Sapphire laser implicit cutting method and system based on femtosecond laser induced micro holes

Abstract

The invention belongs to the technical field of micro-nano machining, and discloses a sapphire laser implicit cutting method and system based on femtosecond laser induced micro holes. The sapphire wafer is fixed on the object carrying moving unit, the femtosecond laser is used for emitting femtosecond laser, the femtosecond laser sequentially passes through the polarization rotating mirror, the first reflecting mirror and the objective lens and then is focused in the sapphire wafer, a micro-hole array is induced to grow in the sapphire wafer, the micro-hole array serves as a modification layer, and the modification layer is used for modifying the sapphire wafer. Carrying out femtosecond laser scanning by combining with a loading moving unit, and processing to obtain a plurality of modified layers; and applying an external force to separate the sapphire wafer after laser modification. According to the invention, the implicit cutting efficiency can be improved, and the fracture surface with lower roughness can be obtained.

Description

Technical Field

[0001] This invention belongs to the field of micro-nano fabrication technology, and more specifically, relates to a method and system for laser-cutting sapphire based on femtosecond laser-induced micropores. Background Technology

[0002] Sapphire is a multifunctional crystal with many unique properties, such as excellent transmission spectrum, high hardness, good chemical stability, corrosion resistance, high temperature resistance, and good thermal shock resistance. It is widely used in micro / nano manufacturing, microelectronic chips, LED substrates, microfluidics, and optical devices. Currently, the most mainstream application of sapphire is as a substrate for light-emitting diodes (LEDs) in the electronics field. With the development of the industry, it has entered the Mini LED and Micro LED technology stage. As the demand for high-precision sapphire substrates gradually increases, reducing LED size is an urgent problem to be solved. Traditional sapphire cutting methods using ultra-thin diamond wheels suffer from low processing efficiency, large kerf width, and severe tool wear, making it difficult to meet the increasing requirements for sapphire cutting.

[0003] Femtosecond laser processing technology is a laser processing technology characterized by a low heat-affected zone, three-dimensional processing capability, high efficiency, and high precision. It can effectively improve processing efficiency, reduce tool wear, reduce kerf width, and offer greater flexibility in the cutting process. Laser cutting is further divided into surface cutting and internal cutting (i.e., stealth cutting). Several methods exist for femtosecond laser surface cutting of sapphire, including laser ablation, laser scribing and cleaving, laser-induced back-side wet etching, and Bezier beam cutting. Laser ablation and laser scribing are both top-down strategies until the material is completely or partially removed; however, both methods generate significant surface spatter and a wide heat-affected zone. Laser-induced back-side wet etching involves applying a working fluid to the workpiece surface and focusing the beam at the liquid-solid interface to remove material, but the process is complex, and the processing quality is greatly affected by various factors (such as cavitation and microjets). Bezier beam cutting utilizes the unique anti-diffraction properties of the Bezier beam, achieving high-precision cutting based on a filamentary structure with "focal extension," but it requires a complex optical system and cannot eliminate material loss and spatter. Existing stealth cutting methods typically suffer from low stealth cutting efficiency and high roughness of the fracture surface. Summary of the Invention

[0004] This invention provides a method and system for sapphire laser slicing based on femtosecond laser-induced micropores, which solves the problems of low slicing efficiency and high roughness of fracture surface in existing sapphire laser slicing schemes.

[0005] This invention provides a method for laser sapphire dicing based on femtosecond laser-induced micropores, comprising the following steps: fixing a sapphire wafer on a carrier moving unit; emitting a femtosecond laser using a femtosecond laser; the femtosecond laser sequentially passing through a polarizing rotating mirror, a first reflecting mirror, and an objective lens before being focused onto the interior of the sapphire wafer, inducing the self-growth of a micropore array within the sapphire wafer; using the micropore array as a modification layer; and performing femtosecond laser scanning in conjunction with the carrier moving unit to obtain multiple layers of the modification layer; and separating the laser-modified sapphire wafer by applying external force.

