A low dielectric constant material slotting system and method based on a spatial light modulator

Abstract

The application relates to a low-dielectric-constant-material slotting system and method based on a spatial light modulator, which comprises a laser, a liquid crystal spatial light modulator, an optical path transmission system and a workbench; the laser is used for emitting a laser beam; the optical path transmission system transmits a main machining light beam to the liquid crystal spatial light modulator for shaping, outputs and focuses the shaped laser beam on the surface of a machined material on the workbench, sequentially forms double-fine-line light spots and multiple strip light spots to successively machine the surface of the machined material, and the energy and the focal plane position are both in a stepped distribution, so that grooves are finally formed on the surface of the machined material. The double-fine-line grooves formed by double-fine-line light spots can effectively isolate the thermal influence of subsequent multiple strip light spot etching, ensure the slotting precision, the spatial light modulator has high diffraction efficiency, greatly improves the energy utilization rate, and the spatial light modulator is flexible in modulation and can flexibly switch the double-fine-line and multiple strip light spots and the width and quantity of the multiple strip light spots according to different requirements.

Description

Technical Field

[0001] This invention relates to the field of semiconductor laser processing technology, and in particular to a grooving system and method for low dielectric constant materials based on a spatial light modulator. Background Technology

[0002] Low-k materials are widely used in modern semiconductor manufacturing, primarily to reduce the capacitance of metal interconnect layers in chips, thereby reducing signal delay and power consumption, and improving chip performance. However, low-k materials have low mechanical strength, are brittle, and are difficult to process, especially in back-end line (BEOL) processes of chip manufacturing, which require precision machining such as grooving and cutting. Traditional mechanical cutting or chemical etching methods can easily damage low-k materials, affecting chip reliability and performance. Therefore, laser grooving technology has gradually become an important solution for processing low-k materials. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a low dielectric constant material grooving system based on a spatial light modulator, which addresses the shortcomings of the prior art.

[0004] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a low dielectric constant material grooving system based on a spatial light modulator, comprising a laser, a liquid crystal spatial light modulator, an optical path transmission system and a worktable;

[0005] The laser is used to emit a laser beam;

[0006] The optical transmission system is used to receive the laser beam and transmit the laser beam to the liquid crystal spatial light modulator;

[0007] The liquid crystal spatial light modulator is disposed in the optical path transmission system and is used to shape the laser beam. The optical path transmission system outputs the shaped laser beam and focuses it onto the surface of the material to be processed on the worktable, thereby forming a double fine line spot and multiple stripe spots on the surface of the material to be processed in sequence.

[0008] The worktable is used to fix the position of the material to be processed, so that the double fine line spot and multiple strip spot formed on the surface of the material to be processed can process the surface of the material to be processed in turn, and form a groove on the surface of the material to be processed.

[0009] Among them, the laser energy density of the first strip spot along the groove direction on the surface of the processed material gradually decreases to the last strip spot, and the focusing position changes in a stepwise manner.

[0010] The beneficial effects of this invention are as follows: The low dielectric constant material grooving system based on a spatial light modulator utilizes a spatial light modulator to adjust the shape of the shaping spot and sequentially form double-fine-line spots and multiple stripe spots on the surface of the material being processed. The double-fine-line grooves formed by etching with the double-fine-line spots can effectively isolate the thermal effects generated during the subsequent etching of multiple stripe spots, ensuring grooving accuracy. The spatial light modulator has high diffraction efficiency, which greatly improves energy utilization compared with the traditional mask method. Furthermore, the spatial light modulator is flexible in modulation and can flexibly switch between double-fine-line and multiple stripe spots, as well as the width, number, and energy distribution of the multiple stripe spots, according to different needs. At the same time, after the double-fine-line grooves are formed by etching with the double-fine-line spots, the etching is carried out simultaneously with the multiple stripe spots, which greatly improves the etching efficiency. Moreover, among the multiple stripe spots, the laser energy density gradually decreases from the first to the last stripe spot along the grooving direction on the surface of the material being processed. While decreasing energy leads to a slight slowdown in single-point processing speed, the introduction of an energy gradient allows for rapid establishment of etching depth in the early stages, followed by fine finishing with lower energy in the later stages, thus ensuring both etching efficiency and precision. Furthermore, this "stepped distribution" is not only reflected in energy density but also simultaneously in the focusing position. The entire spot sequence is divided into several segments, with a fixed focal plane within each segment, while the focal planes change in steps between segments. High-energy segments, combined with surface focusing, enable rapid etching of the material surface; subsequently, the energy decreases and the focal plane gradually moves downwards, preventing excessive depth in the early stages that could cause sidewall recasting, and ensuring sufficient peak power reaches the bottom of the groove in the later stages, avoiding "bottom ablation stagnation."

