KR20210157964A - Laser dicing apparatus - Google Patents

Abstract

According to an embodiment of the present invention, a laser dicing apparatus comprises: an emitter for emitting a pulsed laser beam incident on the upper surface of a substrate; a phase modulation unit for modulating a phase distribution of the pulsed laser beam; a focusing lens unit disposed in a path where the modulated pulsed laser beam is incident on the substrate; and a substrate mounting unit on which the substrate is mounted. The modulated pulsed laser beam is incident on the substrate in a first direction perpendicular to the upper surface of the substrate. The substrate includes: a focusing area determined by a focal length of the focusing lens unit; and a defocusing area defined at a position different from the focusing area in the first direction. The modulated pulsed laser beam has a non-uniform intensity distribution in a second direction parallel to the upper surface of the substrate in at least a portion of the defocusing region, thereby suppressing scattering of the pulsed laser beam, and increasing the throughput of the laser dicing apparatus.

Description

LASER DICING APPARATUS

The present invention relates to a laser cutting device.

The stealth dicing device can expect improved cutting quality compared to other devices such as a blade dicing device and a laser ablation device. The stealth cutting device can cut the substrate into individual semiconductor chips by irradiating a laser beam to the substrate to form cracks and deformation regions. However, a portion of the laser beam may be scattered in a region where the laser beam incident on the substrate and the previously formed cracks and deformation regions overlap, thereby causing optical damage to the substrate. On the other hand, if the laser power is reduced to prevent scattering, it may cause a defect in the cutting device, so it is necessary to suppress the scattering without reducing the laser power.

One of the problems to be achieved by the technical idea of the present invention is to minimize the overlapping area between the laser beam incident on the substrate and the previously formed cracks and deformation regions in order to suppress the scattering of the laser beam without reducing the laser output. It is to provide a laser cutting device that can.

A laser cutting apparatus according to an embodiment of the present invention includes an emitter emitting a pulsed laser beam incident on an upper surface of a substrate, a phase modulation unit for modulating a phase distribution of the pulsed laser beam, and the modulated pulsed laser beam a focusing lens unit disposed on a path incident on the substrate, and a substrate seating unit on which the substrate is mounted, wherein the modulated pulse laser beam is incident on the substrate in a first direction perpendicular to an upper surface of the substrate, and The substrate includes a focusing area determined by a focal length of the focusing lens unit, and a defocusing area defined at a position different from the focusing area in the first direction, wherein the modulated pulsed laser beam comprises: At least a portion of the substrate has a non-uniform intensity distribution along the second direction parallel to the upper surface of the substrate.

A laser cutting apparatus according to an embodiment of the present invention includes an emitter emitting a pulsed laser beam incident on an upper surface of a substrate, a phase modulation unit for modulating a phase distribution of the pulsed laser beam, and the modulated pulsed laser beam a focusing lens unit disposed on a path incident on a substrate, and a substrate seating unit on which the substrate is mounted, wherein the modulated pulsed laser beam is incident on the substrate in a first direction perpendicular to an upper surface of the substrate, The substrate is determined by the focal length of the focusing lens unit and includes a first focusing region and a second focusing region sequentially formed inside the substrate, and a first crack formed between the first focusing region and an upper surface of the substrate and a first deformation region, and a second crack and a second deformation region formed between the second focusing region and the upper surface of the substrate, wherein the phase modulation unit comprises: The phase distribution of the pulsed laser beam is modulated so that an overlapping region between the first crack and the first deformed region is minimized.

A laser cutting apparatus according to an embodiment of the present invention includes an emitter emitting a pulsed laser beam incident on an upper surface of a substrate, a phase modulation unit for modulating a phase distribution of the pulsed laser beam, and the modulated pulsed laser beam A polarizing filter disposed on a path incident on a substrate, a focusing lens unit disposed on a path through which the modulated pulsed laser beam passes through the polarization filter and incident on the substrate, and a substrate mounting unit on which the substrate is mounted, the polarization unit comprising: The filter modulates the modulated pulsed laser beam so that a p-polarized component in which an electric field component vibrates in a direction parallel to an incident surface has a greater value than an s-polarized component in which an electric field component vibrates in a direction perpendicular to the incident surface. polarized the pulsed laser beam.

Laser cutting apparatus according to an embodiment of the present invention, by modulating the phase distribution of the pulsed laser beam using a phase modulation unit, the pulsed laser beam overlaps with the cracks and deformed areas formed in advance to minimize the problem that occurs can In addition, the phase-modulated pulsed laser beam can be focused inside the substrate without loss of output. Therefore, it is possible to improve the cutting quality and process efficiency by suppressing scattering in the wafer cutting process using the laser cutting device.

Various and advantageous advantages and effects of the present invention are not limited to the above, and will be more easily understood in the course of describing specific embodiments of the present invention.

1 is a schematic configuration diagram of a semiconductor processing equipment including a laser cutting device according to an embodiment of the present invention.
2A, 2B, and 2C are side cross-sectional views of a substrate for explaining a process in which an emitted pulse laser beam forms cracks and deformation regions in a laser cutting apparatus according to an embodiment of the present invention.
3A is a side cross-sectional view of a substrate for explaining scattering of a pulsed laser beam in a general laser cutting apparatus.
3B is a plan view of a substrate for explaining scattering of a pulsed laser beam in a general laser cutting apparatus.
4A is a side cross-sectional view for explaining a method for suppressing scattering of a pulsed laser beam in a laser cutting device according to an embodiment of the present invention.
4B is a plan view for explaining a method for suppressing scattering of a pulsed laser beam in a laser cutting device according to an embodiment of the present invention.
5 is a schematic configuration diagram of a laser cutting device according to an embodiment of the present invention.
6 is a view for explaining the intensity distribution of a pulsed laser beam to which a phase modulation unit is not applied in a general laser cutting device.
7A and 7B are diagrams for explaining the intensity distribution of a pulsed laser beam to which an amplitude modulation unit is applied in the improved laser cutting apparatus.
8A and 8B are diagrams for explaining the intensity distribution of a pulsed laser beam to which a phase modulation unit is applied in a laser cutting device according to an embodiment of the present invention.
9 is a plan view of the phase modulation pattern included in the phase modulation unit in the laser cutting device according to an embodiment of the present invention.
10 is a view for explaining a mask pattern for correction and processing of a pulsed laser beam in a laser cutting apparatus according to an embodiment of the present invention.
11 is a configuration diagram of a case in which a light and an image sensor for feedback are further included in the laser cutting device according to an embodiment of the present invention.
12 is a configuration diagram when the phase modulation unit of the laser cutting device according to an embodiment of the present invention is configured to reflect a pulsed laser beam.
13a, 13b, and 13c are diagrams for explaining the effect when a polarizing filter is further included in the laser cutting device according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a schematic configuration diagram of a semiconductor processing equipment including a laser cutting device according to an embodiment of the present invention.

