Platform and method for laser grooving SiC ingot and peeling SiC wafer

Abstract

The present application relates to SiC wafer manufacturing technology field, more specifically, it relates to a kind of platform and method for laser hidden cutting SiC crystal ingot after stripping SiC wafer, comprising: upper force application fixed part, for connecting the SiC crystal ingot of SiC wafer to be stripped;Lower force application fixed part, for connecting the remaining SiC crystal ingot of SiC crystal ingot;Shear force driving part is connected with upper force application fixed part and lower force application fixed part, after laser is carried out modification to the inside of SiC wafer to be stripped, and makes SiC wafer to be stripped and the interface of remaining SiC crystal ingot modification and form laser scribe modification mark, shear force driving part drives upper force application fixed part and lower force application fixed part misplacement movement, so that SiC wafer to be stripped and remaining SiC crystal ingot misplacement separation.A kind of platform and method for laser hidden cutting SiC crystal ingot after stripping SiC wafer of the present application, with high efficiency, high precision, low cost and various advantages.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of SiC wafer manufacturing, and more particularly to a platform and method for stripping SiC wafers after laser stealth cutting of SiC ingots. BACKGROUND

[0002] SiC power devices are gradually replacing traditional Si-based power devices due to their high efficiency, high power density, high withstand voltage, and high switching frequency, and SiC is increasingly becoming a key material in multiple industrial fields. Although SiC wafer manufacturing technology is continuously iteratively developed, the cutting and separation process of the ingot still has great challenges.

[0003] Traditional cutting techniques such as slurry line cutting and diamond line cutting have high material loss rates, slow speeds, and low yields, resulting in increased costs. As the size of the wafer increases, such as from 6 inches to 8 inches or even 12 inches, the requirements for the cutting process also increase, and more and thinner substrates need to be cut, which poses higher standards for existing cutting techniques.

[0004] Laser stealth cutting is a non-damaging cutting technique for the upper and lower surfaces of the ingot. By focusing a laser beam inside the ingot, a modified layer is formed through a photochemical reaction under the high temperature of the laser, and micro-cracks are formed longitudinally in the modified layer, solving the problems of high material loss rate, slow efficiency, and low yield during the cutting process. However, the modified SiC still has a high bonding force, and external force is needed to separate it along the laser modification track. Traditional line cutting methods have the disadvantages of low efficiency, low precision, high cost, and large material loss. SUMMARY

[0005] The present application solves the technical problems of the prior art and provides a platform and method for stripping SiC wafers after laser stealth cutting of SiC ingots.

[0006] The technical solution adopted by the present application is as follows:

[0007] The platform for stripping SiC wafers after laser stealth cutting of SiC ingots comprises: an upper force applying fixing part for connecting the SiC wafer to be stripped of the SiC ingot; a lower force applying fixing part for connecting the remaining SiC ingot of the SiC ingot; and a shearing force driving part connected to the upper force applying fixing part and the lower force applying fixing part. After the laser modifies the inside of the SiC wafer to be stripped and forms laser scribe modification marks at the interface between the SiC wafer to be stripped and the remaining SiC ingot, the shearing force driving part drives the upper force applying fixing part and the lower force applying fixing part to move in a staggered manner, so as to separate the SiC wafer to be stripped and the remaining SiC ingot in a staggered manner.

[0008] Further, the upper force applying fixing part comprises an upper moving platform connected with the shearing force driving part and an upper vacuum chuck connected with the lower surface of the upper moving platform.

[0009] Further, the lower force applying fixing part comprises a lower moving platform connected with the shearing force driving part and a lower vacuum chuck connected with the upper surface of the lower moving platform.

[0010] Further, the oppositely arranged lower moving platform and upper moving platform are of the same structure.

[0011] Further, the oppositely arranged upper vacuum chuck and lower vacuum chuck are of the same structure, and the upper vacuum chuck and the lower vacuum chuck are both connected with the vacuum pump device.

[0012] Further, the shearing force driving part comprises a bracket seat oppositely arranged with two door-shaped brackets, a lower driving unit connected with the lower moving platform is arranged on the bracket seat, an upper driving unit connected with the upper moving platform is arranged between the two door-shaped brackets, and the upper driving unit is connected with the bracket seat through a height adjusting cylinder to slide on the two door-shaped brackets under the driving of the height adjusting cylinder, so as to change the distance between the upper driving unit and the lower driving unit.

[0013] The method for peeling off SiC wafer is applied to the platform for peeling off SiC wafer from the SiC ingot by laser hidden cutting, and comprises the following steps.

[0014] The interface between the SiC wafer to be peeled off and the remaining SiC ingot of the SiC ingot is modified to form a laser scribing modification trace by laser hidden cutting of the SiC ingot.

[0015] The upper force applying fixing part is controlled to be connected with the SiC wafer to be peeled off, and the lower force applying fixing part is controlled to be connected with the remaining SiC ingot.

[0016] The shearing force driving part is controlled to be started, the shearing force driving part drives the upper force applying fixing part and the lower force applying fixing part to move in a staggered manner, and the SiC wafer to be peeled off and the remaining SiC ingot are separated in a staggered manner under the action of the shearing force.

[0017] Further, when the SiC ingot is cut by laser hidden cutting, the focusing depth of the laser emitted by the laser device is set according to the thickness of the SiC wafer to be peeled off and the thickness of the material damage layer, and the laser emitted by the laser device is perpendicular to the SiC wafer to be peeled off of the SiC ingot, the laser emitted by the laser device modifies the inside of the SiC wafer to be peeled off along the x-axis direction or the y-axis direction according to the preset scanning interval, and after the interface between the SiC wafer to be peeled off and the remaining SiC ingot is modified to form a laser scribing modification trace and the front surface of the interface is processed, the laser device is turned off.

[0018] Further, when the upper force applying fixing part is connected with the SiC wafer to be peeled and the lower force applying fixing part is connected with the remaining SiC ingot, the upper force applying fixing part and the lower force applying fixing part are moved to the same x-y coordinate system position, and after the remaining SiC ingot is connected with the lower force applying fixing part, the upper force applying fixing part is moved along the Z axis direction to be connected with the SiC wafer to be peeled.

