Laser processing device for SiC crystal ingot

Abstract

The invention relates to a SiC crystal ingot laser processing device, which comprises a workpiece carrying table, a focusing objective lens, a moving unit, a Raman information acquisition unit, a focusing height acquisition unit, a laser processing unit and a control unit, and is characterized in that the workpiece carrying table and the focusing objective lens are respectively arranged at the moving end of the moving unit; a moving path of the focusing objective lens passes through projection light paths of the Raman information acquisition unit, the focusing height acquisition unit and the laser processing unit, and the moving unit, the Raman information acquisition unit, the focusing height acquisition unit and the laser processing unit are respectively in communication connection with the control unit. Therefore, the projection light passing through the focusing objective lens is focused on the workpiece surface layer and the modified layer on the workpiece carrying table. According to the invention, lossless and accurate facet area measurement is realized based on Raman detection so as to assist in regulating and controlling the subsequent laser processing process, and the device has the advantages of compact structure, high production efficiency and quality, improvement of processing consistency and reduction of material loss of a modified layer.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor device processing, and in particular to a laser processing device for SiC crystal ingots. Background Art

[0002] Semiconductor materials are resistant to high temperatures and radiation, and have excellent properties such as large bandgap width and high breakdown electric field. They have gradually become the main substrate of electronic devices and have important application prospects in the fields of communications, national defense and military industry. In the multiple processes from ingots to qualified substrate sheets, ingot cutting is the main source of material loss. At present, the main ingot cutting technologies are wire cutting and laser stripping. Compared with traditional wire cutting technology, laser stripping technology has the advantages of high production efficiency and low consumables, and has great development potential. The principle of laser stripping technology is to focus the laser at a specified depth inside the semiconductor material, process a large area of ​​modified area, and then strip the wafer. However, during the growth of the ingot, due to different doping concentrations (carrier concentrations), small face areas and non-small face areas with different resistivity, refractive index, and energy absorption rate will be formed. When the modified laser passes through the small face area and the non-small face area, the depth of its focus is inconsistent, which leads to low flatness of the stripped wafer and causes large losses in the subsequent grinding and polishing process. In addition, the uneven resistivity will lead to a large mismatch between the silicon carbide substrate and the epitaxial layer grown on it. Therefore, accurate characterization of the ingot doping concentration is an important step in improving wafer production capacity and guiding subsequent processes.

[0003] The Chinese patent with the authorization announcement number CN110911268B discloses a laser processing device, which forms a peeling layer in a SiC ingot, wherein the laser processing device comprises: a workpiece holding stage, which holds the SiC ingot; a small face region detection unit, which detects the small face region from the upper surface of the SiC ingot held by the workpiece holding stage; a coordinate setting unit, which sets the following two directions as the X-axis and the Y-axis respectively to set the X-coordinate and the Y-coordinate of the boundary between the small face region and the non-small face region; a laser light irradiation unit, which includes a condenser, which radiates a laser beam with a wavelength that is transparent to SiC. The laser beam is irradiated to the SiC ingot with a focal point positioned at a depth from the upper surface of the SiC ingot corresponding to the thickness of the wafer to be generated, so as to form a peeling layer in which SiC is separated into Si and C and cracks extend along the c-plane; an X-axis feed mechanism; a Y-axis feed mechanism; and a control and information processing unit, which increases the energy of the laser beam when irradiating the small face area with the laser beam and increases the position of the condenser according to the X-coordinate and Y-coordinate of the boundary between the small face area and the non-small face area, relative to the energy of the laser beam when irradiating the non-small face area with the laser beam and the position of the condenser. The above method uses a shooting unit to shoot the upper surface of the ingot, and uses an image processing unit to perform binarization processing on the shot image, so as to realize the discrimination between the small face area and the non-small face area. However, the ingot is relatively thick, and it is not easy to discriminate between the small face area and the non-small face area by direct shooting, and errors are prone to occur during implementation.

[0004] The Chinese patent publication number CN115472515A discloses a processing device for generating a plurality of wafers from an ingot, wherein the processing device comprises: a holding unit having a holding surface for holding the ingot; a fluorescence detection unit for irradiating the ingot with excitation light of a specified wavelength from above the ingot and detecting the number of photons of fluorescence generated from the upper surface of the ingot; a laser beam irradiation unit for irradiating the ingot with a focal point of a laser beam of a wavelength that is transparent to the ingot at a depth from the upper surface of the ingot corresponding to the thickness of the wafer to be generated, thereby forming a peeling layer; and a moving unit for moving the holding unit and the focal point of the laser beam in a direction parallel to the holding unit. The method comprises: a storage unit, which stores the distribution of the number of photons of fluorescence on the upper surface of the ingot detected by the fluorescence detection unit in association with the XY coordinate position on the XY plane parallel to the holding surface as two-dimensional data, and stores the position in the height direction of the ingot obtained by the two-dimensional data, i.e., the Z coordinate position, in association with the two-dimensional data; and a three-dimensional data generation unit, which generates three-dimensional data showing the distribution of the number of photons of fluorescence in the entire ingot according to the two-dimensional data of each Z coordinate position of the ingot stored in the storage unit. The above method utilizes a laser of a specific wavelength to irradiate the ingot, and realizes the judgment of the small face area by detecting the fluorescence intensity generated on the upper surface of the ingot, but the laser power density used in the fluorescence detection step is relatively high, which is easy to cause damage to the surface of the ingot.

[0005] A Chinese patent with publication number CN117316791A discloses a small face detection device, which is characterized in that it includes: an irradiation module, which is used to irradiate the first surface of the ingot with a laser beam so that the ingot produces a peeling layer; an acquisition module, which is used to apply ultrasonic waves to the formed ingot based on an ultrasonic vibration component to obtain a wafer corresponding to the peeling layer; a detection module, which is used to emit a detection beam to the wafer based on a light source of a specific wavelength, and record the light source emission intensity at the wafer receiving point; a comparison module, which is used to compare the transmission intensity of the wafer with the light source emission intensity to obtain the transmittance of the wafer; a determination module, which is used to locate the small face area in the wafer based on a preset transmittance threshold and the transmittance of the wafer, and determine the position information corresponding to the small face area; an update module, which is used to update the laser processing conditions of the next wafer adjacent to the wafer based on the position information corresponding to the small face area as guidance information, and peel the next wafer based on the laser processing conditions, wherein the laser processing conditions at least include a laser focusing position and a laser power. The above method completes the detection of the first peeled wafer by comparing the transmission intensity of the wafer and the emission intensity of the light source, and then optimizes the laser processing conditions of the next wafer according to the position information corresponding to the small face area of ​​the previous wafer. Laser energy fluctuations or other types of damage on the wafer surface will affect the measurement results, and there is also the problem of insufficient detection accuracy. Summary of the invention

[0006] The problem to be solved by the present invention is to provide a laser processing device for SiC ingots in response to the above-mentioned deficiencies in the prior art. The device realizes non-destructive and precise measurement of small face areas based on Raman detection, thereby assisting in regulating subsequent laser processing processes. The device has the advantages of compact structure, high production efficiency and quality, improved processing consistency, and reduced loss of modified layer materials.

