An apparatus for preparing silicon carbide release sheets by laser-induced cracking.

Abstract

This invention provides an apparatus for preparing silicon carbide release sheets using laser-induced cracking, belonging to the field of laser processing technology. The apparatus includes: a crystal plane detection unit, an angle determination unit, an angle adjustment unit, a laser scanning unit, an external force application unit, and a fixing unit for fixing and supporting the silicon carbide ingot. The laser scanning unit includes a first laser head capable of generating a first laser beam and is configured to receive the first signal and activate the first laser head to scan the silicon carbide ingot, forming a release surface containing multiple cracks extending along a first plane. The external force application unit is configured to apply vibration to the release surface to obtain the silicon carbide release sheet. The apparatus for preparing silicon carbide release sheets using laser-induced cracking provided by this invention can reduce processing stress in silicon carbide wafers, reduce epitaxial surface shape changes, achieve automated processing, and improve processing efficiency.

Description

Technical Field

[0001] This invention belongs to the field of laser processing technology, specifically relating to an apparatus for preparing silicon carbide release sheets, and more particularly to an apparatus for preparing silicon carbide release sheets by laser cracking. Background Technology

[0002] As industries develop, the performance requirements for components are becoming increasingly demanding, gradually approaching the physical limits of silicon materials. Due to its superior physical properties, silicon carbide substrates offer unparalleled advantages over silicon materials in high-voltage, high-frequency, and high-temperature applications. Currently, they are widely used in power electronics, microwave radio frequency devices, and high-end lighting.

[0003] Silicon carbide crystals have a Mohs hardness of 9.2, second only to diamond. They are extremely stable in physicochemical properties and are typical hard and brittle materials, making ultra-precision machining a persistent challenge for the industry. Current technologies employ mechanical cutting methods, primarily using slurry multi-wire cutting and diamond wire multi-wire cutting. While these two methods differ in the way the abrasive participates in the machining process—one using free abrasive cutting and the other using bonded abrasive machining—they are essentially the same: both are physical contact cutting methods.

[0004] However, both cutting methods also have some problems: (1) In terms of quality: as the size increases, the longitudinal cutting contact area becomes larger and larger, and the cutting force per unit area provided by the abrasive decreases, which will generate large deformation stress during the processing. Processing stress will lead to cracking in subsequent processing, as well as problems with excessive curvature and warping; (2) In terms of efficiency, slurry cutting takes a long time, and diamond wire cutting is short in length, both of which have the problem of low overall cutting efficiency; (3) In terms of automation, multi-wire cutting is a batch processing method, which is difficult to automate.

[0005] Invention patent CN112296540A, "A Silicon Carbide Crystal Laser Slicing Device and Method," discloses a silicon carbide crystal laser slicing device and method, comprising a laser cutting mechanism and a thermal separation mechanism. This invention first uses a cutting light source to reconstruct the crystal structure of the cutting surface, transforming a single-crystal state into an amorphous state. Then, it uses vertical and side radiation light sources to laser-heat the silicon carbide crystal. Due to the previous crystal state change, thermal stress is generated on the cutting surface, ultimately causing thermal cracking and separation of the surface into sheet-like wafers. Although the laser thermal cracking separation of the sheet-like wafers increases the process requirements, the overall efficiency is increased, reducing processing time by more than 40%. Simultaneously, the cutting area formed near the laser focus is smaller than that of mechanical wire cutting, saving at least 50% of material. However, this invention consumes a large amount of energy during the peeling process and is prone to generating processing stress, which can lead to cracking during subsequent processing, as well as excessive bending and warping. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an apparatus for preparing silicon carbide release sheets by laser cracking, which can improve the quality of silicon carbide wafers and achieve automated processing. The apparatus is reasonably designed, easy to operate, and improves processing efficiency.

[0007] This invention provides an apparatus for preparing silicon carbide lifters using laser-induced cracking. The apparatus includes: a crystal plane detection unit, an angle determination unit, an angle adjustment unit, a laser scanning unit, an external force application unit, and a fixing unit for fixing and supporting the silicon carbide ingot.

