanded laser beam L02 expanded by the beam expander 332 may be incident on the polarization filter 324. The beam expander 332 may expand the diameter of the collimated input beam and may emit a collimated output beam having a larger diameter.

[0045] like Figure 4 As shown in , the beam expander 332 may include a combination of multiple lenses. The beam expander 332 may adjust the beam size while maintaining the same output value. The spacing distance V1 between the first light spot P1 and the second light spot P2 in a direction such as a first horizontal direction (X direction) may be determined according to the diameter of the laser beam L02 expanded by the beam expander 322. For example, the diameter or full width at half maximum (FWHM) of the laser beam L02 expanded by the beam expander 332 may be expanded to several times the distance between two cutting lines on the substrate W.

[0046] The polarization filter 324 can polarize the expanded cylindrical vector beam L02 to form an ∞ double o-shaped beam, in which the two beams L10 and L20 are arranged adjacent to each other in the first horizontal direction (X direction). As used herein, the double o-shape can indicate two "o" shapes connected together, and in some cases can be referred to as or can have the shape of a sideways figure 8, or the shape of an infinity symbol (or ∞ symbol), or the shape of a double torus. There can be two lobes or two o's in this shape, and the diameter of each o can be the same or different from each other. In some cases, the two lobes or two o's can be connected, for example, can be matched and connected at a single point; alternatively, in some cases, the two lobes or two o's may not be connected and may not be matched at a single point. The cylindrical vector beam L02 can have various polarization states through the mode converter 322. The polarization filter 324 can be used as a filter that only passes components polarized in a specific direction.

[0047] like Figure 5 As shown in , when the cylindrical vector beam L02 has radial polarization, the polarization filter 324 can only allow the component polarized in the direction parallel to the first horizontal direction (e.g., the X direction) to pass. The two beams L10 and L20 filtered by the polarization filter 324 can have polarization components in the direction parallel to the first horizontal direction (X direction).

[0048] like Figure 6 As shown in , when the cylindrical vector beam L02 has azimuthal polarization, the polarization filter 324 may allow only the component polarized in the direction perpendicular to the first horizontal direction (X direction) to pass. The two beams L10 and L20 filtered by the polarization filter 324 may have polarization components in the direction perpendicular to the first horizontal direction (X direction).

[0049] A spatial light modulator (SLM) 334 may be provided on the optical path of the dual O-shaped light beams L10 and L20, and may modulate the phases of the dual O-shaped light beams L10 and L20. The spatial light modulator 334 may be an optical device capable of spatially modulating a light beam. The spatial light modulator 334 may include an optical element in the form of a two-dimensional array, and may change the phase of an incident laser beam based on a pixel. The spatial light modulator 334 may control the phase of the laser beam spatially. The spatial light modulator 334 may only change the phase without changing the shape of the waveform. The spatial light modulator 334 may adjust the wavefront so that the dual O-shaped light beams L10 and L20 converge into two convergence points through a condenser lens 340.

[0050] like Fig. 7A and Figure 7BAs shown in, the wavefront WF2 of the dual O-shaped light beams L11 and L21 passing through the spatial light modulator 334 can be different from the wavefront WF1 of the two light beams L10 and L20 filtered by the polarization filter 324, and the shape of the dual O-shaped light beams L11 and L21 passing through the spatial light modulator 334 can remain the same as the shape of the two light beams L10 and L20 filtered by the polarization filter 324.

[0051] The condenser lens 340 may condense the dual-o-shaped light beams L11 and L21 having passed through the spatial light modulator 334 into the first laser beam L1 and the second laser beam L2 at the first spot P1 and the second spot P2 spaced apart in the first horizontal direction (X direction) on the substrate W. The condenser lens 340 may be provided on an optical path of the dual-o-shaped light beam, and may include a single-lens optical system having a numerical aperture (NA) of at least 0.6.

[0052] For example, the condenser lens 340 may include a single lens optical system in which a plurality of lenses are sequentially arranged along the optical path. Figure 7C As shown in FIG. 1 , the double o-shaped beams L11 and L21 can be converged into the first laser beam L1 and the second laser beam L2 by a single lens optical system. The spacing distance V1 between the first spot P1 and the second spot P2 on the substrate W as the focal positions of the first laser beam L1 and the second laser beam L2 can be in the range of 0.5 mm to 20 mm.

