A method and system for laser processing of a CVD-SiC block

Abstract

The application relates to a laser processing method and system of a CVD-SiC block, and relates to the technical field of laser processing, and comprises the following steps: fixing a CVD-SiC block on a work platform; coaxially and confocally coupling deep ultraviolet picosecond laser and near-infrared nanosecond laser to obtain a mixed synchronous laser source; using the mixed synchronous laser source, scanning and cutting the CVD-SiC block along a preset three-dimensional path to form a preset fracture surface; completely separating the preset fracture surface to complete cutting processing, so that the efficiency can be improved and the cost can be reduced under the premise of ensuring the yield.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology, and in particular to a laser processing method and system for CVD-SiC bulk materials. Background Technology

[0002] Silicon carbide prepared by chemical vapor deposition has advantages such as high density, high hardness, fine grains, and high purity, which are close to the theoretical density. It can be processed into spray heads and etching rings (focusing rings) through various methods. In the semiconductor field, these products are key consumables in the etching process. They have a longer life and better stability than spray heads and etching rings made of traditional Si materials. At present, they are mainly imported.

[0003] Silicon carbide prepared by chemical vapor deposition (CVD) has extremely high hardness, approaching that of diamond, but also exhibits high brittleness. Ordinary cutting tools cannot penetrate it, resulting in very low processing efficiency and yield. A typical process involves first cutting the material using a diamond wire cutter, followed by processing into finished products using grinding machines, lathes, and other equipment. The biggest problem with diamond wire cutting is its low cutting efficiency and susceptibility to wire breakage, leading to high overall costs for wire cutting machines and requiring a large number of such machines to meet production capacity needs. In summary, this method involves significant fixed asset investment, low cutting efficiency, insufficient stability, and high costs. To address this, those skilled in the art have attempted to introduce laser processing technology. However, single-wavelength lasers have limited penetration depth, making it difficult to construct continuous fracture surfaces within thick materials. Furthermore, the extremely high hardness, high brittleness, and near-theoretical density of silicon carbide prepared by CVD make it difficult for existing technologies to improve efficiency and reduce costs while maintaining yield. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art in which it is difficult to improve efficiency and reduce cost while ensuring yield, thereby providing a laser processing method and system for CVD-SiC bulk materials.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A laser processing method for CVD-SiC bulk materials includes the following steps: Fix the CVD-SiC block to the working platform; By coaxially and confocally coupling deep ultraviolet picosecond lasers and near-infrared nanosecond lasers, a hybrid synchronous laser source is obtained. Using the hybrid synchronous laser source, the CVD-SiC block is scanned and cut along a preset three-dimensional path to form a preset fracture surface; The preset fracture surface is completely separated to complete the cutting process.

[0006] Preferably, the deep ultraviolet picosecond laser has a wavelength of 266 nm, a pulse width of 10–30 ps, ​​and a repetition frequency of 100–300 kHz; the near-infrared nanosecond laser has a wavelength of 1064 nm, a pulse width of 5–20 ns, and a repetition frequency of 1–10 kHz.

[0007] Preferably, the CVD-SiC bulk thickness is 1–15 mm, the energy density of the deep ultraviolet picosecond laser is 0.3–0.6 J / cm², and the energy density of the near-infrared nanosecond laser is 2–5 J / cm².

[0008] Preferably, for outer circle cutting, the preset three-dimensional path is: spiraling down along the cylindrical surface with a step size ≤ 20 μm; for inner hole core taking, the preset three-dimensional path is: first drilling a guide hole in the core, and then scanning radially from the inside to the outside; for concentric inner and outer circles, the preset three-dimensional path is: synchronously controlled inner and outer dual beam paths.

[0009] Preferably, during scanning and cutting, inert gas is sprayed into the cutting area, and coolant is circulated into the bottom of the CVD-SiC block.

[0010] Preferably, the inert gas is argon or nitrogen, and the pressure of the injected inert gas is 0.2–0.5 MPa; the coolant is deionized water, and the temperature is controlled at 20–50°C.

[0011] Preferably, an external force of less than 10N or a thermal shock with a temperature difference of 90-100℃ is applied to completely separate the preset fracture surfaces.

[0012] Preferably, after fixing the CVD-SiC block onto the working platform, pre-injection is performed on the target cutting surface. or Ions, implantation dose Energy 100–300 keV.