[0011] Based on the above technical solution, the present invention can be further improved as follows:

[0012] Further: The optical path transmission system includes a first reflecting mirror, a second reflecting mirror, a beam expander, a first half-wave plate, a polarizing beam splitter, a second half-wave plate, a third reflecting mirror, a first lens, a second lens, a fifth reflecting mirror, and a focusing objective. The laser beam emitted from the laser passes sequentially through the first reflecting mirror, the second reflecting mirror, the beam expander, and the first half-wave plate before being incident on the polarizing beam splitter. The polarizing beam splitter splits the laser beam into a main processing beam and a monitoring beam. The main processing beam passes sequentially through the second half-wave plate and the third reflecting mirror before being incident on the liquid crystal spatial light modulator. The liquid crystal spatial light modulator shapes the main processing beam. The shaped main processing beam passes sequentially through the first lens, the second lens, and the fifth reflecting mirror before reaching the focusing objective. The focusing objective focuses the shaped main processing beam and sequentially forms a double fine line spot and multiple stripe spots on the surface of the material being processed.

[0013] The beneficial effects of the above-mentioned further scheme are: the laser beam can be divided into a main processing beam and a monitoring beam by the polarization beam splitter, so that the surface of the material being processed can be etched by the double fine line spot and multiple stripe spots formed by the main processing beam. The optical path switching is flexible and the control is simple. At the same time, the monitoring beam can be used to check and observe the energy distribution state of the spot.

[0014] Further: The liquid crystal spatial light modulator shapes the laser beam, and the optical path transmission system outputs the shaped laser beam and focuses it onto the surface of the material being processed on the worktable, thereby forming a double fine line spot and multiple stripe spots on the surface of the material being processed in sequence. The specific implementation of this is as follows:

[0015] The liquid crystal spatial light modulator obtains a corresponding double-line hologram based on the width of the cutting groove, and shapes the main processing beam based on the double-line hologram;

[0016] After being shaped, the main processing beam reaches the surface of the material being processed via the optical path transmission system and forms double fine lines to perform hyperbolic processing on the surface of the material being processed, forming hyperbolic grooves.

[0017] The liquid crystal spatial light modulator obtains a corresponding multi-line optical hologram based on the width of the cutting groove, and shapes the main processing beam based on the multi-line optical hologram;

[0018] After being shaped, the main processing beam reaches the surface of the material being processed via the optical path transmission system. Multiple strip-shaped light spots are arranged between the hyperbolic grooves along the cutting direction on the material being processed to perform multi-strip processing on the surface of the material being processed and to form grooves on the surface of the material being processed.

[0019] The beneficial effects of the above-mentioned further scheme are as follows: by first using a double-fine-line hologram to shape the main processing beam to obtain a double-fine-line spot, and then performing hyperbolic processing on the surface of the material to be processed to form a hyperbolic groove, the processing range can be initially constrained, and the heat effect generated during subsequent etching of multiple stripe spots can be effectively isolated, thus ensuring the grooving accuracy. Then, by using a multi-stripe hologram to shape the main processing beam to obtain multiple stripe spots, the portion between the hyperbolic grooves can be etched, which greatly improves the grooving efficiency.

[0020] Furthermore, the optical path transmission system also includes a fourth reflecting mirror, a third lens, and a CCD camera. The monitoring beam is incident on the liquid crystal spatial light modulator after passing through the second half-wave plate and the third reflecting mirror in sequence. The liquid crystal spatial light modulator shapes the monitoring beam. The shaped monitoring beam passes through the first lens and the second lens in sequence to reach the fourth reflecting mirror, and then through the third lens to reach the CCD camera, so as to check and observe the energy distribution state of the light spot formed by the monitoring beam.

[0021] The beneficial effects of the above-mentioned further scheme are: by shaping the monitoring beam through a liquid crystal spatial light modulator, and by checking and observing the energy distribution state of the light spot formed by the monitoring beam with a CCD camera, feedback adjustment can be achieved, ensuring the uniformity of the bottom of the groove and avoiding damage to the silicon substrate, ensuring the stability of the output light spot, and reducing the requirements for the laser source.

[0022] Furthermore, the laser is a picosecond laser, and the pulse width of the emitted laser beam is in the range of 1-1000ps, and the frequency range of the laser beam is 50-500kHz.

[0023] Furthermore, the laser is a femtosecond laser, and the pulse width of the emitted laser beam is in the range of 100-1000 fs, and the frequency range of the laser beam is 1-5 MHz.

