Homogenized fiber-based laser-assisted chemical mechanical polishing apparatus and method

Abstract

The application belongs to the technical field of semiconductor material laser processing. A laser-assisted chemical mechanical polishing device and method based on homogenized optical fiber are provided, which comprises a laser generator, an optical path design unit, a scanning galvanometer, a fine polishing unit and a two-dimensional motion platform. The optical path design unit homogenizes and shapes the pulsed laser through the homogenized optical fiber to obtain a square flat-top light spot, and the scanning galvanometer and the two-dimensional motion platform are cooperatively controlled to realize the close arrangement of the light spots. The method determines the galvanometer scanning parameters by matching the platform moving speed, the wafer size and the light spot size, so that the wafer and the polishing disc form relative motion, the laser rough machining and the fine polishing are synchronously performed, and the dropping of the polishing liquid does not affect the laser processing. The application solves the problems of low efficiency, process fragmentation and poor processing consistency of the traditional chemical mechanical polishing, and the single scanning is equivalent to the effect of traditional multiple scanning, which greatly shortens the processing time, improves the processing efficiency and surface uniformity, and is suitable for large-size SiC wafer super-smooth non-damage polishing.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology for semiconductor materials, and in particular to a laser-assisted chemical mechanical polishing device and method based on homogenizing optical fiber. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Silicon carbide (SiC), a typical representative of third-generation semiconductor materials, has become a key basic material for manufacturing high-voltage, high-temperature, high-frequency, high-power, and radiation-resistant devices due to its excellent physical properties such as wide bandgap, high thermal conductivity, high carrier mobility, and high breakdown electric field strength. However, these excellent properties also make SiC a typical difficult-to-process material. Its extremely high hardness and chemical inertness pose a huge challenge to the preparation of ultra-smooth, damage-free surfaces in wafer back-end processes. Chemical mechanical polishing (CMP) is currently the mainstream technology for achieving global planarization of SiC substrates. It removes material through the synergistic effect of chemical etching and mechanical polishing. However, traditional CMP processes face inherent bottlenecks such as extremely low material removal rates, long processing cycles, easy introduction of surface / subsurface damage (such as micro-scratches, dislocations, and lattice destruction), and difficulty in controlling processing consistency. These problems are particularly prominent in the industrial production of large-size (e.g., 6-inch and above) SiC wafers, and have become key obstacles restricting their cost reduction and widespread application.

[0004] To overcome the efficiency bottleneck of CMP (Chemical Metal Processing), laser-assisted processing technology has attracted widespread attention as a transformative approach. Ultrafast lasers (femtosecond and picosecond lasers), with their extremely high peak power and extremely short pulse duration, can engage in highly controllable nonlinear interactions with materials, achieving a variety of processing effects from surface microstructuring and subsurface modification to precise separation. In the field of laser-assisted cutting, mature processes utilize focused lasers to scan at specific depths within the wafer, inducing modified layers and controlled cracks to achieve material peeling, demonstrating the feasibility of efficient and precise laser modification of SiC. However, simply combining such laser pretreatment with CMP—i.e., "laser modification first, then polishing"—while improving efficiency to some extent, suffers from numerous problems such as process interruption, positioning errors, contaminant introduction, and polishing instability caused by uneven modified layers, failing to fundamentally achieve a synergistic leap in efficiency and quality. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a laser-assisted chemical mechanical polishing device and method based on homogenizing optical fiber. The homogenizing optical fiber is used to homogenize and shape the laser, which is then focused onto the focal plane by a field lens to obtain a square flat-topped spot. By controlling the coordinated operation of the scanning galvanometer and the two-dimensional motion platform, the laser source achieves a close arrangement of square spots during a single emission scan, resulting in uniform processing. The polishing disk lags behind the laser scanning direction, allowing for fine polishing after the laser roughing process, thus improving polishing efficiency.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a laser-assisted chemical mechanical polishing device based on homogenizing optical fiber.

[0008] A laser-assisted chemical mechanical polishing device based on homogenized optical fiber includes: a laser generator, an optical path design unit, a scanning galvanometer, a fine polishing unit, and a two-dimensional motion platform;

[0009] A laser generator is used to produce pulsed laser light.

[0010] The optical path design unit is used to homogenize and shape the pulsed laser through the homogenizing fiber to obtain a square flat-topped laser spot;

[0011] The scanning galvanometer is used to control the scanning speed and scanning path of the laser to complete the scanning processing of the wafer. The scanning speed and scanning length of the scanning galvanometer are determined based on the moving speed of the two-dimensional motion platform, the size of the wafer, and the size of the square flat-top laser spot at the focal point.