[0008] The crystal plane detection unit is configured above the position to be peeled off of the silicon carbide ingot and is able to detect the (0001) crystal plane of the silicon carbide ingot to obtain crystal plane position information.

[0009] The included angle determination unit is configured to receive the crystal plane position information, calculate the included angle value between the crystal plane position information and the first plane, and determine whether the included angle value meets the requirements of the preset included angle value. If it meets the requirements, the first signal is output; if it does not meet the requirements, the second signal is output. The first plane and the first direction where the first laser beam is located are always perpendicular.

[0010] The angle adjustment unit includes an ingot angle adjustment mechanism capable of adjusting the angle of a silicon carbide ingot and / or a first laser beam angle adjustment mechanism capable of adjusting the angle of a first direction, and is configured to receive a second signal and activate the ingot angle adjustment mechanism and / or the first laser beam angle adjustment mechanism.

[0011] The laser scanning unit includes a first laser head capable of generating the first laser beam, and is configured to receive the first signal and start the first laser head to scan the silicon carbide ingot to form a peelable surface containing multiple cracks that extend along the first plane.

[0012] The external force application unit is configured to apply vibration to the surface to be peeled to obtain a silicon carbide release sheet.

[0013] In an exemplary embodiment of the present invention, the laser scanning unit further includes a second laser head capable of generating a second laser beam, the second laser head being configured to scan the silicon carbide ingot around its circumference with the second laser beam. The angle adjustment unit further includes a second laser beam angle adjustment mechanism capable of adjusting the second direction in which the second laser beam is located, and is configured to receive a second signal and activate the second laser beam angle adjustment mechanism, such that the second direction is always within the first plane.

[0014] In another exemplary embodiment of the present invention, the laser stripping apparatus further includes a grinding unit configured to grind the stripping area left on the silicon carbide ingot along the first plane.

[0015] Another aspect of the present invention provides a method for preparing silicon carbide release sheets by laser cracking, wherein the thickness of the silicon carbide release sheet is controlled to be 100-1000 μm.

[0016] Due to the adoption of the above technical solution, the beneficial effects of the present invention include at least one of the following:

[0017] 1. Laser lift-off by the laser scanning unit can reduce the processing stress of silicon carbide wafers and reduce the change in epitaxial profile (<10um);

[0018] 2. By cooperating with the laser scanning unit and the external force application unit, the number of wafers produced per unit length of silicon carbide rod can be increased (>30%).

[0019] 3. By applying external force to the unit, crack propagation is used instead of grinding, achieving zero loss of crystalline materials;

[0020] 4. The apparatus for preparing silicon carbide strips by laser cracking provided by the present invention can realize automated processing and improve processing efficiency. Attached Figure Description

[0021] Figure 1 A schematic diagram of the overall structure of an exemplary embodiment of the apparatus for preparing silicon carbide strips by laser cracking according to the present invention is shown;

[0022] The annotations in the attached figures are explained as follows:

[0023] 11-Directional indicator signal transmitter, 12-Directional indicator signal receiver;

[0024] 211-First adjusting component, 2111-First adjusting knob, 212-Second adjusting component, 2121-Second adjusting knob;

[0025] 31 - Laser head; 32 - Focusing lens;

[0026] 41-Vacuum suction cup. Detailed Implementation

[0027] To more clearly illustrate the overall concept of the present invention, a detailed description will be provided below with reference to the accompanying drawings and examples.

[0028] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0029] Furthermore, in the description of this invention, it should be understood that the terms "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and 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 this invention.

[0030] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] In this invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, mechanism, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, mechanisms, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0032] Example 1

[0033] In an exemplary embodiment of the present invention, the apparatus for preparing silicon carbide lifters by laser cracking comprises a crystal plane detection unit, an angle determination unit, an angle adjustment unit, a laser scanning unit, an external force application unit, and a fixing unit.

[0034] The crystal plane detection unit is positioned above the location to be stripped from the silicon carbide ingot and is capable of detecting the (0001) crystal plane of the silicon carbide ingot to obtain crystal plane position information.

[0035] Specifically, the crystal plane detection unit includes orientation components, such as an orientation instrument, which can use the Bragg diffraction principle to detect crystal plane information and then transmit the detected information to the angle determination unit.