[0024] The present invention also provides a method for grooving low-dielectric-constant materials based on a spatial light modulator, which employs the aforementioned low-dielectric-constant material grooving system based on a spatial light modulator and includes the following steps:

[0025] Install and initialize the optical transmission system according to the described procedure;

[0026] The laser is activated, and the laser beam emitted by the laser is transmitted to the liquid crystal spatial light modulator via the optical path transmission system.

[0027] The liquid crystal spatial light modulator shapes the laser beam, and the optical path transmission system outputs the shaped laser beam and focuses it onto the material being processed on the worktable, thereby forming double fine line spots and multiple stripe spots on the surface of the material being processed in sequence.

[0028] The double fine line spot and multiple stripe spot formed on the material being processed are used to process the surface of the material being processed in turn, and grooves are formed on the surface of the material being processed.

[0029] Among them, the laser energy density of the first strip spot along the groove direction on the surface of the processed material gradually decreases to the last strip spot, and the focusing position changes in a stepwise manner.

[0030] Based on the above technical solution, the present invention can be further improved as follows:

[0031] Further: The optical path transmission system receives the laser beam and splits the laser beam into a main processing beam and a monitoring beam. The main processing beam is transmitted to the liquid crystal spatial light modulator, which shapes the main processing beam.

[0032] The beneficial effects of the above-mentioned further scheme are: by splitting the laser beam into a main processing beam and a monitoring beam, the surface of the material being processed can be etched by the double fine-line spot and multiple stripe spots formed by the main processing beam. The optical path switching is flexible and the control is simple. At the same time, the monitoring beam can be used to check and observe the energy distribution state of the spot.

[0033] Further: The liquid crystal spatial light modulator shapes the laser beam, and the optical path transmission system outputs the shaped laser beam and focuses it onto the workpiece on the worktable, thereby sequentially forming a double fine line spot and multiple stripe spots on the surface of the workpiece. Specifically, this includes the following steps:

[0034] The liquid crystal spatial light modulator obtains a corresponding double-line hologram based on the width of the cutting groove, and shapes the main processing beam based on the double-line hologram;

[0035] After being shaped, the main processing beam reaches the surface of the material being processed via the optical path transmission system and forms double fine lines to perform hyperbolic processing on the surface of the material being processed, forming hyperbolic grooves.

[0036] The liquid crystal spatial light modulator obtains a corresponding multi-line optical hologram based on the width of the cutting groove, and shapes the main processing beam based on the multi-line optical hologram;

[0037] After being shaped, the main processing beam reaches the surface of the material being processed via the optical path transmission system. Multiple strip-shaped light spots are arranged between the hyperbolic grooves along the cutting direction on the material being processed to perform multi-strip processing on the surface of the material being processed and to form grooves on the surface of the material being processed.

[0038] The beneficial effects of the above-mentioned further scheme are as follows: by first using a double-fine-line hologram to shape the main processing beam to obtain a double-fine-line spot, and then performing hyperbolic processing on the surface of the material to be processed to form a hyperbolic groove, the processing range can be initially constrained, and the heat effect generated during subsequent etching of multiple stripe spots can be effectively isolated, thus ensuring the grooving accuracy. Then, by using a multi-stripe hologram to shape the main processing beam to obtain multiple stripe spots, the portion between the hyperbolic grooves can be etched, which greatly improves the grooving efficiency.

[0039] Further: The monitoring beam is incident on the liquid crystal spatial light modulator, the liquid crystal spatial light modulator shapes the monitoring beam, and the shaped monitoring beam is transmitted to the CCD camera by the optical path system so as to check and observe the energy distribution state of the light spot formed by the monitoring beam via the CCD camera.

[0040] The beneficial effects of the above-mentioned further scheme are: by shaping the monitoring beam through a liquid crystal spatial light modulator, and by checking and observing the energy distribution state of the light spot formed by the monitoring beam with a CCD camera, feedback adjustment can be achieved, ensuring the uniformity of the bottom of the groove and avoiding damage to the silicon substrate, ensuring the stability of the output light spot, and reducing the requirements for the laser source. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of a low dielectric constant material grooving system based on a spatial light modulator according to an embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of energy distribution and focal plane position;

[0043] Figure 3 This is a schematic diagram of a groove obtained according to an embodiment of the present invention.