[0007] The above-mentioned object of the present invention is achieved through the following technical solutions: A laser processing device for SiC ingots comprises a workpiece carrier, a focusing objective lens, a moving unit, a Raman information acquisition unit, a focus height acquisition unit, a laser processing unit, and a control unit, wherein the workpiece carrier and the focusing objective lens are respectively arranged at the moving end of the moving unit, and the moving path of the focusing objective lens passes through the projection light paths of the Raman information acquisition unit, the focus height acquisition unit, and the laser processing unit, and the moving unit, the Raman information acquisition unit, the focus height acquisition unit, and the laser processing unit respectively establish communication connections with the control unit to complete the focusing of the projection light passing through the focusing objective lens on the workpiece surface layer and the modified layer on the workpiece carrier.

[0008] Specifically, in the "laser processing device" of the present invention, The specific meaning of the "workpiece" is the solid material used to make semiconductor devices; non-limiting examples include silicon carbide standard products with different doping concentrations n, semi-insulating or conductive silicon carbide ingots, etc. The surface layer is the small facet and non-small facet area on the top of the workpiece corresponding to the Raman information acquisition unit and the focus height acquisition unit focusing on the top surface of the workpiece, and the modified layer is the internal plane area of ​​the workpiece planned when the laser processing unit focuses on the predetermined depth d of the workpiece; The specific meaning of the "workpiece carrier" refers to a table surface for carrying and fixing the workpiece, which has sufficient hardness and precision to ensure the stability and position accuracy of the workpiece during processing, and the design of the workpiece carrier allows it to move in a predetermined direction, so that the Raman information acquisition unit and the focus height acquisition unit can obtain Raman data, image information and position information of different detection points of the surface layer of the workpiece, and facilitate the laser processing unit to accurately process different modified points of the modified layer of the workpiece; The specific meaning of the "focusing objective lens" refers to a laser scanning focusing lens used to focus the projection light emitted by the Raman information acquisition unit and the focusing height acquisition unit on the surface layer of the top surface of the workpiece, or to focus the projection light emitted by the laser processing unit on the modified layer of the predetermined depth d of the workpiece. Its focusing design can ensure that the projection light forms a precise focusing point at the predetermined position of the workpiece, and feeds back the reflected light on the workpiece to the Raman information acquisition unit and the focusing height acquisition unit to acquire the workpiece parameters.

[0009] Furthermore, the mobile unit includes an XY-axis driver, an XY-axis linear module, a Z-axis driver and a Z-axis linear module, the control unit, the XY-axis driver and the XY-axis linear module establish a communication connection in sequence, the workpiece carrier is arranged at the mobile end of the XY-axis linear module, the control unit, the Z-axis driver and the Z-axis linear module establish a communication connection in sequence, and the focusing objective lens is arranged at the mobile end of the Z-axis linear module.

[0010] Specifically, in the "mobile unit" of the present invention, The specific meaning of the "Z axis" refers to a coordinate axis parallel to the height direction of the workpiece on the workpiece stage and parallel to the light emitting direction of the projection light path; The specific meaning of the "X axis" is a coordinate axis perpendicular to the Z axis and parallel to the workpiece modified layer on the workpiece carrier; The specific meaning of the "Y axis" is the coordinate axis perpendicular to the plane where the Z axis and the X axis are located; The specific meaning of the "driver" is an electronic device used to drive the linear module, which converts the electrical signal output by the control unit into a voltage or current signal suitable for the operation of the linear module; The specific meaning of the "linear module" refers to a device used to support and guide moving parts and perform reciprocating linear motion in a given direction; non-limiting examples include rectangular coordinate robots, synchronous belt linear modules, screw linear modules, linear motor linear modules, etc.

[0011] Furthermore, the projection end of the Raman information acquisition unit, the projection end of the focus height acquisition unit, the projection end of the laser processing unit, and the focusing objective lens are sequentially arranged along the moving direction of the Z-axis linear module.

[0012] Furthermore, the Raman information acquisition unit includes a first laser generating module, a Raman detection module, an image acquisition module, and a detection optical path module, the light output end of the first laser generating module is toward the light input end of the detection optical path module, the detection ends of the Raman detection module and the image acquisition module are respectively toward the light output end of the detection optical path module, and the projection optical path of the detection optical path module passes through the focusing objective lens.

[0013] Preferably, the first laser generating module is configured as a continuous laser. The laser wavelength of the continuous laser is 450-1000 nm, the laser detection power is adjustable between 0 and 500 mW, and the beam quality factor M is 2 <1.2, wavelength drift <10pm.

[0014] Preferably, the Raman detection module is configured as a high-resolution Raman spectrometer. The spectral resolution of the high-resolution Raman spectrometer is less than 2 cm -1 , the spectrum covers the range of 100~4000cm -1 It can meet the Raman spectroscopy detection needs of different workpieces, and has high detection sensitivity. It can obtain clear Raman spectroscopy information under low concentration or weak signals, thus improving the accuracy and reliability of the detection results.

[0015] Preferably, the image acquisition module is configured as a CCD camera. The CCD camera has high resolution and high sensitivity, can capture and transmit clear image information in real time, and has a sufficient number of pixels to ensure that the details of the image are clearly visible; at the same time, the high sensitivity enables good imaging effects to be obtained even under low light conditions; in addition, the CCD camera can also be equipped with an illumination light source to assist in dark field or bright field imaging to meet the needs of different detection scenarios.

[0016] Preferably, the detection optical path module includes a first dichroic mirror, a second dichroic mirror, a reflector, a filter group, and a convex lens, the first dichroic mirror (the projection end of the Raman information acquisition unit) is arranged between the focusing objective lens and the image acquisition module, the second dichroic mirror is arranged between the first laser generation module and the first dichroic mirror, and the reflector, the filter group, the convex lens and the Raman detection module are arranged in sequence on the beam splitting path of the second dichroic mirror on the side away from the first laser generation module.