[0036] The angle determination unit is configured to receive crystal plane position information, calculate the angle between the crystal plane position information and the first plane, and determine whether the angle meets the requirements of the preset angle value. If it does, the first signal is output; if it does not, the second signal is output. The first plane and the first direction where the first laser beam is located are always perpendicular.

[0037] Specifically, the first plane is the plane of the silicon carbide ingot that is perpendicular to the first laser beam. The first direction is the direction of irradiation by the first laser beam. The included angle is the angle between the (0001) crystal plane of the silicon carbide ingot and the first plane of the silicon carbide ingot. The preset included angle is a predetermined value selected within the range of 0 to 10°, and further, the preset included angle is a predetermined value selected within the range of 0.5 to 3.5° or 4.5 to 7°. The first signal and the second signal are electrical signals or wireless signals; however, the present invention is not limited thereto.

[0038] If the angle between the (0001) surface of the silicon carbide ingot and the first plane satisfies the preset angle value, a first signal is output to the laser scanning unit. If the angle between the (0001) surface of the silicon carbide ingot and the first plane does not satisfy the preset angle value, a second signal is output to the angle adjustment unit.

[0039] The angle adjustment unit includes an ingot angle adjustment mechanism and / or a first laser beam angle adjustment mechanism.

[0040] Specifically, the ingot angle adjustment mechanism can adjust the angle of the silicon carbide ingot, including a first adjustment component and a second adjustment component disposed below the fixed unit. The first adjustment component is configured to adjust the silicon carbide ingot along the X-axis direction, and the second adjustment component is configured to adjust the silicon carbide ingot along the Y-axis direction. The X-axis and Y-axis directions are located in the same plane and perpendicular to each other, or are located in two parallel planes and are perpendicular to each other. The first laser beam angle adjustment mechanism is configured to adjust the first direction in which the first laser beam is located.

[0041] The angle adjustment unit is configured to receive the second signal transmitted by the angle determination unit, and activate the ingot angle adjustment mechanism to adjust the angle of the silicon carbide ingot according to the received second signal, and / or activate the first laser beam angle adjustment mechanism to adjust the first direction. After adjusting the angle of the silicon carbide ingot and / or the angle of the first direction, the information is transmitted to the angle determination unit again to recalculate the angle value between the crystal surface position information and the first plane, and to determine whether the angle value meets the requirements of the preset angle value.

[0042] The laser scanning unit includes a first laser head capable of generating a first laser beam, and is configured to receive a first signal and activate the first laser head to scan a silicon carbide ingot to form a surface to be peeled off containing multiple cracks extending along a first plane. The first laser beam has an average output power of 0.8–3.5 W, a wavelength of 780–1100 nm, a scanning speed of 300–700 mm / s, a scanning spacing of 0.5–1 mm, a scanning time of 10–40 min, and 2–6 scans.

[0043] Specifically, the first laser head is divided into scanning state and non-scanning state. For example, when the first laser head is in scanning state, the distance between the first laser head and the silicon carbide ingot is 0.5 to 2 cm, and when the first laser head is in non-scanning state, the distance between the first laser head and the silicon carbide ingot is 10 to 20 cm.

[0044] The laser scanning unit also includes a focusing lens, which is used to form a focused spot of uniform size in the entire first plane, which is beneficial for the first laser beam to uniformly irradiate the surface or interior of the silicon carbide ingot.

[0045] After receiving the first signal transmitted by the included angle determination unit, the first laser head changes from a non-scanning state to a scanning state. The focal position is set according to the thickness of the peeled wafer, and the first laser beam is generated to perform a serpentine or circular scan on the silicon carbide ingot along the first plane to generate cracks that are parallel or substantially parallel to the first plane of the silicon carbide ingot.

[0046] The external force application unit is configured to apply vibration to the surface to be peeled to obtain a silicon carbide peel sheet.

[0047] Specifically, the external force application unit is an ultrasonic component capable of emitting ultrasound towards the surface to be peeled. Furthermore, the ultrasonic frequency of the ultrasonic component is 100-150 kHz, and the ultrasonic time is 10-60 seconds.