[0013] Preferably, the deep ultraviolet picosecond laser and the near-infrared nanosecond laser are coaxially and confocally coupled, with the deep ultraviolet picosecond laser emitted first, delayed by 1-10 ns, and then the near-infrared nanosecond laser emitted, and the deep ultraviolet picosecond laser and the near-infrared nanosecond laser are emitted alternately in sequence.

[0014] A laser processing system for CVD-SiC blocks includes a five-axis linkage motion platform, a hybrid synchronous laser source, and an adaptive beam shaping and focus tracking module. The five-axis linkage motion platform is used to fix the CVD-SiC block. The hybrid synchronous laser source includes a deep ultraviolet picosecond laser and a near-infrared nanosecond laser, and the deep ultraviolet picosecond laser and the near-infrared nanosecond laser are coaxially and confocally coupled. The adaptive beam shaping and focus tracking module is used to control the hybrid synchronous laser source to scan and cut the CVD-SiC block along a preset three-dimensional path.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: By coaxially and confocally coupling deep ultraviolet picosecond lasers and near-infrared nanosecond lasers, the beams and focal points of the deep ultraviolet picosecond lasers and near-infrared nanosecond lasers overlap in space. This ensures that the deep ultraviolet picosecond lasers and near-infrared nanosecond lasers are superimposed on the same path inside the CVD-SiC block. The deep ultraviolet picosecond laser acts on the processing surface of the CVD-SiC block to form a crack guiding layer, while the near-infrared nanosecond laser acts below the crack guiding layer and generates thermal stress, causing the crack to propagate. The superimposed mixed wavelength lasers scan and cut the CVD-SiC block along a preset three-dimensional path to form a preset fracture surface, thereby improving efficiency and reducing costs while ensuring yield. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 A flowchart of a laser processing method for CVD-SiC bulk materials provided in an embodiment of the present invention; Figure 2 A partial schematic diagram of a laser processing system for a portion of CVD-SiC bulk materials provided for embodiments of the present invention; Figure 3 A schematic diagram of a laser processing system for a portion of CVD-SiC bulk materials provided in an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1. CVD-SiC block; 2. Three-dimensional path; 3. Hybrid synchronous laser source; 4. Five-axis linkage motion platform. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] Please read carefully. Figures 1 to 3 This invention provides a laser processing method for CVD-SiC bulk materials, comprising the following steps: Fix the CVD-SiC block 1 to the working platform; By coaxially and confocally coupling deep ultraviolet picosecond lasers and near-infrared nanosecond lasers, a hybrid synchrotron laser source 3 is obtained; Using a hybrid synchronous laser source 3, the CVD-SiC block 1 is scanned and cut along a preset three-dimensional path 2 to form a preset fracture surface; Completely separate the pre-set fracture surface to complete the cutting process.

[0023] The CVD-SiC block 1 is fixed to a five-axis linkage motion platform 4, which includes three linear axes and two rotary axes. The three linear axes are used to control the scanning of the hybrid synchronous laser source 3, and the two rotary axes are used to control the rotation of the CVD-SiC block 1. The deep ultraviolet picosecond laser and the near-infrared nanosecond laser are coaxially and confocally coupled to obtain the hybrid synchronous laser source 3, ensuring that the deep ultraviolet picosecond laser and the near-infrared nanosecond laser are superimposed on the same path inside the CVD-SiC block 1. The deep ultraviolet picosecond laser acts on the processing surface of the CVD-SiC block 1 to form a crack guiding layer, and the near-infrared nanosecond laser acts below the crack guiding layer and generates thermal stress, causing the crack to propagate. The deep ultraviolet picosecond laser and the near-infrared nanosecond laser have different energy densities and wavelengths, realizing gradient energy injection from the surface to the deep layer. In the vertical direction, two hybrid synchronous laser sources 3 directly strike the same position on the upper and lower sides of the CVD-SiC block 1, and scan and cut the CVD-SiC block 1 along the preset three-dimensional path 2 to form a preset fracture surface. The preset fracture surface is then processed to completely separate the preset fracture surface, thus completing the cutting process.