[0006] Preferably, the size parameters of the micro-aperture array are controlled by adjusting the laser parameters; the laser parameters include one or more of the following: laser wavelength, laser power, pulse width, repetition frequency, pulse number, laser focusing depth, and scanning speed; the size parameters of the micro-aperture array include the length of the micro-aperture array.

[0007] Preferably, the laser wavelength is 1026nm or 532nm, the laser power is 200mW to 4000mW, the pulse width is 190fs to 10ps, the repetition frequency is 200kHz to 1MHz, the number of pulses is 10 to 150, the laser focusing depth is 30um to 240um, and the scanning speed is 0.1mm / s to 50mm / s.

[0008] Preferably, the length of the micropore array corresponding to the multi-layer modified layers obtained by processing is consistent.

[0009] Preferably, the sapphire laser stencil method based on femtosecond laser-induced micropores further includes: using an energy attenuator to regulate the energy of the femtosecond laser emitted by the femtosecond laser.

[0010] Preferably, the objective lens has a numerical aperture of 0.42 to 0.5, a magnification of 50x to 100x, and a focal spot diameter of 1μm to 2μm.

[0011] Preferably, the sapphire laser etch method based on femtosecond laser-induced micropores further includes: using a monitoring unit to monitor the laser focusing process in real time and to image the processing effect of the sapphire wafer in real time.

[0012] On the other hand, the present invention provides a sapphire laser stencil cutting system based on femtosecond laser-induced micro-holes, comprising: a femtosecond laser, a polarization rotating mirror, a first reflecting mirror, an objective lens, and a material moving unit; the sapphire laser stencil cutting system based on femtosecond laser-induced micro-holes is used to perform the steps in the sapphire laser stencil cutting method based on femtosecond laser-induced micro-holes described above.

[0013] Preferably, the sapphire laser cladding system based on femtosecond laser-induced micropores further includes: an energy attenuator and a monitoring unit; The energy attenuator is disposed between the femtosecond laser and the polarization rotating mirror, and the energy attenuator is used to regulate the energy of the femtosecond laser emitted by the femtosecond laser. The monitoring unit includes a second reflector, a semi-transparent and semi-reflective reflector, a camera, and a light source; the semi-transparent and semi-reflective reflector is disposed between the second reflector and the camera, and the light source faces the semi-transparent and semi-reflective reflector; the monitoring unit is used to monitor the laser focusing process in real time and to image the processing effect of the sapphire wafer in real time.

[0014] Preferably, the moving unit includes a stage, a three-dimensional moving mechanism, and a control component; the sapphire wafer is fixed on the stage, the three-dimensional moving mechanism is disposed below the stage, the three-dimensional moving mechanism is electrically connected to the control component, and the three-dimensional moving mechanism is used to move the stage under the control of the control component.