[0048] The fixing unit is configured to fix and support the silicon carbide ingot, including a clamping mechanism for fixing the silicon carbide ingot. For example, the clamping mechanism can be a vacuum chuck, which uses vacuum negative pressure to adsorb the silicon carbide ingot to achieve the purpose of clamping the workpiece. The vacuum chuck can be made of stainless steel, ceramic, or nitrile rubber; however, the present invention is not limited to these materials.

[0049] Example 2

[0050] In another exemplary embodiment of the present invention, the apparatus for preparing silicon carbide release sheets by laser cracking is based on Embodiment 1, and the laser scanning unit may further include a second laser head capable of generating a second laser beam.

[0051] If the included angle determination unit calculates and determines that the included angle value meets the preset included angle requirement, the second laser beam can be activated to scan the silicon carbide ingot around its circumference, ensuring that the second direction of the second laser beam is always within the first plane, meaning the second laser beam can completely irradiate the surface of the silicon carbide ingot for circumferential peeling. The cracking direction of the first laser beam is perpendicular to the laser incident direction, while the cracking direction of the second laser beam is along the laser incident direction. The cracking direction can be adjusted by spot shaping. This is beneficial for the peeling of the circumferential edge of the silicon carbide ingot and can further optimize the depth of the damaged layer and the depth of surface step cracks. The second laser head is configured to be able to be linked and controlled with the first laser head. The two laser heads peel the silicon carbide ingot sequentially. The first laser head generates a first laser beam to peel the area of ​​the silicon carbide ingot except for the circumferential edge, and the second laser head generates a second laser beam to peel the circumferential edge area of ​​the silicon carbide ingot. The focus of the first laser beam and the position of the second laser beam are controlled to ensure that both generate cracks in the same plane. Compared to the results of ablation using only the first laser beam, using a second laser beam can optimize the depth of the damaged layer and the depth of surface step cracks by at least 10%. The average output power of the second laser beam is 0.3 to 0.5 times that of the first laser beam, the wavelength is 780 to 1100 nm, the scanning speed is 0.3 to 0.5 times that of the first laser beam, the scanning interval is 0.1 to 0.5 mm, the scanning time is 10 to 40 min, and the number of scans is 2 to 6.

[0052] The angle adjustment unit further includes a second laser beam angle adjustment mechanism capable of adjusting the second direction in which the second laser beam is located, and is configured to receive a second signal and activate the second laser beam angle adjustment mechanism, ensuring that the second direction is always within the first plane. The angle adjustment unit receives the second signal transmitted by the angle determination unit, and activates the ingot angle adjustment mechanism to adjust the angle of the silicon carbide ingot according to the received second signal, and / or activates the first laser beam angle adjustment mechanism to adjust the first direction, while simultaneously activating the second laser beam angle adjustment mechanism to adjust the second direction. After adjusting the angle of the silicon carbide ingot and / or the angle of the first direction, and after adjusting the angle of the second direction, the information is transmitted again to the angle determination unit to recalculate the angle value between the crystal surface position information and the first plane, and to determine whether the angle value meets the requirements of the preset angle value.

[0053] Example 3

[0054] In yet another exemplary embodiment of the present invention, the apparatus for preparing silicon carbide release sheets by laser cracking may further include a grinding unit, based on the above embodiments.

[0055] Specifically, one operation mode of the device in this embodiment is as follows: the grinding unit grinds the stripping area left on the silicon carbide ingot along the first plane; the crystal surface detection unit detects the crystal surface information; the angle determination unit recalculates the angle between the crystal surface position information and the first plane, and determines whether the angle meets the requirements of the preset angle value. If it does, the first laser head is activated to generate a first laser beam to scan the silicon carbide ingot again to form another stripping surface containing multiple cracks and extending along the first plane. Then, the external force application unit applies vibration to the stripping surface to obtain another silicon carbide strip. If it does not meet the requirements, the angle adjustment unit adjusts the angle of the silicon carbide ingot and / or the angle of the first direction. Then, the information is transmitted to the angle determination unit again to recalculate the angle between the crystal surface position information and the first plane, and determines whether the angle meets the requirements of the preset angle value.