[0024] In a preferred embodiment, the deep ultraviolet picosecond laser has a wavelength of 266 nm, a pulse width of 10–30 ps, ​​and a repetition frequency of 100–300 kHz; the near-infrared nanosecond laser has a wavelength of 1064 nm, a pulse width of 5–20 ns, and a repetition frequency of 1–10 kHz. The 266 nm deep ultraviolet picosecond laser is a cold light source, which is strongly absorbed in the CVD-SiC bulk 1, and its energy is almost deposited on the surface, forming a microcrack guiding layer on the surface of the CVD-SiC bulk 1, which plays a role in cold guidance. The 1064 nm near-infrared nanosecond laser is a hot light source, which is weakly absorbed in the CVD-SiC bulk 1, but penetrates deeper, with an absorption depth of tens to hundreds of micrometers. Its energy can be deposited into deeper layers inside the CVD-SiC bulk 1 material, driving the microcracks to propagate stably into the depth of the CVD-SiC bulk 1 material.

[0025] In a preferred embodiment, the CVD-SiC bulk material 1 has a thickness of 1–15 mm. The energy density of the deep ultraviolet picosecond laser is 0.3–0.6 J / cm², and the energy density of the near-infrared nanosecond laser is 2–5 J / cm². The deep ultraviolet picosecond laser and the near-infrared nanosecond laser have different wavelengths and energy densities, and are coaxially and confocally coupled to achieve gradient energy injection into the 1–15 mm thick CVD-SiC bulk material 1. The energy of the deep ultraviolet picosecond laser is controlled to induce surface modification of the CVD-SiC bulk material 1, forming a microcrack guiding layer. The energy of the near-infrared nanosecond laser generates controllable thermal stress below the guiding layer, driving the crack to propagate stably along a predetermined three-dimensional path 2. This energy ratio ensures that the total energy remains below the SiC melting threshold, thereby avoiding thermal damage and remelting.

[0026] As a preferred embodiment, for outer circle cutting, the preset three-dimensional path 2 is: spiraling down along the cylindrical surface with a step size ≤ 20 μm; for inner hole core taking, the preset three-dimensional path 2 is: first drilling a guide hole in the core, and then scanning radially from the inside to the outside; for concentric inner and outer circles, the preset three-dimensional path 2 is: synchronously controlled inner and outer dual beam paths.

[0027] The laser processing method for CVD-SiC block 1 provided by the present invention will be described in detail below with reference to embodiments.

[0028] Example 1 (taking the outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 100keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 10 ps, ​​an energy density of 0.3 J / cm², and a repetition frequency of 100 kHz was coaxially and confocally coupled with a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 5 ns, an energy density of 2 J / cm², and a repetition frequency of 1 kHz to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, the laser is spirally descended along the outer surface of the CVD-SiC block 1 to perform scanning and cutting. The pitch is 10 μm and the speed is 5 mm / s. At the same time, argon gas with a pressure of 0.2 MPa is injected into the cutting area, and deionized water at a temperature of 20℃ is circulated into the bottom of the CVD-SiC block 1 to form a predetermined fracture surface. Apply a 5N external force to the preset fracture surface to completely separate the preset fracture surface and complete the cutting process.

[0029] Example 2 (taking the outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 200keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 10 ps, ​​an energy density of 0.3 J / cm², and a repetition frequency of 100 kHz was coaxially and confocally coupled with a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 5 ns, an energy density of 2 J / cm², and a repetition frequency of 1 kHz to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, the laser is spirally descended along the outer surface of the CVD-SiC block 1 to perform scanning and cutting. The pitch is 10 μm and the speed is 5 mm / s. At the same time, argon gas with a pressure of 0.2 MPa is injected into the cutting area, and deionized water at a temperature of 20℃ is circulated into the bottom of the CVD-SiC block 1 to form a predetermined fracture surface. Apply a 5N external force to the preset fracture surface to completely separate the preset fracture surface and complete the cutting process.

[0030] Example 3 (taking the outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. He⁺ with an energy of 300 keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 10 ps, ​​an energy density of 0.3 J / cm², and a repetition frequency of 100 kHz was coaxially and confocally coupled with a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 5 ns, an energy density of 2 J / cm², and a repetition frequency of 1 kHz to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, the laser is spirally descended along the outer surface of the CVD-SiC block 1 to perform scanning and cutting. The pitch is 10 μm and the speed is 5 mm / s. At the same time, argon gas with a pressure of 0.2 MPa is injected into the cutting area, and deionized water at a temperature of 20℃ is circulated into the bottom of the CVD-SiC block 1 to form a predetermined fracture surface. Apply a 5N external force to the preset fracture surface to completely separate the preset fracture surface and complete the cutting process.