[0053] The first light spot P1 and the second light spot P2 may be local positions where the first laser beam L1 and the second laser beam L2 are focused. When the substrate W is a wafer such as a silicon wafer or a germanium wafer or a silicon-germanium wafer or a silicon on insulator (SOI) wafer, a plurality of die regions D may be arranged in a matrix shape and divided by scribe lane regions. The number and / or size of the die regions D is not limited to Figure 1 In some example embodiments, the number of die regions D may be greater or less than Figure 1 In some example embodiments, the die region D may be rectangular, for example, square; example embodiments are not limited thereto. In some cases, the die region D may or may not extend to the edge of the substrate W.

[0054] The driving part of the laser processing device 10 can move the first laser beam L1 and the second laser beam L2 relative to the substrate W in a second horizontal direction different from (for example, perpendicular to) the first horizontal direction (X direction), so that the first laser beam L1 and the second laser beam L2 are simultaneously scanned along two cutting lines or incision lines on the substrate W. For example, the second horizontal direction may be a direction (Y direction) perpendicular to the first horizontal direction (X direction).

[0055] The stage 20 can be moved in one direction at a scanning speed (such as a dynamically determined speed, or alternatively, a preset scanning speed) by the stage driver 22. The scanning speed of the first laser beam L1 and the second laser beam L2 can be determined by the speed of the stage 20. The scanning speed of the first laser beam L1 and the second laser beam L2 can be in the range of 300 mm / s to 2000 mm / s. In some cases, the scanning speeds of the first laser beam L1 and the second laser beam L2 can be the same or different from each other. In some cases, the scanning speeds of the first laser beam L1 and the second laser beam L2 can be constant, or alternatively, can vary along the dimension of the substrate W.

[0056] As described above, the laser processing device 10 may include a laser beam splitter 320 for converting the laser beam L00 emitted from the laser light source 310 as a single light source into a double O-shaped beam in which two beams L10 and L20 are arranged adjacent to each other in the first horizontal direction (X direction), and a condensing lens 340 for converging the double O-shaped beam into the first laser beam L1 and the second laser beam L2 at the first light spot P1 and the second light spot P2. In addition, the laser processing device 10 may further include a refractive index adjuster 330 to adjust the spacing distance between the first light spot P1 and the second light spot P2 in the first horizontal direction (X direction).

[0057] The first laser beam L1 and the second laser beam L2 may be simultaneously scanned along two cutting lines on the substrate W. The distance between the first spot position P1 and the second spot position P2 of the first laser beam L1 and the second laser beam L2 may be adjusted according to the size (or dimension, such as width and / or length) of the die to be cut from the substrate W. The first laser beam L1 and the second laser beam L2 may be focused by a single-lens optical system.

[0058] Therefore, the first laser beam L1 and the second laser beam L2 can be scanned simultaneously while tracking the surface height in real time along two adjacent cutting lines without increasing the size of the optical system or replacing a new optical system. Therefore, the productivity of the cutting process can be improved. Alternatively or additionally, the distance between the first laser beam L1 and the second laser beam L2 can be more easily optically adjusted.

[0059] In the following, the use of Figure 1 A laser processing method of a laser processing device.

[0060] Figure 8 is a flowchart illustrating a laser processing method according to example embodiments. Fig. 9 is a cross-sectional view showing a wafer on which a first laser beam and a second laser beam are irradiated. Fig.10 is a plan view showing two cutting lines on a wafer, Fig. 9The first laser beam and the second laser beam are scanned along the cutting line. Fig.11 is shown along Fig.10 A perspective view of two cutting lines irradiated by a first laser beam and a second laser beam.