[0012] The fine polishing unit is used to fine polish the wafer after laser scanning to form a high-quality polished surface;

[0013] A two-dimensional motion platform is used to carry the wafer and control the relative movement between the wafer and the polishing pad to complete the wafer processing on a preset path.

[0014] In one implementation of the first aspect of the present invention, the optical path design unit includes an energy attenuation module for adjusting energy according to the power required during processing.

[0015] In one implementation of the first aspect of the present invention, the fine polishing unit includes a polishing disk and a polishing slurry titration unit, wherein the polishing slurry titration unit is used to add polishing slurry to the wafer between the laser processing step of the scanning galvanometer and the polishing step of the fine polishing unit.

[0016] In one implementation of the first aspect of the present invention, the wafer is disposed on a two-dimensional motion platform, which is used to adjust the relative position between the wafer and the fine polishing unit.

[0017] Secondly, the present invention provides a laser-assisted chemical mechanical polishing method based on homogenized optical fiber.

[0018] A laser-assisted chemical mechanical polishing method based on homogenized optical fiber, utilizing the laser-assisted chemical mechanical polishing apparatus based on homogenized optical fiber according to the first aspect of the present invention, includes the following processes:

[0019] Based on the moving speed of the two-dimensional motion platform, the size of the wafer, and the size of the square flat-top light spot at the focal point, the scanning speed and scanning length of the scanning galvanometer are determined.

[0020] A two-dimensional motion platform is used to support the wafer, which moves relative to the polishing disk and the scanning galvanometer. Polishing fluid is dripped between the polishing process of the polishing disk and the laser processing process of the scanning galvanometer. The square flat-top light spot after being shaped by the homogenizing fiber is closely arranged under the coordinated control of the scanning galvanometer and the two-dimensional motion platform to form a uniform processing.

[0021] The wafer and polishing pad are controlled to move relative to each other using a two-dimensional motion platform, and the wafer is processed along a preset path.

[0022] In one implementation of the second aspect of the present invention, before homogenizing and shaping the pulsed laser with a homogenizing fiber to form a flat-top square spot, a lens is used to focus the pulsed laser into the homogenizing fiber.

[0023] In one implementation of the second aspect of the present invention, flat-top square spots of different sizes are obtained by adjusting the distance between the lens and the scanning galvanometer, and the close arrangement of the flat-top square spots is achieved by coordinating the control of the scanning galvanometer and the motion platform.

[0024] In one implementation of the second aspect of the present invention, the center of the polishing disc is located on the wafer surface during processing, and the rotational speed and pressure of the polishing disc are controlled to achieve the desired processing effect.

[0025] In one implementation of the second aspect of the present invention, the relative spatial position between the scanning position of the scanning galvanometer and the polishing disk is controlled so that the dripping of polishing slurry does not affect the laser processing.

[0026] In one implementation of the second aspect of the present invention, the resulting square flat-top light spots are closely arranged, so that the effect achieved by a single processing is greater than or equal to the effect of three processing steps for circular light spots.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] This invention achieves rapid and large-format laser scanning through the coordinated control of a scanning galvanometer and a two-dimensional motion platform. By controlling the relative spatial position between the laser and the polishing disk, synchronous finishing after laser roughing is achieved, improving processing efficiency. The flat-topped square spots after homogenization and shaping by the homogenizing fiber are closely arranged, with an effective overlap rate higher than that of traditional circular Gaussian spots. Multiple scanning processes can be achieved with a single scan, reducing the number of scans, reducing processing time, and improving processing efficiency.

[0029] This invention fundamentally changes the limitation of decoupling energy distribution and depth of action in traditional laser processing by introducing a synergistic control mechanism of spatial light modulation and dynamic focusing. In specific implementation, the system uses a programmable phase modulator to control the incident laser wavefront in real time, combined with the high-speed deflection of the scanning galvanometer and the nanoscale displacement feedback of the Z-axis piezoelectric platform, enabling the focal position and light intensity distribution to adaptively adjust according to the surface morphology of the material. This "morphology-energy" closed-loop control method allows the laser to maintain a constant modification depth and uniform energy density on non-planar or locally undulating wafer surfaces, avoiding local overburning or insufficient modification caused by focal plane offset. The resulting effects are: not only improved overall consistency of the laser-assisted polishing process, but also significantly enhanced process adaptability to different batches and wafers with different warpages, providing a fundamental guarantee for high-yield, mass production.