Referring to FIG. 1 , a laser cutting apparatus 40 according to an embodiment of the present invention may be included in the semiconductor processing equipment 1 . As an example, the semiconductor processing equipment 1 includes a cassette elevator 10 for elevating and lowering a cassette station in which a wafer W to be cut is accommodated, a pre-alignment stage for aligning the central axis of the wafer W ( 20), and may further include a transfer robot 30 . On the other hand, the configuration of the semiconductor processing equipment 1 for cutting the wafer W is not limited thereto, and a plurality of tables and/or a wafer W scanner that proceeds the above steps according to the steps required for cutting are further added. may include

For example, the wafer W may be a semiconductor substrate including a semiconductor material. The laser cutting apparatus according to an embodiment of the present invention may divide the wafer W on which the desired integrated circuits are formed by performing a cutting process into a plurality of semiconductor devices, and produce a plurality of semiconductor chips from the wafer W can However, according to embodiments, the processing target may not be limited to the wafer W. For example, various substrates other than the wafer W, for example, a mother substrate for a display may be processed.

The laser cutting apparatus 40 according to an embodiment of the present invention may receive the wafer W on the cassette elevator 10 and the pre-alignment stage 20 and proceed with the process. As an example, the transfer robot 30 removes the process target such as the wafer W from the cassette elevator 10 and delivers it to the pre-alignment stage 20, or transfers the process target aligned in the pre-alignment stage 20 to the process target of the present invention. It can be transferred to the laser cutting device 40 according to an embodiment. In one embodiment, the transfer robot 30 may be a handler, and may consist of a plurality of handlers according to stages and uses. Meanwhile, the transfer robot 30 may include a chuck for fixing the process target, and a plurality of protrusions contacting the process target may be formed on the chuck. As an example, the transfer robot 30 may further include a linear stage for transferring the process target.

The laser cutting apparatus 40 according to an embodiment of the present invention may be a processing apparatus used to produce a semiconductor chip by cutting a substrate having semiconductor elements formed thereon. For example, the laser cutting device 40 may be a stealth dicing (SD) laser device. The stealth cutting laser device may use a lens to focus a pulsed laser beam having a wavelength that can penetrate the substrate, and collect the pulsed laser beam inside the substrate. When the stealth cutting laser device is used, the process can be selectively performed only on local points of the substrate without damaging the front and back surfaces of the substrate.

2A, 2B, and 2C are side cross-sectional views of a substrate for explaining a process in which an emitted pulsed laser beam forms cracks and deformation regions in a laser cutting apparatus according to an embodiment of the present invention.

Referring to Figure 2a, the pulsed laser beam (L1) emitted from the laser cutting device according to an embodiment of the present invention may pass through the lens to be incident on the substrate (S). On the other hand, the pulsed laser beam L1 may be a pulse signal oscillating at a predetermined frequency, and the peak power density can be highly condensed in the vicinity of the region where the pulsed laser beam L1 is focused by using a specific level of diffraction. have. For example, the pulsed laser beam L1 passing through the substrate S in the first direction (z-direction) perpendicular to the substrate S and incident into the substrate S is focused on the pulse laser beam L1. Energy can be condensed near the area. Due to the highly condensed peak power density, a nonlinear multi-photon absorption phenomenon may occur with high frequency near the region where the pulsed laser beam L1 is focused. For example, the region where the pulsed laser beam L1 is focused may be determined by a focal length of a lens through which the pulsed laser beam L1 passes.

Due to this, as the particles of the substrate S absorb the energy of the condensed pulsed laser beam L1, a thermal melting phenomenon may occur, and the deformation region P and the crack C, which are the starting point of cutting, form the substrate ( S) may be formed inside. As an example, the deformation region P may be a region modified by thermal melting, The crack C may be a crack according to stress generated due to a phase change in the modified region. The laser cutting apparatus according to an embodiment of the present invention may form a deformation region P and a crack C in the vicinity of an inner region of the substrate S on which the pulse laser beam L1 is focused. For example, the crack C may be formed to extend in the first direction (z-direction) into which the pulsed laser beam L1 is incident near the region where the pulsed laser beam L1 is focused, and the deformation region ( P) may be formed in the vicinity of the region where the pulsed laser beam L1 is focused. However, the shape of the crack C and the deformation region P is not limited to the embodiment, and may be formed in various shapes according to the characteristics of the pulsed laser beam L1 and the substrate S. For example, the characteristic may be the intensity, shape, and/or material of the substrate S of the pulsed laser beam L1.

Referring to Figure 2b, the laser cutting apparatus according to an embodiment of the present invention can break the balance of intermolecular forces of the substrate (S) by forming a plurality of deformation regions (P) and cracks (C). For example, when an external force is applied to the substrate S, the substrate S may be cut based on the plurality of deformation regions P and cracks C formed. After the laser cutting device according to an embodiment of the present invention forms one deformation region P and a crack C at a specific position of the substrate S, the scan is performed in the second direction (x-direction) A plurality of deformation regions P and cracks C may be sequentially formed with respect to each other. However, this is only an example, and the plurality of deformable regions P and cracks C may be formed in various directions and sequences as needed.

Referring to Figure 2c, the laser cutting apparatus according to an embodiment of the present invention is a plurality of deformation regions (P) and cracks (C) at different depths in the first direction (z-direction) inside the substrate (S) It can be formed in a plurality of layers positioned. For example, the depth at which each layer is formed may be determined by adjusting a focused position of the pulsed laser beam L1. Meanwhile, the interlayer spacing and/or the number of cracks C formed are not limited to the embodiment, and the cutting process may be performed in various forms according to the characteristics of the substrate S and the pulsed laser beam L1. By forming the plurality of deformation regions P and cracks C in multiple layers, flexibility of the substrate S cutting process can be improved.

3A and 3B are a side cross-sectional view and a plan view of a substrate for explaining scattering of a pulsed laser beam, respectively, in a general laser cutting apparatus.

3A and 3B, the pulsed laser beam L2 emitted from a general laser cutting device is incident on the upper surface of the substrate S in the first direction (z-direction) perpendicular to the substrate S, and the substrate ( S) can be focused inside. At least one of the pulsed laser beam L2 and the substrate S may move in a second direction (x-direction) parallel to the substrate. At this time, the second direction (x-direction) is a direction in which the laser cutting device moves, and may be defined as a scan direction.