[0044] The attached diagram lists the components represented by each number as follows:

[0045] 1. Laser, 2. First reflector, 3. Second reflector, 4. Beam expander, 5. First half-wave plate, 6. Polarizing beam splitter, 7. Second half-wave plate, 8. Beam receiver, 9. Third reflector, 10. Liquid crystal spatial light modulator, 11. First lens, 12. Second lens, 13. Fourth reflector, 14. Fifth reflector, 15. Focusing objective lens, 16. Material to be processed, 17. Worktable, 18. Third lens, 19. CCD camera. Detailed Implementation

[0046] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0047] like Figure 1 As shown, a low dielectric constant material grooving system based on a spatial light modulator includes a laser 1, a liquid crystal spatial light modulator 10, an optical path transmission system, and a worktable 17.

[0048] The laser 1 is used to emit a laser beam;

[0049] The optical path transmission system is used to receive the laser beam and transmit the laser beam to the liquid crystal spatial light modulator 10;

[0050] The liquid crystal spatial light modulator 10 is disposed in the optical path transmission system and is used to shape the laser beam. The optical path transmission system outputs the shaped laser beam and focuses it onto the surface of the workpiece 16 on the worktable 17, thereby forming a double fine line spot and multiple stripe spots on the surface of the workpiece 16 in sequence.

[0051] The worktable 17 is used to fix the position of the material to be processed, so that the double fine line spot and multiple strip spot formed on the surface of the material to be processed 16 can process the surface of the material to be processed 16 in turn and form a groove on the surface of the material to be processed 16.

[0052] Among them, the laser energy density of the first strip spot along the groove direction on the surface of the processed material 16 gradually decreases to the last strip spot, and the focusing position changes in a stepwise manner.

[0053] The low dielectric constant material grooving system based on a spatial light modulator of the present invention utilizes a spatial light modulator to adjust the shape of the shaping light spot and sequentially form a double fine-line light spot and multiple stripe-shaped light spots on the surface of the material to be processed 16. The double fine-line groove formed by etching with the double fine-line light spot can effectively isolate the heat effect generated during the subsequent etching of the multiple stripe-shaped light spots, ensuring grooving accuracy. The spatial light modulator has high diffraction efficiency, which greatly improves energy utilization compared with the traditional mask method. Moreover, the spatial light modulator is flexible in modulation and can flexibly switch between double fine-line and multiple stripe-shaped light spots, as well as the width and number of multiple stripe-shaped light spots, according to different needs. At the same time, after the double fine-line light spot is etched to form the double fine-line groove, the etching is carried out simultaneously with the multiple stripe-shaped light spots, which greatly improves the etching efficiency. Furthermore, among the multiple stripe-shaped light spots, the laser energy density gradually decreases from the first to the last stripe-shaped light spot along the grooving direction on the surface of the material to be processed. While decreasing energy leads to a slight slowdown in single-point processing speed, the introduction of an energy gradient allows for rapid establishment of etching depth in the early stages, followed by fine finishing with lower energy in the later stages, thus ensuring both etching efficiency and precision. Furthermore, this "stepped distribution" is not only reflected in energy density but also simultaneously in the focusing position. The entire spot sequence is divided into several segments, with a fixed focal plane within each segment, while the focal planes change in steps between segments. High-energy segments, combined with surface focusing, enable rapid etching of the material surface; subsequently, the energy decreases and the focal plane gradually moves downwards, preventing excessive depth in the early stages that could cause sidewall recasting, and ensuring sufficient peak power reaches the bottom of the groove in the later stages, avoiding "bottom ablation stagnation."

[0054] In one or more embodiments of the present invention, the optical path transmission system includes a first reflecting mirror 2, a second reflecting mirror 3, a beam expander 4, a first half-wave plate 5, a polarizing beam splitter 6, a second half-wave plate 7, a third reflecting mirror 9, a first lens 11, a second lens 12, a fifth reflecting mirror 14, and a focusing objective lens 15. The laser beam emitted from the laser 1 passes sequentially through the first reflecting mirror 2, the second reflecting mirror 3, the beam expander 4, and the first half-wave plate 5 before entering the polarizing beam splitter 6. The polarizing beam splitter 6 splits the laser beam into a primary beam and a secondary beam. The main processing beam and the monitoring beam are separated. The main processing beam passes sequentially through the second half-wave plate 7 and the third reflecting mirror 9 before entering the liquid crystal spatial light modulator 10. The liquid crystal spatial light modulator 10 shapes the main processing beam. The shaped main processing beam then passes sequentially through the first lens 11, the second lens 12, and the fifth reflecting mirror 14 before reaching the focusing objective lens 15. The focusing objective lens 15 focuses the shaped main processing beam, forming a double fine-line spot and multiple stripe spots on the surface of the material being processed 16. The polarizing beam splitter 6 can separate the laser beam into the main processing beam and the monitoring beam. This allows the double fine-line spot and multiple stripe spots formed by the main processing beam to etch the surface of the material being processed 16. The optical path switching is flexible and the control is simple. At the same time, the monitoring beam can be used to check and observe the energy distribution of the spot.