[0030] This invention ingeniously integrates a photothermal-photochemical dual-action mechanism, simultaneously exciting lattice vibrations (phonon excitation) and localized plasmon resonance effects on the material surface in the laser irradiation area, thereby softening the covalent bond network of hard and brittle materials such as SiC at the microscale. Compared to traditional CMP processes that rely solely on mechanical shearing forces, this composite mechanism significantly reduces the external load required for effective removal, alleviating problems such as abrasive embedding, scratches, and surface cracks. More importantly, because laser-induced micro-area activation is highly spatiotemporally localized, acting only on the area about to be washed away by the polishing fluid, it does not cause overall heat accumulation or structural degradation. This design essentially realizes the green processing concept of "softening on demand and removing immediately," preserving the intrinsic properties of the material while significantly improving surface integrity and process sustainability.

[0031] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0032] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0033] Figure 1A schematic diagram of a laser-assisted chemical mechanical polishing device based on homogenizing optical fiber, provided as an exemplary embodiment of the present invention;

[0034] Figure 2 A schematic diagram of a single "zigzag" scanning processing path for a Gaussian circular spot provided as an exemplary embodiment of the present invention;

[0035] Figure 3 A schematic diagram of a single "Z"-shaped scanning processing path for a flat-top square spot provided as an exemplary embodiment of the present invention;

[0036] Figure 4 A schematic diagram showing the relative spatial position and processing path of the laser and the polishing disk, provided as an exemplary embodiment of the present invention;

[0037] Among them, 100 is the laser generation unit; 200 is the optical path design unit; 300 is the scanning galvanometer; 400 is the polishing disk; 500 is the wafer; 600 is the polishing fluid titration unit; and 700 is the two-dimensional motion platform. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0040] This implementation proposes a laser-assisted chemical mechanical polishing device based on homogenizing fiber. The homogenizing fiber is used to homogenize and shape the laser, and then the laser spot is focused on the focal plane by a field lens to obtain a square flat-topped spot. By controlling the coordinated control of the scanning galvanometer and the two-dimensional motion platform, the square spot is closely arranged during the laser source's single emission scan, achieving a uniform processing effect. The polishing disk lags behind the laser's scanning direction, and fine polishing is performed after the laser roughing process, thus improving the polishing efficiency.

[0041] like Figure 1As shown in the figure, it includes a laser generating unit 100, an optical path design unit 200, a scanning galvanometer 300, a polishing disc 400, a wafer 500, a polishing liquid titration unit 600, and a two-dimensional motion platform 700. The laser generating unit 100 is used to generate pulsed laser; the optical path design unit 200 is used to perform spot shaping on the pulsed laser generated by the laser generating unit 100; the scanning galvanometer 300 is used to scan and process the laser emitted by the optical path design unit 200 at a specific speed and path; the polishing disc 400 is used to finely polish the surface of the wafer 500 after rough laser processing; by controlling the two-dimensional motion platform 700 unit, a relative motion is generated between the wafer 500 and the polishing disc 400, and a large-area and fast scanning of the laser is carried out in cooperation with the scanning galvanometer 300.

[0042] The traditional method of laser scanning and processing of silicon carbide wafer 500 is to focus the processing laser on the surface of silicon carbide wafer 500, scan the single-focus pulsed laser along a preset path on the silicon carbide wafer 500, and then scan again at different intervals after the scanning is completed, and finally obtain the processed wafer, as Figure 2 shown, the scanning path is in the shape of a "ji" character.

[0043] The laser-assisted chemical mechanical polishing device based on a homogenizing optical fiber proposed in the present invention performs scanning processing on the silicon carbide wafer 500, as Figure 3 shown, the specific operation process is as follows: the laser generating unit 100 is used to generate pulsed laser, the optical path design unit 200 is used to perform spot shaping on the pulsed laser generated by the laser generating unit 100, the scanning galvanometer 300 is used to scan and process the laser emitted by the optical path design unit 200 at a specific speed and path, as Figure 4 shown, the polishing disc 400 is used to finely polish the surface of the wafer 500 after rough laser processing, and by controlling the two-dimensional motion platform 700 unit, a relative motion is generated between the wafer 500 and the polishing disc 400, and a large-area and fast scanning of the laser is carried out in cooperation with the scanning galvanometer 300.