[0031] Example 4 (taking the outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 100keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 20 ps, ​​an energy density of 0.45 J / cm², and a repetition frequency of 200 kHz, and a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 12.5 ns, an energy density of 3.5 J / cm², and a repetition frequency of 5 kHz were coaxially confocally coupled to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, the laser is spirally descended along the outer surface of the CVD-SiC block 1 to perform scanning and cutting. The pitch is 10 μm and the speed is 5 mm / s. At the same time, argon gas with a pressure of 0.2 MPa is injected into the cutting area, and deionized water at a temperature of 20℃ is circulated into the bottom of the CVD-SiC block 1 to form a predetermined fracture surface. Apply a 5N external force to the preset fracture surface to completely separate the preset fracture surface and complete the cutting process.

[0032] Example 5 (taking the outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 100keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 30 ps, ​​an energy density of 0.6 J / cm², and a repetition frequency of 300 kHz, and a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 20 ns, an energy density of 5 J / cm², and a repetition frequency of 10 kHz were coaxially confocally coupled to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, the laser is spirally descended along the outer surface of the CVD-SiC block 1 to perform scanning and cutting. The pitch is 10 μm and the speed is 5 mm / s. At the same time, argon gas with a pressure of 0.2 MPa is injected into the cutting area, and deionized water at a temperature of 20℃ is circulated into the bottom of the CVD-SiC block 1 to form a predetermined fracture surface. Apply a 5N external force to the preset fracture surface to completely separate the preset fracture surface and complete the cutting process.

[0033] Example 6 (Taking the outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 100keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 10 ps, ​​an energy density of 0.3 J / cm², and a repetition frequency of 100 kHz was coaxially and confocally coupled with a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 5 ns, an energy density of 2 J / cm², and a repetition frequency of 1 kHz to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, the laser is spirally descended along the outer surface of the CVD-SiC block 1 to perform scanning and cutting. The pitch is 15 μm and the speed is 8 mm / s. At the same time, argon gas with a pressure of 0.35 MPa is injected into the cutting area, and deionized water at a temperature of 35℃ is circulated into the bottom of the CVD-SiC block 1 to form a predetermined fracture surface. Apply a 5N external force to the preset fracture surface to completely separate the preset fracture surface and complete the cutting process.

[0034] Example 7 (Taking the outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 100keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 10 ps, ​​an energy density of 0.3 J / cm², and a repetition frequency of 100 kHz was coaxially and confocally coupled with a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 5 ns, an energy density of 2 J / cm², and a repetition frequency of 1 kHz to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, the laser is spirally descended along the outer surface of the CVD-SiC block 1 to perform scanning and cutting. The pitch is 20 μm and the speed is 10 mm / s. At the same time, argon gas with a pressure of 0.5 MPa is injected into the cutting area, and deionized water at a temperature of 50°C is circulated at the bottom of the CVD-SiC block 1 to form a predetermined fracture surface. Apply a 5N external force to the preset fracture surface to completely separate the preset fracture surface and complete the cutting process.

[0035] Example 8 (taking the outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 100keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 10 ps, ​​an energy density of 0.3 J / cm², and a repetition frequency of 100 kHz was coaxially and confocally coupled with a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 5 ns, an energy density of 2 J / cm², and a repetition frequency of 1 kHz to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, the laser is spirally descended along the outer surface of the CVD-SiC block 1 to perform scanning and cutting. The pitch is 10 μm and the speed is 5 mm / s. At the same time, argon gas with a pressure of 0.2 MPa is injected into the cutting area, and deionized water at a temperature of 20℃ is circulated into the bottom of the CVD-SiC block 1 to form a predetermined fracture surface. An external force of 8N is applied to the preset fracture surface to completely separate the preset fracture surface, thus completing the cutting process.

[0036] Example 9 (taking the outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 100keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 10 ps, ​​an energy density of 0.3 J / cm², and a repetition frequency of 100 kHz was coaxially and confocally coupled with a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 5 ns, an energy density of 2 J / cm², and a repetition frequency of 1 kHz to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, the laser is spirally descended along the outer surface of the CVD-SiC block 1 to perform scanning and cutting. The pitch is 10 μm and the speed is 5 mm / s. At the same time, nitrogen gas with a pressure of 0.2 MPa is sprayed into the cutting area, and deionized water at a temperature of 20°C is circulated into the bottom of the CVD-SiC block 1 to form a preset fracture surface. Apply a 9N external force to the preset fracture surface to completely separate the preset fracture surface and complete the cutting process.