[0061] Reference Figures 1 to 9 First, a substrate W as or corresponding to an object to be processed may be supported on a stage 20 (S10), a laser beam of a column vector beam L01 may be emitted (S20), the column vector beam L01 may be polarized by a polarization filter 324 to form a double O-shaped beam, wherein two beams L10 and L20 are adjacently arranged in a first horizontal direction (X direction) (S30), and the double O-shaped beam may be converged into a first laser beam L1 and a second laser beam L2 at a first spot P1 and a second spot P2 spaced apart in the first horizontal direction (X direction) on the substrate W by a condenser lens 340 (S40). The distance between the first spot P1 and the second spot P2 may be determined by, for example, the length or width of the die region D.

[0062] In some example embodiments, the substrate W is placed on Figure 1 After being placed on the stage 20, the laser beam L00 may be generated by the laser light source 310 as a single light source, and the laser beam L00 may be converted into the cylindrical vector beam L01 by the mode converter 322. For example, the laser beam L00 generated by the laser light source 310 may include a Gaussian beam, and the cylindrical vector beam L01 converted and emitted by the mode converter 322 may have a ring laser mode.

[0063] In some example embodiments, in order to adjust the spacing distance V1 between the first light spot P1 and the second light spot P2 in the first horizontal direction (X direction), the cylindrical vector beam L01 may be expanded by a beam expander 332 provided on the optical path of the cylindrical vector beam L01. The laser beam L02 expanded by the beam expander 332 may have a diameter larger than that of the cylindrical vector beam L01.

[0064] Then, the polarization filter 324 may polarize the expanded cylindrical vector beam L02 to form a double o-shaped beam in which two beams L10 and L20 are adjacently arranged in the first horizontal direction (X direction). The cylindrical vector beam L02 may have various polarization states through the mode converter 322. The polarization filter 324 may be used as a filter that passes only a component polarized in a specific direction.

[0065] For example, when the cylindrical vector beam L02 has radial polarization, the polarization filter 324 may pass only the component polarized in a direction parallel to the first horizontal direction (X direction). The two beams L10 and L20 filtered by the polarization filter 324 may have polarization components in a direction parallel to the first horizontal direction (X direction).

[0066] Alternatively, when the cylindrical vector beam L02 has azimuthal polarization, the polarization filter 324 may pass only the component polarized in the direction perpendicular to the first horizontal direction (X direction). The two beams L10 and L20 filtered by the polarization filter 324 may have polarization components in the direction perpendicular to the first horizontal direction (X direction).

[0067] In some example embodiments, the phase of the dual-O-shaped beam may be modulated by a spatial light modulator 334 provided on the optical path of the dual-O-shaped beam. The spatial light modulator 334 may spatially control the phase of the laser beam. The spatial light modulator 334 may only change the phase without changing the shape of the waveform.

[0068] For example, the wavefront of the dual O-shaped beams L11 and L21 that have passed through the spatial light modulator 334 can be changed, while the shape of the dual O-shaped beams L11 and L21 that have passed through the spatial light modulator 334 can be maintained to be the same as the shape of the two beams L10 and L20 filtered by the polarization filter 324.

[0069] Then, the condenser lens 340 may condense the dual-O-shaped beams L11 and L21 having passed through the spatial light modulator 334 into the first laser beam L1 and the second laser beam L2 at the first spot and the second spot spaced apart in the first horizontal direction (X direction) on the substrate W. The condenser lens 340 may be provided on an optical path of the dual-O-shaped beam, and may include a single-lens optical system having a numerical aperture (NA) of 0.6 or more.

[0070] For example, the condenser lens 340 may include a single lens optical system in which a plurality of lenses are sequentially arranged along the optical path. The double o-shaped light beams L11 and L21 may pass through the single lens optical system and converge into the first laser beam L1 and the second laser beam L2, respectively. The spacing distance V1 between the first light spot P1 and the second light spot P2 on the substrate W corresponding to the focal positions of the first laser beam L1 and the second laser beam L2 may be in the range of 0.5 mm to 20 mm. Depending on the orientation of the substrate W on the stage 20 and the orientation along which the line is cut, the spacing distance V1 may be the same or different.

[0071] Reference Fig.10 and Fig.11 , the first laser beam L1 and the second laser beam L2 may be scanned along two cutting lines S1 and S2 on the substrate W ( S50 ).

