Crystal ingot stripping method, control device, and stripping apparatus

Abstract

The application provides a crystal ingot stripping method, a control device and a stripping device, relates to the technical field of crystal ingot stripping, and the crystal ingot stripping method comprises the following steps: performing laser modification processing on wafer material to be processed to obtain modified wafer material; applying vibration energy to the modified wafer material through an ultrasonic vibration plate to generate microcracks at a modified position of the modified wafer material, so that stripped wafer material is obtained; determining a stripping state of the stripped wafer material; and after the wafer surface of the stripped wafer material is treated according to the stripping state, a target crystal ingot is obtained. The application effectively reduces wafer crack rates and fragment rates and improves wafer stripping precision by means of laser modification processing combined with ultrasonic vibration energy application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of crystal ingot stripping, in particular to a crystal ingot stripping method, a control device and a stripping device. BACKGROUND

[0002] The existing technical solution often separates the crystal ingot by mechanical methods such as mechanical force applied by a wedge-shaped blade when stripping the crystal ingot, resulting in a high crystal ingot breakage rate and micro-cracks during the stripping process, which affects the quality of the wafer. SUMMARY

[0003] The main purpose of the present application is to provide a crystal ingot stripping method, which aims to reduce the crystal ingot breakage rate and micro-crack generation, and improve the quality of the wafer.

[0004] To achieve the above-mentioned purpose, the present application provides a crystal ingot stripping method, which comprises:

[0005] laser modification processing of the wafer material to be processed to obtain a modified wafer material;

[0006] applying vibration energy to the modified wafer material by an ultrasonic vibration plate to generate micro-cracks at the modified position of the modified wafer material, and obtaining a stripped wafer material;

[0007] determining the stripping state of the stripped wafer material;

[0008] processing the wafer surface of the stripped wafer material according to the stripping state, and outputting a target crystal ingot.

[0009] Optionally, the laser modification processing of the wafer material to be processed to obtain a modified wafer material comprises:

[0010] transferring the wafer material to a laser processing station, and arranging the stripping surface of the wafer material to be processed opposite to a laser emitter;

[0011] controlling the laser emitter to emit a laser beam focused on the modified position of the wafer material to be processed at a preset wavelength to perform laser energy deposition on the wafer material to be processed, and generate the modified wafer material.

[0012] Optionally, the control of the laser emitter to emit a laser beam focused on the modified position of the wafer material to be processed at a preset wavelength to perform laser energy deposition on the wafer material to be processed, and generate the modified wafer material comprises:

[0013] matching the laser wavelength based on the optical properties of the wafer material to be processed, and focusing the laser energy on a target depth inside the wafer material to be processed;

[0014] The laser beam is controlled to scan the wafer material to be processed according to a preset spatial distribution mode, so as to form a network of interrelated modified points;

[0015] The evolution state of the network of modified points is monitored, and the laser parameters are dynamically adjusted according to the crack propagation degree between adjacent modified points;

[0016] The processing is terminated when the network of modified points develops into a continuous weakening interface penetrating the cross section of the ingot, and a modified wafer material is obtained.

[0017] Optionally, the modified wafer material is subjected to vibration energy by the ultrasonic vibration plate to generate micro-cracks at the modified positions of the modified wafer material, and a peeled wafer material is obtained, comprising:

[0018] The modified wafer material is adsorbed to the ultrasonic vibration plate by a vacuum chuck;

[0019] The vacuum chuck drives the modified wafer material to reciprocate on the ultrasonic vibration plate according to a preset trajectory;

[0020] The modified wafer material reciprocating according to the preset trajectory is subjected to vibration treatment according to a preset frequency of vibration energy, so as to generate micro-cracks at the modified positions of the modified wafer material, and a peeled wafer material is obtained.

[0021] Optionally, the determination of the peeling state of the peeled wafer material comprises:

[0022] The peeling position of the peeled wafer material is scanned by a multi-spectral imaging device to obtain a distribution map of interfacial bonding state;

[0023] An abnormal reflection feature area in the distribution map of interfacial bonding state is extracted, and an area ratio value of an abnormal area of the abnormal reflection feature area to a total interface area is determined;

[0024] A detection acoustic wave is emitted to the peeling position, and a reflection wave phase shift is analyzed to measure the interfacial stress concentration degree of the peeling position;

[0025] The area ratio value and the reflection wave phase shift are weightedly fused to determine the peeling state, and the peeling state includes complete peeling, partial peeling or no peeling.

[0026] Optionally, after the wafer surface of the peeled wafer material is processed according to the peeling state, a target ingot is output, comprising:

[0027] When the peeling state is complete peeling, the wafer is directly transferred to a thinning station for grinding treatment, so that the wafer reaches a preset target thickness, and the target ingot is output.

[0028] Optionally, after the wafer surface of the peeled wafer material is processed according to the peeling state, a target ingot is output.

[0029] When the peeling state is partial peeling or no peeling, the normal separation force is applied by the vacuum chuck to peel the ingot on the peeled wafer material by the vacuum chuck;

[0030] The separated ingot is transferred to a thinning station for grinding treatment, so that the wafer reaches a preset target thickness, and the target ingot is output.