[0037] Example 10 (Taking the outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 100keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 10 ps, ​​an energy density of 0.3 J / cm², and a repetition frequency of 100 kHz was coaxially and confocally coupled with a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 5 ns, an energy density of 2 J / cm², and a repetition frequency of 1 kHz to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, the laser is spirally descended along the outer surface of the CVD-SiC block 1 to perform scanning and cutting. The pitch is 10 μm and the speed is 5 mm / s. At the same time, nitrogen gas with a pressure of 0.2 MPa is sprayed into the cutting area, and deionized water at a temperature of 20°C is circulated into the bottom of the CVD-SiC block 1 to form a preset fracture surface. The CVD-SiC block 1 is heated to 140°C using a heating plate, and then quickly immersed in a 50°C water bath to create a 90°C temperature difference inside the CVD-SiC block 1, completely separating the preset fracture surface and completing the cutting process.

[0038]

[0039] As shown in the table above, the laser processing method for CVD-SiC bulk materials provided by this invention has a processing time of no more than 25 minutes for outer diameter cutting, no microcracks were detected, and material loss is less than 20 μm. Examples 1, 2, and 3 only differ in... The amount and energy of ion implantation were studied using different ratios. Changes in parameter indicators after ion-cleaned CVD-SiC block 1 processing; Examples 1, 4, and 5 successively increased the pulse width, energy density, and repetition frequency of deep ultraviolet picosecond laser and near-infrared nanosecond laser, and the comparison showed that processing time and material loss were improved sequentially; Examples 1, 6, and 7 successively increased the pitch and speed, while simultaneously increasing the pressure of argon gas injected into the cutting zone and the temperature of deionized water, and the comparison showed that processing time and material loss were also improved sequentially; Examples 1, 8, and 9 successively increased the external force applied to the preset fracture surface to study the effect of different external forces on the parameter indicators after CVD-SiC block 1 processing; Examples 1 and 10... Ion replacement By replacing ions and nitrogen with argon and using temperature difference to completely separate the preset fracture surfaces, the processing time and material consumption were slightly improved compared to the previous results.

[0040] Example 11 (Taking the inner hole core sampling of CVD-SiC block 1 with a thickness of 8mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 100keV ion; Deep ultraviolet picosecond laser and near-infrared nanosecond laser are coaxially confocalized. First, a deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 10 ps, ​​an energy density of 0.3 J / cm², and a repetition frequency of 100 kHz is emitted to create a guide hole with a depth of 2 mm. After a delay of 1 ns, a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 5 ns, an energy density of 2 J / cm², and a repetition frequency of 1 kHz is emitted. The deep ultraviolet picosecond laser and the near-infrared nanosecond laser are alternately emitted at the same working point and scanned and cut radially from the inside to the outside, with an increment of 50 μm per revolution. Argon gas at a pressure of 0.2 MPa is injected into the cutting area, and deionized water at a temperature of 20°C is circulated into the bottom of the CVD-SiC block 1 to form a predetermined fracture surface; Apply a 5N external force to the preset fracture surface to completely separate the preset fracture surface and complete the cutting process.

[0041] Example 12 (Taking the inner hole core sampling of CVD-SiC block 1 with a thickness of 8mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 100keV ion; Deep ultraviolet picosecond laser and near-infrared nanosecond laser are coaxially confocalized. First, a deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 20 ps, ​​an energy density of 0.45 J / cm², and a repetition frequency of 200 kHz is emitted to create a guide hole with a depth of 4 mm. After a delay of 5 ns, a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 12.5 ns, an energy density of 3.5 J / cm², and a repetition frequency of 5 kHz is emitted. The deep ultraviolet picosecond laser and the near-infrared nanosecond laser are alternately emitted at the same working point and scanned and cut radially from the inside to the outside, with an increment of 50 μm per revolution. Argon gas at a pressure of 0.2 MPa is injected into the cutting area, and deionized water at a temperature of 20°C is circulated into the bottom of the CVD-SiC block 1 to form a predetermined fracture surface; Apply a 5N external force to the preset fracture surface to completely separate the preset fracture surface and complete the cutting process.