[0072] The focal points P1 and P2 of the first laser beam L1 and the second laser beam L2 may be located within the substrate W, and the first laser beam L1 and the second laser beam L2 may be moved in a second horizontal direction (Y direction) relative to the substrate along the cutting lines S1 and S2. The spacing distance V1 between the first light spot P1 and the second light spot P2 may be substantially equal to the spacing distance V2 between the cutting lines S1 and S2. The scanning speed of the first laser beam L1 and the second laser beam L2 may be in the range of 300 mm / s to 2000 mm / s. When scanning along the cutting lines S1 and S2 on the substrate W, the scanning speed of the first laser beam L1 and the second laser beam L2 may be constant, or may be variable (e.g., may increase and decrease).

[0073] Therefore, if Fig.11 As shown in FIG. 1 , a laser-scribed layer M as a modified region may be formed in the substrate W. The laser-damaged layers B1 and B2 (ie, scribe areas) formed along the cutting lines S1 and S2 may be used as cutting start areas. The laser-scribed layer M may be formed continuously or intermittently.

[0074] For example, when the first laser beam L1 and the second laser beam L2 are focused within the substrate W, the first laser beam and the second laser beam may be absorbed in the first light spot P1 and the second light spot P2 to cause them to melt, expand, shrink, and solidify. During the shrinkage process, the two side regions of each of the first light spot P1 and the second light spot P2 may shrink earlier, so that cracks begin to appear in the middle region of each of the first light spot P1 and the second light spot P2, and after the shrinkage stage, the cracks may grow in the upward and downward directions to form vertical cracks. The first laser beam L1 and the second laser beam L2 are intermittently irradiated while the first laser beam and the second laser beam are moved relative to the substrate W along the cutting lines S1 and S2 through the above process to form an invisible cutting line in the substrate W along the Y-axis direction, as shown in FIG. Fig.11 as shown in .

[0075] Hereinafter, a method of cutting a substrate using the above-mentioned laser processing apparatus and laser processing method will be described.

[0076] Fig.12 is a flowchart illustrating a substrate cutting method according to example embodiments. Figures 13 to 17 is a view illustrating a substrate cutting method according to example embodiments.

[0077] Reference Figures 12 to 17 First, a protective tape 110 for protecting circuit elements may be attached to (laminated on) a first surface (active surface) 12 of a substrate W (S100), and then a first laser beam L1 and a second laser beam L2 may be irradiated along two cutting lines on a second surface 14 opposite to the first surface 12 of the substrate 10 to form a laser scribing layer M (S110).

[0078] like Fig.13 As shown in FIG. 1 , in some example embodiments, a protective tape 110 may be attached to the first surface 12 of the substrate W using a tape attaching device 100 . The protective tape 110 may protect circuit elements formed in the first surface 12 of the substrate W.

[0079] like Fig.14 As shown in , a laser processing device 10 can be used to irradiate a first laser beam L1 and a second laser beam L2 into a substrate W, and simultaneously position a first light spot and a second light spot inside the substrate W to form an optically damaged portion (laser scribing layer) M by multiphoton absorption. The first laser beam L1 and the second laser beam L2 can move relative to the substrate W along two cutting lines S1 and S2 to form a laser damaged layer M inside the substrate W, and the laser damaged layer M is a modified region. The laser damaged layer M (i.e., scribing region) formed along the cutting lines S1 and S2 can be a cutting start region.

[0080] like Fig.15 As shown in FIG. 1 , the second surface 14 of the substrate W in which the laser damaged layer M is formed can be ground using the grinding device 200 (S120). By grinding the second surface 14 of the substrate W, the thickness of the substrate W can be thinned to have a desired thickness. At this time, during the grinding process, the laser damaged layer M can be used as a cutting start area, thereby generating fine vertical cracks R.

[0081] After the grinding process is performed, the protection tape 110 may be removed from the substrate W.

[0082] like Fig.16 and Fig.17 As shown in FIG. 1 , the substrate W may be cut into individual chips ( S130 ).