[0056] Another possible operation of the device in this embodiment is as follows: after grinding the stripping area left on the silicon carbide ingot along the first plane, the first laser head is directly activated to generate a first laser beam to scan the silicon carbide ingot again, so as to form another stripping surface containing multiple cracks and extending along the first plane. Then, the external force application unit is used to apply vibration to the stripping surface to obtain another silicon carbide strip. Setting up a grinding unit can improve the stripping quality of the silicon carbide strip and improve processing efficiency.

[0057] Example 4

[0058] Figure 1 A schematic diagram of the overall structure of an exemplary embodiment of the apparatus for preparing silicon carbide strips by laser cracking according to the present invention is shown.

[0059] In this embodiment, as Figure 1 As shown, the apparatus for preparing silicon carbide lifters by laser cracking consists of a crystal plane detection unit, an angle determination unit (not shown), an angle adjustment unit, a laser scanning unit, an external force application unit (not shown), and a fixing unit.

[0060] The crystal plane detection unit is configured above the position to be stripped of the silicon carbide ingot. It includes an orienting signal transmitter 11 and an orienting signal receiver 12. It uses the Bragg diffraction principle to detect the (0001) crystal plane of the silicon carbide ingot and obtains the crystal plane position information. Then, the detected crystal plane information is transmitted to the angle determination unit.

[0061] The angle determination unit is configured to receive crystal plane position information, calculate the angle between the crystal plane position information and the first plane, and determine whether the angle meets the preset angle requirement. If it does, a first signal is output; otherwise, a second signal is output. The first plane and the first direction of the first laser beam are always perpendicular. The preset angle is a value selected within the range of 0 to 10°, and further, a value selected within the range of 0.5 to 3.5° or 4.5 to 7°. The first and second signals are electrical signals. After determination, if the angle between the (0001) plane of the silicon carbide ingot and the first plane meets the preset angle, the first signal is output to the laser scanning unit; if the angle between the (0001) plane of the silicon carbide ingot and the first plane does not meet the preset angle, the second signal is output to the angle adjustment unit.

[0062] The angle adjustment unit includes an ingot angle adjustment mechanism and / or a first laser beam angle adjustment mechanism (not shown). The ingot angle adjustment mechanism is capable of adjusting the angle of the silicon carbide ingot and includes a first adjustment component 211 and a second adjustment component 212 disposed below the fixing unit. The first adjustment component 211 includes a first adjustment knob 2111, which adjusts the movement of the silicon carbide ingot along the X-axis direction by rotating clockwise or counterclockwise. The second adjustment component 212 includes a second adjustment knob 2121, which adjusts the movement of the silicon carbide ingot along the Y-axis direction by rotating clockwise or counterclockwise. The X-axis and Y-axis directions are located in the same plane and are perpendicular to each other. The first laser beam angle adjustment mechanism is configured to adjust the first direction in which the first laser beam is located.

[0063] The angle adjustment unit is configured to receive the second signal transmitted by the angle determination unit, and activate the ingot angle adjustment mechanism to adjust the angle of the silicon carbide ingot according to the received second signal, and / or activate the first laser beam angle adjustment mechanism to adjust the first direction. After adjusting the angle of the silicon carbide ingot and / or the angle of the first direction, the information is transmitted to the angle determination unit again to recalculate the angle value between the crystal surface position information and the first plane, and to determine whether the angle value meets the requirements of the preset angle value.

[0064] The laser scanning unit includes a first laser head 31 capable of generating a first laser beam and a focusing lens 32. The laser scanning unit is configured to receive a first signal and activate the first laser head 31 to scan a silicon carbide ingot to form a surface to be peeled off containing multiple cracks extending along a first plane. The first laser beam generated by the first laser head 31 has an average output power of 0.8–3.5 W, a wavelength of 780–1100 nm, a scanning speed of 300–700 mm / s, a scanning spacing of 0.5–1 mm, a scanning time of 10–40 min, and 2–6 scans.