Meanwhile, as the scan is performed by the laser cutting device, a plurality of deformation regions P and cracks C may be formed inside the substrate S. When the pulse laser beam L2 is incident on the upper surface of the substrate S, the inside of the substrate S includes at least one deformation region P and a crack C previously formed by the pulse laser beam L2. there may be The incident pulsed laser beam L2 may form a deformation region P and a crack C at a new position inside the substrate S. However, inside the substrate S, an overlapping region D in which the region through which the pulsed laser beam L2 incident on the upper surface passes and the previously formed deformation region P and/or the crack C overlap may occur. have. At least a portion of the pulsed laser beam L2 may be scattered in the overlapping region D, and the scattered pulsed laser beam L2' may cause optical damage to a semiconductor device formed on the substrate S.

On the other hand, in order to improve the cutting power in a general laser cutting device, it is possible to irradiate the pulsed laser beam L2 close to the upper surface of the substrate S. However, when the pulse laser beam L2 is irradiated from an area adjacent to the substrate S, the size of the overlapping area D may increase. In this case, the intensity of the scattered pulsed laser beam L2 ′ may increase together, thereby increasing damage to the substrate S. In other words, suppression of scattering of the pulsed laser beam L2 and improvement of cutting power may have a trade-off relationship with each other.

4A and 4B are a side cross-sectional view and a plan view, respectively, for explaining a method for suppressing scattering of a pulsed laser beam in a laser cutting apparatus according to an embodiment of the present invention.

4A and 4B , the pulsed laser beam L3 emitted from the laser device according to an embodiment of the present invention is directed toward the substrate S in a first direction (z-direction) perpendicular to the substrate S. It may be incident on the upper surface and concentrated inside the substrate (S). The scanning direction of the laser cutting device may be determined by movement of at least one of the pulsed laser beam L3 and the substrate S. For example, the scan direction may be a second direction (x-direction) parallel to the substrate.

As the scan by the laser cutting device according to an embodiment of the present invention proceeds, a plurality of deformable regions P and cracks C may be formed inside the substrate S. In the overlapping region D where the region corresponding to the traveling path of the pulsed laser beam L3 in the substrate S and the previously formed deformation region P and/or the crack C overlap, the pulsed laser beam L3 Some of it may be scattered. Accordingly, it is necessary to minimize the overlapping region D in order to suppress scattering and prevent optical damage to the semiconductor device formed on the substrate S.

For example, when the pulsed laser beam L3 travels inside the substrate S, the intensity of the beam is relative to a portion of a plane perpendicular to the first direction (z-direction), which is the incident direction of the pulsed laser beam L3. can have a weakly asymmetrical intensity distribution. For example, the partial region may include an overlapping region D. Meanwhile, when the intensity of the pulsed laser beam L3 passing through the overlapping area D is decreased, the pulsed laser beam L3 scattered from the overlapping area D may also be reduced.

The laser cutting apparatus according to an embodiment of the present invention controls the pulsed laser beam L3 to have a relatively weak intensity in some areas so that at least one cross section of the pulsed laser beam L3 has an asymmetrical intensity distribution. can Through this, by reducing or removing the intensity of the pulsed laser beam L3 passing through the overlapping region D, scattering of the pulsed laser beam L3 is suppressed and optical damage to the semiconductor device formed on the substrate S is reduced. can be prevented

On the other hand, the laser cutting apparatus according to an embodiment of the present invention can irradiate the pulse laser beam (L3) at a position close to the upper surface of the substrate (S). In the laser cutting apparatus according to an embodiment of the present invention, even if the pulsed laser beam (L3) is irradiated at a position close to the substrate (S), the overlapping area (D) by controlling the pulsed laser beam (L3) to have an asymmetrical intensity It is possible to minimize the intensity of the pulsed laser beam L3 incident on the . Accordingly, it is possible to minimize the scattered pulsed laser beam L3 ′ and improve the cutting power without additional damage to the substrate S. Therefore, using the laser cutting apparatus according to an embodiment of the present invention, it is possible to improve the cutting performance while suppressing the scattering of the pulsed laser beam (L2).

5 is a schematic configuration diagram of a laser cutting device according to an embodiment of the present invention.

Referring to FIG. 5 , the laser cutting apparatus 100 according to an embodiment of the present invention includes an emitter 110 , a phase modulation unit 120 , a focusing lens unit 130 , and a substrate seating unit 140 . can do.

The emitter 110 may emit a pulsed laser beam L. The pulsed laser beam L may have a short pulse width and may be emitted with a large output for a short time. The pulsed laser beam L may be a Gaussian beam according to an embodiment. However, the present invention is not limited thereto, and the pulsed laser beam L may be emitted in various forms, such as a square wave or a plane wave. The emitted pulsed laser beam L is refracted and/or reflected by an optical module including a plurality of lenses and/or mirrors as necessary until it is incident on the upper surface of the substrate S, and is then reflected on the upper surface of the substrate S. can get in For example, the laser cutting apparatus 100 according to an embodiment of the present invention may include a plurality of lenses and / or mirrors that can modulate the pulse laser beam (L) in various ways. However, this is not limited to the embodiment shown in FIG. 5 , and an additional configuration of the laser cutting apparatus 100 may be determined according to the characteristics of the pulsed laser beam L and the substrate S to be cut.

The phase modulation unit 120 may modulate a phase distribution of the emitted pulsed laser beam L. The phase modulation unit 120 may use the interference phenomenon of the pulsed laser beam L whose phase distribution is modulated to minimize the overlapping area between the pulsed laser beam L and the previously formed deformation region and/or crack. .

The phase modulation unit 120 may be a transmissive phase shift plate. The transmissive phase shift plate may be a transparent substrate comprising a phase modulation filter with a tailored phase distribution. In addition, the transmission phase shift plate can be made of transparent glass such as fused silica or BK-7 glass, and an etching process or a deposition process of a transparent material can be applied to generate a phase modulation pattern in small phase units. have.

The focusing lens unit 130 may be disposed on a path where the modulated pulsed laser beam L is incident on the substrate S to focus the modulated pulsed laser beam L on the substrate S. For example, the focusing lens unit 130 may include at least one convex lens. On the other hand, the pulsed laser beam L focused inside the substrate S by the focusing lens unit 130 may form a crack and/or a deformation region that is a starting point of cutting in the vicinity of a position where the beam is focused.