[0019] Further, the shear force driving part drives the upper force applying fixing part and the lower force applying fixing part to move in a staggered manner, and under the action of the shear force, the SiC wafer to be peeled and the remaining SiC ingot are separated in a staggered manner, the upper force applying fixing part and the lower force applying fixing part move in opposite directions along the x axis or the y axis at a slow speed, and the moving direction is parallel to the laser scribing direction of the laser scribing modification trace.

[0020] From the above scheme, the beneficial effects of the present application are:

[0021] The platform and method for peeling the SiC wafer after laser hidden cutting the SiC ingot of the present application, after the laser modifies the inside of the SiC wafer to be peeled and modifies the interface between the SiC wafer to be peeled and the remaining SiC ingot to form a laser scribing modification trace, the shear force driving part drives the upper force applying fixing part and the lower force applying fixing part to move in a staggered manner, so that the SiC wafer to be peeled and the remaining SiC ingot are separated in a staggered manner, which has the advantages of high efficiency, high precision, low cost and the like.

[0022] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are used for explanation, and do not constitute a limitation on the present application. In the drawings: BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the specification, and are used to explain the present application together with the embodiments of the present application, and do not constitute a limitation on the present application. In the drawings:

[0024] Figure 1 A platform for peeling the SiC wafer after laser hidden cutting the SiC ingot provided by the embodiments of the present application is shown in the schematic diagram of the SiC ingot peeling;

[0025] Figure 2 The peeling process diagram for peeling the SiC wafer to be peeled 4 in the SiC ingot provided by the embodiments of the present application is shown in Figure One ;

[0026] Figure 3 The peeling process diagram for peeling the SiC wafer to be peeled 4 in the SiC ingot provided by the embodiments of the present application is shown in Figure Two ;

[0027] Figure 4A schematic diagram of a peeling process for peeling the SiC wafer 4 to be peeled in the SiC ingot according to the embodiment of the present application Figure Three ;

[0028] Figure 5 A schematic diagram of a peeling process for peeling the SiC wafer 4 to be peeled in the SiC ingot according to the embodiment of the present application Figure Four ;

[0029] Figure 6 A laser confocal scanning instrument line roughness test diagram of the peeled SiC wafer according to the embodiment of the present application

[0030] Figure 7 A peeling surface microscopic image of the peeled SiC wafer according to the embodiment of the present application

[0031] Figure 8 A surface roughness test diagram of the peeled SiC wafer according to the embodiment of the present application

[0032] Figure 9 A schematic diagram of the shear force driving part according to the embodiment of the present application Figure One ;

[0033] Figure 10 A schematic diagram of the shear force driving part according to the embodiment of the present application Figure Two ;

[0034] Figure 11 A schematic diagram of the upper driving unit according to the embodiment of the present application

[0035] Figure 12 A schematic diagram of the lower driving unit according to the embodiment of the present application Figure One ;

[0036] Figure 13 A schematic diagram of the lower driving unit according to the embodiment of the present application Figure Two ;

[0037] Figure 14 A schematic diagram of the calibration detector according to the embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to make the technical solutions in the embodiments of the present application clearer, more complete and complete, apparently, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0039] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0040] Example 1

[0041] See also Figures 1-8 The present invention provides a platform for peeling off SiC wafers after laser implicit cutting of SiC crystal ingots, comprising: an upper force-applying fixing portion for connecting the SiC wafer 4 to be peeled off of the SiC crystal ingot; a lower force-applying fixing portion for connecting the remaining SiC crystal ingot 5 of the SiC crystal ingot; a shear force driving portion connected to the upper force-applying fixing portion and the lower force-applying fixing portion. After the laser modifies the interior of the SiC wafer 4 to be peeled off and modifies the interface between the SiC wafer 4 to be peeled off and the remaining SiC crystal ingot 5 to form a laser scribing modification mark 3, the shear force driving portion drives the upper force-applying fixing portion and the lower force-applying fixing portion to perform dislocation movement, so that the SiC wafer 4 to be peeled off and the remaining SiC crystal ingot 5 are dislocated and separated.

[0042] The working principle and technical effects of the above technical solution are as follows:

[0043] The present invention provides a platform for peeling off SiC wafers after laser stealth cutting of SiC ingots. When processing the SiC wafer 4 to be peeled off of the SiC ingot, the SiC ingot is first cut stealthily by laser, and the interface between the SiC wafer 4 to be peeled off and the remaining SiC ingot 5 of the SiC ingot is modified to form a laser scribing modification mark 3; then the upper force-applying fixing part is controlled to be connected to the SiC wafer 4 to be peeled off, and the lower force-applying fixing part is controlled to be connected to the remaining SiC ingot 5; finally, the shear force driving part is controlled to start, and the shear force driving part drives the upper force-applying fixing part and the lower force-applying fixing part to move in an offset manner, so that the SiC wafer 4 to be peeled off and the remaining SiC ingot 5 are offset and separated under the action of shear force; compared with the traditional wire cutting method, peeling off the wafer by using shear force after laser stealth cutting of the SiC ingot is an efficient, high-precision, and low-cost peeling method. The surface roughness of the wafer after peeling is as low as 2.58μm, and the maximum height and depth are as low as 15.55μm; the specific advantages are as follows:

[0044] 1. High efficiency: Through the method of laser invisible cutting and shear force peeling, compared with the traditional wire cutting method, this method significantly improves processing efficiency and reduces processing time.

[0045] 2. High precision: Laser invisible cutting can accurately modify the SiC wafer, forming laser scribing modification marks, ensuring the precise separation between the wafer and the remaining ingot during the peeling process, thereby improving the precision of peeling.

[0046] 3. Low cost: Compared with traditional mechanical cutting methods, laser invisible cutting does not require expensive cutting tools and complex mechanical devices, reducing production costs.

[0047] 4. Low surface roughness: such as Figure 8 As shown in the figure, the surface roughness Sa of the SiC wafer after peeling is as low as 2.58μm, and the maximum height depth Sz is as low as 15.55μm, indicating that this method can effectively ensure the low material loss rate of the subsequent polishing wafer, and greatly saves material costs compared with the wire cutting method.