[0042] Example 13 (Taking the inner hole core sampling of CVD-SiC block 1 with a thickness of 8mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 100keV ion; Deep ultraviolet picosecond laser and near-infrared nanosecond laser are coaxially confocalized. First, a deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 30 ps, ​​an energy density of 0.6 J / cm², and a repetition frequency of 300 kHz is emitted to create a guide hole with a depth of 5 mm. After a delay of 10 ns, a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 20 ns, an energy density of 5 J / cm², and a repetition frequency of 10 kHz is emitted. The deep ultraviolet picosecond laser and the near-infrared nanosecond laser are alternately emitted at the same working point and scanned and cut radially from the inside to the outside, with an increment of 50 μm per revolution. Argon gas at a pressure of 0.2 MPa is injected into the cutting area, and deionized water at a temperature of 20°C is circulated into the bottom of the CVD-SiC block 1 to form a predetermined fracture surface; Apply a 5N external force to the preset fracture surface to completely separate the preset fracture surface and complete the cutting process.

[0043]

[0044] As shown in the table above, comparative examples 11, 12, and 13 successively increased the pulse width, energy density, and repetition frequency of the deep ultraviolet picosecond laser and the near-infrared nanosecond laser, as well as the delay time between the deep ultraviolet picosecond laser and the near-infrared nanosecond laser. In summary, the processing time for laser core drilling did not exceed 17 minutes, no microcracks were detected, material loss was less than 20 μm, and the processing time decreased sequentially.

[0045] Example 14 (Taking the synchronous inner and outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 300keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 10 ps, ​​an energy density of 0.3 J / cm², and a repetition frequency of 100 kHz was coaxially and confocally coupled with a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 5 ns, an energy density of 2 J / cm², and a repetition frequency of 1 kHz to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, a dual-beam system is used to synchronously scan the CVD-SiC block 1 along its axial direction. Both the outer and inner circular paths are spiraled downwards with a pitch of 20 μm and a speed of 10 mm / s. At the same time, argon gas with a pressure of 0.5 MPa is injected into the cutting area, and deionized water at a temperature of 50°C is circulated at the bottom of the CVD-SiC block 1 to form a predetermined fracture surface. The CVD-SiC block 1 is heated to 150°C using a heating plate, and then quickly immersed in a 50°C water bath to create a 100°C temperature difference inside the CVD-SiC block 1, completely separating the preset fracture surface and completing the cutting process.

[0046] Example 15 (Taking the synchronous inner and outer circle cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 300keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 20 ps, ​​an energy density of 0.45 J / cm², and a repetition frequency of 200 kHz, and a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 12.5 ns, an energy density of 3.5 J / cm², and a repetition frequency of 5 kHz were coaxially confocally coupled to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, a dual-beam system is used to synchronously scan the CVD-SiC block 1 along its axial direction. Both the outer and inner circular paths are spiraled downwards with a pitch of 20 μm and a speed of 10 mm / s. At the same time, argon gas with a pressure of 0.5 MPa is injected into the cutting area, and deionized water at a temperature of 50°C is circulated at the bottom of the CVD-SiC block 1 to form a predetermined fracture surface. The CVD-SiC block 1 is heated to 150°C using a heating plate, and then quickly immersed in a 50°C water bath to create a 100°C temperature difference inside the CVD-SiC block 1, completely separating the preset fracture surface and completing the cutting process.

[0047] Example 16 (Taking the synchronous inner and outer circular cutting of a CVD-SiC block 1 with a thickness of 10mm as an example) The CVD-SiC block 1 is fixed to the five-axis linkage motion platform 4, and the dose is injected into the target cutting surface. Energy of 300keV ion; A deep ultraviolet picosecond laser with a wavelength of 266 nm, a pulse width of 30 ps, ​​an energy density of 0.6 J / cm², and a repetition frequency of 300 kHz was coaxially and confocally coupled with a near-infrared nanosecond laser with a wavelength of 1064 nm, a pulse width of 20 ns, an energy density of 5 J / cm², and a repetition frequency of 10 kHz to obtain a hybrid synchrotron laser source 3. Using a hybrid synchronous laser source 3, a dual-beam system is used to synchronously scan the CVD-SiC block 1 along its axial direction. Both the outer and inner circular paths are spiraled downwards with a pitch of 20 μm and a speed of 10 mm / s. At the same time, argon gas with a pressure of 0.5 MPa is injected into the cutting area, and deionized water at a temperature of 50°C is circulated at the bottom of the CVD-SiC block 1 to form a predetermined fracture surface. The CVD-SiC block 1 is heated to 150°C using a heating plate, and then quickly immersed in a 50°C water bath to create a 100°C temperature difference inside the CVD-SiC block 1, completely separating the preset fracture surface and completing the cutting process.