[0031] Optionally, the ingot peeling method further comprises:

[0032] The surface of the ultrasonic vibration plate is activated before laser modification processing, to generate an atomic-level smooth contact surface;

[0033] During the vibration treatment process, the contact stress distribution between the wafer and the vibration plate is continuously monitored through the atomic-level smooth contact surface;

[0034] The ultrasonic vibration frequency and the motion parameters of the vacuum chuck are dynamically adjusted according to the contact stress distribution.

[0035] In addition, to achieve the above-mentioned purpose, the application further provides a control device, which comprises a memory, a processor, and an ingot peeling program stored in the memory and executable on the processor, and the ingot peeling program is configured to implement the ingot peeling method as described above.

[0036] In addition, to achieve the above-mentioned purpose, the application further provides a peeling device comprising the control device as described above.

[0037] The embodiment of the application peels the wafer material by laser modification processing to obtain a modified wafer material, then applies vibration energy to the modified wafer material by an ultrasonic vibration plate to generate micro-cracks at the modified position of the modified wafer material, to obtain a peeled wafer material, then determines the peeling state of the peeled wafer material, and finally processes the wafer surface of the peeled wafer material according to the peeling state to output a target ingot. In this way, by laser modification processing combined with ultrasonic vibration energy application, the wafer crack rate and the fragment rate are effectively reduced, and the wafer peeling precision is improved. BRIEF DESCRIPTION OF DRAWINGS

[0038] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and serve to explain the principles of the application together with the specification.

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0040] Figure 1 A flowchart of a crystal ingot stripping method according to an embodiment of the present application is shown in FIG. 1.

[0041] Figure 2 A flowchart of step S100 in FIG. 1 is shown in FIG. 2. Figure 1

[0042] Figure 3 A flowchart of step S120 in FIG. 1 is shown in FIG. 3. Figure 2

[0043] Figure 4 A flowchart of step S200 in FIG. 1 is shown in FIG. 4. Figure 1

[0044] Figure 5 A flowchart of step S300 in FIG. 1 is shown in FIG. 5. Figure 1

[0045] Figure 6 A flowchart of a crystal ingot stripping method according to another embodiment of the present application is shown in FIG. 6.

[0046] Figure 7 A flowchart of step S400 in FIG. 6 is shown in FIG. 7. Figure 1

[0047] Figure 8 A flowchart of a crystal ingot stripping method according to still another embodiment of the present application is shown in FIG. 8.

[0048] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the drawings. DETAILED DESCRIPTION

[0049] ​​​​​With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The well-known modules, units and connections, links, communications or operations therebetween are not shown or not described in detail. Furthermore, the described features, architectures or functions can be combined in any way in one or more embodiments. It should be understood by those skilled in the art that the following various embodiments are only used for illustration, but not for limiting the protection scope of the present application. It can also be easily understood that the modules or units or processing manners in the embodiments described herein and shown in the drawings can be combined and designed in various different configurations. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0050] In the following embodiments, the definition of various nouns or methods is generally based on the broad concept that can be implemented on the premise of the disclosed content in the embodiments, except for the cases that are logically impossible. Under such understanding, various specific sub-limits of the nouns or methods should be regarded as the invention content of the present application, and should not be regarded as the specific limit not disclosed in the specification, or be interpreted in a narrow sense or biased. Similarly, under the premise that the order of steps in the method is flexible and changeable, the specific sub-limits of the broad concept of various nouns or methods are within the protection scope of the present application.

[0051] In the prior art, when the crystal ingot is stripped, the crystal ingot is often separated by mechanical methods such as mechanical force of a wedge-shaped blade, resulting in a high crystal ingot fragment rate, and micro-cracks are easily generated in the stripping process, affecting the quality of the wafer.

[0052] The main solution of the embodiment of the present application is: the wafer material to be processed is subjected to laser modification processing to obtain a modified wafer material, ultrasonic vibration plates are used to apply vibration energy to the modified wafer material to generate micro-cracks at the modified position of the modified wafer material, a stripped wafer material is obtained, the stripping state of the stripped wafer material is determined, and finally the wafer surface of the stripped wafer material is treated according to the stripping state, and a target crystal ingot is obtained.

[0053] In the present embodiment, the following is described with the control device as the execution subject for the convenience of description.

[0054] The present application provides a solution, which effectively reduces the wafer crack rate and the fragment rate by laser modification processing combined with ultrasonic vibration energy application, and improves the wafer stripping precision.

[0055] To this end, the present application proposes a crystal ingot stripping method; it can be understood that a control device for storing and executing the following method is arranged in the stripping device, and the control device can be realized by a main controller, such as MCU (Microcontroller Unit), DSP (Digital Signal Process), FPGA (Field Programmable Gate Array), SOC (System On Chip), etc.

[0056] In the prior art, during the manufacturing process of a semiconductor wafer, the crystal ingot stripping link faces significant technical challenges. In the existing wafer stripping process, mechanical stripping auxiliary means is often used to separate the crystal ingot by applying mechanical force through a wedge-shaped blade, but the thin wafer has weak stress bearing capacity, and the broken piece rate is difficult to effectively reduce. These methods are difficult to balance the processing efficiency and wafer integrity in the thin wafer processing scene.