[0048] 5. Non-contact processing: Laser invisible cutting is a non-contact processing method that reduces physical damage to the wafer surface and avoids tool wear and surface scratches that may occur in traditional cutting methods.

[0049] In summary, this solution significantly improves the efficiency, precision and economy of SiC wafer peeling through innovative technical means, while maintaining good surface quality, and has broad application prospects.

[0050] The upper force-applying fixed portion includes: an upper motion platform 1 connected to the shear force driving portion and an upper vacuum suction cup 2 connected to the lower surface of the upper motion platform 1. The lower force-applying fixed portion includes: a lower motion platform 7 connected to the shear force driving portion and a lower vacuum suction cup 6 connected to the upper surface of the lower motion platform 7. The lower motion platform 7 and the upper motion platform 1, which are arranged opposite each other, have the same structure. The upper vacuum suction cup 2 and the lower vacuum suction cup 6, which are arranged opposite each other, have the same structure and are both connected to a vacuum pump device.

[0051] In a platform for peeling off SiC wafers after laser stealth cutting of SiC ingots of the present invention, an upper vacuum suction cup 2 and a lower vacuum suction cup 6 are both connected to a vacuum pump device. The upper vacuum suction cup 2 can be controlled by the vacuum pump device to be adsorbed on the upper surface of the SiC wafer 4 to be peeled off, and the lower vacuum suction cup 6 can be controlled by the vacuum pump device to be adsorbed on the lower surface of the remaining SiC ingot 5. The vacuum pump device exhausts air to generate a pressure difference between the inside and outside of the upper vacuum suction cup 2 and the lower vacuum suction cup 6, so that the upper vacuum suction cup 2 and the lower vacuum suction cup 6 have a strong binding force on the surfaces of the SiC wafer 4 to be peeled off and the remaining SiC ingot 5, respectively, to overcome the shear force and prevent the sample from moving; the shear force driving part can adopt an electric or pneumatic driving device to drive the lower motion platform 7 and the upper motion platform 1 to move in opposite directions to generate sufficient shear force to peel off the SiC wafer 4 to be peeled off; the electric or pneumatic driving device can be a servo motor or a cylinder, and the magnitude and direction of the shear force can be adjusted as needed.

[0052] The advantages of the above solution include:

[0053] 1. High precision adsorption and positioning: through the connection of the upper vacuum chuck 2 and the lower vacuum chuck 6 with the vacuum pump device, the accurate adsorption and positioning of the SiC wafer 4 and the remaining SiC ingot 5 can be realized. The pressure difference generated by the vacuum chuck provides strong binding force, ensuring that the sample does not move during the shearing process, thereby improving the precision and stability of the peeling process.

[0054] 2. High degree of automation: the shearing force driving part adopts electric or pneumatic driving device (such as servo motor or air cylinder), which can realize automatic shearing operation. By adjusting the driving device, the size and direction of the shearing force can be accurately controlled to meet the peeling requirements of SiC wafers of different sizes and materials.

[0055] 3. Symmetrical and modular design: the upper and lower motion platforms 1 and 7, the upper and lower vacuum chucks 2 and 6 are symmetrically arranged, which embodies the characteristics of symmetrical design and modular design. This design not only simplifies the manufacturing and maintenance of the platform, but also improves the stability and reliability of the platform.

[0056] 4. Strong mechanical control ability: the combination of vacuum pump device and electric / pneumatic driving device enables the platform to provide strong shearing force and adsorption force, ensuring that the SiC wafer 4 to be peeled and the remaining SiC ingot 5 can be firmly fixed during the peeling process.

[0057] 5. High flexibility: the electric or pneumatic driving device can adjust the size and direction of the shearing force according to actual needs, with high flexibility. For example, the speed of the servo motor or the pressure of the air cylinder can be adjusted to adapt to SiC wafers of different thickness and hardness, thereby adapting to different production needs.

[0058] 6. Environmental protection and energy saving: the use of vacuum pump device reduces mechanical contact, reduces mechanical wear and energy consumption, and also reduces environmental pollution.

[0059] Example two

[0060] Please refer to Figures 1-14 , the present application provides a platform for laser hidden cutting SiC ingot and peeling SiC wafer, the shearing force driving part includes: two door-shaped supports 100 are installed on the support seat 200, the lower driving unit 300 connected with the lower motion platform 7 is installed on the support seat 200, the upper driving unit 400 connected with the upper motion platform 1 is installed between the two door-shaped supports 100, the upper driving unit 400 is connected with the support seat 200 through the height adjusting cylinder 500, and slides on the two door-shaped supports 100 under the driving of the height adjusting cylinder 500, changes the distance between the upper driving unit 400 and the lower driving unit 300.

[0061] The application provides a platform for laser hidden cutting of SiC crystal ingot and stripping of SiC wafer, wherein the shearing force driving part can adopt the special design scheme, the lower driving unit 300 connected with the lower movement platform 7 is installed on the support seat 200, the movement of the lower movement platform 7 is controlled through the lower driving unit 300, the upper driving unit 400 connected with the upper movement platform 1 is installed between the two door-shaped supports 100, the movement of the upper movement platform 1 is controlled through the upper driving unit 400, the upper driving unit 400 is connected with the support seat 200 through the height-adjusting cylinder 500, and the upper driving unit 400 slides on the two door-shaped supports 100 under the driving of the height-adjusting cylinder 500, so that the distance between the upper driving unit 400 and the lower driving unit 300 is changed, and the upper vacuum chuck 2 on the lower surface of the upper movement platform 1 is controlled to contact the SiC wafer 4 to be stripped.

[0062] The shearing force driving part of the above scheme has the following advantages:

[0063] 1. High structural stability

[0064] The design of the support seat 200 of the door-shaped support 100: the two door-shaped supports 100 are oppositely installed on the support seat 200, forming a stable support structure, which can withstand large shearing force and dynamic load generated in the stripping process, and ensures the stability of the equipment in the stripping process.

[0065] Modular design: the upper driving unit 400 and the lower driving unit 300 are respectively installed on the door-shaped support 100 and the support seat 200, the modular design facilitates assembly, maintenance and upgrading, and improves the overall reliability of the equipment.