The substrate mounting unit 140 may align and mount the substrate S to be cut. Meanwhile, at least one of the substrate S and the pulse laser beam L mounted on the substrate mounting unit 140 may move according to a cutting pattern. However, the cutting pattern of the laser cutting apparatus 100 according to an embodiment of the present invention is not limited to the embodiment, and the cutting process may be performed in various patterns. In addition, the laser cutting apparatus 100 according to an embodiment of the present invention receives a cutting pattern and changes the position of at least one of the pulse laser beam (L) and the substrate (S) to cut the substrate (S) at high speed mechanism can be applied. For example, the laser cutting apparatus 100 may further include a memory for storing an algorithm for applying the mechanism.

6 is a view for explaining the intensity distribution of a pulsed laser beam to which a phase modulation unit is not applied in a general laser cutting device.

Referring to FIG. 6 , in a general laser cutting device 200 , the pulsed laser beam L2 emitted from the emitter may pass through the focusing lens unit 230 without going through the phase modulation unit. The pulsed laser beam L2 passing through the focusing lens unit 230 may be incident on the upper surface of the substrate S in the first direction (z-direction). On the other hand, the region inside the substrate S through which the pulsed laser beam L2 passes is a focusing region 250 on which the pulsed laser beam L2 is focused, and a focusing region 250 in the first direction (z-direction). It may include a defocusing area 255 existing at a position different from the . For example, the focusing area 250 may be located at a focal length of the focusing lens unit 230 . Meanwhile, the focusing region 250 may be located at a specific depth of the substrate S, and the defocusing region 255 may be located at a shallower depth than the focusing region 250 . For example, the depth of the focusing region 250 may be determined according to the arrangement between the focus lens unit 230 and the substrate S.

The general laser cutting apparatus 200 shown in FIG. 6 uses a pulsed laser beam L2 to form a deformation region P in the vicinity of the focusing region 250 of the substrate S, and the focusing region 250 and A crack C may be formed between the upper surfaces of the substrate S. For example, the crack C may be formed to extend in the first direction (z-direction) inside the substrate S. However, the deformable region P and the crack C shown in FIG. 6 are merely exemplary and are not limited thereto, and may be formed in various shapes at positions different from those of the exemplary embodiment.

On the other hand, in the laser cutting apparatus 200 shown in Figure 6, at least one of the substrate (S) and the pulse laser beam (L2) may move according to the cutting pattern. Accordingly, a plurality of focusing regions 250 and 250 ′ and a plurality of defocusing regions 255 and 255 ′ may be defined on the substrate S. In addition, at least one deformation region P and a crack C may be formed inside the substrate S.

For example, the substrate S may include a first focusing region 250 ′ and a second focusing region 250 in which the pulsed laser beam L2 is sequentially formed. The first focusing area 250 ′ and the second focusing area 250 may be located at a focal length of the focusing lens unit 230 , and may be located at different first and second depths, respectively. However, this is only an exemplary embodiment, and the first depth and the second depth at which the first focusing area 250 ′ and the second focusing area 250 are located may be the same as each other.

In addition, in a specific area at a position different from the first focusing area 250 ′ and the second focusing area 250 in the first direction (z-direction), the first defocusing area 255' and the second defocusing area ( 255) can be defined respectively. Meanwhile, a first deformation region may be formed near the first focusing region 250 ′, and a first crack may be formed between the first focusing region 250 ′ and the upper surface of the substrate S. Similarly, a second deformation region may be formed near the second focusing region 250 , and a second crack may be formed between the second focusing region 250 and the upper surface of the substrate S. For example, at least a portion of the second defocusing region 255 may overlap at least a portion of the previously formed first crack and/or the first deformable region. The pulsed laser beam L2 may be scattered in the overlapping area.

In the general laser cutting apparatus 200 shown in FIG. 6 , the modulated pulsed laser beam L2 incident on the second focusing area 250 may pass through the second defocusing area 255 . Meanwhile, the modulated pulsed laser beam L2 passing through the second defocusing region 255 may include a first end surface 251 and a second end surface 252 parallel to the upper surface of the substrate S. Meanwhile, the pulsed laser beam L2 may have intensity distributions such as I250, I251, and I252 in the second focusing region 250 , the first cross-section 251 , and the second cross-section, respectively.

Referring to I251 and I252, the pulsed laser beam L2 may have a uniform intensity distribution in the angular direction with respect to the midpoint of the first and second cross-sections 251 and 252. Meanwhile, the pulsed laser beam L2 incident to the second focusing region 250 may pass through at least a portion of the first crack C. As shown in FIG. The pulsed laser beam L2 passing through at least a portion of the first crack C may be scattered to cause optical damage to the surrounding semiconductor substrate.

7A and 7B are diagrams for explaining the intensity distribution of a pulsed laser beam to which an amplitude modulation unit is applied in the improved laser cutting apparatus.

Referring to FIG. 7A , in the improved laser cutting apparatus 400 , the pulsed laser beam L4 emitted from the emitter may pass through the amplitude modulation unit 420 . The pulsed laser beam L4 in which the amplitude distribution of the beam is modulated using the amplitude modulation unit 420 passes through the focusing lens unit 430 and is incident on the upper surface of the substrate S in the first direction (z-direction). have. On the other hand, in the improved laser cutting apparatus 400, the focusing area 450 and the defocusing area 455 may be defined similarly to the general laser cutting apparatus 200 shown in Fig. 6 described above. For example, the focusing area 450 may be an area inside the substrate S on which the pulsed laser beam L4 is focused, and the defocusing area 455 may be a focusing area 450 in the first direction (z-direction). It may be a region inside the substrate S that is present at a different position from the .

The improved laser cutting apparatus 400 shown in FIG. 7A uses a pulsed laser beam L4 to form a deformation region P in the vicinity of a focusing region 450 of a substrate S, and a focusing region 450 . A crack C may be formed between the upper surface of the substrate S and the substrate S. Meanwhile, at least one of the substrate S and the pulsed laser beam L4 may move according to the cutting pattern, and accordingly, at least one deformation region P and a crack C may be formed inside the substrate S. have. For example, the process in which at least one deformation region P and crack C are sequentially formed while the cutting process is performed by the improved laser cutting device 400 shown in FIG. 7A is a general laser device shown in FIG. It may be similar to the process of forming the deformation region P and the crack C in 200 . For example, at least a portion of the defocusing region 455 may overlap at least a portion of the previously formed crack C and/or the deformation region P. The pulsed laser beam L4 may be scattered in the overlapping area.