[0055] In practice, the transmitted light from the polarizing beam splitter 6 is split into the main processing beam and the monitoring beam and enters the subsequent optical path, while the reflected light from the polarizing beam splitter 6 is received by the beam receiver 8.

[0056] In one or more embodiments of the present invention, the liquid crystal spatial light modulator 10 shapes the laser beam, and the optical path transmission system outputs the shaped laser beam and focuses it onto the surface of the workpiece 16 on the worktable 17, thereby forming a double fine line spot and multiple stripe spots on the surface of the workpiece 16 in sequence.

[0057] The liquid crystal spatial light modulator 10 obtains a corresponding double-line hologram based on the width of the cutting groove, and shapes the main processing beam based on the double-line hologram;

[0058] After being shaped, the main processing beam reaches the surface of the material 16 after passing through the optical path transmission system, and forms a double fine line to perform hyperbolic processing on the surface of the material 16 to form a hyperbolic groove.

[0059] The liquid crystal spatial light modulator 10 obtains a corresponding multi-strip light hologram based on the width of the cutting groove, and shapes the main processing beam based on the multi-strip light hologram;

[0060] After being shaped, the main processing beam reaches the surface of the work material 16 via the optical path transmission system. Multiple strip-shaped light spots are arranged between the hyperbolic grooves along the cutting direction on the work material 16 to perform multi-strip processing on the surface of the work material 16 and form grooves on the surface of the work material 16. The thickness of the surface removed is 8-20μm.

[0061] By first shaping the main processing beam using a double-fine-line hologram to obtain a double-fine-line spot, hyperbolic processing is performed on the surface of the material 16 to form a hyperbolic groove. This initially constrains the processing range and effectively isolates the heat-affected zone generated during subsequent multi-strip etch, ensuring grooving accuracy. Then, the main processing beam is shaped using a multi-strip hologram to obtain multiple stripe spots for etching the area between the hyperbolic grooves, greatly improving grooving efficiency. Figure 2 As shown, this is a groove with a width of 60μm and a depth of 15μm obtained in this embodiment.

[0062] Here, after the double-fine-line grooves are formed by etching with dual fine-line spots, the laser energy density of the first to the last stripe along the groove direction on the surface of the workpiece is gradually reduced. For example, the energy densities of the five stripes are set to E, 0.95E, 0.9E, 0.85E, and 0.8E respectively (all higher than the material ablation threshold). The main material is removed quickly with higher energy first, and then the energy is gradually reduced for fine finishing. This allows for rapid approach to the target depth in the early stage while avoiding ineffective etching due to insufficient energy in the later stage, balancing efficiency and accuracy. Of course, in practice, the laser energy density distribution (ratio) of the multiple stripes can be flexibly set according to the actual situation.

[0063] It should be particularly noted that, in the embodiments of the present invention, the setting parameters of the liquid crystal spatial light modulator 10 can be flexibly adjusted according to the actual needs of etching the width and shape of the groove, thereby adjusting the bar light hologram. In this way, the main processing beam is shaped according to the multiple bar light holograms. After being shaped, the main processing beam reaches the surface of the work-to-work material 16 through the optical path transmission system. Multiple corresponding bar light spots are arranged between the hyperbolic grooves along the cutting direction on the work-to-work material 16 to perform multi-bar processing on the surface of the work-to-work material 16 and form grooves of the required width and shape on the surface of the work-to-work material 16.

[0064] In one or more embodiments of the present invention, the optical path transmission system further includes a fourth reflecting mirror 13, a third lens 18, and a CCD camera 19. The monitoring beam is incident on the liquid crystal spatial light modulator 10 after passing sequentially through the second half-wave plate 7 and the third reflecting mirror 9. The liquid crystal spatial light modulator 10 shapes the monitoring beam. The shaped monitoring beam passes sequentially through the first lens 11 and the second lens 12 to the fourth reflecting mirror 13, and then through the third lens 18 to the CCD camera 19, so as to check and observe the energy distribution state of the light spot formed by the monitoring beam. By shaping the monitoring beam through the liquid crystal spatial light modulator 10 and checking and observing the energy distribution state of the light spot formed by the monitoring beam through the CCD camera 19, feedback adjustment can be achieved, ensuring the uniformity of the groove bottom and avoiding damage to the silicon substrate, ensuring the stability of the output light spot, and reducing the requirements for the laser source.