[0057] And the rigid contact of mechanical stripping can aggravate the risk of brittle fracture of the thin wafer. Based on this, in some embodiments of the present application, laser energy deposition and vibration energy transmission are combined, the energy input mode is controlled in stages, non-contact vibration energy is introduced after the formation of the modified layer, and the crack is promoted to expand along the predetermined path to avoid damage to the wafer surface caused by excessive processing.

[0058] Based on the above content, with reference to Figure 1 In an embodiment of the present application, the crystal ingot stripping method comprises steps S100-S400, wherein:

[0059] S100, laser modification processing is performed on the wafer material to be processed to obtain a modified wafer material;

[0060] S200, vibration energy is applied to the modified wafer material by an ultrasonic vibration plate to generate micro-cracks at the modified position of the modified wafer material, and a stripped wafer material is obtained;

[0061] S300, the stripping state of the stripped wafer material is determined;

[0062] S400, after processing the wafer surface of the stripped wafer material according to the stripping state, a target crystal ingot is obtained.

[0063] The laser modification processing refers to a process of forming a weakened interface inside the wafer by using laser energy. A wavelength-matched laser beam can be focused on the target depth. By controlling the scanning path of the light beam, a modification point network is formed. Its role is to reduce the energy threshold required for subsequent peeling. The ultrasonic vibration plate applies vibration energy by transmitting energy to the wafer interface through high-frequency mechanical vibration. A piezoelectric ceramic can be used to drive the vibration plate to generate ultrasonic waves of a specific frequency. Its role is to promote the propagation of micro-cracks along the modification layer through resonance effect. The peeling state determination refers to the quantitative evaluation of the interfacial bonding strength of the wafer. Multi-spectral imaging combined with acoustic reflection analysis can be used. Its role is to provide a dynamic decision basis for subsequent processing.

[0064] The laser modification stage forms a uniformly distributed modification layer inside the wafer by optimizing the laser wavelength and scanning path, avoiding local energy overload and causing disordered crack propagation. Subsequently, the ultrasonic vibration energy is transmitted to the wafer interface in a non-contact manner, promoting the directional extension of micro-cracks along the modification layer through resonance effect, and realizing the controllable separation of the ingot and the substrate. The peeling state monitoring system collects interface bonding data in real time, judges the peeling completion degree through multi-dimensional signal fusion, and guides the selection of subsequent surface treatment process. For completely peeled wafers, thinning processing is directly performed. For partially peeled wafers, a normal separation force is applied to complete the final separation, ensuring that the wafer structure integrity can be maintained under different peeling states.

[0065] Compared with the prior art, the traditional laser peeling relies on a single energy input mode, which can easily lead to uneven stress distribution inside the wafer. The present embodiment realizes gradient regulation of the stress field through staged energy input. The rigid contact of mechanical peeling method can easily cause damage to thin wafers. The present embodiment uses vibration energy transmission method to avoid direct mechanical contact and reduce the risk of interface stress concentration. The prior art lacks real-time state feedback mechanism. The present embodiment realizes closed-loop control of the processing process through multi-modal sensing technology.

[0066] Through the above technical solutions, the present embodiment effectively reduces the risk of hidden cracks in the wafer processing process, avoids the problem of broken pieces caused by mechanical peeling, and also improves the process adaptability and processing stability through dynamic monitoring mechanism, providing reliable technical support for thin wafer manufacturing.

[0067] The present embodiment performs laser modification processing on the wafer material to be processed to obtain a modified wafer material. Then, the ultrasonic vibration plate is used to apply vibration energy to the modified wafer material to generate micro-cracks at the modified position of the modified wafer material, and a peeled wafer material is obtained. The peeling state of the peeled wafer material is determined. Finally, the wafer surface of the peeled wafer material is processed according to the peeling state, and a target ingot is obtained. In this way, by combining laser modification processing with ultrasonic vibration energy application, the wafer hidden crack rate and broken piece rate are effectively reduced, and the wafer peeling precision is improved.

[0068] Optionally, referring to Figure 2 Another embodiment of the present application provides a crystal ingot stripping method based on the above-mentioned Figure 1 As shown in the embodiment, the laser modification processing is performed on the wafer material to be processed to obtain a modified wafer material, including steps S110-S120, wherein:

[0069] S110, transferring the wafer material to a laser processing station, and arranging the stripping surface of the wafer material to be processed opposite the laser emitter;

[0070] S120, controlling the laser emitter to emit a laser beam focused on a modification position of the wafer material to be processed at a preset wavelength, to perform laser energy deposition on the wafer material to be processed, and generate the modified wafer material.

[0071] The laser processing station refers to a processing area configured with a laser emitter and a positioning mechanism, which can be realized by using a high-precision mechanical arm cooperating with a visual positioning system. The laser processing station is used to ensure the spatial alignment of the wafer material and the laser beam. The preset wavelength refers to the laser parameter selected according to the optical absorption characteristics of the wafer material, which can be realized by matching the absorption peak wavelength after measuring the material transmittance curve by a spectrum analyzer. The preset wavelength is used to optimize the deposition efficiency of laser energy in the wafer. The focusing refers to the operation of converging the laser beam to a specific depth inside the wafer, which can be realized by using a multi-axis dynamic focusing lens group cooperating with a real-time thickness detection device. The laser beam focused at the preset wavelength is used to control the energy deposition position to form an accurate modification layer.