[0066] 2. Flexible distance adjustment

[0067] Height-adjusting cylinder 500 driving: the sliding position of the upper driving unit 400 on the door-shaped support 100 is adjusted through the height-adjusting cylinder 500, so that the distance between the upper driving unit 400 and the lower driving unit 300 is flexibly changed. This design enables the equipment to adapt to SiC wafers 4 of different thicknesses, and enhances the adaptability and flexibility of the equipment.

[0068] Precise control of contact: by adjusting the distance, the contact between the upper vacuum chuck 2 on the lower surface of the upper movement platform 1 and the SiC wafer 4 to be stripped can be precisely controlled, and the stable connection between the SiC wafer 4 to be stripped and the remaining SiC crystal ingot 5 in the stripping process is ensured.

[0069] 3. High positioning accuracy: by adjusting the precision of the height adjustment cylinder 500, the distance between the upper driving unit 400 and the lower driving unit 300 can be accurately matched with the thickness of the SiC wafer 4 to be peeled, thereby improving the positioning accuracy of the SiC wafer 4 to be peeled and the remaining SiC ingot 5 during the peeling process. The accurate contact between the upper vacuum chuck 2 and the SiC wafer 4 to be peeled ensures the stability and consistency of the peeling process, avoiding peeling failure or deviation due to poor contact.

[0070] The upper driving unit 400 includes two lifting slides 401 sliding on the longitudinal beams of the two door-shaped supports 100, and the two lifting slides 401 are connected to the support seat 200 through one or more height adjustment cylinders 500 respectively. The two lifting slides 401 are connected through two or more bearing beams 402, and the upper driving seat 403 sliding on the two or more bearing beams 402 is connected to one end of the electric push rod 404, and the other end of the electric push rod 404 is connected to one of the lifting slides 401. The upper driving seat 403 is provided with an upper connecting plate 405 connected to the upper moving platform 1 at the bottom, and is further provided with an alignment slide 406 matched with the lower driving unit 300.

[0071] The upper connecting plate 405 is used to connect with the upper moving platform 1, and a plurality of bolt connection holes are provided on the upper connecting plate 405, which is convenient to install or disassemble. The height adjustment cylinder 500 can drive the lifting slide 401 to slide in the upward and downward directions on the longitudinal beams of the door-shaped supports 100, which is convenient to adjust the horizontal height of the upper moving platform 1. The two lifting slides 401 are connected through two or more bearing beams 402, and the upper driving seat 403 sliding on the two or more bearing beams 402 is connected to one end of the electric push rod 404, and the other end of the electric push rod 404 is connected to one of the lifting slides 401. The electric push rod 404 can control the sliding of the upper driving seat 403 on the two bearing beams 402, which is used to control the dislocation separation of the SiC wafer 4 to be peeled and the remaining SiC ingot 5. The upper driving seat 403 is further provided with an alignment slide 406 matched with the lower driving unit 300, which is convenient to improve the precision of the adsorption of the SiC wafer 4 and the remaining SiC ingot 5 by the upper vacuum chuck 2 and the lower vacuum chuck 6;

[0072] In the application, the two lifting slides 401 are slid on the longitudinal beams of the door-shaped support 100, are connected with the support seat 200 through the multiple height-adjusting cylinders 500, form a stable support structure, can bear a large shear force and dynamic load generated in the peeling process, are connected through the multiple bearing beams 402 between the two lifting slides 401, ensure the stability and rigidity of the upper driving seat 403, and avoid structural deformation or instability caused by single-point support; the height-adjusting cylinders 500 can drive the lifting slides 401 to slide in the upward and downward directions on the longitudinal beams of the door-shaped support 100, facilitate the adjustment of the horizontal height of the upper movement platform 1, and adapt to SiC wafers of different thicknesses; the electric push rods 404 can control the sliding of the upper driving seat 403 on the bearing beams 402, realize accurate adjustment in the horizontal direction, are used for controlling the dislocation separation of the SiC wafer 4 to be peeled and the remaining SiC ingot 5, and improve the flexibility and precision of peeling; the upper driving seat 403 is provided with the alignment slide 406 matched with the lower driving unit 300, so that the upper driving unit 400 and the lower driving unit 300 can be accurately aligned, and the precision of the adsorption of the SiC wafer 4 and the remaining SiC ingot 5 by the upper vacuum chuck 2 and the lower vacuum chuck 6 is improved.

[0073] The lower driving unit 300 comprises two bearing frames 301 fixed on the support seat 200, a transverse screw rod 302 and a transverse worm 303 rotationally connected between the two bearing frames 301 and arranged in parallel, a screw rod motor 304 and a worm motor 305 connected with the transverse screw rod 302 and the transverse worm 303 and arranged on the bearing frame 301, a lower driving seat 306 threadedly connected to the middle part of the transverse screw rod 302, a lower connecting plate 307 for connecting the lower movement platform 7 arranged on the lower driving seat 306, and the lower driving seat 306 slidingly fitted on the transverse worm 303; the transverse worm 303 is engaged with a worm wheel 309 fixed on an axle 308, the axle 308 transversely arranged on the lower driving seat 306 is perpendicular to the transverse screw rod 302; an unlocking gear 310 is fixed to the middle part of the axle 308, the unlocking gear 310 is engaged with an alignment rack 311 slid in the longitudinal slide of the lower driving seat 306, and the upper driving unit 400 and the lower driving unit 300 can be inserted into the alignment slide 406 of the upper driving seat 403 when moving to the same x-y coordinate system position.