[0065] In one or more embodiments of the present invention, the laser 1 is a picosecond laser, the pulse width of the emitted laser beam is in the range of 1-1000ps, and the frequency range of the laser beam is 50-500kHz.

[0066] In one or more embodiments of the present invention, the laser 1 is a femtosecond laser, the pulse width of the emitted laser beam is in the range of 100-1000 fs, and the frequency range of the laser beam is 1-5 MHz.

[0067] like Figure 2 As shown, the present invention also provides a method for grooving low-dielectric-constant materials based on a spatial light modulator, which employs the aforementioned low-dielectric-constant material grooving system based on a spatial light modulator, and includes the following steps:

[0068] Install and initialize the optical transmission system according to the described procedure;

[0069] The laser 1 is activated, and the laser beam emitted by the laser 1 is transmitted to the liquid crystal spatial light modulator 10 via the optical path transmission system.

[0070] The liquid crystal spatial light modulator 10 shapes the laser beam, and the optical path transmission system outputs the shaped laser beam and focuses it onto the workpiece 16 on the worktable 17, thereby forming a double fine line spot and multiple stripe spots on the surface of the workpiece 16 in sequence.

[0071] The double fine line spot and multiple stripe spot formed on the workpiece 16 process the surface of the workpiece 16 in turn, and form grooves on the surface of the workpiece 16.

[0072] Among them, the laser energy density of the first strip spot along the groove direction on the surface of the processed material 16 gradually decreases to the last strip spot, and the focusing position changes in a stepwise manner.

[0073] In one or more embodiments of the present invention, the optical path transmission system receives a laser beam and splits it into a main processing beam and a monitoring beam. The main processing beam is transmitted to a liquid crystal spatial light modulator 10, which shapes the main processing beam. By splitting the laser beam into a main processing beam and a monitoring beam, the surface of the material 16 being processed can be etched using dual fine-line spots and multiple stripe spots formed by the main processing beam. The optical path switching is flexible and simple to control, while the monitoring beam can be used to check and observe the energy distribution of the spots.

[0074] In one or more embodiments of the present invention, the liquid crystal spatial light modulator 10 shapes the laser beam, and the optical path transmission system outputs the shaped laser beam and focuses it onto the workpiece 16 on the worktable 17, thereby sequentially forming a double fine line spot and multiple stripe spots on the surface of the workpiece 16. Specifically, this includes the following steps:

[0075] The liquid crystal spatial light modulator 10 obtains a corresponding double-line hologram based on the width of the cutting groove, and shapes the main processing beam based on the double-line hologram;

[0076] After being shaped, the main processing beam reaches the surface of the material 16 after passing through the optical path transmission system, and forms a double fine line to perform hyperbolic processing on the surface of the material 16 to form a hyperbolic groove.

[0077] The liquid crystal spatial light modulator 10 obtains a corresponding multi-strip light hologram based on the width of the cutting groove, and shapes the main processing beam based on the multi-strip light hologram;

[0078] After being shaped, the main processing beam reaches the surface of the work-to-work material 16 via the optical path transmission system. Multiple strip-shaped light spots are arranged between the hyperbolic grooves along the cutting direction on the work-to-work material 16 to perform multi-strip processing on the surface of the work-to-work material 16 and form grooves on the surface of the work-to-work material 16.

[0079] By first shaping the main processing beam using a double-fine-line hologram to obtain a double-fine-line spot, hyperbolic processing is performed on the surface of the material 16 to form a hyperbolic groove. This can initially constrain the processing range and effectively isolate the heat effect generated during subsequent multi-strip holographic etching, ensuring the grooving accuracy. Then, the main processing beam is shaped using a multi-strip hologram to obtain multiple strip holograms to etch the portion between the hyperbolic grooves, greatly improving the grooving efficiency.

[0080] In one or more embodiments of the present invention, the monitoring beam is incident on the liquid crystal spatial light modulator 10, which shapes the monitoring beam. The shaped monitoring beam is then transmitted by the optical path system to a CCD camera 19, whereby the CCD camera 19 inspects and observes the energy distribution of the light spot formed by the monitoring beam. By shaping the monitoring beam with the liquid crystal spatial light modulator 10 and inspecting and observing the energy distribution of the light spot formed by the monitoring beam with the CCD camera 19, feedback adjustment can be achieved, ensuring the uniformity of the groove bottom and avoiding damage to the silicon substrate, guaranteeing the stability of the output light spot, and reducing the requirements for the laser source.