[0044] Optionally, in some other implementation manners, if the scanning speed of the scanning galvanometer 300 does not match the moving speed of the two-dimensional motion platform 700, resulting in gaps (too fast speed) or excessive overlaps (too slow speed) in the spot arrangement, which destroys the processing uniformity and cannot achieve precise control of the "ji-shaped" scanning path. In view of this, an optional implementation manner is proposed below to limit the moving speed of the two-dimensional motion platform 700:

[0045] (1);

[0046] wherein, represents the moving speed of the two-dimensional motion platform 700 (mm / s), the uniform moving speed of the two-dimensional motion platform 700 along the Y direction; This represents the scanning speed (mm / s) of the scanning galvanometer 300, which is the scanning linear velocity of the scanning galvanometer 300 along the X-axis. Represents the side length (mm) of a square flat-topped light spot; This represents the effective overlap rate of the target light spot; This represents the length of a single scan line of the galvanometer (mm), which is the X-axis length of the 500 effective processing area of ​​the wafer.

[0047] This speed limit ensures dynamic speed synchronization between the scanning galvanometer 300 and the two-dimensional motion platform 700, guaranteeing that the light spots achieve the target overlap rate (η≥80%) in both the X and Y directions, with no gaps or excessive overlap, thus ensuring the uniformity of the processed surface. Real-time linkage adjustment is achieved through the motion control system. and For example, when , , At that time, if ,but It accurately matches the "U" shaped scanning path.

[0048] In the device of this invention, rapid and large-format laser scanning is achieved through the coordinated control of the scanning galvanometer 300 and the two-dimensional motion platform 700. By controlling the relative spatial position between the laser and the polishing disk 400, simultaneous fine processing after laser roughing is realized. The flat-topped square spots after homogenization and shaping by the homogenizing fiber are closely arranged, with an effective overlap rate higher than that of traditional circular Gaussian spots. Multiple scanning processes can be achieved with a single scan. The following is a basic method to achieve this goal:

[0049] First, a pulsed laser beam is prepared. Then, a homogenizing fiber is added, and a focusing lens couples the pulsed laser into the fiber. The homogenizing fiber homogenizes the laser through internal total internal reflection; the square fiber core ensures that the emitted laser becomes a flat-topped square spot after focusing. By adjusting the laser scanning line spacing and scanning speed, the flat-topped square spots can be closely aligned. The coordinated control of the scanning galvanometer 300 and the two-dimensional motion platform 700 enables rapid, large-format laser scanning. The two-dimensional motion platform 700 controls the relative movement of the wafer 500 and the polishing disk 400, while the laser and the polishing disk 400 remain relatively stationary. After laser roughing, the surface of the wafer 500 is immediately finished by the polishing disk 400, improving polishing efficiency. The modulated focal point is focused on the surface of the silicon carbide ingot. By appropriately adjusting the distance between the lens and the field mirror under the scanning galvanometer 300, flat-topped square spots of different sizes can be achieved, and the coordinated control of the galvanometer and motion platform ensures the close alignment of these spots.

[0050] It should be noted that the above process only provides a basic description of how to modulate a circular Gaussian pulse laser into a flat-topped square spot using a homogenizing fiber, and how to adjust the galvanometer and motion platform to achieve synchronous polishing of the laser and the polishing disk 400. Specific implementation methods and adjustment steps may vary depending on the actual application and equipment. Furthermore, this invention can meet various processing requirements, increase processing freedom, and achieve highly efficient silicon carbide ingot processing without changing the hardware.

[0051] In summary, the laser-assisted chemical mechanical polishing (CMP) device based on homogenized optical fiber provided by this invention, compared with the traditional single-focus two-scan processing method, only requires one scan of the silicon carbide wafer 500, achieving an improvement in the number of scans and thus significantly shortening the processing time. Furthermore, reducing the number of scans to a single scan also improves processing stability. Moreover, this invention can control the size of the flat-top square spot as needed, achieving controlled and selective scanning processing, greatly improving processing efficiency. This invention significantly solves the problems of low processing efficiency and long processing time in existing methods.

[0052] This implementation also provides a laser-assisted chemical mechanical polishing method based on homogenized optical fiber, including determining the scanning speed and scanning length of the scanning galvanometer 300 based on the moving speed of the two-dimensional motion platform 700, the size of the wafer 500, and the size of the square flat-top light spot at the focal point.

[0053] The two-dimensional motion platform 700 carries the wafer 500 and forms a relative motion between the polishing disk 400 and the laser. Polishing fluid is dripped between the polishing disk 400 and the laser through the polishing fluid titration unit 600. The square flat-top light spot after being shaped by the homogenizing fiber is closely arranged under the coordinated control of the scanning galvanometer 300 and the two-dimensional motion platform 700 to form a uniform processing.