[0072] The wafer material can be transferred to the laser processing area by the mechanical arm, and then the wafer posture is adjusted by the visual positioning system so that the stripping surface is opposite the laser emission direction. The laser emitter adjusts the output wavelength according to the pre-obtained optical parameters of the wafer, so that the laser energy is effectively absorbed by the wafer material. The dynamic focusing system adjusts the focal point position according to the wafer thickness detection data, so that the laser beam penetrates the surface and forms an energy deposition area at the target depth. The laser beam scans the wafer surface according to the preset path, forming a continuous distribution of modification point network in the material inside. When the energy deposition amount reaches the critical value, a penetrating weakening interface is formed, and the wafer modification processing is completed.

[0073] The prior art laser stripping technology does not consider the optical characteristic matching problem of the wafer material, resulting in low energy absorption efficiency and easy to cause thermal damage. The embodiment realizes accurate deposition of laser energy at the target depth through wavelength matching and dynamic focusing control, avoiding lattice damage caused by energy diffusion. The positioning accuracy of the wafer in the prior art is insufficient, resulting in deviation of the modification layer. The embodiment cooperates the visual positioning system with the high-precision mechanical arm to ensure that the laser action position is completely coincided with the preset trajectory.

[0074] The embodiment realizes the accurate formation of the modification layer inside the wafer material, effectively reduces the risk of micro-crack propagation caused by uneven energy absorption in the laser processing process. Through wavelength matching and dynamic focusing control, the laser energy utilization efficiency is significantly improved, and the wafer hidden crack problem caused by heat accumulation in the traditional method is avoided. The improvement of positioning accuracy ensures the uniformity of the modification layer distribution, providing a structurally complete weakened interface for the subsequent stripping process.

[0075] Optionally, referring to Figure 3 , another embodiment of the present application provides a crystal ingot stripping method, based on the above Figure 1 The embodiment shown, the laser emitter emits a laser beam with a preset wavelength focused on the modification position of the wafer material to be processed, to deposit laser energy on the wafer material to be processed, to generate the modified wafer material, comprising steps S121-S124, wherein:

[0076] S121, based on the optical properties of the wafer material to be processed, the laser wavelength is matched, and the laser energy is focused on the target depth inside the wafer material to be processed;

[0077] S122, control the laser beam to scan the wafer material to be processed according to the preset spatial distribution mode, form a network of interrelated modification points;

[0078] S123, monitor the evolution state of the modification point network, and dynamically adjust the laser parameters according to the crack propagation degree between adjacent modification points;

[0079] S124, when the modification point network develops into a continuous weakened interface penetrating the cross section of the crystal ingot, the processing is terminated, and the modified wafer material is obtained.

[0080] Wherein, the optical property matching laser wavelength refers to selecting the corresponding laser wavelength according to the absorption coefficient and scattering characteristics of the wafer material to light, which can be measured by a spectrum analyzer to measure the wafer transmittance curve, combined with the laser wavelength adjustment module to realize the matching, so as to ensure that the laser energy is focused on the target depth. The preset spatial distribution mode refers to the scanning path rule formed by the laser beam on the wafer surface or inside, which can be realized by using spiral progressive or grid staggered path planning algorithm to form a uniformly distributed modification point network. The evolution state monitoring refers to capturing the crack propagation form around the modification point through an optical sensor or a high-speed camera, which can be extracted by using an image processing algorithm to extract the crack length and bifurcation angle, and fed back to the laser control system in real time. Dynamic adjustment of laser parameters refers to adjusting the laser power, pulse frequency or focusing position according to the crack propagation trend, which can be realized by using a fuzzy control algorithm to establish the mapping relationship between crack propagation rate and laser parameters. The continuous weakened interface refers to the structure formed by the interconnection of the modification point network, which can be judged by the connectivity detection algorithm of the crack propagation path to determine the termination processing time.

[0081] In the laser processing process, first, a laser beam with a matching wavelength is selected according to the optical properties of the wafer material, for example, a near-infrared laser with a wavelength near 1064 nm can be selected for silicon material. After the laser beam is adjusted to the target depth by the focusing lens, a regular arrangement of modified points is formed inside the wafer according to the preset spiral scanning path. During the scanning process, the high-speed camera is used to capture the crack propagation direction between adjacent modified points in real time. When the crack propagation speed exceeds the threshold value, the laser power is automatically reduced or the pulse interval is increased to inhibit the excessive diffusion of the crack. When the crack network covers the entire target cross section and forms a continuous interface, the laser processing is automatically terminated, and a complete weakened layer is formed inside the wafer.

[0082] The traditional laser lift-off process uses fixed wavelength and constant scanning parameters, which cannot adapt to the differences in optical properties of different materials, resulting in energy deposition position deviation or crack propagation out of control. However, the embodiment can accurately control the crack propagation path and avoid hidden cracks or interface fractures caused by uneven energy distribution through wavelength matching and dynamic parameter adjustment. The embodiment can optimize the laser action position according to the material properties, inhibit the disordered expansion of the crack, and form a uniform and continuous weakened interface, thereby reducing the risk of damage during wafer peeling and improving the processing yield.