[0074] After the lead screw motor 304 is started, the lead screw motor 304 drives the horizontal lead screw 302 to rotate, which can change the contact position of the horizontal lead screw 302 and the lower driving base 306, thereby controlling the sliding of the lower driving base 306 on the horizontal worm 303, adjusting the position of the lower driving base 306, facilitating the adjustment of the position of the lower moving platform 7 and the lower vacuum chuck 6 according to the actual situation, thereby controlling the position of the remaining SiC crystal ingot 5 for adjustment. The horizontal lead screw 302 not only can support the lower driving base 306, but also can cooperate with the lead screw motor 304 to adjust the position of the lower driving base 306; when the upper driving unit 400 and the lower driving unit 300 move to the same x-y coordinate system position, the alignment rack 311 can be inserted into the alignment slide 406 of the upper driving base 403, thereby more accurately positioning the position of the upper driving unit 400 and the lower driving unit 300, ensuring the accuracy of the connection between the to-be-peeled SiC wafer 4 and the remaining SiC crystal ingot 5; the horizontal worm 303 is connected with the worm motor 305, and the worm motor 305 can control the rotation of the horizontal worm 303 when started. When the horizontal worm 303 rotates, the worm gear 309 can be engaged to rotate, thereby controlling the rotation of the axle 308. When the axle 308 rotates, the unlocking gear 310 is driven to rotate. The rotation of the unlocking gear 310 can engage the alignment rack 311 to slide up and down in the longitudinal slide of the lower driving base 306. After the alignment rack 311 is completely aligned and corrected by being inserted into the alignment slide 406 of the upper driving base 403, when the to-be-peeled SiC wafer 4 and the remaining SiC crystal ingot 5 need to be separated by misalignment, the worm motor 305 is started to control the rotation of the unlocking gear 310, and the alignment rack 311 is controlled to slide downward in the longitudinal slide of the lower driving base 306, thereby releasing the fiber between the upper driving unit 400 and the lower driving unit 300. The operation is very convenient. The horizontal worm 303 not only can play a guiding and supporting role, but also can cooperate with other structures to assist in controlling the alignment rack 311, which is practical, functional, and has a small movement range. When the worm motor 305 stops moving, the worm gear 309 rolls on the horizontal worm 303, which does not affect the movement of the upper driving base 403. Although the worm gear 309 rolls to make the alignment rack 311 slide up and down by a certain distance, the alignment rack 311 is not inserted into the alignment slide 406, which does not hinder the overall work of the present application.

[0075] In the present application, the combination of the transverse screw 302 and the transverse worm 303 realizes the accurate adjustment of the lower driving seat 306 in the transverse and longitudinal directions; the screw motor 304 drives the transverse screw 302 to rotate, changes the contact position of the transverse screw 302 and the lower driving seat 306, and thus accurately controls the sliding position of the lower driving seat 306 on the transverse worm 303; when the upper driving unit 400 and the lower driving unit 300 move to the same x-y coordinate system position, the alignment rack 311 can be inserted into the alignment slide 406 of the upper driving seat 403, realizing the accurate alignment of the upper driving unit 400 and the lower driving unit 300, and ensuring the accuracy of the adsorption of the SiC wafer 4 and the remaining SiC ingot 5; through the electric control of the screw motor 304 and the worm motor 305, the automatic adjustment of the lower driving seat 306 is realized, the manual intervention is reduced, and the production efficiency is improved; the linkage design of the unlocking gear 310 and the alignment rack 311 enables quick unlocking after alignment, improving the response speed and flexibility of the equipment; the two bearing frames 301 are fixed on the support seat 200, the transverse screw 302 and the transverse worm 303 are connected with the bearing frame 301 respectively, forming a stable support structure that can withstand large shear force and dynamic load generated in the peeling process; the transverse worm 303 not only plays a guiding and supporting role, but also cooperates with other structures to realize the accurate control of the alignment rack 311, ensuring the stability and precision of the lower driving seat 306; the cooperation design of the alignment rack 311 and the alignment slide 406 enables the alignment and unlocking operation of the upper driving unit 400 and the lower driving unit 300 to be quick and convenient, reduces the alignment time, and improves the production efficiency.

[0076] The middle of the lower surface of the lower driving seat 306 is fixed with a calibration motor 312, the output shaft of the calibration motor 312 is connected with a driving screw 313, the adapter plate 314 threaded on the driving screw 313 is rotatably connected with one end of four articulated connecting rods 315, the other end of the four articulated connecting rods 315 is rotatably connected with four telescopic slides 316 which are evenly and slidably arranged on the four sides of the lower driving seat 306, the limiting protrusions on the upper surfaces of the four telescopic slides 316 are slidably arranged in the four limiting sliding ports on the lower surface of the lower driving seat 306; the upper surfaces of the four telescopic slides 316 are connected with four calibration detectors 317, so that the four calibration detectors 317 are in contact with the four sides of the remaining SiC ingot 5 of the SiC ingot.

[0077] When the SiC crystal ingot is placed on the lower vacuum chuck 6 on the lower surface of the lower moving platform 7, the position of the SiC crystal ingot is first calibrated before the remaining SiC crystal ingot 5 is adsorbed on the bottom surface, to ensure the stability of subsequent adsorption and fixation, and finally improve the peeling effect. When calibrating, the calibration motor 312 is controlled to start, and after the calibration motor 312 starts, the drive screw 313 is controlled to rotate. When the drive screw 313 rotates, it can change the contact position with the adapter plate 314, thereby controlling the adapter plate 314 to drive one end of the four hinged connecting rods 315 to move in the upward and downward directions. When calibrating, the end of the four hinged connecting rods 315 needs to be controlled to move downward, and the other end of the four hinged connecting rods 315 drives the four telescopic slides 316 to slide into the slide channel on the four sides of the lower drive base 306, thereby driving the four calibration detectors 317 to abut and fit on the four sides of the remaining SiC crystal ingot 5 of the SiC crystal ingot, so that the SiC crystal ingot moves to the center position of the lower vacuum chuck 6. The position of the SiC crystal ingot is calibrated and positioned.