[0083] In some example embodiments, the dicing tape 60 may be attached to the lower surface 54 of the ring frame 50, and the adhesive film 120 may be attached to the substrate W on which the plurality of semiconductor chips are formed. The dicing tape 60 may be attached to the ring frame 50 by the adhesive force of the adhesive material layer 64 of the dicing tape 60. The adhesive film 120 may be spaced apart from the inner surface of the ring frame 50. The adhesive film 120 may include a die attach film (DAF) as an organic adhesive.

[0084] Then, the dicing tape 60 may be expanded to separate the substrate W into a plurality of semiconductor chips D.

[0085] In some example embodiments, after the attachment area of ​​the ring frame 50 and the dicing tape 60 is inserted and fixed between the fixing member 412 and the stage 410, the column pressing member 400 may be raised to expand the dicing tape 60. Thus, the separated chips on the dicing tape 60 may be spaced apart from each other in the radial direction. At this time, the adhesive film 120 may also be separated.

[0086] Then, a pickup process may be performed to pick up the individual separated semiconductor chips D. Thus, the semiconductor chip D to which the adhesive film 120 is attached may be attached to a package substrate or another semiconductor chip to form a semiconductor package.

[0087] The semiconductor package formed by the above-mentioned laser processing device may include semiconductor devices such as one or more of logic devices or memory devices. The semiconductor package may include a logic device (such as one or more of a central processing unit (CPU), a main processing unit (MPU), an application processor (AP), etc.) and a volatile memory device (such as a DRAM device, a hybrid memory (HBM) device) or a non-volatile memory device (such as one or more of a flash memory device, a PRAM device, an MRAM device, a ReRAM device, etc.).

[0088] Any of the elements and / or functional blocks disclosed above may include or be implemented in a processing circuit, the processing circuit being hardware such as including a logic circuit; a hardware / software combination such as a processor that executes software; or a combination thereof. For example, the processing circuit may more specifically include, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a system on a chip (SoC), a programmable logic unit, a microprocessor, an application specific integrated circuit (ASIC), etc. The processing circuit may include electronic components such as at least one of a transistor, a resistor, a capacitor, etc. The processing circuit may include electronic components such as a logic gate, the logic gate including at least one of an AND gate, an OR gate, a NAND gate, a NOT gate, etc.

[0089] The foregoing is an illustration of example embodiments and should not be construed as limiting thereof. Although several example embodiments have been described, it will be readily appreciated by those skilled in the art that many modifications may be made in some example embodiments without substantially departing from the novel teachings and advantages of the present invention. Therefore, all such modifications are intended to be included within the scope of the variously described example embodiments as defined in the claims. Furthermore, the example embodiments are not necessarily mutually exclusive of one another. For example, some example embodiments may include one or more features described with reference to one or more figures, and may also include one or more other features described with reference to one or more other figures.

[0090] This application claims the priority benefit of Korean Patent Application No. 10-2023-0138650 filed on October 17, 2023 in the Korean Intellectual Property Office, the contents of which are hereby incorporated by reference in their entirety.

Claims

1. A laser processing device, comprising: a stage configured to support a substrate as an object to be processed; a laser light source configured to generate a laser beam; a mode converter configured to convert the laser beam into a cylindrical vector beam; a polarization filter configured to polarize the cylindrical vector beam to form a double-O-shaped beam in which two beams are arranged adjacent to each other in a first horizontal direction; a condenser lens configured to converge the double-O-shaped light beam into a first laser beam and a second laser beam at a first light spot and a second light spot on the substrate, the first laser beam and the second laser beam being spaced apart in the first horizontal direction; as well as The driving section is configured to relatively move the first laser beam and the second laser beam relative to the substrate in a second horizontal direction different from the first horizontal direction. 2 . The laser processing apparatus according to claim 1 , wherein the laser beam comprises a Gaussian beam, and the cylindrical vector beam comprises a ring laser mode beam. 3 . The laser processing apparatus according to claim 1 , wherein the polarization filter is configured to pass a component polarized in a direction parallel to the first horizontal direction in response to the cylindrical vector beam having radial polarization. 4 . The laser processing apparatus according to claim 1 , wherein the polarization filter is configured to pass a component polarized in a direction perpendicular to the first horizontal direction in response to the cylindrical vector beam having azimuthal polarization. The laser processing apparatus according to claim 1 , wherein the second horizontal direction is perpendicular to the first horizontal direction.