[0081] The present invention relates to a low dielectric constant material grooving system and method based on a spatial light modulator. A femtosecond or picosecond pulsed laser is used as the light source. After passing through a beam expander, a half-wave plate, a polarizing beam splitter, a spatial light modulator, and a lens group, a main processing beam and a monitoring beam are formed. The main processing beam dynamically loads a double-line hologram or a multi-strip hologram through a liquid crystal spatial light modulator. After being focused by the lens group, a customized light spot array is formed on the surface of the low dielectric constant material. The double-line mode achieves precise narrow groove processing through two high-energy fine lines; the multi-strip mode utilizes parallel processing of multiple light spots to quickly remove material. Simultaneously, a fourth reflecting mirror guides the monitoring beam to a CCD camera 19, which monitors the energy distribution of the light spots in real time and provides feedback adjustment to ensure uniformity of the groove bottom and avoid damage to the silicon substrate.

[0082] The low dielectric constant material grooving system and method based on spatial light modulator of the present invention has the following advantages:

[0083] 1. Significantly improved energy efficiency: The diffraction efficiency of the liquid crystal spatial light modulator is >90%, and the overall energy efficiency of the system is over 80% (compared to only 30%-40% for the traditional mask method).

[0084] 2. Flexible and efficient processing: The hologram switching time is 0.0167s, and it can switch between various widths of slots (slot width 25μm-125μm).

[0085] 3. High precision and reliability: The groove width error is <±1μm, the groove depth consistency error is <±1μm, and there is no substrate thermal damage. The groove shape can be automatically adjusted according to the laser status through liquid crystal spatial light modulator algorithm and CCD camera monitoring. The flatness of the groove bottom is ≤0.5μm.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-dielectric-constant material grooving system based on a spatial light modulator, characterized in that: It includes a laser (1), a liquid crystal spatial light modulator (10), an optical path transmission system, and a worktable (17). The laser (1) is used to emit a laser beam; The optical path transmission system is used to receive the laser beam and transmit the laser beam to the liquid crystal spatial light modulator (10). The liquid crystal spatial light modulator (10) is disposed in the optical path transmission system and is used to shape the laser beam. The optical path transmission system outputs the shaped laser beam and focuses it on the surface of the workpiece (16) on the worktable (17), thereby forming a double fine line spot and multiple stripe spots on the surface of the workpiece (16). The worktable (17) is used to fix the position of the material to be processed, so that the double fine line spot and multiple strip spot formed on the surface of the material to be processed (16) are processed sequentially, and a groove is formed on the surface of the material to be processed (16). Among them, the laser energy density of the first strip spot along the groove direction on the surface of the material being processed (16) gradually decreases from the last strip spot to the first strip spot, and the focusing position changes in a stepwise manner.

2. The low dielectric constant material grooving system based on a spatial light modulator according to claim 1, characterized in that: The optical transmission system includes a first reflector (2), a second reflector (3), a beam expander (4), a first half-wave plate (5), a polarizing beam splitter (6), a second half-wave plate (7), a third reflector (9), a first lens (11), a second lens (12), a fifth reflector (14), and a focusing objective (15). The laser beam emitted from the laser (1) passes sequentially through the first reflector (2), the second reflector (3), the beam expander (4), and the first half-wave plate (5) before entering the polarizing beam splitter (6). The polarizing beam splitter (6) splits the laser beam into a primary beam and a secondary beam. The main processing beam and the monitoring beam are sequentially incident on the liquid crystal spatial light modulator (10) after passing through the second half-wave plate (7) and the third reflector (9). The liquid crystal spatial light modulator (10) shapes the main processing beam. The shaped main processing beam passes through the first lens (11), the second lens (12) and the fifth reflector (14) in sequence and reaches the focusing objective (15). The focusing objective (15) focuses the shaped main processing beam and sequentially forms a double fine line spot and multiple stripe spots on the surface of the processed material (16).

3. The low dielectric constant material grooving system based on a spatial light modulator according to claim 2, characterized in that: The liquid crystal spatial light modulator (10) shapes the laser beam, and the optical path transmission system outputs the shaped laser beam and focuses it onto the surface of the workpiece (16) on the worktable (17), thereby forming a double fine line spot and multiple stripe spots on the surface of the workpiece (16) in sequence. The liquid crystal spatial light modulator (10) obtains a corresponding double-line hologram based on the width of the cutting groove, and shapes the main processing beam based on the double-line hologram; After being shaped, the main processing beam reaches the surface of the material to be processed (16) through the optical path transmission system and forms a double fine line to perform hyperbolic processing on the surface of the material to be processed (16) to form a hyperbolic groove. The liquid crystal spatial light modulator (10) obtains a corresponding multi-strip light hologram according to the width of the cutting groove, and shapes the main processing beam according to the multi-strip light hologram; After being shaped, the main processing beam reaches the surface of the material to be processed (16) through the optical path transmission system. Multiple strip-shaped light spots are arranged between the hyperbolic grooves along the cutting direction on the material to be processed (16) to perform multi-strip processing on the surface of the material to be processed (16) and to form grooves on the surface of the material to be processed (16).