In the improved laser cutting apparatus 400 shown in FIG. 7A , the amplitude modulation unit 420 may include an amplitude modulation pattern 425 for modulating the amplitude distribution of the pulsed laser beam L4 . For example, the amplitude modulation pattern 425 may be designed to have an asymmetric pattern that blocks at least a portion of the pulsed laser beam L4 and allows only another portion to pass therethrough. The region where the beam is blocked by the amplitude modulation unit 420 may include a region overlapping the previously formed crack C and/or the deformation region P. As an example, the amplitude modulation pattern 425 may have a shape that blocks the pulsed laser beam L4 with respect to a sector-shaped region including the previously formed crack C and/or the deformation region P.

In the improved laser cutting apparatus 400 shown in FIG. 7A , the modulated pulsed laser beam L4 incident on the focusing area 450 may pass through the defocusing area 455 . Meanwhile, the modulated pulsed laser beam L4 passing through the defocusing region 455 may include a first end surface 451 and a second end surface 452 parallel to the upper surface of the substrate S. Meanwhile, the pulsed laser beam L4 may have the same intensity distribution as I450, I451, and I452 in the focusing region 450 , the first end surface 451 , and the second end surface 452 , respectively.

In the improved laser cutting apparatus 400 shown in FIG. 7A , referring to I451 and I452 , the pulsed laser beam L4 is a second parallel to the upper surface of the substrate S in at least a portion of the defocusing area 455 . It may have a non-uniform intensity distribution along the direction. For example, the second direction may be an angular direction with respect to the optical axis of the modulated pulsed laser beam L4. That is, the modulated pulsed laser beam L4 may have a non-uniform intensity distribution with respect to the angular direction based on the midpoints of the first and second end surfaces 451 and 452 .

For example, the pulsed laser beam L4 passing through at least a portion of the crack C may be scattered to cause optical damage to the surrounding semiconductor substrate. However, as described above, the amplitude modulation unit 420 may reduce the intensity of the beam in a region overlapping the crack C among the pulsed laser beam L4 . Therefore, when the cutting process is performed using the laser cutting device 400 of FIG. 7A , optical damage to the semiconductor substrate can be suppressed.

Figure 7b is a graph (G250, G250, respectively) showing the intensity distribution of the pulse laser beams (L2, L4) in the focusing regions (250, 450) simulated by the above-described laser cutting devices (200, 400) with respect to the x, y section, respectively. G250', G450, G450'). Referring to Figure 7b, the intensity distribution graph (G450, G450') of the pulse laser beam (L4) in the laser cutting device 400 shown in Figure 7a, and the pulse laser in the laser cutting device 200 shown in Figure 6 The intensity distribution graphs G250 and G250' of the beam L2 may be compared.

Referring to FIG. 7B , when the amplitude modulation unit 420 is applied, the intensity of the focused pulsed laser beam L4 may be significantly reduced compared to the case where the amplitude modulation unit 420 is not applied. For example, according to the simulation result, when the amplitude modulation unit 420 is applied, the intensity of the pulsed laser beam L4 may be reduced by 20% or more compared to the case where the amplitude modulation unit 420 is not applied. However, this is only an exemplary embodiment and is not limited thereto, and the reduction rate of the beam intensity may be 20% or less depending on the shape of the amplitude and the modulation unit 420 .

Also, a maximum point in which the intensity of light is conspicuous may appear at a point other than the center of the focused pulsed laser beam L4. For example, according to the simulation result, a maximum point having the intensity of the beam may appear at a point separated by several μm from the center of the beam. However, this is only an embodiment and is not limited thereto, and the separation distance from the center to the maximum point and the intensity of the beam at the maximum point may be different. Accordingly, when the amplitude modulation unit 420 is applied, scattering of the pulsed laser beam L4 may be suppressed, but the intensity of the beam may be reduced and noise may be easily generated, thereby reducing cutting efficiency.

8A and 8B are diagrams for explaining the intensity distribution of a pulsed laser beam to which a phase modulation unit is applied in a laser cutting device according to an embodiment of the present invention.

Referring to FIG. 8A , in the laser cutting apparatus 300 according to an embodiment of the present invention, the pulsed laser beam L3 emitted from the emitter may pass through the phase modulation unit 320 . The pulsed laser beam L3 of which the phase distribution of the beam is modulated using the phase modulation unit 320 passes through the focusing lens unit 330 and is incident on the upper surface of the substrate S in the first direction (z-direction). have. On the other hand, in the laser cutting apparatus 300 according to an embodiment of the present invention, the focusing area 350 and the defocusing area 355 are defined similarly to the general laser cutting apparatus 200 shown in FIG. 6 described above. can For example, the focusing area 350 may be an area inside the substrate S on which the pulsed laser beam L3 is focused, and the defocusing area 355 may be a focusing area 350 in the first direction (z-direction). It may be a region inside the substrate S that is present at a different position from the .

Laser cutting apparatus 300 according to an embodiment of the present invention, using a pulsed laser beam (L3) to form a deformation region (P) in the vicinity of the focusing region 350 of the substrate (S), the focusing region (350) ) and a crack C may be formed between the upper surface of the substrate S. Meanwhile, at least one of the substrate S and the pulsed laser beam L4 may move according to the cutting pattern, and accordingly, at least one deformation region P and a crack C may be formed inside the substrate S. have. For example, the process in which at least one deformation region (P) and crack (C) are sequentially formed while the cutting process is performed by the laser cutting device 300 according to an embodiment of the present invention is a general laser shown in FIG. The process of forming the deformation region P and the crack C in the device 200 may be similar. For example, at least a portion of the defocusing region 355 may overlap with at least a portion of the previously formed crack C and/or the deformation region P. The pulsed laser beam L3 may be scattered in the overlapping area.

In the laser cutting apparatus 300 according to an embodiment of the present invention, the phase modulation unit 320 may include a phase modulation pattern 325 for modulating the phase distribution of the pulsed laser beam (L3). For example, the phase modulation pattern 325 may be divided into a plurality of regions, and at least some of the plurality of regions may modulate the phase of the pulsed laser beam L3 differently from each other. The characteristics and design method of the phase modulation pattern 325 for modulating the phase distribution of the pulsed laser beam L3 will be described later.

In the laser cutting apparatus 300 according to an embodiment of the present invention, the modulated pulsed laser beam L3 incident to the focusing area 350 may pass through the defocusing area 355 . Meanwhile, the modulated pulsed laser beam L3 passing through the defocusing region 355 may include a first end surface 351 and a second end surface 352 parallel to the upper surface of the substrate S. Meanwhile, the pulsed laser beam L3 may have intensity distributions such as I350 , I351 , and I352 in the focusing region 350 , the first end surface 351 , and the second end surface 352 , respectively.