[0083] Alternatively, referring to Figure 4 , a third embodiment of the present application provides a crystal ingot peeling method based on the above Figure 1 embodiment, the modified wafer material is subjected to vibration energy by an ultrasonic vibration plate to generate micro-cracks at the modified position of the modified wafer material, and a peeled wafer material is obtained, comprising steps S210-S230, wherein:

[0084] S210, using a vacuum chuck to adsorb the modified wafer material to the ultrasonic vibration plate;

[0085] S220, driving the vacuum chuck to drive the modified wafer material to reciprocate on the ultrasonic vibration plate according to a preset trajectory;

[0086] S230, applying vibration energy to the reciprocating modified wafer material according to a preset frequency to vibrate and process the modified wafer material to generate micro-cracks at the modified position of the modified wafer material, and obtain a peeled wafer material.

[0087] The vacuum chuck refers to a device for fixing the wafer by using the negative pressure adsorption principle, can be realized by using the linkage structure of the porous ceramic substrate and the vacuum pump, and the wafer is stably fixed by adjusting the vacuum degree distribution of the adsorption area. The preset trajectory refers to a pre-set motion path, which can be realized by using a spiral line or a grid scanning mode to ensure that the vibration energy uniformly covers the modified interface. The preset frequency refers to a vibration parameter matched with the inherent frequency of the wafer material, which can generate ultrasonic waves of 20 kHz to 60 kHz through a piezoelectric ceramic transducer, and promote crack propagation by using resonance effect. The reciprocating motion refers to a periodic back-and-forth mechanical displacement, which can realize micro-amplitude vibration of 0.1 mm to 2 mm by driving a linear slide rail through a servo motor, so as to avoid surface scratches caused by wafer slip.

[0088] After the modified wafer material is adsorbed by the vacuum chuck, it is regularly moved along the preset trajectory under the control of the servo system, and the ultrasonic vibration plate generates high-frequency vibration. The vibration energy is transmitted to the wafer interior through the contact surface, so that the stress release occurs in the weakened interface in the modified layer, and the micro-crack is directed to expand along the modified point network. Since the vibration energy is transmitted in the form of wave, the stress distribution presents the uniformization characteristics, and the local stress concentration generated by the traditional mechanical peeling is avoided. When the crack expands to the critical length, the crystal ingot and the wafer are naturally separated at the interface without the need of additional mechanical external force.

[0089] The mechanical peeling of the prior art adopts a wedge-shaped blade to apply a one-way separation force, which is easy to cause stress concentration at the edge of the wafer to cause a broken piece. The embodiment avoids the direct contact between the tool and the wafer by uniformly transmitting the vibration energy in the three-dimensional space to make the crack naturally expand along the modified layer. In addition, the adsorption and fixation of the vacuum chuck can prevent the wafer from being displaced and deviated during the vibration process, so as to ensure that the crack expansion path is accurately aligned with the modified interface. The embodiment realizes the uniformization control of the stress distribution in the crystal ingot peeling process, effectively reduces the risk of hidden cracks caused by stress concentration on the wafer surface. The synergistic effect of the vibration energy and the modified layer structure makes the crack expansion path controllable, and avoids the structural damage to the thin wafer caused by the traditional mechanical peeling. The combined application of vacuum adsorption and ultrasonic vibration improves the stability of the peeling process, and provides a reliable process basis for the large-scale production of ultra-thin wafers.

[0090] Optionally, referring to Figure 5 , the embodiment of the present application also provides a crystal ingot peeling method based on the above-mentioned Figure 1 , determines the peeling state of the peeled wafer material, including steps S310-S340, wherein:

[0091] S310, the peeling position of the peeled wafer material is scanned by a multi-spectral imaging device, and an interface bonding state distribution map is obtained;

[0092] S320, extract the abnormal reflection feature region in the interface bonding state distribution map, and determine an area ratio value of an abnormal region area of the abnormal reflection feature region to a total interface area;

[0093] S330, emit a detection acoustic wave to the peeling position and analyze a reflection wave phase shift amount to measure an interface stress concentration degree of the peeling position;

[0094] S340, weight and fuse the area ratio value and the reflection wave phase shift amount to determine the peeling state, the peeling state including complete peeling, partial peeling or no peeling.

[0095] Wherein, the multispectral imaging device refers to a detection device capable of simultaneously collecting multiple waveband optical signals, which can be realized by an imaging system integrating visible light, near-infrared and short-wave infrared sensors, and is used to capture the reflection characteristic differences of material interfaces at different wavelengths. The abnormal reflection feature region refers to a region where the spectral reflectance suddenly changes due to abnormal interface bonding force, which can be realized by threshold segmentation of multispectral data through image processing algorithms, and is used to identify local defects of the interface bonding state. The detection acoustic wave refers to a mechanical wave with a frequency range of 1 MHz to 10 MHz, which can be realized by emitting a pulse signal using a piezoelectric transducer, and is used to evaluate the stress distribution through the reflection phase change of the acoustic wave at the interface. Weighted fusion refers to the comprehensive calculation of different physical quantities through normalization processing and assigning weight coefficients, which can be realized by a linear weighting model or a fuzzy logic algorithm, and is used to eliminate the errors of a single detection method and improve the judgment accuracy.