[0048]

[0049] As shown in the table above, by increasing the pulse width, energy density, and repetition frequency of the deep ultraviolet picosecond laser and the near-infrared nanosecond laser in comparative examples 14, 15, and 16 respectively, it can be concluded that the laser synchronous cutting time for inner and outer circles does not exceed 15 minutes, no microcracks are detected, the material loss is less than 20 μm, and the processing time decreases in that order.

[0050] Comparison Column 1 The same CVD-SiC block 1 as in Example 1 was selected. The difference from Example 1 is that the outer circle was cut using a conventional diamond wire cutting machine.

[0051] Compared to column 1, the processing time is 4-6 hours, microcracks were detected, material loss is 150-200μm, and the maximum processable thickness does not exceed 20mm.

[0052] Comparison Column 2 The same CVD-SiC block 1 as in Example 1 was selected. The difference from Example 1 is that an internal mechanical saw was used for external circular cutting.

[0053] Compared to column 1, the processing time is 3-5 hours, obvious cracks were detected, material loss is 300-500μm, and the maximum processable thickness does not exceed 10mm.

[0054] Comparative Example 3 The same CVD-SiC block 1 as in Example 11 was selected. The difference from Example 11 is that a conventional diamond wire cutting machine was used to pre-process a guide hole with a depth of about 1 mm. The diamond wire was passed through the guide hole and the two ends of the wire were fixed on the spool of the cutting machine to form a closed loop.

[0055] Compared to column 3, the processing time exceeds 8 hours and requires multiple reversals. Microcracks were detected, material loss is 150-200μm, and the maximum processable thickness does not exceed 20mm.

[0056] Comparative Example 4 8-inch and 12-inch CVD-SiC blocks 1 were processed respectively. The difference from Example 14 is that a conventional diamond wire cutting machine was used.

[0057] The processing times for Comparative Example 4 were 60-75 min and 80-90 min, respectively.

[0058] Comparing Examples 1-10 with Comparative Examples 1 and 2, the processing time of Comparative Examples 1 and 2 both exceeded 3 hours, microcracks were detected, and the material loss was at least greater than 150 μm. The hybrid synchronous laser source 3 was used to cut the outer circle of the CVD-SiC block 1. In Examples 1-10, no microcracks appeared in the CVD-SiC block 1, the processing time did not exceed 25 min, and the material loss was less than 20 μm. It can be seen that the processing method of this application can improve efficiency and reduce costs while ensuring yield.

[0059] Comparing Examples 11-13 with Comparative Example 3, Comparative Example 3 had a processing time exceeding 8 hours, detected microcracks, and a material loss of 150-200 μm. In the case of the hybrid synchronous laser source 3 performing core sampling on the CVD-SiC block 1, no microcracks were found in the CVD-SiC block 1 in Examples 11-13, the processing time did not exceed 17 minutes, and the material loss was less than 20 μm. It can be seen that the processing method of this application can improve efficiency and reduce costs while ensuring yield.

[0060] Comparing Examples 14-16 with Comparative Example 4, the processing time of Comparative Example 4 exceeded one hour; the two-beam hybrid synchronous laser source 3 performed synchronous inner and outer circular cutting on the CVD-SiC block 1. In Examples 11-13, no microcracks appeared on the CVD-SiC block 1, the processing time did not exceed 15 minutes, and the material loss was less than 20 μm. It can be seen that the processing method of this application can improve efficiency.

[0061] In summary, the laser processing method provided in this application can improve product efficiency and reduce costs while ensuring yield when cutting CVD-SiC blocks 1 with a thickness of 1–15 mm.