Referring to I351 and I352 , the pulsed laser beam L3 may have a non-uniform intensity distribution in at least a portion of the defocusing area 355 in a second direction parallel to the top surface of the substrate S. For example, the second direction may be an angular direction with respect to the optical axis of the modulated pulsed laser beam L3. That is, the modulated pulsed laser beam L3 may have a non-uniform intensity distribution with respect to the angular direction based on the midpoints of the first and second end surfaces 351 and 352 .

For example, at least one of the cross-sections of the modulated pulsed laser beam L3 incident on the focusing region 350 may include a first region 352a and a second region 352b. The first region 352a may be a region closer to the crack C and the deformation region P than the second region 352b. Also, the intensity of the pulsed laser beam L3 modulated in the first region 352a may be weaker than the intensity of the pulsed laser beam L3 modulated in the second region 352b. The intensity distribution of the pulsed laser beam L3 modulated from the first region 352a and the second region 352b may be uniform. However, this is only an exemplary embodiment, and the cross-section of the modulated pulsed laser beam L3 may include three or more regions or may have a discontinuous intensity distribution.

The pulsed laser beam L3 passing through at least a portion of the crack C may be scattered to cause optical damage to the surrounding semiconductor substrate. However, as described above, the phase modulation unit 320 modulates the phase distribution of the pulsed laser beam L3 to use the light interference phenomenon, thereby reducing the intensity of light in a specific region. For example, the specific region may include a region overlapping the previously formed crack C and/or the deformation region P. Therefore, when the cutting process is performed using the laser cutting apparatus 300 according to an embodiment of the present invention, optical damage to the semiconductor substrate can be suppressed.

On the other hand, the configuration of the laser cutting apparatus 300 according to an embodiment of the present invention is not limited to the above embodiment, and is shown in FIG. 7a to additionally modulate the amplitude distribution of the pulsed laser beam L3 as necessary. It may further include an amplitude modulation unit 420 . However, the shape of the amplitude modulation pattern 425 is not limited thereto, and may be designed in various ways according to the cut pattern and the shape of the crack C and the deformation region P. For example, by dividing the amplitude modulation pattern 425 into a plurality of regions, the amplitude modulation degree in each of the plurality of regions may be designed to be different.

FIG. 8B shows the intensity distribution of the pulsed laser beams L2, L3, and L4 in the focusing regions 250, 350, and 450 simulated by the laser cutting devices 200, 300, and 400 described above with respect to the x and y cross-sections. It is a graph (G250, G250', G350, G350', G450, G450') respectively shown. Referring to Figure 8b, the laser cutting apparatus 300 according to an embodiment of the present invention can be compared with the existing laser cutting apparatus (200, 400).

Referring to FIG. 8B , when the phase modulation unit 320 is applied, the intensity of the beam is only reduced in a specific region due to the interference phenomenon, and the pulse laser beam L3 may not be actually blocked. Accordingly, the intensity of the pulsed laser beam L3 in the focusing area 350 may be greater than that in which the amplitude modulation unit 420 is applied.

Also, unlike the case where the amplitude modulation unit 420 is applied, the maximum point of the focused pulsed laser beam L3 may not be conspicuous at a point other than the center. However, this is only an exemplary embodiment and is not limited thereto, and the intensity of the beam at the maximum point may be different. Accordingly, when the phase modulation unit 320 is applied, scattering is suppressed without significantly reducing the intensity of the light of the pulsed laser beam L3 , thereby improving cutting quality and process efficiency.

For example, when the substrate S is cut using the general laser cutting apparatus 200 shown in FIG. 6 , the output of the scattered beam may be 10% or more of the total beam output. On the other hand, when the substrate S is cut using the improved laser cutting device 400 shown in FIG. 7A, the output of the scattered beam may be improved to 1% or more and 2% or less of the total beam output, The output of the beam lost by the amplitude modulation filter 420 may be 10% or more. On the other hand, in the case of cutting the substrate S using the laser cutting device 300 according to an embodiment of the present invention, the output of the scattered beam while almost no output of the lost beam is 0.01% or more of the total beam output and It can be greatly improved to 1% or less.

9 is a plan view of the phase modulation pattern included in the phase modulation unit in the laser cutting device according to an embodiment of the present invention.

Referring to FIG. 9 , the phase modulation unit may include a phase modulation pattern 325 including a plurality of regions. The phase modulation unit may modulate the phases of the pulsed laser beams passing through at least some of the plurality of regions constituting the phase modulation pattern 325 differently from each other. For example, the phase of the pulsed laser beam passing through the first region 326 may be modulated more than the phase of the pulsed laser beam passing through the second region 327 .

Also, in some of the plurality of regions, the phase of the pulsed laser beam may be equally modulated. For example, the phase of the pulse laser beam passing through the first region 326 may be the same as the phase of the pulse laser beam passing through the third region 328 disposed at a different position from the first region 326 .

The plurality of regions may be disposed along a distance direction and an angular direction with respect to the midpoint of the phase modulation pattern 325 . For example, the first region 326 and the second region 327 may be disposed at the same position in the angular direction based on the midpoint of the phase modulation pattern 325 and may be disposed at different positions in the distance direction. Also, the first region 326 and the third region 328 may be disposed at the same position in the distance direction and may be disposed at different positions in the angular direction.

For example, the plurality of regions may be dividedly arranged at three positions in the distance direction, and dividedly arranged at eight positions in the angular direction. Accordingly, in the embodiment shown in FIG. 9 , the phase modulation pattern 325 may include 24 regions. However, this is only an exemplary embodiment, and the phase modulation pattern 325 may be divided into a number of regions less than 24 for simplifying the process, or into more than 24 regions for improving cutting efficiency. .

In the laser cutting apparatus according to an embodiment of the present invention, the phase modulation pattern 325 may be designed to reduce the intensity of the pulsed laser beam passing through the previously formed crack (C) and the deformation region (P). For example, in order to adjust the intensity of a beam using interference, the phase modulation pattern 325 is asymmetrical with respect to at least one axis extending in a direction parallel to the substrate through the midpoint of the phase modulation pattern 325 . can be designed Meanwhile, the phase modulation pattern 325 may be symmetric with respect to an axis that passes through the midpoint of the phase modulation pattern 325 and extends in the scan direction (x-direction) of the substrate. However, the shape of the phase modulation pattern 325 is not limited thereto, and may be designed in various ways according to the cut pattern and the shape of the crack C and the deformation region P. For example, the degree of modulating the phase according to the region of the phase modulation pattern 325 may be designed to be completely irregular.