4. The low dielectric constant material grooving system based on a spatial light modulator according to claim 2, characterized in that: The optical path transmission system also includes a fourth reflector (13), a third lens (18), and a CCD camera (19). The monitoring beam passes through the second half-wave plate (7) and the third reflector (9) in sequence and is then incident on the liquid crystal spatial light modulator (10). The liquid crystal spatial light modulator (10) shapes the monitoring beam. The shaped monitoring beam passes through the first lens (11) and the second lens (12) in sequence and then reaches the fourth reflector (13), and passes through the third lens (18) and then reaches the CCD camera (19) to check and observe the energy distribution state of the light spot formed by the monitoring beam.

5. The low dielectric constant material grooving system based on a spatial light modulator according to any one of claims 1-4, characterized in that: The laser (1) is a picosecond laser, and the pulse width of the emitted laser beam is 1-1000ps, and the frequency range of the laser beam is 50-500kHz.

6. The low dielectric constant material grooving system based on a spatial light modulator according to any one of claims 1-4, characterized in that: The laser (1) is a femtosecond laser, and the pulse width of the emitted laser beam is 100-1000 fs, and the frequency range of the laser beam is 1-5 MHz.

7. A method for grooving low-dielectric-constant materials based on a spatial light modulator, comprising the low-dielectric-constant material grooving system based on a spatial light modulator as described in any one of claims 1-5, characterized in that: Includes the following steps: Install and initialize the optical transmission system according to the described procedure; The laser (1) is activated and the laser beam emitted by the laser (1) is transmitted to the liquid crystal spatial light modulator (10) via the optical path transmission system. The liquid crystal spatial light modulator (10) shapes the laser beam, and the optical path transmission system outputs the shaped laser beam and focuses it onto the workpiece (16) on the worktable (17), and forms double fine line spots and multiple stripe spots on the surface of the workpiece (16) in sequence. The double fine line spot and multiple stripe spot formed on the processed material (16) are used to process the surface of the processed material (16) in turn, and grooves are formed on the surface of the processed material (16). Among them, the laser energy density of the first strip spot along the groove direction on the surface of the material being processed (16) gradually decreases from the last strip spot to the first strip spot, and the focusing position changes in a stepwise manner.

8. The method for grooving low dielectric constant materials based on spatial light modulators according to claim 7, characterized in that: The optical path transmission system receives the laser beam and divides the laser beam into a main processing beam and a monitoring beam. The main processing beam is transmitted to the liquid crystal spatial light modulator (10), which shapes the main processing beam.

9. The method for grooving low dielectric constant materials based on spatial light modulators according to claim 8, characterized in that: The liquid crystal spatial light modulator (10) shapes the laser beam, and the optical path transmission system outputs the shaped laser beam and focuses it onto the workpiece (16) on the worktable (17), thereby forming a double fine line spot and multiple stripe spots on the surface of the workpiece (16) in sequence. The specific steps include the following: The liquid crystal spatial light modulator (10) obtains a corresponding double-line hologram based on the width of the cutting groove, and shapes the main processing beam based on the double-line hologram; After being shaped, the main processing beam reaches the surface of the material to be processed (16) through the optical path transmission system and forms a double fine line to perform hyperbolic processing on the surface of the material to be processed (16) to form a hyperbolic groove. The liquid crystal spatial light modulator (10) obtains a corresponding multi-strip light hologram according to the width of the cutting groove, and shapes the main processing beam according to the multi-strip light hologram; After being shaped, the main processing beam reaches the surface of the material to be processed (16) through the optical path transmission system. Multiple strip-shaped light spots are arranged between the hyperbolic grooves along the cutting direction on the material to be processed (16) to perform multi-strip processing on the surface of the material to be processed (16) and to form grooves on the surface of the material to be processed (16).

10. The method for grooving low dielectric constant materials based on spatial light modulators according to claim 8, characterized in that: The monitoring beam is incident on the liquid crystal spatial light modulator (10), the liquid crystal spatial light modulator (10) shapes the monitoring beam, and the shaped monitoring beam is transmitted by the optical path transmission system to the CCD camera (19) so as to check and observe the energy distribution state of the light spot formed by the monitoring beam via the CCD camera (19).

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