[0054] In this implementation, a two-dimensional motion platform 700 controls the relative movement of the wafer 500 and the polishing disk 400, completing the processing of the wafer 500 along a preset path. Before the relative movement between the wafer 500, polishing disk 400, and laser is established using the two-dimensional motion platform 700, the relative position between the scanning galvanometer 300 and the polishing disk 400 is adjusted to ensure that the polishing fluid added between them does not affect the laser processing. The homogenizing fiber uses total internal reflection technology to homogenize and shape the incident light, generating a flat-top square spot. The flat-top square spot is uniformly processed by controlling the galvanometer and the motion platform. The resulting flat-top square spot can control its size and can be closely packed to achieve a higher effective overlap rate, allowing the effect of a single processing step to be greater than or equal to three steps.

[0055] Optionally, in some other implementations, the lag distance of the polishing disk 400 relative to the laser scanning direction is inappropriate, resulting in an unstable modified layer after laser roughing (premature polishing) or interference of the polishing slurry with laser transmission (excessive lag), making it impossible to achieve the integrated requirement of "laser roughing + synchronous fine polishing". Therefore, an optional method for determining the lag distance of the polishing disk 400 relative to the laser scanning center is proposed:

[0056] (2);

[0057] in, The distance (mm) represents the lag distance of the polishing disk 400 relative to the laser scanning center, that is, the Y-axis distance between the laser scanning center and the processing center of the polishing disk 400; This represents the 700-meter moving speed (mm / s) of the two-dimensional motion platform. The laser-modified layer stabilization time (s) represents the time it takes for a stable modified layer to form on SiC material after laser processing. Represents the diffusion coefficient of the polishing slurry (mm) The s / N ratio is determined by the viscosity and surface tension of the polishing slurry. Represents the kinematic viscosity of the polishing fluid (mm) 2 / s); This represents the pressure applied to the polishing pad per square millimeter of wafer (N / mm). 2 ).

[0058] By precisely controlling the hysteresis distance, the stability of the modified layer after laser roughing is ensured (to prevent material springback), while the polishing slurry has diffused into the processing area (to avoid interfering with laser transmission), achieving simultaneous "roughing-finishing". During use, adjust the relative installation positions of the two-dimensional motion platform 700 and the polishing disc 400, for example, when... , , , , hour, By fixing the lag distance, integrated processing can be achieved.

[0059] Compared to existing technologies, this embodiment achieves rapid and large-format laser scanning through the coordinated control of the scanning galvanometer 300 and the two-dimensional motion platform 700. By controlling the relative spatial position between the laser and the polishing disk 400, synchronous finishing after laser roughing is achieved, improving processing efficiency. The flat-top square spots after homogenization and shaping by the homogenizing fiber are closely arranged, with an effective overlap rate higher than that of traditional circular Gaussian spots. Multiple scanning processes can be achieved with a single scan, reducing the number of scans, reducing processing time, and improving processing efficiency.

[0060] Optionally, in some other implementations, the edge of the wafer 500 exhibits laser energy attenuation and uneven polishing pressure distribution (edge ​​pressure ≤ 70% of center pressure), resulting in poor edge processing quality (thickness deviation > 100 nm), failing to meet the requirements for an ultra-smooth surface. Therefore, an optional processing uniformity correction coefficient is proposed:

[0061] (3);

[0062] in, This represents the processing uniformity correction coefficient, used to compensate for edge effects; Represents the edge laser power density deviation (W / mm²). , For the laser power density at the edge of the wafer (500), For the center power density; Represents the edge polishing pressure deviation (N); This represents the center polishing pressure (N) of the wafer 500.