Meanwhile, the phase modulation pattern 325 may be designed using a nonlinear optimization algorithm. To optimize the phase modulation pattern 325, a set of parameters to optimize, an appropriate cost function, and an appropriate optimization algorithm may be selected. For example, the Nelder-Mead method may be used as an algorithm for optimizing the phase modulation pattern 325 . For example, the Nelder-Mead method may be an optimization method that iteratively attempts to find new solutions over and over again. However, this is only an example, and optimization and design of the phase modulation pattern 325 may be performed using at least one of various algorithms.

10 is a view for explaining a mask pattern for correction and processing of a pulsed laser beam in a laser cutting apparatus according to an embodiment of the present invention.

Referring to FIG. 10 , in the laser cutting device according to an embodiment of the present invention, the phase modulation pattern may be implemented by mixing a mask pattern for correction and processing of a pulsed laser beam. For example, the mask pattern may correct vortex, aberration, or defocusing appearing in the pulsed laser beam. By correcting the pulsed laser beam, the volume of the focusing region formed inside the substrate may be minimized. In addition, the mask pattern may be processed to simultaneously form a plurality of focusing regions where the pulsed laser beam is concentrated.

For example, the mask pattern implemented by being mixed with the phase modulation pattern for correction of the pulsed laser beam may be the first mask pattern (a). The phase of the first mask pattern (a) may be modulated differently according to an angle with respect to the center of the mask pattern. Since the pulsed laser beam may not be focused on an accurate focus due to a vortex, it is possible to reduce noise due to a vortex of the pulsed laser beam and clarify the focus by using the first mask pattern (a).

In addition, the mask pattern mixed with the phase modulation pattern for correction of the pulsed laser beam may be the second mask pattern (b) or the third mask pattern (c). In particular, the phase of the third mask pattern (c) may be modulated differently according to a distance from the center of the mask pattern. The pulse laser beam to which the second mask pattern (b) and the third mask pattern (c) are applied, respectively, is caused by unintentional aberration by the optical system used in the laser cutting device according to an embodiment of the present invention and the focusing lens unit The image can be made clear by correcting the spherical aberration.

The mask pattern mixed with the phase modulation pattern for processing the pulsed laser beam may be the fourth mask pattern (d). The fourth mask pattern (d) may modulate the phase to be the same in the axial direction with respect to one axis on the mask pattern and to modulate the phase differently in the direction perpendicular to the axis. Cutting efficiency may be improved by simultaneously forming a plurality of focusing regions where the pulsed laser beam is concentrated using the fourth mask pattern d.

On the other hand, in the laser cutting apparatus according to an embodiment of the present invention, the mask pattern mixed with the phase modulation pattern may be at least any one of the mask patterns, the mask patterns may be all mixed. However, the mixed mask pattern is not limited thereto, and when a substrate is cut using the laser cutting apparatus according to an embodiment of the present invention, another pattern for modulating a pulsed laser beam to improve cutting quality or cutting efficiency it may be

11 is a configuration diagram of a case in which a light and an image sensor for feedback are further included in the laser cutting device according to an embodiment of the present invention.

Referring to FIG. 11 , the laser cutting device 500 according to an embodiment of the present invention may further include an illumination 560 and an image sensor 570 . The image sensor 570 may detect a focused position of the modulated pulsed laser beam L using light emitted from the illumination 560 and incident on the substrate S. For example, the light emitted from the illumination 560 may be incident and reflected in a first direction (z-direction) perpendicular to the substrate S, and then may be detected by the image sensor 570 . However, the embodiment is not limited to the arrangement of the lighting 560 and the image sensor 570, and may be arranged and operated in other ways, such as being installed outside the laser cutting device 500 of the present invention, if necessary.

On the other hand, a feedback operation may be performed as needed by using the position at which the pulse laser beam L detected by the illumination 560 and the image sensor 570 is focused. For example, when the position at which the crack and deformation region are to be formed and the position at which the detected pulsed laser beam L is focused are different, the laser cutting apparatus 500 of the present invention may be adjusted so that the two positions correspond. For example, a position at which the pulsed laser beam L is focused may be adjusted by a distance between the upper surface of the substrate S and the focusing lens unit 530 . However, this is only an embodiment, and the feedback operation in the laser cutting device 500 according to an embodiment of the present invention may be performed in a different way.

12 is a configuration diagram when the phase modulation unit of the laser cutting device according to an embodiment of the present invention is configured to reflect a pulsed laser beam.

12, the phase modulation unit 620' in the laser cutting device 600 according to an embodiment of the present invention is not limited to the above-described transmission phase shift plate, and by reflecting the pulse laser beam (L), the phase It may include at least one of a reflective phase shift plate that modulates the distribution, and a spatial light modulator (SLM). For example, the pulsed laser beam L whose phase distribution is modulated by the phase modulation unit 620 ′ may be incident on the focusing lens unit 630 . The phase modulation unit 620 ′ may project the phase modulation pattern on one surface on which the pulse laser beam L is reflected. On the other hand, the characteristics of the pulsed laser beam L in which the phase is modulated using a reflective phase shift plate or a spatial light modulator as the phase modulation unit 620' is a pulsed laser beam (L) whose phase is modulated using a transmission phase shift plate ( L) may be similar. For example, the pulsed laser beam L, which is reflected by the phase modulation unit 620 ′ and whose phase distribution is modulated, is moved to the region where the pulsed laser beam L passes through the substrate S by using an interference phenomenon of light. It is possible to minimize the deformation region and/or the region where cracks overlap.

However, when a spatial light modulator is used, various phase modulation patterns may be changed and applied as needed. For example, when the characteristics of the substrate (S) are different from the substrate (S) used in the existing process, or the location of cracks and/or deformation regions is different, laser cutting apparatus 600 according to an embodiment of the present invention can proceed with the cutting process by applying different phase modulation patterns. In addition, when using the spatial light modulator as the phase modulation unit 620' in the laser cutting device 600 according to an embodiment of the present invention, the spatial light modulator is used before the cutting process or the cutting process. It can be calibrated considering the surrounding environment. For example, the ambient environment may be an internal temperature of a process stage, or the like.

On the other hand, the laser cutting device 600 according to an embodiment of the present invention may further include a prism mirror 680 disposed between the emitter 610 and the phase modulation unit 620'. For example, the prism mirror 680 may make the pulsed laser beam L incident on the phase modulation unit 620 ′ in a desired direction even if it proceeds with a specific inclination. However, such a configuration is merely an embodiment and is not limited thereto, and additional configurations may be variously applied as needed.

13A, 13B, and 13C are diagrams for explaining the effect of a case in which a polarizing filter is further included in the laser cutting device according to an embodiment of the present invention.