[0078] Through the abutting and fitting of the four calibration detectors 317, the remaining SiC crystal ingot 5 obtains four-point support during the peeling process, forming a stable multi-point fixing structure, which avoids the crystal ingot from falling off due to unstable adsorption. The abutting and fitting of the calibration detector 317 can monitor the position of the crystal ingot in real time and correct the deviation, ensuring the stability of the position of the crystal ingot during the peeling process and avoiding adverse consequences caused by deviation. During the peeling process, the remaining SiC crystal ingot 5 may fall off due to insufficient adsorption force or other factors, and the abutting and fitting of the calibration detector 317 can effectively prevent the crystal ingot from falling off and avoid damaging the crystal ingot. By improving the peeling stability, the surface scratches and other mechanical damage caused by the crystal ingot falling off or shaking are reduced, protecting the integrity and surface quality of the remaining SiC crystal ingot 5. The linkage design of the calibration motor 312 and the drive screw 313 ensures that the SiC crystal ingot can be accurately aligned before adsorption, so that it is located at the center position of the lower vacuum chuck 6, improving the stability of adsorption and reducing the deviation or sliding of the crystal ingot during the adsorption process. The accurate calibration reduces the mechanical damage of the SiC crystal ingot during the adsorption and peeling process, protecting the quality and integrity of the wafer; the accurate alignment of the crystal ingot before adsorption ensures the uniformity of stress distribution during the peeling process, avoiding wafer damage caused by uneven peeling.

[0079] The calibration detector 317 comprises a contact roller 319 fixed on a driven shaft 318, the driven shaft 318 is rotatably connected to a contact beam near one end of the remaining SiC crystal ingot 5, the other end of the contact beam away from the remaining SiC crystal ingot 5 is fixed on the telescopic sliding table 316 through a vertical rod 320, the driven sprocket 321 fixed on the driven shaft 318 is connected with the driving sprocket fixed on the output shaft of the rotary motor 322 through a chain, and the rotary motor 322 is assembled on the vertical rod 320 through a motor base; the contact roller 319 is a pressure detection roller. The structure of the calibration detector 317 is arranged so that it can not only contact and fix the remaining SiC crystal ingot 5 of the SiC crystal ingot, but also control the rotation of the remaining SiC crystal ingot 5 of the SiC crystal ingot, and detect the flatness of the outer side surface of the remaining SiC crystal ingot 5. The rotary motor 322 is started, the rotary motor 322 can drive the driving sprocket to rotate, the driving sprocket drives the driven sprocket 321 to rotate through the chain, so as to drive the driven shaft 318 to rotate through the driven sprocket 321. When the driven shaft 318 rotates, the contact roller 319 rotates, and before the lower vacuum suction disc 6 is adsorbed on the bottom surface of the remaining SiC crystal ingot 5, the contact roller 319 rotates to drive the remaining SiC crystal ingot 5 to rotate around its own axis, so as to detect whether the remaining SiC crystal ingot 5 is a standard cylindrical structure. If the remaining SiC crystal ingot 5 is deformed or has quality problems, that is, it is not a standard cylindrical structure, it cannot rotate, which is convenient for judgment. In addition, after being adsorbed on the bottom surface of the remaining SiC crystal ingot 5 by the lower vacuum suction disc 6, the stability of the lower vacuum suction disc 6 adsorbed on the bottom surface of the remaining SiC crystal ingot 5 can also be detected by driving the contact roller 319 to rotate. If the adsorption is unstable, the contact roller 319 can drive the remaining SiC crystal ingot 5 to rotate. If the adsorption is stable, it cannot rotate. During peeling, the calibration detector 317 can also monitor the position and state of the remaining SiC crystal ingot 5 in real time. When the stability of the lower vacuum suction disc 6 adsorbed on the bottom surface of the remaining SiC crystal ingot 5 is high, since the contact roller 319 is a pressure detection roller, the pressures of the four pressure detection rollers in contact with the SiC crystal ingot 5 are the same. If the remaining SiC crystal ingot 5 is displaced during peeling, the pressures borne by the four pressure detection rollers will be different. At this time, the pressure detection roller with a larger pressure change transmits a signal to the controller, and the controller controls the present application to stop peeling work, which is convenient for maintenance and repair, timely detects and corrects the deviation in the peeling process, prevents error accumulation, improves the peeling precision, prevents work error from affecting the peeling effect, and causes peeling failure and other problems.

[0080] Example three

[0081] Please refer to Figures 1-14 The present application provides a method for peeling SiC wafer, which is applied to the platform for laser hidden cutting SiC crystal ingot and peeling SiC wafer, and comprises the following steps:

[0082] The interface between the SiC wafer 4 to be peeled and the remaining SiC ingot 5 is modified to form a laser scribe modified trace 3 by laser stealth cutting of the SiC ingot;

[0083] The upper force applying fixing part is connected with the SiC wafer 4 to be peeled, and the lower force applying fixing part is connected with the remaining SiC ingot 5;

[0084] The shear force driving part is started, and the shear force driving part drives the upper force applying fixing part and the lower force applying fixing part to move in a staggered manner, so that the SiC wafer 4 to be peeled and the remaining SiC ingot 5 are separated in a staggered manner under the action of the shear force.

[0085] The method can be effectively used for peeling the SiC wafer after laser stealth cutting of the SiC ingot, and can improve the efficiency and precision of peeling the SiC wafer and ensure the peeling effect.

[0086] According to the thickness of the SiC wafer 4 to be peeled and the thickness of the material damage layer, the focusing depth of the laser 8 is set, and the laser emitted by the laser 8 is perpendicular to the SiC wafer 4 to be peeled of the SiC ingot, the laser emitted by the laser 8 is modified inside the SiC wafer 4 to be peeled along the x-axis direction or the y-axis direction according to the preset scanning interval, and after the interface between the SiC wafer 4 to be peeled and the remaining SiC ingot 5 is modified to form a laser scribe modified trace 3, the front surface processing of the interface is completed, and the laser 8 is turned off.

[0087] By setting the focusing depth of the laser 8 according to the thickness of the SiC wafer 4 to be peeled off and the thickness of the material damage layer, the focusing position of the laser can be accurately controlled, ensuring that the laser does not cause unnecessary damage to other parts of the wafer when modifying the inside of the SiC wafer 4 to be peeled off. This high-precision control helps improve the accuracy and consistency of the peeling process; the laser 8 can adjust the focusing depth, scanning pitch, and scanning direction (x-axis or y-axis direction) of the laser according to actual needs, adapting to the peeling needs of SiC wafers of different thicknesses and materials; this flexibility makes the method widely applicable to various SiC wafer processing scenarios; the laser 8 can quickly and accurately modify the inside of the SiC wafer 4 to be peeled off and form laser scribe modification marks 3 at the interface, significantly improving processing efficiency. Compared with traditional mechanical cutting methods, laser stealth cutting can complete modification processing in a short time; laser stealth cutting can accurately form laser scribe modification marks at the interface between the SiC wafer 4 to be peeled off and the remaining SiC ingot 5, ensuring that the surface roughness of the peeled wafer is as low as 2.58 μm and the maximum high-low depth is as low as 15.55 μm. This low surface roughness is very important for subsequent microelectronic processing and device manufacturing. This scheme significantly improves the efficiency, accuracy, and reliability of SiC wafer peeling through laser stealth cutting technology, while having the advantages of low cost, low surface roughness, high automation, etc., and is suitable for large-scale production and high-precision processing needs.