6. The laser processing device according to claim 1, further comprising: A refractive index adjuster, on the optical path of the cylindrical vector beam or on the dual-O-shaped beam or on both the optical path and the dual-O-shaped beam, the refractive index adjuster is configured to adjust the spacing distance between the first light spot and the second light spot in the first horizontal direction. 7 . The laser processing apparatus according to claim 6 , wherein the refractive index adjuster comprises a beam expander which is on the optical path of the cylindrical vector beam and is configured to expand the cylindrical vector beam.

8. The laser processing apparatus according to claim 6, wherein the refractive index adjuster comprises a spatial light modulator, which is on an optical path of the dual-O-shaped beam and is configured to modulate a phase of the dual-O-shaped beam. 9 . The laser processing device according to claim 1 , wherein a spacing distance between the first light spot and the second light spot in the first horizontal direction is in a range of 0.5 mm to 20 mm.

10. The laser processing apparatus according to claim 1, wherein the condensing lens is on an optical path of the double-O-shaped beam and comprises a single-lens optical system having a numerical aperture of 0.6 or more.

11. A laser processing device, comprising: a stage configured to support a substrate to be processed; a laser irradiator configured to converge the first laser beam and the second laser beam and irradiate the first light spot and the second light spot on the substrate, wherein the first light spot and the second light spot are spaced apart in a first horizontal direction; as well as a driving section configured to move the stage or the laser irradiator and to move the first laser beam and the second laser beam in a second horizontal direction different from the first horizontal direction relative to the substrate, The laser irradiator comprises: a laser light source configured to generate a laser beam; a mode converter configured to convert the laser beam into a cylindrical vector beam; a polarization filter configured to polarize the cylindrical vector beam to form a double-O-shaped beam in which two beams are arranged adjacent to each other in the first horizontal direction; a condenser lens disposed on an optical path of the double-O-shaped beam and configured to converge the double-O-shaped beam into the first laser beam and the second laser beam on the substrate; as well as A refractive index adjuster, on the optical path of the cylindrical vector beam or the double-O-shaped beam, or on both the optical path of the cylindrical vector beam and the double-O-shaped beam, the refractive index adjuster being configured to adjust the spacing distance between the first light spot and the second light spot in the first horizontal direction. 12 . The laser processing apparatus according to claim 11 , wherein the laser beam comprises a Gaussian beam, and the cylindrical vector beam comprises a laser beam in a ring laser mode. 13 . The laser processing apparatus according to claim 11 , wherein the polarization filter is configured to pass a component polarized in a direction parallel to the first horizontal direction in response to the cylindrical vector beam having radial polarization. 14 . The laser processing apparatus according to claim 11 , wherein the polarization filter is configured to pass a component polarized in a direction perpendicular to the first horizontal direction in response to the cylindrical vector beam having azimuthal polarization. 15 . The laser processing apparatus according to claim 11 , wherein the second horizontal direction is perpendicular to the first horizontal direction, and the laser irradiator is configured to scan the first laser beam and the second laser beam along two cutting lines on the substrate, respectively. 16 . The laser processing apparatus according to claim 15 , wherein a scanning speed of the first laser beam and the second laser beam is in a range of 300 mm / s to 2000 mm / s. 17 . The laser processing apparatus according to claim 11 , wherein the refractive index adjuster comprises a beam expander which is on the optical path of the cylindrical vector beam and is configured to expand the cylindrical vector beam.

18. The laser processing apparatus according to claim 11, wherein the refractive index adjuster comprises a spatial light modulator which is on the optical path of the dual-O-shaped beam and is configured to modulate a phase of the dual-O-shaped beam. 19 . The laser processing device according to claim 11 , wherein the spacing distance between the first light spot and the second light spot in the first horizontal direction is in a range of 0.5 mm to 20 mm. 20 . The laser processing apparatus according to claim 11 , wherein the condensing lens comprises a single-lens optical system having a numerical aperture of 0.6 or more.

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