[0063] Edge effects are compensated by a correction coefficient, for example when , ( ), , ( )hour, That is, the edge laser power needs to be increased to The pressure increased to To ensure consistent removal rates between the edges and the center, the energy attenuation unit of the optical path design unit 200 dynamically adjusts the laser power in the edge region; simultaneously, it adjusts the pressure distribution of the polishing disk 400 (e.g., using a flexible polishing pad) to optimize edge processing conditions. After correction, it is aligned with the center, ultimately achieving a wafer thickness deviation of ≤50nm across the entire 500mm area, meeting the requirements for an ultra-smooth, damage-free surface.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A laser-assisted chemical mechanical polishing method based on homogenized optical fiber, characterized in that, A laser-assisted chemical mechanical polishing device based on homogenizing optical fiber is used. The device includes a laser generator, an optical path design unit, a scanning galvanometer, a fine polishing unit, and a two-dimensional motion platform. The laser generator is used to generate pulsed laser light; The optical path design unit is used to homogenize and shape the pulsed laser through a homogenizing fiber to obtain a square flat-topped laser spot. The scanning galvanometer is used to control the scanning speed and scanning path of the laser to complete the scanning processing of the wafer; The fine polishing unit is used to fine polish the wafer after laser scanning to form a high-quality polished surface. The two-dimensional motion platform is used to carry the wafer and control the relative movement between the wafer and the polishing disk. The two-dimensional motion platform is also used to adjust the relative position between the wafer and the fine polishing unit. The method The process includes the following: Based on the moving speed of the two-dimensional motion platform, the size of the wafer, and the size of the square flat-top light spot at the focal point, the scanning speed and scanning length of the scanning galvanometer are determined. A two-dimensional motion platform is used to support the wafer, so that it moves relative to the polishing disk and the scanning galvanometer. Polishing fluid is dripped between the polishing process of the polishing disk and the laser processing process of the scanning galvanometer. The square flat-top light spot after being shaped by the homogenizing fiber is closely arranged under the coordinated control of the scanning galvanometer and the two-dimensional motion platform to form a uniform processing. The moving speed of the two-dimensional motion platform is as follows: ； in, Represents the moving speed (mm / s) of the two-dimensional motion platform, which is the uniform moving speed of the two-dimensional motion platform along the Y direction; This represents the scanning speed of the scanning galvanometer (mm / s), which is the scanning linear velocity of the scanning galvanometer along the X-axis. Represents the side length (mm) of a square flat-topped light spot; Represents the effective overlap rate of the target light spot; This represents the length of a single scan line of the galvanometer (mm), which is the length of the effective processing area of ​​the wafer in the X direction; Synchronization of laser processing and polishing is achieved by controlling the lag distance of the polishing disk relative to the laser scanning center. The lag distance of the polishing disk relative to the laser scanning center is determined as follows: ； in, The distance (mm) representing the lag distance of the polishing disk relative to the laser scanning center is the Y-axis distance between the laser scanning center and the polishing disk processing center. Represents the moving speed of the two-dimensional motion platform (mm / s); The laser-modified layer stabilization time (s) represents the time it takes for a stable modified layer to form on SiC material after laser processing. Represents the diffusion coefficient of the polishing slurry (mm) The s / N ratio is determined by the viscosity and surface tension of the polishing slurry. Represents the kinematic viscosity of the polishing fluid (mm) 2 / s); This represents the pressure applied to the polishing pad per square millimeter of wafer (N / mm). 2 ); The wafer and polishing pad are controlled to move relative to each other using a two-dimensional motion platform, and the wafer is processed along a preset path.

2. The laser-assisted chemical mechanical polishing method based on homogenized optical fiber as described in claim 1, characterized in that, The optical path design unit includes an energy attenuation module for adjusting energy according to the power required during processing.

3. The laser-assisted chemical mechanical polishing method based on homogenized optical fiber as described in claim 1, characterized in that, The fine polishing unit includes a polishing disk and a polishing slurry titration unit. The polishing slurry titration unit is used to add polishing slurry to the wafer between the laser processing step of the scanning galvanometer and the polishing step of the fine polishing unit.

4. The laser-assisted chemical mechanical polishing method based on homogenized optical fiber as described in claim 1, characterized in that, Before using a homogenizing fiber to homogenize and shape the pulsed laser to form a flat-top square spot, a lens is used to focus the pulsed laser and couple it into the homogenizing fiber.

5. The laser-assisted chemical mechanical polishing method based on homogenized optical fiber as described in claim 4, characterized in that, By adjusting the distance between the lens and the scanning galvanometer, flat-topped square spots of different sizes can be obtained.

6. The laser-assisted chemical mechanical polishing method based on homogenized optical fiber as described in claim 1, characterized in that, The center of the polishing disc is located on the wafer surface during processing, and the rotation speed and pressure of the polishing disc are controlled to achieve the desired processing effect.

7. The laser-assisted chemical mechanical polishing method based on homogenized optical fiber as described in claim 1, characterized in that, Control the scanning position of the scanning galvanometer and the relative spatial position between them and the polishing disk so that the dripping of polishing slurry does not affect the laser processing.

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