[0017] Furthermore, the focus height acquisition unit includes a focus finding module and a focus optical path module, the light emitting end and the detection end of the focus finding module are respectively directed toward the focus optical path module, and the projection optical path of the focus optical path module passes through the focus objective lens.

[0018] Preferably, the focus-finding module is configured as a line laser focus sensor. The line laser focus sensor has the characteristics of high precision and high speed, and can quickly and accurately determine the focal position, thereby improving the focusing efficiency and accuracy of the entire unit. During the focus-finding process, the line laser focus sensor emits a line laser and receives the reflected light signal, and determines the focal position according to the intensity change of the light signal. Its working principle is based on the triangulation method of light. By measuring the focal range of the laser beam on the surface of the workpiece, combined with the known laser beam angle and the surface characteristics of the workpiece, the height of the focusing objective lens corresponding to the focal point formed on the surface layer of the workpiece can be calculated, and then the focus can be completed through the control unit.

[0019] Preferably, the focusing light path module includes a third dichroic mirror, and the third dichroic mirror (projection end of the focusing height acquisition unit) is arranged between the focusing objective lens and the first dichroic mirror, and the focusing light path module is arranged on the beam splitting path on the side of the third dichroic mirror away from the first dichroic mirror.

[0020] Furthermore, the laser processing unit includes a second laser generating module, a laser power monitoring module, and a processing optical path module, the light output end of the second laser generating module is toward the light input end of the processing optical path module, and the light input ends of the laser power monitoring module and the focusing objective lens are respectively toward the light output end of the processing optical path module.

[0021] Preferably, the second laser generating module is configured as a pulse laser, wherein the pulse laser has a laser pulse width of 200 fs to 10 ns, a laser wavelength of 400 to 1100 nm, and a laser energy of 0.01 to 1500 mJ.

[0022] Preferably, the laser power monitoring module is set as a high-precision optical power meter. The high-precision optical power meter can monitor the laser power in the laser processing process in real time to ensure the stability and accuracy of the laser power; through real-time monitoring of the laser power, abnormal fluctuations in the laser power can be discovered in time, thereby avoiding quality problems in the laser processing process; in addition, the high-precision optical power meter also has the characteristics of high sensitivity and high resolution, and can accurately measure small changes in laser power, providing strong support for the precise control of laser processing.

[0023] Preferably, the processing optical path module includes a fourth dichroic mirror and a fifth dichroic mirror, the fourth dichroic mirror (projection end of the laser processing unit) is arranged between the focusing objective lens and the first dichroic mirror, the fifth dichroic mirror is arranged between the second laser generating module and the fourth dichroic mirror, and the laser power monitoring module is arranged on the beam splitting path on the side of the fifth dichroic mirror away from the fourth dichroic mirror.

[0024] Furthermore, the control unit includes a data processing module and a control module, and the data processing module and the control module are communicatively connected; The XY axis driver, the first laser generating module, the Raman detection module and the image acquisition module respectively establish communication connections with the control module, and the data processing module associates the Raman characteristic peak frequency, image information and the corresponding XY coordinate position of the focus point to complete the construction of the doping concentration distribution map of the surface layer of the workpiece and the power distribution map of the modified layer of the workpiece in sequence; The Z-axis driver and the focus search module respectively establish communication connections with the control module, and the data processing module associates the Z-axis coordinate position of the focusing lens and the corresponding XY coordinate position of the focus point to complete the construction of the morphology distribution map of the surface layer of the workpiece; The XY axis driver, Z axis driver, second laser generating module and laser power monitoring module respectively establish communication connections with the control module, so that the workpiece and the focal point on the workpiece carrier can move relative to each other approximately in the XY direction and form a modified layer on the workpiece.

[0025] Specifically, the control process of the laser processing device is: S1 establishes a communication connection between the data processing module and the control module, and configures an XY axis driver and a Z axis driver in the control module; S2 provides a workpiece on the workpiece carrier, and the control module sends detection instructions to the XY axis driver and the first laser generating module in turn. The workpiece carrier moves to the position according to the predetermined Raman detection scanning path, and the first laser beam passing through the focusing objective lens is focused on the surface layer of the workpiece. The Raman detection module obtains the Raman characteristic peak frequency ω at different focusing points on the surface layer of the workpiece iThe image acquisition module obtains the inspection image of the workpiece, and the XY axis linear module feedbacks the XY coordinate position of the focus point (X i , Y j ), the data processing module determines the doping concentration n based on the Δω-n linear model ij , and these doping concentrations n ij , the detection image, and the corresponding XY coordinate position to construct the doping concentration distribution map of the workpiece surface layer (X i , Y j , n ij ); Among them, the fitting function of the Δω-n linear model is n=1.27×10 17 Δω (R=99%), the specific implementation method is to provide multiple silicon carbide standards with different doping concentrations n on the workpiece carrier, and the Raman detection module obtains the Raman characteristic peak frequency ω of these standards n The data processing module uses the Raman characteristic peak frequency ω of one of the standard samples n The difference is calculated as the reference, and the relative Raman frequency shift Δω is determined, and then a Δω-n linear model of the relative Raman frequency shift Δω and the doping concentration n is established based on the least square method; The data processing module determines the laser processing power P at different focal points on the surface layer of the workpiece based on the doping concentration distribution diagram and the nP curve model between the preset doping concentration n and the laser processing power P. ij , and these laser processing powers P ij , the detection image, and the corresponding XY coordinate position to construct the power distribution diagram of the workpiece modified layer (X i , Y j , P ij ); where the fitting function of the nP curve model is P=0.57e [n / (1.18×10^18)] (R=99%); At the same time, the control module sends a focus command to the Z-axis driver and the focus module in turn. The Z-axis linear module feeds back the actual height of the focusing lens. The focus module obtains the focal range of the surface layer of the workpiece. The data processing module parses and generates focal displacement information. The control module sends a focus command again. The focus lens moves to the position according to the predetermined focal displacement. The Z-axis linear module feeds back the Z-axis coordinate position (Z ij ), the data processing module associates these focused Z-axis coordinate positions with the corresponding XY coordinate positions to construct a morphology distribution map of the workpiece surface layer (X i , Y j , Z ij ); The S3 control module sends processing instructions to the XY axis driver, Z axis driver and the second laser generation module (X i , Yj , n ij , P ij ), controls the focal point coordinate position, feed speed, feed direction and laser processing power, the workpiece carrier moves into position according to the predetermined laser processing scanning path, and the focusing lens moves into position according to the predetermined focal range displacement, so that the second laser beam passing through the focusing objective lens is focused on the predetermined depth d of the workpiece for internal modification, so as to complete the movement of the focal point approximately along the XY projection plane and perform laser modification on different areas of the modified layer of the workpiece.