[0088] When the upper force applying fixing part is connected with the SiC wafer 4 to be peeled off and the lower force applying fixing part is connected with the remaining SiC ingot 5, the upper force applying fixing part and the lower force applying fixing part are moved to the same x-y coordinate system position; after the remaining SiC ingot 5 is connected with the lower force applying fixing part, the upper force applying fixing part is moved along the Z-axis direction to be connected with the SiC wafer 4 to be peeled off.

[0089] By controlling the upper force applying fixing part and the lower force applying fixing part to move to the same x-y coordinate system position, the accuracy of the alignment of the upper force applying fixing part and the lower force applying fixing part in the horizontal direction is ensured; such high-precision positioning helps to ensure the positional accuracy of the SiC wafer 4 to be peeled and the remaining SiC ingot 5 during the connection process; by controlling the movement of the upper force applying fixing part along the Z-axis direction to connect with the SiC wafer 4 to be peeled, the accuracy of the vertical contact between the upper force applying fixing part and the SiC wafer 4 to be peeled is ensured; such precise control in the vertical direction helps to avoid tilting or misalignment during the connection process, improving the accuracy of the connection. The entire connection process is realized through automatic control, reducing manual intervention and improving the accuracy and consistency of the connection. Automatic control can accurately adjust the position of the upper force applying fixing part and the lower force applying fixing part, ensuring the accuracy of the connection, reducing errors in manual operation, and ensuring that the upper force applying fixing part and the lower force applying fixing part can accurately connect with the SiC wafer 4 to be peeled and the remaining SiC ingot 5, improving the reliability of the connection; accurate connection ensures the positional accuracy of the SiC wafer 4 to be peeled and the remaining SiC ingot 5 during the peeling process, avoiding peeling deviations caused by inaccurate connection, and improving the peeling accuracy; accurate connection can ensure that the shear force is uniformly applied to the interface between the SiC wafer 4 to be peeled and the remaining SiC ingot 5, reducing local stress concentration caused by inaccurate connection, thereby reducing damage to the material; accurate connection ensures the stability and consistency of the peeling process, reduces peeling failures or repeated operations caused by inaccurate connection, and improves the peeling efficiency; accurate connection ensures the smoothness and consistency of the SiC wafer surface after peeling, avoiding increased surface roughness or uneven depth caused by inaccurate connection, and ensuring the peeling quality.

[0090] The shear force driving part drives the upper force applying fixing part and the lower force applying fixing part to move slowly in opposite directions along the x-axis or y-axis, and the moving direction is parallel to the laser scribing direction of the laser scribing modification mark 3.

[0091] In the above scheme, the upper force applying fixing part and the lower force applying fixing part move slowly in opposite directions along the x-axis or y-axis, and the moving direction is parallel to the laser scribing direction of the laser scribing modification mark 3, which has the following advantages:

[0092] 1. Improve peeling accuracy

[0093] Uniform force: slow movement can ensure that the shear force is uniformly applied to the modified interface of the SiC wafer 4 to be peeled and the remaining SiC ingot 5, avoiding local stress concentration or uneven peeling caused by rapid movement, thereby improving the peeling accuracy.

[0094] Reduced bias: Slow movement reduces vibrations and shocks during the peeling process, reducing the likelihood of peeling bias, ensuring the boundaries of the peeled SiC wafer 4 and the remaining SiC ingot 5 are neat.

[0095] 2. Avoid material damage

[0096] Reduced crack propagation: Slow movement allows shear force to gradually act on the weak areas of the modified interface, avoiding rapid crack propagation caused by sudden shear force, thereby reducing mechanical damage to the SiC wafer 4 and the remaining SiC ingot 5.

[0097] Protect the material structure: By moving parallel to the direction of the laser scribing modification trace 3, the shear force can be evenly distributed along the pre-modified weak area, avoiding unnecessary damage to the unmodified area and protecting the integrity of the wafer.

[0098] 3. Improve peeling consistency

[0099] Separation along the scribe line direction: The movement direction is parallel to the direction of the laser scribing modification trace 3, ensuring that the shear force can accurately separate the SiC wafer 4 and the remaining SiC ingot 5 along the weak area of the modification trace, avoiding deviation or deviation during the peeling process, and improving the consistency of the peeling.

[0100] High repeatability: The slow and parallel movement method makes the peeling process highly repeatable, ensuring that the separation interface of the SiC wafer 4 and the remaining SiC ingot 5 is consistent each time.

[0101] 4. Reduce peeling failure rate

[0102] Uniform separation: By slow and parallel movement, the shear force can gradually act on the entire modified interface, avoiding peeling failure caused by excessive local stress.

[0103] Avoid sample movement: Slow movement reduces sample vibration or displacement during the peeling process, ensuring that the SiC wafer 4 and the remaining SiC ingot 5 to be peeled remain stably connected during the peeling process, reducing the likelihood of peeling failure.

[0104] 5. Protect the quality of subsequent processing

[0105] Reduce surface roughness: Slow and uniform shear force action can maintain the smoothness of the peeled SiC wafer 4 surface, avoiding rough or uneven peeling interface, providing high-quality basis for subsequent microelectronic processing.

[0106] Protect the wafer edge: By moving parallel to the laser scribing direction, mechanical damage to the wafer edge during the peeling process is avoided, ensuring that the edge of the peeled SiC wafer 4 is neat, meeting the requirements of subsequent processing.