[0015] One or more technical solutions provided in this invention have at least the following technical effects or advantages: This invention fixes a sapphire wafer on a carrier moving unit. A femtosecond laser is emitted and focused onto the interior of the sapphire wafer after passing through a polarizing rotating mirror, a first reflecting mirror, and an objective lens. This induces the self-growth of a micro-pore array within the sapphire wafer. The micro-pore array serves as a modification layer, and femtosecond laser scanning, combined with the carrier moving unit, produces multiple modified layers. The laser-modified sapphire wafer is then separated by applying external force. In other words, this invention provides a sapphire wafer laser hidden cutting scheme based on a femtosecond laser-induced micro-pore array (i.e., laser-induced multiple micro-explosion microstructures). This invention utilizes femtosecond laser micro-nano processing technology, inducing the self-growth of a micro-pore array within the sapphire wafer using a femtosecond laser. The self-grown micro-pore array serves as a modification layer, and the sapphire wafer is separated by applying external force. This eliminates the need for surface scribing, improving the hidden cutting efficiency and achieving a fracture surface with lower roughness. The method provided by this invention allows for in-situ processing to induce the self-growth of micro-pore arrays and also offers advantages such as speed, convenience, and reproducibility. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of laser scanning and monitoring in a sapphire laser stencil method based on femtosecond laser-induced micropores provided in Embodiment 1 of the present invention; Figure 2 This is a scanning electron microscope image of a micro-hole array obtained using a sapphire laser stencil method based on femtosecond laser-induced micro-holes provided in Embodiment 1 of the present invention. Figure 3 This is a graph showing the correspondence between laser parameters and the length of the laser-affected zone; where, Figure 3 Figure (a) shows the relationship between the number of pulses and the length of the laser-affected region. Figure 3 Figure (b) shows the relationship between laser energy and the length of the laser-affected zone. Figure 3 (c) in the figure shows the correspondence between the focusing depth and the length of the laser-affected zone. Figure 3 (d) in the figure shows the relationship between focusing depth and laser-affected zone length under different laser energies; Figure 4 This is a schematic diagram of a sapphire laser stencil cutting method based on femtosecond laser-induced micropores provided in Embodiment 1 of the present invention; wherein, Figure 4 (a) in the diagram is a schematic diagram of the multi-layer modified layer obtained through processing. Figure 4 (b) is a schematic diagram of separating a laser-modified sapphire wafer by applying external force; Figure 5 These are scanning electron microscope (SEM) images and three-dimensional morphology images of the fracture surface of a sapphire wafer after cleaving; among them, Figure 5 Image (a) is a scanning electron microscope image. Figure 5 (b) in the figure is a three-dimensional topographic image. Detailed Implementation

[0017] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0018] Example 1: Example 1 provides a sapphire laser stencil cutting method based on femtosecond laser-induced micropores, see [link to example]. Figure 1 The process includes the following steps: fixing a sapphire wafer 110 on a carrier moving unit, emitting a femtosecond laser using a femtosecond laser 101, the femtosecond laser passing sequentially through a polarization rotating mirror 103, a first reflecting mirror 104, and an objective lens 109 before being focused onto the interior of the sapphire wafer 110, inducing the self-growth of a micropore array inside the sapphire wafer 110, using the micropore array as a modification layer, and performing femtosecond laser scanning in conjunction with the carrier moving unit to process multiple layers of the modification layer; and separating the laser-modified sapphire wafer 110 by applying external force.

[0019] The object moving unit includes a stage 111, a three-dimensional moving mechanism, and a control component. The sapphire wafer 110 is fixed on the stage 111. The three-dimensional moving mechanism is located below the stage 111 and is electrically connected to the control component. The three-dimensional moving mechanism is used to move the stage 111 under the control of the control component.

[0020] Before fixing the sapphire wafer 110 onto the stage 111, the sapphire wafer 110 may be ultrasonically cleaned.

[0021] The size parameters of the micro-aperture array are controlled by adjusting the laser parameters; the laser parameters include one or more of the following: laser wavelength, laser power, pulse width, repetition frequency, pulse number, laser focusing depth, and scanning speed; the size parameters of the micro-aperture array include the length of the micro-aperture array.

[0022] Specifically, the laser wavelength is selected as 1026nm or 532nm, the laser power is 200mW to 4000mW, the pulse width is 190fs to 10ps, the repetition frequency is 200kHz to 1MHz, the number of pulses is 10 to 150, the laser focusing depth is 30um to 240um, and the scanning speed is 0.1mm / s to 50mm / s.

[0023] The effects (speed, depth, quality, etc.) of laser processing strongly depend on the polarization state of the laser beam relative to the material surface and the processing direction. The polarization rotating mirror 103 is a core tool for precisely controlling the laser polarization state. Adjusting the polarization rotating mirror 103 during laser processing can overcome the strong dependence of material absorptivity on the polarization direction and the challenges posed by changes in the processing contour direction. The core advantages of adjusting the polarization rotating mirror 103 in this invention include significantly improved process quality and efficiency in laser processing. By precisely controlling the laser polarization direction to maintain optimal matching with the local processing direction or process requirements, it can lead to increased processing speed, reduced energy consumption, significantly improved processing quality (consistency, precision, surface finish), enhanced process stability, and protection of optical components.