[0026] Furthermore, it also includes a resistivity probe, which is installed at the mobile end of the mobile unit in a manner that the detection point faces the workpiece carrier, and the resistivity probe establishes a communication connection with the control unit to complete the resistivity detection of the workpiece surface layer on the workpiece carrier.

[0027] Furthermore, the resistivity probe is a contact resistivity probe, and the detection range of the resistivity probe is 0.1~100mΩ·cm, and the measurement accuracy is ≤0.5mΩ·cm.

[0028] Furthermore, the resistivity probe and the focusing lens are installed together or independently at the moving end of the Z-axis linear module. The resistivity probe and the focusing lens can be directly installed at the moving end of the Z-axis linear module to achieve common control of the moving path, or they can be installed at the moving end of the Z-axis linear module through a common transmission pair to achieve separate control of the moving path.

[0029] Furthermore, the XY-axis driver, Z-axis driver and resistivity probe respectively establish communication connections with the control module so that the detection end of the resistivity probe contacts the workpiece surface of the workpiece carrier and performs resistivity detection on different areas of the workpiece surface layer.

[0030] Alternatively, the resistivity probe is a non-contact resistivity probe, and the detection range of the resistivity probe is 0.1-100 mΩ·cm, and the measurement accuracy is ≤0.5 mΩ·cm.

[0031] Furthermore, the XY axis driver and the resistivity probe respectively establish communication connections with the control module, so that the detection end of the resistivity probe passes through the outside of the workpiece of the workpiece carrier and performs resistivity detection on different areas of the workpiece surface layer.

[0032] Specifically, the control process of the laser processing device is: S1 establishes a communication connection between the data processing module and the control module, and configures an XY axis driver and a Z axis driver in the control module; S2 provides a workpiece on the workpiece carrier, and the control module sends a focus command to the Z-axis driver and the focus module in turn. The Z-axis linear module feeds back the actual height of the focusing lens, and the focus module obtains the focal range of the workpiece surface layer. The data processing module parses and generates the focal displacement information. The control module sends a focus command again, and the focus lens moves to the position according to the predetermined focal displacement. The Z-axis linear module feeds back the Z-axis coordinate position (Z ij ), the data processing module associates these focused Z-axis coordinate positions with the corresponding XY coordinate positions to construct a morphology distribution map of the workpiece surface layer (X i , Y j , Z ij ); S3 provides a workpiece on the workpiece carrier, and the control module sequentially initiates resistivity detection instructions to the XY axis driver, or the XY axis driver and the Z axis driver. The workpiece carrier moves to the position according to the predetermined resistivity detection scanning path, and the resistivity probe selectively moves to the position according to the morphology distribution map obtained in S2. The detection point of the resistivity probe obtains the resistivity ρ of different detection areas on the surface layer of the workpiece. k The data processing module converts the resistivity ρ of different detection areas into k Compared with the resistivity threshold, if the resistivity ρ k Exceeding the resistivity threshold, and then preliminarily screening out the resistivity abnormal area; The S4 control module sends detection instructions to the XY axis driver and the first laser generating module in turn. The workpiece carrier moves to the position according to the predetermined Raman detection scanning path, and the first laser beam passing through the focusing objective lens is focused on the surface layer of the workpiece. The Raman detection module obtains the Raman characteristic peak frequency ω at different focusing points on the surface layer of the workpiece. i The image acquisition module obtains the inspection image of the workpiece, and the XY axis linear module feedbacks the XY coordinate position of the focus point (X i , Y j ); S5 combines the detection data of S3 and S4. The data processing module is based on the preset n-ρ inverse proportional function model of doping concentration n and resistivity ρ (ρ=437.7 / n, R=99%), and the Δω-n linear model of Raman frequency shift Δω and doping concentration n (n=1.27×10 17 Δω, R=99%), determine the doping concentration n ij , and these doping concentrations n ij , the detection image, and the corresponding XY coordinate position to construct the doping concentration distribution map of the workpiece surface layer (X i , Y j , n ij ) The S5 data processing module determines the laser processing power P at different focal points on the surface layer of the workpiece based on the doping concentration distribution diagram and the nP curve model between the preset doping concentration n and the laser processing power P. ij , and these laser processing powers P ij , the detection image, and the corresponding XY coordinate position to construct the power distribution diagram of the workpiece modified layer (X i , Y j , P ij ); where the fitting function of the nP curve model is P=0.57e [n / (1.18×10^18)] (R=99%); The S3 control module sends processing instructions to the XY axis driver, Z axis driver and the second laser generation module (X i , Y j , n ij , P ij ), controls the focal point coordinate position, feed speed, feed direction and laser processing power, the workpiece carrier moves into position according to the predetermined laser processing scanning path, and the focusing lens moves into position according to the predetermined focal area displacement (obtained by the topography distribution diagram), so that the second laser beam passing through the focusing objective lens is focused on the predetermined depth d of the workpiece for internal modification, so as to complete the movement of the focal point approximately along the XY projection plane and perform laser modification on different areas of the modified layer of the workpiece.

[0033] In summary, the beneficial technical effects of the present invention are: 1. The present invention integrates processing structures such as a workpiece carrier, a focusing objective lens, a moving unit and a laser processing unit, and detection structures such as a Raman information acquisition unit and a focusing height acquisition unit into an optical path system, thereby avoiding the back and forth transmission of the crystal ingot in the two links of detection and processing, thereby saving equipment space, reducing costs and improving production efficiency; 2. The Raman information acquisition unit of the present invention uses a low-power laser with a photon energy far lower than the band gap energy of silicon carbide to generate Raman signals, and establishes a relationship model between doping concentration (carrier concentration) and Raman characteristic peak frequency offset (Raman frequency shift). The doping concentration value of the ingot can be determined by detecting the Raman frequency shift, avoiding the interference of laser scattered light and fluorescence signals on the Raman characteristic peak, and realizing non-destructive and accurate measurement; 3. The Raman information acquisition unit of the present invention cuts off the laser through the filter group, highly transmits the Raman spectrum band carrying the doping concentration information, improves the signal-to-noise ratio, and uses a convex lens to converge the Raman signal. The Raman characteristic peak frequency is finally obtained, and then the parameters of the processing laser can be synchronously optimized according to the doping concentration at the ingot detection point, avoiding the phenomenon of inconsistent depth and completion of the ingot modified layer caused by uneven doping concentration, improving the wafer stripping quality, and reducing material loss; 4. The focus height acquisition unit of the present invention emits reference light to the upper surface of the workpiece, and controls the Z-axis feed through the returned reference light, so that the final focus point is located on the surface layer of the workpiece, thereby effectively limiting the depth of the Raman signal to the surface of the ingot, improving the signal-to-noise ratio of the Raman characteristic peak, and being able to more accurately obtain the spatial information of the surface layer of the workpiece, thereby improving the detection accuracy; 5. The present invention also utilizes the three-dimensional coordinate position of the detection point to construct the morphological information of the ingot surface, so as to adjust the processing depth in real time according to the morphological fluctuations of the ingot surface layer during laser processing, that is, the Z-axis coordinate position of the focusing lens of the processing laser beam, so that the workpiece and the focusing point move relative to each other approximately in the XY direction, and finally achieve the consistency of the processing depth of the ingot modified layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the structure of the laser processing device of Example 1 of the present invention.