[0065] The first laser head 31 is divided into a scanning state and a non-scanning state. When the first laser head 31 is in the scanning state, the distance between the first laser head 31 and the silicon carbide ingot is 0.5 to 2 cm. When the first laser head 31 is in the non-scanning state, the distance between the first laser head 31 and the silicon carbide ingot is 10 to 20 cm. After receiving the first signal transmitted by the included angle determination unit, the laser scanning unit switches from the non-scanning state to the scanning state. The focal position is set according to the thickness of the peeled wafer, and a first laser beam is generated to perform a serpentine scan of the silicon carbide ingot along the first plane to generate cracks that are parallel or substantially parallel to the first plane of the silicon carbide ingot.

[0066] The focusing lens 32 is used to form a focused spot of uniform size for the first laser beam in the entire first plane, which is beneficial for the first laser beam to uniformly irradiate the surface or interior of the silicon carbide ingot.

[0067] The external force application unit is an ultrasonic component capable of emitting ultrasound towards the surface to be peeled. Ultrasonic vibration is applied to the surface to be peeled to obtain a silicon carbide peel sheet. The ultrasonic frequency of the ultrasonic component is 100-150 kHz, and the ultrasonic time is 10-60 s.

[0068] A fixing unit is configured to fix and support a silicon carbide ingot. It includes a vacuum chuck 41 for fixing the silicon carbide ingot, which uses vacuum negative pressure to adsorb the silicon carbide ingot to clamp the workpiece. The vacuum chuck 41 can be made of ceramic.

[0069] Example 5

[0070] In yet another exemplary embodiment of the present invention, a method for preparing silicon carbide release sheets using the laser-induced cracking apparatus of the present invention is provided, specifically comprising the following steps:

[0071] S01. Use the crystal plane detection unit to detect the (0001) crystal plane of the silicon carbide ingot and obtain the crystal plane position information;

[0072] S02. Calculate the angle between the crystal plane position information and the first plane using the angle determination unit, and determine whether the angle meets the requirements of the preset angle value. The first plane and the first direction where the first laser beam is located are always perpendicular.

[0073] S03a. If satisfied, the first laser head of the laser scanning unit is activated to generate a first laser beam to scan the silicon carbide ingot, so as to form a surface to be peeled off containing multiple cracks and extending along the first plane.

[0074] S03b If not satisfied, the angle of the silicon carbide ingot and / or the angle of the first direction are adjusted using the angle adjustment unit, and the process returns to step S02. The included angle determination unit is used again to calculate the included angle between the crystal surface position information and the first plane until the included angle meets the requirements of the preset included angle.

[0075] S04. Vibration is applied to the surface to be peeled using an external force application unit to obtain a silicon carbide peel sheet.

[0076] Example 6

[0077] In yet another exemplary embodiment of the present invention, a method for preparing silicon carbide release sheets using the laser-induced cracking apparatus of the present invention is provided, specifically comprising the following steps:

[0078] S01. Use the crystal plane detection unit to detect the (0001) crystal plane of the silicon carbide ingot and obtain the crystal plane position information;

[0079] S02. Calculate the angle between the crystal plane position information and the first plane using the angle determination unit, and determine whether the angle meets the requirements of the preset angle value. The first plane and the first direction where the first laser beam is located are always perpendicular.

[0080] S03a. If satisfied, the first laser head of the laser scanning unit is activated to generate a first laser beam to scan the silicon carbide ingot, so as to form a surface to be peeled off containing multiple cracks and extending along the first plane.

[0081] S03b If not satisfied, the angle of the silicon carbide ingot and / or the angle of the first direction are adjusted using the angle adjustment unit, and the process returns to step S02. The included angle determination unit is used again to calculate the included angle between the crystal surface position information and the first plane until the included angle meets the requirements of the preset included angle.

[0082] S04. Vibration is applied to the surface to be peeled using an external force application unit to obtain a silicon carbide peel sheet.

[0083] S05. Using a grinding unit, grind the stripping area left on the silicon carbide ingot in step S04 along the first plane, and repeat steps S01 to S04 to obtain another silicon carbide stripping sheet.

[0084] Alternatively, after using the grinding unit to grind the stripping area left on the silicon carbide ingot in step S04 along the first plane, the first laser beam is directly activated to scan the silicon carbide ingot again to form another stripping surface containing multiple cracks and extending along the first plane. Then, step S04 is performed to obtain another silicon carbide stripping sheet.