[0062] A laser processing system for CVD-SiC blocks includes a five-axis linkage motion platform 4, two hybrid synchronous laser sources 3, an adaptive beam shaping and focus tracking module, a real-time acoustic emission monitoring unit, and a gas-liquid composite cooling and chip removal device. The five-axis linkage platform is used to fix the CVD-SiC block 1, and the real-time acoustic emission monitoring unit provides real-time feedback on the progress of the preset fracture surface. The hybrid synchronous laser sources 3 include a deep ultraviolet picosecond laser and a near-infrared nanosecond laser, and the deep ultraviolet picosecond laser and the near-infrared nanosecond laser are coaxially and confocally coupled. Coaxial confocal coupling means that the propagation axes of the two beams coincide in three-dimensional space, and the focal points of the two beams also coincide in three-dimensional space. (Please read carefully along the vertical direction.) Figure 2 During cutting, the hybrid synchrotron laser source 3 can be directly aimed at the cutting area on the upper or lower side of the CVD-SiC block. Please read carefully. Figure 3 Alternatively, two hybrid synchronous laser sources 3 can be directly directed at the same cutting point on the upper and lower sides of the CVD-SiC block 1. The two hybrid synchronous laser sources 3 move along the same step size and trajectory. The area where the hybrid synchronous laser sources 3 are directed at the CVD-SiC block 1 is set up to avoid gaps, while the other areas are fixed on the five-axis linkage motion platform 4. This allows for arbitrary cutting of CVD-SiC blocks 1 with a thickness of 1–15 mm, while improving product efficiency and reducing costs while ensuring yield. The adaptive beam shaping and focus tracking module is based on a confocal displacement sensor. It controls the hybrid synchronous laser sources 3 to scan and cut the CVD-SiC block 1 along a preset three-dimensional path 2. The bottom of the CVD-SiC block 1 is cooled by a circulating gas-liquid composite cooling system to control the overall temperature rise of the CVD-SiC block 1 to be less than 50°C. The chip removal device is used to promptly remove the chips generated during cutting.

[0063] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A laser processing method for CVD-SiC bulk materials, characterized in that, Includes the following steps: Fix the CVD-SiC block to the working platform; By coaxially and confocally coupling deep ultraviolet picosecond lasers and near-infrared nanosecond lasers, a hybrid synchronous laser source is obtained. Using the hybrid synchronous laser source, the CVD-SiC block is scanned and cut along a preset three-dimensional path to form a preset fracture surface; The preset fracture surface is completely separated to complete the cutting process.

2. The laser processing method according to claim 1, characterized in that, The deep ultraviolet picosecond laser has a wavelength of 266 nm, a pulse width of 10–30 ps, ​​and a repetition frequency of 100–300 kHz; the near-infrared nanosecond laser has a wavelength of 1064 nm, a pulse width of 5–20 ns, and a repetition frequency of 1–10 kHz.

3. The laser processing method according to claim 1 or 2, characterized in that, The CVD-SiC bulk thickness is 1–15 mm, the energy density of the deep ultraviolet picosecond laser is 0.3–0.6 J / cm², and the energy density of the near-infrared nanosecond laser is 2–5 J / cm².

4. The laser processing method according to claim 1, characterized in that, For outer circle cutting, the preset three-dimensional path is: spiraling down along the cylindrical surface with a step size ≤ 20 μm; for inner hole core taking, the preset three-dimensional path is: first drilling a guide hole in the core, and then scanning radially from the inside to the outside; for concentric inner and outer circles, the preset three-dimensional path is: synchronously controlled inner and outer dual beam paths.

5. The laser processing method according to claim 1, characterized in that, During scanning and cutting, inert gas is sprayed into the cutting area, and coolant is circulated into the bottom of the CVD-SiC block.

6. The laser processing method according to claim 5, characterized in that, The inert gas is argon or nitrogen, and the pressure of the injected inert gas is 0.2–0.5 MPa; the coolant is deionized water, and the temperature is controlled at 20–50°C.

7. The laser processing method according to claim 1, characterized in that, Apply an external force of less than 10N, or apply a thermal shock with a temperature difference of 90-100℃, to completely separate the preset fracture surfaces.

8. The laser processing method according to claim 1, characterized in that, After fixing the CVD-SiC block onto the work platform, pre-injection is performed on the target cutting surface. or Ions, implantation dose Energy 100–300 keV.

9. The laser processing method according to claim 1, characterized in that, The deep ultraviolet picosecond laser and the near-infrared nanosecond laser are coaxially and confocally coupled. The deep ultraviolet picosecond laser is emitted first, delayed by 1-10 ns, and then the near-infrared nanosecond laser is emitted. The deep ultraviolet picosecond laser and the near-infrared nanosecond laser are emitted alternately in sequence.

10. A laser processing system for CVD-SiC bulk materials, characterized in that, The system includes a five-axis linkage motion platform, a hybrid synchronous laser source, and an adaptive beam shaping and focus tracking module. The five-axis linkage motion platform is used to fix the CVD-SiC block. The hybrid synchronous laser source includes a deep ultraviolet picosecond laser and a near-infrared nanosecond laser, and the deep ultraviolet picosecond laser and the near-infrared nanosecond laser are coaxially and confocally coupled. The adaptive beam shaping and focus tracking module is used to control the hybrid synchronous laser source to scan and cut the CVD-SiC block along a preset three-dimensional path.

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