[0096] Wherein, in the peeling state detection process, the multispectral imaging device scans the wafer surface after peeling to generate an optical image reflecting the interface bonding state. The abnormal reflection region is extracted through image processing technology, and the area ratio is calculated to evaluate the distribution range of the interface bonding defect. In addition, the piezoelectric transducer emits a high-frequency acoustic wave to the wafer, and the interface stress concentration degree is judged by analyzing the phase shift amount of the reflected wave. Finally, the optical detection result and the acoustic measurement data are weighted and fused, for example, the area ratio value is assigned a weight coefficient of 0.6, and the phase shift amount is assigned a weight coefficient of 0.4, and according to the comprehensive score threshold, the peeling state is determined to be complete peeling, partial peeling or no peeling.

[0097] Compared with the prior art, the traditional method usually only relies on visual inspection or single physical quantity detection, such as observing the crack propagation only through an optical microscope, and cannot quantitatively evaluate the relationship between the interfacial bonding state and the stress distribution. However, the embodiment can simultaneously obtain the spatial distribution characteristics and mechanical state parameters of the interfacial defects by means of the dual-mode detection of multispectral imaging and acoustic wave detection combined with a data fusion algorithm, thereby significantly improving the comprehensiveness and reliability of the peeling state judgment. The embodiment effectively solves the misjudgment problem caused by the single detection dimension of the traditional detection method, and reduces the risk of wafer breakage caused by forcibly performing subsequent processing due to incomplete peeling. At the same time, by quantitatively evaluating the stress concentration degree of the interface, data support can be provided for subsequent processing processes, such as adjusting the separation force parameters for the partially peeled area, so as to achieve a higher yield rate in the processing of thin wafers.

[0098] Optionally, with reference to Figure 6 , another embodiment of the present application provides a crystal ingot peeling method based on the above Figure 1 The embodiment shown, after processing the wafer surface of the peeled wafer material according to the peeling state, a target crystal ingot is output, including step S410.

[0099] S410, when the peeling state is complete peeling, the wafer is directly transferred to a thinning station for grinding treatment, so that the wafer reaches a preset target thickness, and the target crystal ingot is output.

[0100] Wherein, the complete peeling refers to that the crystal ingot at the modified interface has been completely separated from the wafer, although it is visually adhered together, but there is no residual bonding area, which can be determined by the multispectral imaging and acoustic wave reflection detection. The thinning station refers to a processing equipment configured with a grinding disc and a polishing liquid, which can realize precise control of the wafer thickness by using a multi-axis linkage numerical control machine tool. The grinding treatment refers to removing the residual damage layer on the wafer surface by mechanical grinding or chemical mechanical polishing, which can realize surface flattening by using a combination process of diamond grinding wheel and silica slurry. The preset target thickness refers to the final thickness parameter set according to the wafer application scene, which can match different thickness ranges based on the wafer material strength and device structure requirements.

[0101] Wherein, when the peeling state is detected as complete peeling, the crystal ingot and the wafer have formed a complete separation interface, at this time, no additional separation force needs to be applied to directly transfer the wafer. By transferring the wafer to the thinning station, the wafer surface is in contact with the grinding medium during the rotation of the grinding disc, and the surface micro-cracks and modified layer residues are gradually removed. In this process, the grinding pressure and rotation speed are adjusted in real time according to the wafer thickness to ensure that the material removal rate and surface roughness meet the preset target requirements. When the thickness monitoring system detects that the wafer reaches the target value, the grinding is terminated and the finished product is output.

[0102] Compared with the prior art, the traditional method still needs to use a mechanical separation device to process the wafer after complete peeling, which is easy to cause surface damage due to contact stress. The embodiment directly transfers the completely peeled wafer to the thinning station, avoids secondary mechanical intervention, and eliminates the risk of hidden cracks caused by external force. In addition, the existing technology needs to reposition the wafer after separation, which reduces the processing efficiency, and the embodiment reduces the wafer transfer times through process integration. The embodiment can eliminate unnecessary mechanical operations in the completely peeled state, reduce the micro-crack density of the wafer surface caused by secondary processing. At the same time, by optimizing the process flow, the processing cycle is shortened, and the yield stability of the thin wafer in the thinning stage is improved, which is especially suitable for wafer manufacturing scenarios with a thickness of less than 200 microns.

[0103] Optionally, referring to Figure 7 , another embodiment of the present application provides a crystal ingot peeling method based on the above Figure 1 The embodiment shown, after processing the wafer surface of the peeled wafer material according to the peeling state, a target crystal ingot is output, including steps S420-S430, wherein:

[0104] S420, when the peeling state is partial peeling or no peeling, a normal separation force is applied by the vacuum chuck to peel the crystal ingot on the peeled wafer material through the vacuum chuck;

[0105] S430, the separated crystal ingot is transferred to a thinning station for grinding treatment, so that the wafer reaches a preset target thickness, and the target crystal ingot is output.