Referring to FIG. 13A , the laser cutting apparatus 700 according to an embodiment of the present invention may further include a polarizing filter 790 . The polarization filter 790 may be disposed on a path in which a pulsed laser beam travels between the phase modulation unit 720 ′ and the focusing lens unit 730 . However, this is only an embodiment, and is not limited thereto, and the polarization filter 790 may be disposed in various ways.

On the other hand, depending on the direction of polarization, a p-polarized pulsed laser beam may have an electric field component oscillating in a direction parallel to the incident plane, whereas an s-polarized pulsed laser beam has an electric field component in a direction perpendicular to the incident plane. can vibrate In the laser cutting apparatus 700 according to an embodiment of the present invention, the pulsed laser beam passing through the polarization filter 790 may be a p-polarized beam. However, the present invention is not limited thereto, and the pulsed laser beam passing through the polarization filter 790 includes both a p-polarized component and an s-polarized component, but the size of the p-polarized component is the size of the s-polarized component. can be larger

Referring to FIG. 13B , the p-polarized beam may have less reflectance in oblique incident light compared to the s-polarized beam. That is, when the p-polarized pulsed laser beam is incident at an angle, transmittance to the substrate S may be high. For example, when the pulsed laser beam is radially polarized to be rotational symmetric, transmittance for the substrate S may be increased.

Referring to FIG. 13C , when a quarter-wave plate (QWP) is applied, circularly polarized rotationally symmetric radially polarized light can be generated when linearly polarized light passes through the axis of the wave plate at 45 degrees. . That is, by using the polarizing filter 790 to increase the transmittance for the substrate S, the throughput of the laser cutting apparatus 700 can be improved, and further, the efficiency of the pulsed laser beam can be improved. However, this is only an embodiment and is not limited thereto, and the same effect may be obtained by polarizing the pulsed laser beam using various polarization filters 790 .

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited by the appended claims. Therefore, various types of substitution, modification and change will be possible by those skilled in the art within the scope not departing from the technical spirit of the present invention described in the claims, and it is also said that it falls within the scope of the present invention. something to do.

1: Semiconductor processing equipment
40, 100, 200, 300, 400, 500, 600, 700: laser cutting device
110,510, 610: emitter
120,320, 520, 620', 720': phase modulation unit
325: phase modulation pattern
130, 230, 330, 430, 530, 630, 730: focusing lens unit
140, 540, 640: substrate mounting unit
560, 660: lighting; 570, 670: image sensor
680: prism mirror
790: polarizing filter
S: substrate; L: pulsed laser beam; C: crack; P: deformation region; D: overlapping area

Claims (10)

an emitter emitting a pulsed laser beam incident on the upper surface of the substrate;
a phase modulation unit for modulating a phase distribution of the pulsed laser beam;
a focusing lens unit disposed in a path through which the modulated pulsed laser beam is incident on the substrate; and
a substrate mounting unit on which the substrate is mounted; including,
The phase modulation unit includes a phase modulation pattern including a plurality of regions, the plurality of regions being disposed along a distance direction and an angular direction with respect to a midpoint of the phase modulation pattern, and at least one of the plurality of regions Some are laser cutting devices that modulate the phase of the pulsed laser beam differently.
According to claim 1,
The modulated pulsed laser beam is incident on the substrate in a first direction perpendicular to the upper surface of the substrate,
The substrate includes a focusing area located at a focal length of the focusing lens unit, and a defocusing area defined at a position different from the focusing area in the first direction,
The modulated pulsed laser beam has a non-uniform intensity distribution along a second direction parallel to the upper surface of the substrate in at least a portion of the defocusing area.
3. The method of claim 2,
The second direction is an angular direction with respect to the optical axis of the modulated pulsed laser beam.
According to claim 1,
The plurality of regions includes a first region and a second region defined at different positions, wherein the first region and the second region modulate the phase of the pulsed laser beam to be equal to each other.
According to claim 1,
The phase modulation pattern extends in a direction in which the substrate is scanned and is symmetrical with respect to an axis passing through the midpoint of the phase modulation pattern.
The method of claim 1,
The phase modulation pattern is composed of a pattern in which a mask pattern for correction and processing of the pulsed laser beam is mixed,
The mask pattern corrects vortex, aberration, or defocusing appearing in the pulsed laser beam, or is processed to simultaneously form a plurality of focusing areas where the pulsed laser beam is focused. A laser cutting device that performs one modulation.
According to claim 1,
The phase modulation unit is a spatial light modulator (Spatial Light Modulator, SLM), a laser cutting device comprising at least one of a transmission phase shift plate, a reflective phase shift plate.
an emitter emitting a pulsed laser beam incident on the upper surface of the substrate;
a phase modulation unit for modulating a phase distribution of the pulsed laser beam;
a focusing lens unit disposed in a path through which the modulated pulsed laser beam is incident on the substrate; and
a substrate mounting unit on which the substrate is mounted; including,
The modulated pulsed laser beam is incident on the substrate in a first direction perpendicular to an upper surface of the substrate, the substrate comprising:
a first focusing area and a second focusing area positioned at a focal length of the focusing lens unit and sequentially formed inside the substrate;
a first deformable region formed near the first focusing region;
a first crack formed between the first focusing region and an upper surface of the substrate;
a second deformation region formed near the second focusing region; and
a second crack formed between the second focusing region and an upper surface of the substrate; including,
The phase modulating unit is configured to modulate a phase distribution of the pulsed laser beam such that an overlapping region between the modulated pulsed laser beam incident to the second focusing region and the first crack and the first deformed region is minimized. cutting device.
9. The method of claim 8,
at least one cross-section of the modulated pulsed laser beam incident on the second focusing region comprises a first region and a second region;
The first region is closer to the first crack and the first deformation region than the second region,
The intensity of the modulated pulse laser beam in the first region is weaker than the intensity of the modulated pulse laser beam in the second region.
an emitter emitting a pulsed laser beam incident on the upper surface of the substrate;
a phase modulation unit for modulating a phase distribution of the pulsed laser beam;
a polarization filter disposed in a path through which the modulated pulsed laser beam is incident on the substrate;
a focusing lens unit disposed in a path through which the modulated pulsed laser beam passes through the polarization filter and is incident on the substrate; and
a substrate mounting unit on which the substrate is mounted; including,
In the polarization filter, in the modulated pulsed laser beam, a p-polarization component in which an electric field component vibrates in a direction parallel to an incident surface is greater than an s-polarization component in which an electric field component vibrates in a direction perpendicular to the incident surface. A laser cutting device for polarizing the modulated pulsed laser beam to have a.

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