[0085] This invention was funded by the Taishan Industrial Leading Talent Project Special Fund.

[0086] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. An apparatus for preparing silicon carbide release sheets by laser-induced cracking, characterized in that, include: The system includes a crystal plane detection unit, an angle determination unit, an angle adjustment unit, a laser scanning unit, an external force application unit, and a fixing unit for fixing and supporting the silicon carbide ingot. The crystal plane detection unit is configured above the position to be peeled off of the silicon carbide ingot and is able to detect the (0001) crystal plane of the silicon carbide ingot to obtain crystal plane position information. The included angle determination unit is configured to receive the crystal plane position information, calculate the included angle value between the crystal plane position information and the first plane, and determine whether the included angle value meets the requirements of the preset included angle value. If it meets the requirements, the first signal is output; if it does not meet the requirements, the second signal is output. The first plane and the first direction where the first laser beam is located are always perpendicular. The angle adjustment unit includes an ingot angle adjustment mechanism capable of adjusting the angle of a silicon carbide ingot and / or a first laser beam angle adjustment mechanism capable of adjusting the angle of a first direction, and is configured to receive a second signal and activate the ingot angle adjustment mechanism and / or the first laser beam angle adjustment mechanism. The laser scanning unit includes a first laser head capable of generating the first laser beam, and is configured to receive the first signal and activate the first laser head to scan the silicon carbide ingot to form a peelable surface containing multiple cracks extending along the first plane; the laser scanning unit also includes a second laser head capable of generating a second laser beam, the second laser head being configured to scan the silicon carbide ingot around its circumference; the second laser head is configured to be linked and controlled with the first laser head, and to ensure that the second direction in which the second laser beam is located is always within the first plane; The angle adjustment unit further includes a second laser beam angle adjustment mechanism capable of adjusting the second direction in which the second laser beam is located, and is configured to receive a second signal and activate the second laser beam angle adjustment mechanism so that the second direction is always within the first plane; The external force application unit is configured to apply vibration to the surface to be peeled to obtain a silicon carbide release sheet.

2. The apparatus for preparing silicon carbide release sheets by laser-induced cracking according to claim 1, characterized in that, The ingot angle adjustment mechanism includes a first adjustment component and a second adjustment component disposed below the fixed unit. The first adjustment component is configured to adjust the silicon carbide ingot along the X-axis direction, and the second adjustment component is configured to adjust the silicon carbide ingot along the Y-axis direction. The X-axis direction and the Y-axis direction are located in the same plane and are perpendicular to each other, or are parallel to two planes respectively and are perpendicular to each other.

3. The apparatus for preparing silicon carbide release sheets by laser-induced cracking according to claim 1, characterized in that, The preset included angle value is a predetermined value selected within the range of 0 to 10.

4. The apparatus for preparing silicon carbide release sheets by laser-induced cracking according to claim 3, characterized in that, The preset included angle value is a predetermined value selected within the range of 0.5~3.5 or 4.5~7.

5. The apparatus for preparing silicon carbide release sheets by laser-induced cracking according to claim 1, characterized in that, The apparatus also includes a grinding unit configured to grind down the stripped area left on the silicon carbide ingot along the first plane.

6. The apparatus for preparing silicon carbide release sheets by laser-induced cracking according to claim 1, characterized in that, The first laser beam has an average output power of 0.8 to 3.5 W, a wavelength of 780 to 1100 nm, a scanning speed of 300 to 700 mm / s, a scanning spacing of 0.5 to 1 mm, a scanning time of 10 to 40 min, and a scanning number of 2 to 6 times.

7. The apparatus for preparing silicon carbide release sheets by laser-induced cracking according to claim 1, characterized in that, The external force application unit is an ultrasonic component capable of emitting ultrasonic waves toward the surface to be peeled.

8. The apparatus for preparing silicon carbide release sheets by laser-induced cracking according to claim 7, characterized in that, The ultrasonic frequency of the ultrasonic component is 100~150 kHz.

9. A method for preparing a silicon carbide release sheet using the laser-induced cracking apparatus according to any one of claims 1 to 8, wherein the method controls the thickness of the silicon carbide release sheet to be 100 to 1000 μm.

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