[0024] The objective lens 109 has a numerical aperture of 0.42 to 0.5, a magnification of 50 to 100 times, and a focal spot diameter of 1 μm to 2 μm.

[0025] In addition, the sapphire laser holographic cutting method based on femtosecond laser-induced micropores may also include the following steps: using an energy attenuator 102 to regulate the energy of the femtosecond laser emitted by the femtosecond laser 101.

[0026] After fixing the sapphire wafer 110 to the stage 111, the laser parameters are adjusted, and the laser beam is focused inside the sapphire wafer 110, so that the micropore array is obtained by in-situ self-growth at the focused position.

[0027] Furthermore, the sapphire laser etch method based on femtosecond laser-induced micro-holes may further include the following steps: real-time monitoring of the laser focusing process using a monitoring unit, and real-time imaging of the processing effect of the sapphire wafer 110. Specifically, the monitoring unit includes a second reflector 105, a semi-transparent reflector 106, a camera 107, and a light source 108; the semi-transparent reflector 106 is disposed between the second reflector 105 and the camera 107, and the light source 108 faces the semi-transparent reflector 106. See also Figure 1 ,in Figure 1 The red arrows in the diagram correspond to the laser scanning path, and the yellow arrows correspond to the monitoring path. The monitoring unit can assist in sample focusing, monitor the processing status in real time, and further improve the quality of laser processing.

[0028] The reaction process and working principle of the sapphire laser stencil method based on femtosecond laser-induced micropores provided in Example 1 are as follows: (1) Under the action of a high-repetition-frequency, high-energy femtosecond laser pulse, the sapphire in the focal region absorbs the laser energy through multiphotons, generating a large number of free electrons through nonlinear ionization, thus creating a high-temperature, high-pressure plasma in the focal region. This high temperature and pressure drive a shock wave to diffuse outward from the focal region, accompanied by rarefaction waves propagating inward, inducing micro-explosions, ultimately forming an initial cavity encased in a densified spherical shell (see...). Figure 2 (marked 1 in the text).

[0029] (2) Initial hole (see) Figure 2 Mark 1) indicates that after the laser focal region is formed, under continuous pulse irradiation, the dynamic competition between self-focusing and self-defocusing caused by the hole will lead to multiple refocusing and multiple micro-explosions, forming a laser-induced regenerated hole (see [reference]). Figure 2 Markers 2 to 7 in the diagram are used to form an array of holes (see [reference]). Figure 2 (Marked 1 to 7 in the diagram). By focusing the laser at one location, multiple micro-explosion zones can be formed, which greatly reduces the time required to form multiple modified layers, thereby improving the stealth cutting efficiency. (3) Under the continuous application of high repetition rate pulses, a thermal accumulation effect occurs in the laser irradiation area. Due to the influence of thermal diffusion or impact effects, a laser thermally affected zone will be generated in the region far from the focal point (see...). Figure 2 The thermally affected zone (TAD) of femtosecond lasers is relatively smaller than that of nanosecond and picosecond lasers, which is the main reason for the reduced surface roughness of the fracture. The specific reasons are as follows: a. Energy deposition time is much shorter than thermal diffusion time: femtosecond pulse time << electron-lattice thermal relaxation time << thermal diffusion time. Energy is deposited before heat diffusion, leading to non-thermal removal of the material. Nanosecond and picosecond lasers are different. During their longer pulses, heat has sufficient time (nanoseconds) or a certain amount of time (picoseconds) to diffuse around the laser spot via thermal conduction, causing the surrounding area to be heated, melted, or even have its properties altered, forming a large heat-affected zone.