[0107] In the description of the application, it needs to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

Claims

1. A platform for peeling SiC wafers after laser cutting of SiC ingots, characterized in that: include: An upper force-applying fixing portion is used for connecting a SiC wafer (4) to be peeled off of a SiC crystal ingot; a lower force-applying fixing portion is used for connecting a remaining SiC crystal ingot (5) of the SiC crystal ingot; a shear force driving portion is connected to the upper force-applying fixing portion and the lower force-applying fixing portion, and after the laser modifies the interior of the SiC wafer (4) to be peeled off and modifies the interface between the SiC wafer (4) to be peeled off and the remaining SiC crystal ingot (5) to form a laser-scribed modified trace (3), the shear force driving portion drives the upper force-applying fixing portion and the lower force-applying fixing portion to move in a dislocated manner, so that the SiC wafer (4) to be peeled off and the remaining SiC crystal ingot (5) are dislocated and separated; The upper force-applying fixing portion comprises: an upper motion platform (1) connected to the shear force driving portion and an upper vacuum suction cup (2) connected to the lower surface of the upper motion platform (1); The lower force-applying fixing portion comprises: a lower motion platform (7) connected to the shear force driving portion and a lower vacuum suction cup (6) connected to the upper surface of the lower motion platform (7); The shear force driving portion includes: a bracket base on which two gate-shaped brackets are relatively mounted, a lower driving unit connected to the lower motion platform is mounted on the bracket base, an upper driving unit connected to the upper motion platform is mounted between the two gate-shaped brackets, and the upper driving unit is connected to the bracket base via a height adjustment cylinder so that the upper driving unit slides on the two gate-shaped brackets under the drive of the height adjustment cylinder to change the distance between the upper driving unit and the lower driving unit; The upper drive unit includes: two lifting slides slidingly mounted on two longitudinal beams of the gate-shaped support, and the two lifting slides are respectively connected to the support base via one or more height adjustment cylinders; the two lifting slides are connected via two or more load-bearing beams, and the upper drive seat slidingly mounted on the two or more load-bearing beams is connected to one end of the electric push rod, and the other end of the electric push rod is connected to one of the lifting slides; the bottom of the upper drive seat is provided with an upper mounting plate connected to the upper motion platform; the upper drive seat is also provided with an alignment slideway arranged in cooperation with the lower drive unit; The lower driving unit includes: two supporting frames fixed on the bracket seat, and the two supporting frames are rotatably connected with a parallel transverse screw and a transverse worm, the transverse screw and the transverse worm are respectively connected to the screw motor and the worm motor installed on the supporting frame, the middle part of the transverse screw is threadedly connected to the lower driving seat, and the lower driving seat is provided with a lower mounting plate for connecting the lower motion platform, and the lower driving seat slides on the transverse worm; the transverse worm is engaged with the worm gear fixed on the wheel axle, and the wheel axle rotated laterally on the lower driving seat is vertically staggered with the transverse screw; an unlocking gear is fixed to the middle of the wheel axle, and the unlocking gear is engaged with the alignment rack sliding in the longitudinal slide of the lower driving seat. When the upper driving unit and the lower driving unit move to the same xy coordinate system position, the alignment rack can be inserted into the alignment slide of the upper driving seat.

2. The platform for laser cutting SiC ingots and then peeling SiC wafers according to claim 1, characterized in that: The lower motion platform (7) and the upper motion platform (1) arranged opposite to each other have the same structure.

3. The platform for laser cutting SiC ingots and then peeling off SiC wafers according to claim 1, characterized in that: The upper vacuum suction cup (2) and the lower vacuum suction cup (6) arranged opposite to each other have the same structure, and both the upper vacuum suction cup (2) and the lower vacuum suction cup (6) are connected to a vacuum pump device.

4. A method for peeling a SiC wafer, applied to the platform for peeling a SiC wafer after laser stealth cutting of a SiC ingot according to any one of claims 1 to 3, characterized in that: The following steps are involved: The SiC ingot is cut stealthily by laser, and the interface between the SiC wafer (4) to be peeled off and the remaining SiC ingot (5) of the SiC ingot is modified to form a laser-lined modified trace (3); the upper force-applying fixing part is controlled to be connected to the SiC wafer (4) to be peeled off, and the lower force-applying fixing part is controlled to be connected to the remaining SiC ingot (5); the shear force driving part is controlled to start, and the shear force driving part drives the upper force-applying fixing part and the lower force-applying fixing part to move in a dislocated manner, so that the SiC wafer (4) to be peeled off and the remaining SiC ingot (5) are dislocated and separated under the action of the shear force.

5. The method according to claim 4, characterized in that When cutting a SiC ingot by invisible laser cutting, the focus depth of the laser emitted by the laser (8) is set according to the thickness of the SiC wafer (4) to be peeled and the thickness of the material damage layer, and the laser light emitted by the laser is perpendicular to the SiC wafer (4) to be peeled of the SiC ingot. The laser light emitted by the laser (8) is used to modify the interior of the SiC wafer (4) to be peeled along the x-axis direction or the y-axis direction according to a preset scanning interval. After the interface between the SiC wafer (4) to be peeled and the remaining SiC ingot (5) is modified to form a laser scribing modification mark (3), the front processing at the interface is completed and the laser (8) is turned off.

6. The method according to claim 5, characterized in that When the upper force-applying fixing part is controlled to be connected to the SiC wafer (4) to be peeled off and the lower force-applying fixing part is controlled to be connected to the remaining SiC crystal ingot (5), the upper force-applying fixing part and the lower force-applying fixing part are controlled to move to the same xy coordinate system position; after the remaining SiC crystal ingot (5) is controlled to be connected to the lower force-applying fixing part, the upper force-applying fixing part is controlled to move along the Z-axis direction until it is connected to the SiC wafer (4) to be peeled off.

7. The method according to claim 6, characterized in that The shear force driving part drives the upper force fixing part and the lower force fixing part to move in a dislocated manner. When the SiC wafer (4) to be peeled and the remaining SiC crystal ingot (5) are dislocated and separated under the action of the shear force, the upper force fixing part and the lower force fixing part move slowly in opposite directions along the x-axis or the y-axis, and the moving direction is parallel to the laser marking direction of the laser marking modification mark (3).

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