[0106] Wherein, the normal separation force refers to the separation force perpendicular to the wafer surface, which can be realized by adjusting the negative pressure intensity of the vacuum chuck and the motion parameters of the mechanical arm to avoid lateral shear stress causing wafer damage. The vacuum chuck refers to a device that uses negative pressure to adsorb and fix the wafer, which can be realized by using porous ceramic materials in combination with a vacuum pump system to ensure that the wafer remains stable during separation. The thinning station refers to a device for processing the thickness of the wafer, which can be realized by using a diamond grinding wheel in combination with a precision displacement sensor to control the grinding amount in a closed loop to achieve the target thickness of the wafer.

[0107] Wherein, when it is detected that the peeling interface has an incomplete separation area, the vacuum chuck applies a controllable separation force in the vertical direction to gradually break the residual bonding area of the modified interface, avoiding lateral stress damage to the wafer structure. The separated crystal ingot is transferred to the thinning station, the surface damage layer is removed by grinding, and the thickness is accurately controlled, and finally the target wafer meeting the specifications is obtained.

[0108] Traditional mechanical exfoliation relies on wedge-shaped blades to apply lateral force, which is prone to stress concentration at the edge of thin wafers, resulting in chipping. In contrast, normal separation force can uniformly act on the entire interface, combined with vacuum suction fixation to effectively prevent wafer deviation or local overload. In the prior art, friction damage often occurs at the contact surface between the wafer and the tool. However, the stable suction of the vacuum chuck reduces relative sliding, greatly reducing the risk of surface defects. The present embodiment solves the problem of wafer damage caused by uneven stress in the partial exfoliation state, ensuring the structural integrity of thin wafers during the separation process. At the same time, by precisely controlling the grinding amount, the target thickness is stably produced, improving yield and processing consistency.

[0109] Alternatively, referring to Figure 8 , a further embodiment of the present application provides a crystal ingot exfoliation method based on the above Figure 1 embodiments, the crystal ingot exfoliation method further comprises steps S500-S700, wherein:

[0110] S500, surface activation treatment is performed on the ultrasonic vibration plate before laser modification processing to generate an atomic-level smooth contact surface;

[0111] S600, during the vibration treatment process, the contact stress distribution between the wafer and the vibration plate is continuously monitored through the atomic-level smooth contact surface;

[0112] S700, dynamically adjusting the ultrasonic vibration frequency and the motion parameters of the vacuum chuck according to the contact stress distribution.

[0113] Wherein, the surface activation treatment refers to removing the micro convex on the surface of the ultrasonic vibration plate through chemical etching or ion beam polishing process, which can be realized by hydrogen fluoride solution immersion or argon ion bombardment, so that the surface roughness of the vibration plate is reduced to sub-nanometer level. The atomic-level smooth contact surface refers to a plane with a surface roughness of less than 0.5 nanometers, which can be detected by atomic force microscope to realize the surface topography, which can eliminate the local stress concentration between the wafer and the vibration plate. The contact stress distribution refers to the spatial variation of the pressure per unit area of the wafer and the vibration plate contact area, which can be realized by embedding a pressure sensor array on the surface of the vibration plate to realize real-time measurement, which is used to identify abnormal stress areas.

[0114] Wherein, the surface activation treatment is performed on the ultrasonic vibration plate before laser processing, the surface oxide layer and impurities are removed by chemical etching to form an atomic-level flat contact interface. During the vibration treatment stage, the wafer is fixed on the surface of the vibration plate by the vacuum chuck, and the pressure sensor array collects contact stress data in real time. When local stress exceeds the threshold value, the control module automatically reduces the ultrasonic vibration frequency and adjusts the translation speed of the vacuum chuck to make the stress distribution uniform. For example, when stress peaks appear at the edge of the wafer, the control device can simultaneously reduce the vibration frequency and slow down the moving speed of the chuck to avoid the expansion of micro-cracks out of control.

[0115] The traditional method does not perform precision treatment on the surface of the vibration plate, and micro-unevenness exists on the contact surface of the wafer and the vibration plate, which leads to uneven vibration energy transmission and easily causes hidden cracks or fragments. The surface activation treatment is used to eliminate the defects on the contact surface in the embodiment, and the real-time stress monitoring and dynamic parameter adjustment are combined to solve the technical problem of uneven stress distribution. The embodiment effectively reduces the risk of hidden cracks of the wafer in the vibration treatment stage, avoids the problem of fragments caused by local stress concentration, and is especially suitable for the processing scene of thin wafers with a thickness of less than 200 microns, and significantly improves the stability and yield of the stripping process.

[0116] Reference Figures 1 to 8 The overall principle of the disclosed application is as follows in combination with all the above embodiments:

[0117] The crystal ingot and wafer are moved to a thinning station for grinding, the crystal ingot is processed by laser modification, the crystal ingot is adsorbed by a vacuum chuck (mechanical hand), the round surface of the crystal ingot is attached to the ultrasonic plate, the surface of the ultrasonic plate is as smooth as possible, the mechanical hand provides a small force (0-20N) to make the crystal ingot tightly attached to the ultrasonic plate, and the risk of wafer fragmentation is reduced during movement, the mechanical hand drives the crystal ingot to move on the ultrasonic plate in a reciprocating manner, high-frequency vibration is performed for 2 minutes and low-frequency vibration is performed for 1 minute, and whether the crystal ingot is stripped is checked, if not, the crystal ingot is connected by the vacuum chuck (mechanical hand) after stripping, and then the crystal ingot and wafer are moved to the thinning station for grinding, and if yes, the crystal ingot and wafer are moved to the thinning station for grinding.