[0030] b. Different energy transfer mechanisms: femtoseconds mainly lead to electronic excitation and non-thermal removal (Coulomb explosion, phase explosion), while nanoseconds / picoseconds mainly lead to lattice heating and thermal removal (melting, vaporization).

[0031] c. Heat conduction is suppressed: In femtosecond processing, heat is removed before it can be conducted to the surrounding area.

[0032] d. Extremely high peak power: The high peak power of femtosecond lasers drives non-thermal processes.

[0033] Laser parameters (such as laser energy, pulse number, and laser focusing depth) affect the three-dimensional dimensional performance of micropore arrays (mainly the length of the micropore array, i.e., the length of the laser-affected zone). This invention characterizes the morphology and structure of self-assembled micropore arrays prepared using different laser energies, pulse numbers, and focusing depths, obtaining the correspondence between the micropore array length and the laser parameters, such as... Figure 3 As shown. This invention has found that as the number of pulses and laser energy increase, the length of the laser-affected zone increases, and then remains essentially constant after reaching a certain extreme value. See [link to related document]. Figure 3 (a) and Figure 3 (b) in the text; however, increasing the laser focusing depth leads to a decrease in the length of the laser-affected zone, see [reference]. Figure 3 (c) Furthermore, this invention also investigated the correspondence between focusing depth and laser-affected zone length under different laser energies, see diagram [link to diagram]. Figure 3 (d) Based on the above research, selecting appropriate laser parameters can precisely control the length of the laser-affected zone, which is beneficial for the flexible design and fabrication of optical devices. Furthermore, correlating the above data also forms a database of micro / nano fabrication parameters for preparing micro-pore arrays.

[0034] The present invention will be further illustrated below with reference to the parameters.

[0035] according to Figure 1The assembled micro / nano fabrication system is shown. A laser beam is emitted from the femtosecond laser, passes through the energy attenuator, then sequentially through the polarizing rotating mirror, the first reflecting mirror, and is focused by the objective lens before finally illuminating the stage. The objective lens has a numerical aperture (NA) of 0.5 and a magnification of 100x. The laser parameters are designed as follows: laser wavelength of 1026 nm, pulse width of 190 fs, repetition rate of 200 kHz, laser power of 4000 mW, and pulse number of 10.

[0036] The sapphire wafer is ultrasonically cleaned for 5 minutes to remove surface contaminants. Then it is fixed on the stage, the horizontal position is adjusted, and the adsorption device (e.g., air pump) of the stage is turned on to make the sapphire wafer fit tightly against the stage.

[0037] A femtosecond laser beam with precisely tuned parameters is focused onto the interior of the sapphire wafer. Due to the self-focusing effect, a self-assembled micropore array will grow in situ at the focused location, such as... Figure 2 As shown, the entire sample focusing process can be monitored in real time by the camera in the monitoring unit.

[0038] Taking the processing of 8 improved layers as an example, such as Figure 4 As shown in (a), the sapphire wafer is fixed on the stage of the femtosecond processing system. A femtosecond laser is focused on the interior of the sapphire wafer and scans upwards to form eight modified layers. The laser scanning direction is parallel to the A-plane (main positioning plane). Based on the effect of laser stealth cutting of the sapphire wafer, to ensure a low roughness of the fracture surface, the length of each micropore array modified layer (i.e., the length of the laser-affected zone) remains consistent. Figure 3 In section (d), when the pulse number is 10, select an appropriate laser energy within the dashed box. The energy ranges selectable from bottom to top for the eight focusing depths are 1-6µJ, 1-6µJ, 1-8µJ, 12-8µJ, 3-10µJ, 4-13µJ, 6-16µJ, and 9-20µJ, respectively. Specifically, the laser energies we selected from top to bottom are 18µJ, 16µJ, 13µJ, 9µJ, 7µJ, 6µJ, 5µJ, and 4µJ.