[0035] Figure 2 It is a schematic diagram of the connection relationship between the workpiece carrier, focusing objective lens, moving unit and control unit of Example 2 of the present invention.

[0036] Figure 3 It is a schematic diagram of the connection relationship between the workpiece carrier, focusing objective lens, XY axis driver, XY axis linear module, Raman information acquisition unit and control unit of Example 4 of the present invention.

[0037] Figure 4 It is a schematic diagram of the connection relationship between the workpiece carrier, focusing objective lens, Z-axis driver, Z-axis linear module, focusing height acquisition unit and control unit of Example 5 of the present invention.

[0038] Figure 5 It is a schematic diagram of the connection relationship between the workpiece carrier, focusing objective lens, moving unit, laser processing unit and control unit of Example 6 of the present invention.

[0039] Figure 6 It is a schematic diagram of the structure of the laser processing device of Example 9 of the present invention.

[0040] In the figure, 1. workpiece carrier; 2. focusing objective lens; 3. moving unit; 31. XY axis linear module; 32. XY axis driver; 33. Z axis linear module; 34. Z axis driver; 4. Raman information acquisition unit; 41. first laser generating module; 42. Raman detection module; 43. image acquisition module; 44. first dichroic mirror; 45. second dichroic mirror; 46. reflecting mirror; 47. filter group; 48. convex lens; 5. focusing height acquisition unit; 51. focus search module; 52. third dichroic mirror; 6. laser processing unit; 61. second laser generating module; 62. laser power monitoring module; 63. fourth dichroic mirror; 64. fifth dichroic mirror; 7. control unit; 71. data processing module; 72. control module; 8. resistivity probe. DETAILED DESCRIPTION

[0041] In order to make the technical means, creative features, objectives and functions achieved by the present invention clearer and easier to understand, the present invention is further explained below in conjunction with the accompanying drawings and specific implementation methods.

[0042] Example 1: Reference Figure 1 , is a laser processing device for SiC ingot disclosed in the present invention, comprising a workpiece carrier 1, a focusing lens 2, a moving unit 3, a Raman information acquisition unit 4, a focus height acquisition unit 5, a laser processing unit 6, and a control unit 7. The workpiece carrier 1 and the focusing lens 2 are respectively arranged at the moving end of the moving unit 3, and the moving path of the focusing lens 2 passes through the projection light paths of the Raman information acquisition unit 4, the focus height acquisition unit 5 and the laser processing unit 6. The moving unit 3, the Raman information acquisition unit 4, the focus height acquisition unit 5 and the laser processing unit 6 respectively establish communication connections with the control unit 7 to complete the focusing of the projection light passing through the focusing lens 2 on the workpiece surface layer and the modified layer on the workpiece carrier 1.

[0043] Example 2: Reference Figure 2 , is a laser processing device for SiC ingot disclosed in the present invention, which is different from Example 1 in that the moving unit 3 includes an XY axis driver 32, an XY axis linear module 31, a Z axis driver 34 and a Z axis linear module 33. Among them, the control unit 7, the XY axis driver 32 and the XY axis linear module 31 establish communication connections in sequence, the workpiece carrier 1 is set at the moving end of the XY axis linear module 31, the control unit 7, the Z axis driver 34 and the Z axis linear module 33 establish communication connections in sequence, and the focusing objective lens 2 is set at the moving end of the Z axis linear module 33.

[0044] The XY axis linear module 31 and the Z axis linear module 33 respectively use linear motor type linear modules. The linear motor is the core component of the mobile unit 3, which can convert electrical energy into mechanical energy, generate power and linear motion. Its working principle can be briefly summarized as follows: the user inputs instructions to the control unit 7 through the human-machine interface or other input devices, such as setting the motor's feed speed, direction and other parameters; the control unit 7 receives the input signal, and calculates according to the preset algorithm, control strategy and feedback signal to generate a control signal; the control module 72 of the control unit 7 reads the feedback signal of the motor, which is usually obtained through a sensor, such as using an encoder to feedback the motor's feed speed and position information; the controller sends the calculated control signal to the driver; the driver receives the control signal The control signal is converted into voltage or current according to the characteristics of the signal, and a voltage or current signal suitable for the motor operation of the linear module is output; the drive signal flows through the motor winding, generates an electromagnetic field, drives the motor to rotate, the voltage signal controls the speed and direction of the DC motor, and the current signal controls the frequency and phase of the AC motor; the controller continuously monitors the state and environmental conditions of the motor, such as current, temperature, etc., and compares them with the preset protection parameters. If the set range is exceeded, the protection device is triggered to prevent the motor from being damaged by overload, overheating, short circuit, etc.; by continuously looping the above steps, the control unit 7 can stably control the feed speed, direction and position information of the linear module through the driver, realize the user's expected action, and obtain the coordinate position of the moving part.

[0045] Example 3: Reference Figure 1 , is a laser processing device for SiC ingot disclosed in the present invention, which is different from Example 2 in that the projection end of the Raman information acquisition unit 4, the projection end of the focusing height acquisition unit 5, the projection end of the laser processing unit 6, and the focusing objective lens 2 are arranged sequentially along the moving direction of the Z-axis linear module 33.