[0118] The application further provides a control device, which comprises a memory, a processor and a crystal ingot stripping program stored in the memory and executable on the processor, and the crystal ingot stripping program is configured to implement the crystal ingot stripping method.

[0119] It is worth noting that, since the control device is based on the above-mentioned crystal ingot stripping method, the embodiments of the control device include all the technical solutions of all the above-mentioned crystal ingot stripping methods, and the technical effects achieved are also completely the same, which will not be repeated here.

[0120] The application further provides a stripping device, which comprises the control device as described in the above embodiments.

[0121] It is worth noting that, since the stripping device is based on the above-mentioned control device, the embodiments of the stripping device include all the technical solutions of all the above-mentioned control devices, and the technical effects achieved are also completely the same, which will not be repeated here.

[0122] It should be noted that, in this document, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises... a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.

[0123] The above-mentioned embodiment numbers of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0124] From the above description of the embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be realized by means of software and the necessary general hardware platform, of course, they can also be realized by hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, which is stored in a storage medium (such as a ROM / RAM, a magnetic disk, or an optical disk) as described above, and includes a number of instructions for making a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) execute the methods described in the various embodiments of the present application.

[0125] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent flow transformation made by using the content of the specification and drawings, or directly or indirectly applied to other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for ingot stripping, characterized in that, The ingot stripping method includes: Laser modification is performed on the wafer material to be processed to obtain modified wafer material, including: The wafer material is transferred to the laser processing station, with the peeling surface of the wafer material to be processed facing the laser emitter. Controlling the laser emitter to emit a laser beam at a preset wavelength and focusing it on the modification site of the wafer material to be processed, so as to perform laser energy deposition on the wafer material to be processed to generate the modified wafer material, including: The laser wavelength is matched with the optical properties of the wafer material to be processed, so that the laser energy is focused on the target depth inside the wafer material to be processed. The laser beam is controlled to scan the wafer material to be processed according to a preset spatial distribution pattern, forming an interconnected network of modified particles; The evolution of the modified particle network is monitored, and the laser parameters are dynamically adjusted according to the degree of crack propagation between adjacent modified particles. Processing is terminated when the modified particle network develops into a continuous weakened interface that penetrates the cross section of the ingot, and modified wafer material is obtained. Vibrational energy is applied to the modified wafer material using an ultrasonic transducer to generate microcracks at the modification sites, thereby obtaining the stripped wafer material. Determining the stripping state of the stripped wafer material includes: The peeling location of the peeled wafer material is scanned using a multispectral imaging device to obtain an interface bonding state distribution map. Extract the abnormal reflection feature regions from the interface state distribution map, and determine the area ratio of the abnormal region area to the total interface area. A sound wave is emitted toward the peeling location and the phase shift of the reflected wave is analyzed to measure the degree of interface stress concentration at the peeling location. The area ratio value and the reflected wave phase offset are weighted and fused to determine the peeling state, which includes complete peeling, partial peeling, or no peeling. After processing the wafer surface of the stripped wafer material according to the stripping state, the target ingot is produced.

2. The ingot stripping method as described in claim 1, characterized in that, The step of applying vibrational energy to the modified wafer material using an ultrasonic transducer to induce microcracks at the modification sites, thereby obtaining the stripped wafer material, includes: The modified wafer material is adsorbed onto the ultrasonic transducer using a vacuum chuck; The vacuum chuck drives the modified wafer material to reciprocate along a preset trajectory on the ultrasonic vibrating plate. Vibration energy is applied at a preset frequency to vibrate the reciprocating modified wafer material, thereby creating microcracks at the modification sites of the modified wafer material and obtaining the stripped wafer material.

3. The ingot stripping method as described in claim 1, characterized in that, The step of processing the wafer surface of the stripped wafer material according to the stripping state to produce the target ingot includes: When the stripping state is complete, the wafer is directly transferred to the thinning station for grinding to achieve the preset target thickness and produce the target ingot.

4. The ingot stripping method as described in claim 1, characterized in that, The step of processing the wafer surface of the stripped wafer material according to the stripping state to produce the target ingot includes: When the peeling state is partial peeling or no peeling, the vacuum chuck is controlled to apply a normal separation force to peel the ingot from the peeling wafer material through the vacuum chuck. The separated ingots are transferred to a thinning station for grinding to achieve a preset target thickness, thus producing the target ingot.

5. The ingot stripping method as described in claim 1, characterized in that, The ingot stripping method further includes: Before laser modification, the ultrasonic transducer plate is surface activated to generate an atomically smooth contact surface. During the vibration treatment process, the contact stress distribution between the wafer and the vibration plate is continuously monitored through the atomically smooth contact surface; The ultrasonic vibration frequency and the motion parameters of the vacuum chuck are dynamically adjusted according to the contact stress distribution.

6. A control device, characterized in that, The control device includes: a memory, a processor, and an ingot stripping program stored in the memory and executable on the processor, the ingot stripping program being configured to implement the ingot stripping method as described in any one of claims 1 to 5.

7. A stripping device, characterized in that, Includes the control device as described in claim 6.

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