[0039] See Figure 4 As shown in (a), the first modified layer 1 is 2µm to 50µm away from the back surface of the sapphire wafer. The horizontal spacing between adjacent holes in the same modified layer is 3µm to 5µm, and the vertical spacing between adjacent modified layers is approximately 10µm to 50µm. The scanning speed of the laser is set to 0.1 mm / s to 50 mm / s, and the number of scans is 1-2.

[0040] Specifically, we selected a sapphire wafer thickness of 430µm, a first modified layer 1 distance of 50µm from the back surface of the sapphire wafer, a horizontal spacing of 3µm between adjacent holes in the same modified layer, a vertical spacing of approximately 30µm between adjacent modified layers, and set the laser scanning speed to 10mm / s and the number of scans to 1.

[0041] Applying external force along the crack direction to a laser-modified sapphire wafer, such as... Figure 4 As shown in (b), the cleavage separation of the 430µm thick sapphire wafer was finally achieved. Furthermore, this invention utilizes a scanning electron microscope (SEM) and a profilometer to obtain SEM images and three-dimensional morphology images of the fracture surface of a sapphire wafer after cleaving. Figure 5 (a) in the image is a scanning electron microscope (SEM) image. Figure 5 (b) in the figure is a three-dimensional topography diagram. The surface roughness (Sa) of the split surface of the wafer after the hidden cutting was measured to be 1.967 μm, which is significantly lower than that of the picosecond laser hidden cutting method (Sa=4.7 μm), indicating that the laser hidden cutting method has certain application prospects.

[0042] In summary, Example 1 utilizes femtosecond lasers to fabricate a self-assembled micropore array inside a sapphire wafer as a modification layer, achieving laser stealth cutting, improving stealth cutting efficiency, and obtaining a fracture surface with lower roughness.

[0043] Example 2: Example 2 provides a sapphire laser holographic cutting system based on femtosecond laser-induced micropores, which mainly includes: a femtosecond laser, a polarization rotating mirror, a first reflecting mirror, an objective lens, and a material moving unit.

[0044] In addition, the sapphire laser holographic stencil system based on femtosecond laser-induced micropores may also include: an energy attenuator; the energy attenuator is disposed between the femtosecond laser and the polarization rotating mirror, and the energy attenuator is used to regulate the energy of the femtosecond laser emitted by the femtosecond laser.

[0045] Furthermore, the sapphire laser etched system based on femtosecond laser-induced micro-holes may also include: a monitoring unit; the monitoring unit includes a second reflector, a semi-transparent and semi-reflective mirror, a camera, and a light source; the semi-transparent and semi-reflective mirror is disposed between the second reflector and the camera, and the light source faces the semi-transparent and semi-reflective mirror; the monitoring unit is used to monitor the laser focusing process in real time and to image the processing effect of the sapphire wafer in real time.

[0046] The camera can be a CCD camera with a resolution of 0.1μm to 1μm; the light source can be an LED light source.

[0047] The object-carrying and moving unit includes a stage, a three-dimensional moving mechanism, and a control component. The sapphire wafer is fixed on the stage, and the three-dimensional moving mechanism is disposed below the stage. The three-dimensional moving mechanism is electrically connected to the control component and is used to move the stage under the control of the control component.

[0048] In application, the stage can be adjusted according to the laser's position, and during laser scanning, the stage is moved by the three-dimensional moving mechanism at a preset scanning speed. The control component can use SCA control software to operate the three-dimensional moving mechanism.

[0049] Overall, the present invention fixes the sapphire wafer on the stage, uses an energy attenuator to regulate the energy of the laser, focuses the femtosecond laser beam with adjusted parameters inside the sapphire wafer, and controls the movement of the stage through the control component to achieve femtosecond laser scanning.

[0050] The sapphire laser stencil cutting system based on femtosecond laser-induced micropores provided in Example 2 is used to perform the steps in the sapphire laser stencil cutting method based on femtosecond laser-induced micropores as described in Example 1.

[0051] Since the functions of each device in the sapphire laser stencil system provided in Example 2 correspond to the steps in the sapphire laser stencil method provided in Example 1, Example 2 can be understood by referring to the description of Example 1, and will not be repeated here.