[0046] Example 4: Reference Figure 3 , is a SiC ingot laser processing device disclosed in the present invention, which is different from Example 3 in that the Raman information acquisition unit 4 includes a first laser generating module 41, a Raman detection module 42, an image acquisition module 43, and a detection optical path module. Among them, the light output end of the first laser generating module 41 is toward the light input end of the detection optical path module, the detection ends of the Raman detection module 42 and the image acquisition module 43 are respectively toward the light output end of the detection optical path module, and the projection optical path of the detection optical path module passes through the focusing objective lens 2.

[0047] Specifically, the first laser generating module 41 is configured as a continuous laser; the Raman detecting module 42 is configured as a high-resolution Raman spectrometer; the image acquiring module 43 is configured as a CCD camera with an illumination light source; the detecting optical path module comprises a first dichroic mirror 44, a second dichroic mirror 45, a reflecting mirror 46, a filter group 47, and a convex lens 48, the first dichroic mirror 44 is arranged between the focusing objective lens 2 and the image acquiring module 43, the second dichroic mirror 45 is arranged between the first laser generating module 41 and the first dichroic mirror 44, the reflecting mirror 46, the filter group 47, the convex lens 48 and the Raman detecting module 42 are sequentially arranged on the beam splitting path of the second dichroic mirror 45 on the side away from the first laser generating module 41.

[0048] During the facet detection process, the detection optical path module forms two projection optical paths through the focusing objective lens 2. After the first laser beam is emitted by the first laser generating module 41, one of the projection optical paths is first transmitted by the second dichroic mirror 45, reflected by the first dichroic mirror 44, and then focused on the surface layer of the workpiece by the focusing objective lens 2 to form a detection point, and the surface fluorescence of the workpiece returns to the focusing objective lens 2, and then is reflected by the first dichroic mirror 44, the second dichroic mirror 45, and the reflector 46. The filter group 47 cuts off the laser, and the convex lens 48 converges the Raman signal. Then, the Raman detection module 42 forms a Raman spectrum and obtains the final Raman characteristic peak frequency.

[0049] At the same time, another projection light path emits illumination light from the image acquisition module 43, which is first transmitted by the first dichroic mirror 44, and then focused on the surface layer of the workpiece by the focusing objective lens 2 to form an illumination area, and the workpiece surface image returns to the focusing objective lens 2, and then is transmitted by the first dichroic mirror 44, and then the image information is acquired by the image acquisition module 43 to obtain the final detection image.

[0050] Example 5: Reference Figure 4 , is a SiC ingot laser processing device disclosed in the present invention, which is different from Example 4 in that the focus height acquisition unit 5 includes a focus finding module 51 and a focus optical path module. The light emitting end and the detection end of the focus finding module 51 are respectively directed toward the focus optical path module, and the projection optical path of the focus optical path module passes through the focus objective lens 2.

[0051] Specifically, the focus finding module 51 is configured as a line laser focus sensor; the focusing optical path module includes a third dichroic mirror 52, which is arranged between the focusing objective lens 2 and the first dichroic mirror 44, and the focusing optical path module is arranged on the beam splitting path of the third dichroic mirror 52 on the side away from the first dichroic mirror 44.

[0052] During the focusing process, a line laser is first emitted by the focusing module 51, which is then reflected by the third dichroic mirror 52 and focused on the top of the workpiece by the focusing objective lens 2. The light spot on the surface of the workpiece returns to the focusing objective lens 2 and is then reflected by the third dichroic mirror 52. The focal range is then captured by the focusing module 51.

[0053] Example 6: Reference Figure 5 , is a laser processing device for SiC ingot disclosed in the present invention, which is different from Example 5 in that the laser processing unit 6 includes a second laser generating module 61, a laser power monitoring module 62, and a processing optical path module. Among them, the light output end of the second laser generating module 61 is toward the light input end of the processing optical path module, and the light input ends of the laser power monitoring module 62 and the focusing objective lens 2 are respectively toward the light output end of the processing optical path module.

[0054] Specifically, the second laser generating module 61 is configured as a pulsed laser; the laser power monitoring module 62 is configured as a high-precision optical power meter; the processing optical path module includes a fourth dichroic mirror 63 and a fifth dichroic mirror 64, the fourth dichroic mirror 63 is arranged between the focusing objective lens 2 and the third dichroic mirror 52, the fifth dichroic mirror 64 is arranged between the second laser generating module 61 and the fourth dichroic mirror 63, and the laser power monitoring module 62 is arranged on the beam splitting path of the fifth dichroic mirror 64 on the side away from the fourth dichroic mirror 63.

[0055] During the laser modification process, the second laser beam emitted by the pulsed laser is divided into a third laser beam and a fourth laser beam by the fifth dichroic mirror 64 at a ratio of 99:1. After the third laser beam is reflected by the fourth dichroic mirror 63, it is focused at a predetermined depth on the back of the workpiece through the focusing objective lens 2 to form a modified point. At the same time, the laser power monitoring module 62 receives the fourth laser beam, and monitors and feeds back the energy of the processing laser in real time.

[0056] Example 7: Reference Figure 1 , is a SiC ingot laser processing device disclosed in the present invention, which is different from Example 6 in that the control unit 7 includes a data processing module 71 and a control module 72, and the data processing module 71 and the control module 72 are communicatively connected; The XY axis driver 32, the first laser generating module 41, the Raman detection module 42 and the image acquisition module 43 respectively establish communication connections with the control module 72, and the data processing module 71 associates the Raman characteristic peak frequency, image information and the corresponding XY coordinate position of the focus point to complete the construction of the doping concentration distribution map of the surface layer of the workpiece and the power distribution map of the modified layer of the workpiece in sequence; The Z-axis driver 34 and the focus search module 51 respectively establish communication connections with the control module 72, and the data processing module 71 associates the Z-axis coordinate position of the focusing lens 2 with the corresponding XY coordinate position of the focus point to complete the construction of the morphology distribution map of the surface layer of the workpiece; The XY axis driver 32, the Z axis driver 34, the second laser generating module 61 and the laser power monitoring module 62 respectively establish communication connections with the control module 72, so that the workpiece and the focal point on the workpiece carrier 1 move relative to each other approximately in the XY direction and form a modified layer on the workpiece.