[0052] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A sapphire laser-cutting method based on femtosecond laser-induced micropores, characterized in that, The process includes the following steps: fixing a sapphire wafer on a carrier moving unit, emitting a femtosecond laser using a femtosecond laser, which is then focused onto the interior of the sapphire wafer after passing through a polarizing rotating mirror, a first reflecting mirror, and an objective lens in sequence, inducing the self-growth of a micropore array inside the sapphire wafer, using the micropore array as a modification layer, and performing femtosecond laser scanning in conjunction with the carrier moving unit to process multiple layers of the modification layer; and separating the laser-modified sapphire wafer by applying external force.

2. The sapphire laser stencil cutting method based on femtosecond laser-induced micropores according to claim 1, characterized in that, The size parameters of the micro-aperture array are controlled by adjusting the laser parameters; the laser parameters include one or more of the following: laser wavelength, laser power, pulse width, repetition frequency, pulse number, laser focusing depth, and scanning speed; the size parameters of the micro-aperture array include the length of the micro-aperture array.

3. The sapphire laser stencil cutting method based on femtosecond laser-induced micropores according to claim 2, characterized in that, The laser wavelength is selected as 1026nm or 532nm, the laser power is 200mW to 4000mW, the pulse width is 190fs to 10ps, the repetition frequency is 200kHz to 1MHz, the number of pulses is 10 to 150, the laser focusing depth is 30um to 240um, and the scanning speed is 0.1mm / s to 50mm / s.

4. The sapphire laser-cutting method based on femtosecond laser-induced micropores according to claim 2, characterized in that, The length of the micropore array corresponding to the multilayer modified layers obtained by processing remains consistent.

5. The sapphire laser stencil cutting method based on femtosecond laser-induced micropores according to claim 1, characterized in that, It also includes: using an energy attenuator to regulate the energy of the femtosecond laser emitted by the femtosecond laser.

6. The sapphire laser stencil cutting method based on femtosecond laser-induced micropores according to claim 1, characterized in that, The objective lens has a numerical aperture of 0.42 to 0.5, a magnification of 50x to 100x, and a focal spot diameter of 1μm to 2μm.

7. The sapphire laser stencil cutting method based on femtosecond laser-induced micropores according to claim 1, characterized in that, It also includes: using a monitoring unit to monitor the laser focusing process in real time and to image the processing effect of sapphire wafers in real time.

8. A sapphire laser-cutting system based on femtosecond laser-induced micropores, characterized in that, include: Femtosecond laser, polarization rotating mirror, first reflecting mirror, objective lens, and object moving unit; The sapphire laser stencil system based on femtosecond laser-induced micropores is used to perform the steps in the sapphire laser stencil method based on femtosecond laser-induced micropores as described in any one of claims 1-7.

9. The sapphire laser-cutting system based on femtosecond laser-induced micropores according to claim 8, characterized in that, Also includes: Energy attenuator and monitoring unit; The energy attenuator is disposed between the femtosecond laser and the polarization rotating mirror, and the energy attenuator is used to regulate the energy of the femtosecond laser emitted by the femtosecond laser. The monitoring unit includes a second reflector, a semi-transparent and semi-reflective reflector, a camera, and a light source; the semi-transparent and semi-reflective reflector is disposed between the second reflector and the camera, and the light source faces the semi-transparent and semi-reflective reflector; the monitoring unit is used to monitor the laser focusing process in real time and to image the processing effect of the sapphire wafer in real time.

10. The sapphire laser-cutting system based on femtosecond laser-induced micropores according to claim 8, characterized in that, The object-carrying and moving unit includes a stage, a three-dimensional moving mechanism, and a control component; the sapphire wafer is fixed on the stage, the three-dimensional moving mechanism is disposed below the stage, the three-dimensional moving mechanism is electrically connected to the control component, and the three-dimensional moving mechanism is used to move the stage under the control of the control component.

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