[0057] Example 8: Reference Figures 2~5 , is a SiC ingot laser processing device disclosed in the present invention, which is different from Example 7 in that the control process of the laser processing device is: S1 establishes a communication connection between the data processing module 71 and the control module 72, and configures the XY axis driver 32 and the Z axis driver 34 in the control module 72; S2 provides a workpiece on the workpiece carrier 1, and the control module 72 sends detection instructions to the XY axis driver 32 and the first laser generating module 41 in turn. The workpiece carrier 1 moves to the position according to the predetermined Raman detection scanning path, and the first laser beam passing through the focusing lens 2 is focused on the surface layer of the workpiece. The Raman detection module 42 obtains the Raman characteristic peak frequency ωi of different focal points on the surface layer of the workpiece, and the image acquisition module 43 obtains the detection image of the workpiece. The XY axis linear module 31 feeds back the XY coordinate position (X i , Y j ), the data processing module 71 determines the doping concentration n based on the Δω-n linear model ij , and these doping concentrations n ij , the detection image, and the corresponding XY coordinate position to construct the doping concentration distribution map of the workpiece surface layer (X i , Y j , n ij ); Among them, the fitting function of the Δω-n linear model is n=1.27×10 17 Δω (R=99%), specifically implemented as follows: a plurality of silicon carbide standard products with different doping concentrations n are provided on the workpiece carrier 1, the Raman detection module 42 obtains the Raman characteristic peak frequencies ωn of these standard products, the data processing module 71 performs difference calculation based on the Raman characteristic peak frequency ωn of one of the standard products, and determines the relative Raman frequency shift Δω, and then establishes a Δω-n linear model of the relative Raman frequency shift Δω and the doping concentration n based on the least squares method; The data processing module 71 determines the laser processing power P at different focus points on the surface layer of the workpiece based on the doping concentration distribution diagram and the nP curve model between the preset doping concentration n and the laser processing power P.ij , and these laser processing powers P ij , the detection image, and the corresponding XY coordinate position to construct the power distribution diagram of the workpiece modified layer (X i , Y j , P ij ); where the fitting function of the nP curve model is P=0.57e [n / (1.18×10^18)] (R=99%); At the same time, the control module 72 sends a focus command to the Z-axis driver 34 and the focus module 51 in turn, the Z-axis linear module 33 feeds back the actual height of the focusing lens 2, the focus module 51 obtains the focal range of the surface layer of the workpiece, the data processing module 71 parses and generates the focal displacement information, the control module 72 sends a focus command again, the focus lens moves to the position according to the predetermined focal displacement, and the Z-axis linear module 33 feeds back the Z-axis coordinate position (Z ij ), the data processing module 71 associates these focused Z-axis coordinate positions with the corresponding XY coordinate positions to construct a morphology distribution map (XY) of the surface layer of the workpiece i , Y j , Z ij ); S3 The control module 72 sends a processing instruction to the XY axis driver 32, the Z axis driver 34 and the second laser generating module 61 (X i , Y j , n ij , P ij ), controls the focal point coordinate position, feed speed, feed direction and laser processing power, the workpiece carrier 1 moves into position according to the predetermined laser processing scanning path, and the focusing lens moves into position according to the predetermined focal range displacement, so that the second laser beam passing through the focusing objective lens 2 is focused on the predetermined depth d of the workpiece for internal modification, so as to complete the movement of the focal point approximately along the XY projection plane and perform laser modification on different areas of the modified layer of the workpiece.

[0058] Example 9: Reference Figure 6 , is a laser processing device for SiC ingot disclosed in the present invention. It is different from Example 7 in that it also includes a resistivity probe 8. The resistivity probe 8 is installed on the moving end of the moving unit 3 in a manner that the detection point faces the workpiece carrier 1, and the resistivity probe 8 establishes a communication connection with the control unit 7 to complete the resistivity detection of the workpiece surface layer on the workpiece carrier 1.

[0059] If the resistivity probe 8 is a contact resistivity probe 8, and the detection range of the resistivity probe 8 is 0.1-100 mΩ·cm, and the measurement accuracy is ≤0.5 mΩ·cm, the resistivity probe 8 and the focusing lens 2 are independently mounted on the moving end of the Z-axis linear module 33 (not shown in the figure). At the same time, the XY-axis driver 32, the Z-axis driver 34 and the resistivity probe 8 are respectively connected to the control module 72 to make the detection end of the resistivity probe 8 contact the workpiece surface of the workpiece carrier 1, and perform resistivity detection on different areas of the workpiece surface layer.

[0060] If the resistivity probe 8 is a non-contact resistivity probe 8, and the detection range of the resistivity probe 8 is 0.1-100 mΩ·cm, the measurement accuracy is ≤0.5 mΩ·cm. At the same time, the XY axis driver 32 and the resistivity probe 8 are respectively connected to the control module 72 to allow the detection end of the resistivity probe 8 to pass through the outside of the workpiece of the workpiece carrier 1 and perform resistivity detection on different areas of the surface layer of the workpiece.

[0061] Specifically, if the resistivity probe 8 is a contact resistivity probe 8, the control process of the laser processing device is as follows: S1 establishes a communication connection between the data processing module 71 and the control module 72, and configures the XY axis driver 32 and the Z axis driver 34 in the control module 72; S2 provides a workpiece on the workpiece carrier 1, and the control module 72 sends a focus command to the Z-axis driver 34 and the focus module 51 in turn. The Z-axis linear module 33 feeds back the actual height of the focusing lens 2, and the focus module 51 obtains the focal range of the surface layer of the workpiece. The data processing module 71 parses and generates focal displacement information. The control module 72 sends a focus command again, and the focus lens moves to the position according to the predetermined focal displacement. The Z-axis linear module 33 feeds back the Z-axis coordinate position (Z ij ), the data processing module 71 associates these focused Z-axis coordinate positions with the corresponding XY coordinate positions to construct a morphology distribution map (XY) of the surface layer of the workpiece i , Y j , Z ij ); S3 provides a workpiece on the workpiece carrier 1, and the control module 72 sequentially initiates resistivity detection instructions to the XY axis driver 32, or the XY axis driver 32 and the Z axis driver 34, and the workpiece carrier 1 moves to a position according to a predetermined resistivity detection scanning path, and the resistivity probe 8 selectively moves to a position according to the morphology distribution map obtained in S2, and the detection point of the resistivity probe 8 obtains the resistivity ρ of different detection areas on the surface layer of the workpiece k The data processing module 71 converts the resistivity ρ of different detection areas into k Compared with the resistivity threshold, if the resistivity ρ kExceeding the resistivity threshold, and then preliminarily screening out the resistivity abnormal area; S4 The control module 72 sends detection instructions to the XY axis driver 32 and the first laser generating module 41 in turn. The workpiece carrier 1 moves to the position according to the predetermined Raman detection scanning path, and the first laser beam passing through the focusing lens 2 is focused on the surface layer of the workpiece. The Raman detection module 42 obtains the Raman characteristic peak frequency ω at different focusing points on the surface layer of the workpiece. i The image acquisition module 43 obtains the detection image of the workpiece, and the XY axis linear module 31 feeds back the XY coordinate position (X i , Y j ); S5 combines the detection data of S3 and S4, and the data processing module 71 is based on the preset n-ρ inverse proportional function model of the doping concentration n and the resistivity ρ (ρ=437.7 / n, R=99%), and the Δω-n linear model of the Raman frequency shift Δω and the doping concentration n (n=1.27×10 17 Δω, R=99%), determine the doping concentration n ij , and these doping concentrations n ij , the detection image, and the corresponding XY coordinate position to construct the doping concentration distribution map of the workpiece surface layer (X i , Y j , n ij ) S5 The data processing module 71 determines the laser processing power P at different focus points on the surface layer of the workpiece based on the doping concentration distribution diagram and the nP curve model between the preset doping concentration n and the laser processing power P. ij , and these laser processing powers P ij , the detection image, and the corresponding XY coordinate position to construct the power distribution diagram of the workpiece modified layer (X i , Y j , P ij ); where the fitting function of the nP curve model is P=0.57e [n / (1.18×10^18)] (R=99%); S3 The control module 72 sends a processing instruction to the XY axis driver 32, the Z axis driver 34 and the second laser generating module 61 (X i , Y j , n ij , P ij), controls the focal point coordinate position, feed speed, feed direction and laser processing power, the workpiece carrier 1 is moved into position according to the predetermined laser processing scanning path, and the focusing lens is moved into position according to the predetermined focal area displacement (obtained by the topography distribution diagram), so that the second laser beam passing through the focusing objective lens 2 is focused on the predetermined depth d of the workpiece for internal modification, so as to complete the movement of the focal point approximately along the XY projection plane and perform laser modification on different areas of the modified layer of the workpiece.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A laser processing device for SiC ingot, characterized in that: The invention comprises a workpiece carrier (1), a focusing lens (2), a moving unit (3), a Raman information acquisition unit (4), a focus height acquisition unit (5), a laser processing unit (6), and a control unit (7); the workpiece carrier (1) and the focusing lens (2) are respectively arranged at the moving end of the moving unit (3); the moving path of the focusing lens (2) passes through the projection light path of the Raman information acquisition unit (4), the focus height acquisition unit (5), and the laser processing unit (6); the moving unit (3), the Raman information acquisition unit (4), the focus height acquisition unit (5), and the laser processing unit (6) respectively establish communication connections with the control unit (7) to complete the focusing of the projection light passing through the focusing lens (2) on the workpiece surface layer and the modified layer on the workpiece carrier (1).

2. The laser processing device for SiC ingot according to claim 1, characterized in that: The mobile unit (3) comprises an XY-axis driver (32), an XY-axis linear module (31), a Z-axis driver (34) and a Z-axis linear module (33); the control unit (7), the XY-axis driver (32) and the XY-axis linear module (31) are sequentially connected to each other in communication; the workpiece carrier (1) is arranged at the mobile end of the XY-axis linear module (31); the control unit (7), the Z-axis driver (34) and the Z-axis linear module (33) are sequentially connected to each other in communication; and the focusing lens (2) is arranged at the mobile end of the Z-axis linear module (33).

3. The laser processing device for SiC ingot according to claim 2, characterized in that: The projection end of the Raman information acquisition unit (4), the projection end of the focus height acquisition unit (5), the projection end of the laser processing unit (6), and the focusing objective lens (2) are sequentially arranged along the moving direction of the Z-axis linear module (33).

4. The laser processing device for SiC ingot according to claim 3, characterized in that: The Raman information acquisition unit (4) comprises a first laser generating module (41), a Raman detection module (42), and a detection light path module, wherein the light output end of the first laser generating module (41) faces the light input end of the detection light path module, the detection end of the Raman detection module (42) faces the light output end of the detection light path module, and the projection light path of the detection light path module passes through the focusing objective lens (2).

5. The laser processing device for SiC ingot according to claim 4, characterized in that: The Raman information acquisition unit (4) further comprises an image acquisition module (43), wherein the detection end of the image acquisition module (43) faces the light output end of the detection light path module.

6. The laser processing device for SiC ingot according to claim 4, characterized in that: The focus height acquisition unit (5) comprises a focus finding module (51) and a focus light path module, wherein a light emitting end and a detection end of the focus finding module (51) are respectively directed toward the focus light path module, and a projection light path of the focus light path module passes through the focus objective lens (2).

7. The laser processing device for SiC ingot according to claim 6, characterized in that: The laser processing unit (6) comprises a second laser generating module (61) and a processing light path module, wherein the light output end of the second laser generating module (61) faces the light input end of the processing light path module, and the light input end of the focusing objective lens (2) faces the light output end of the processing light path module.

8. The laser processing device for SiC ingot according to claim 7, characterized in that: The laser processing unit (6) further comprises a laser power monitoring module (62), wherein the light input end of the laser power monitoring module (62) faces the light output end of the processing optical path module.

9. The laser processing device for SiC ingot according to claim 8, characterized in that: The control unit (7) comprises a data processing module (71) and a control module (72), and the data processing module (71) and the control module (72) are communicatively connected; The XY axis driver (32), the first laser generating module (41), the Raman detection module (42) and the image acquisition module (43) respectively establish communication connections with the control module (72), and the data processing module (71) associates the Raman characteristic peak frequency, image information and corresponding XY coordinate position of the focus point to complete the construction of the doping concentration distribution map of the workpiece surface layer and the power distribution map of the workpiece modified layer in sequence; The Z-axis driver (34) and the focus search module (51) are respectively connected to the control module (72) in communication, and the data processing module (71) associates the Z-axis coordinate position of the focusing lens (2) and the corresponding XY coordinate position of the focus point to complete the construction of the topography distribution map of the surface layer of the workpiece; The XY axis driver (32), the Z axis driver (34), the second laser generating module (61) and the laser power monitoring module (62) are respectively connected to the control module (72) so that the workpiece and the focal point on the workpiece carrier (1) can move relative to each other approximately in the XY direction and form a modified layer on the workpiece.

10. The laser processing device for SiC ingot according to claim 1, characterized in that: It also includes a resistivity probe (8), which is installed at the moving end of the moving unit (3) in a manner such that the detection point faces the workpiece carrier (1), and the resistivity probe (8) establishes a communication connection with the control unit (7) to complete the resistivity detection of the workpiece surface layer on the workpiece carrier (1).

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