Crystal ingot slicing device, method and system

Abstract

The invention provides an ingot slicing device, method and system, and relates to semiconductor processing. According to the invention, the linear flat-topped light beam is creatively adopted to perform crystal ingot fragmentation, that is, the laser for crystal ingot fragmentation can be converted into the flat-topped light and then converted into the linear flat-topped light beam, and the linear flat-topped light beam forms linear light spots with uniform energy distribution on the focal plane of the linear flat-topped light beam. Based on the light shaping process, the light spot length of the linear flat-topped light can be dozens of microns, and compared with a traditional circular light spot of 1-2 microns, the linear flat-topped light beam provided by the invention can have a larger working range, so that the moving path and the working time of the crystal ingot during slicing are reduced, and the working efficiency of the crystal ingot slicing is remarkably improved.

Description

Technical Field

[0001] The present application relates to semiconductor processing, and in particular to a crystal ingot slicing device, method and system. Background Art

[0002] An ingot is a cylindrical object formed by polycrystalline or single crystal silicon. It is the raw material for making wafers. In semiconductor processing, the ingot needs to be sliced ​​first to obtain wafers for subsequent processing (such as etching circuits).

[0003] However, with the continuous development of semiconductor technology, especially the rapid development of the third generation of semiconductors represented by silicon carbide (SiC), SiC has become a new choice for making high-temperature, high-frequency and high-power electronic components, considering its high breakdown electric field, high thermal conductivity, and significantly higher electron saturation rate than other semiconductor materials and strong radiation resistance. However, its ultra-high hardness also makes it difficult to process.

[0004] Therefore, how to achieve efficient slicing of ingots (especially silicon carbide ingots) is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] In view of this, the embodiments of the present application provide a crystal ingot slicing device, method and system. The present application uses laser stripping technology to provide a suitable stripping spot for the crystal ingot, thereby achieving crystal ingot slicing.

[0006] In a first aspect, the present application provides a crystal ingot slicing device, which includes: a laser, a laser modulation module, and a crystal ingot carrier, wherein the laser modulation module is used to modulate the laser generated by the laser into a linear flat-top beam and focus it on the inside of the crystal ingot to be processed on the crystal ingot carrier, and the crystal ingot carrier is used to carry and move the crystal ingot to be processed. The laser modulation module includes a beam expansion module, a flat-top light shaping module, a linear shaping module, and a focusing objective lens, which are sequentially arranged along the output optical path of the laser. The beam expansion module and the flat-top light shaping module are used to convert the laser generated by the laser into a flat-top beam, the linear shaping module is used to convert the flat-top beam into a linear flat-top beam, and the focusing objective lens is arranged directly with respect to the crystal ingot to be processed and is used to focus the focal plane of the linear flat-top beam on the inside of the crystal ingot to be processed on the crystal ingot carrier, wherein the linear flat-top beam forms a linear light spot at the focal plane, and the linear light spot is in the shape of a straight line with uniform energy distribution.

[0007] In a second aspect, the present application provides a method for slicing an ingot, the method comprising: loading the ingot to be processed on an ingot carrier. Driving a laser to emit laser, wherein the laser generated by the laser is modulated into a linear flat-top beam by a laser modulation module, and the linear flat-top beam forms a linear light spot at a focal plane, and the linear light spot is a straight line with uniform energy distribution. Focusing the focal plane of the linear flat-top beam on the inside of the ingot to be processed, wherein microcracks are formed in the area where the linear light spot is located in the ingot to be processed. Driving the ingot carrier to carry the ingot to be processed to move, and forming a microcrack layer inside the ingot to be processed. Peeling a wafer from the ingot to be processed based on the microcrack layer.

[0008] In a third aspect, the present application provides an ingot slicing system, the ingot slicing system comprising an ingot slicing device and a controller communicatively connected to the ingot slicing system. The ingot slicing device comprises a laser, a laser modulation module and an ingot carrier. The controller is used to control the ingot slicing device to perform the ingot slicing method described in the second aspect.

[0009] The embodiments of the present application provide a crystal ingot slicing device, method and system, which creatively adopts a linear flat-top beam for crystal ingot slicing, that is, the present application can convert the laser used for crystal ingot slicing into a flat-top light and then into a linear flat-top beam, and the linear flat-top beam forms a linear light spot with uniform energy distribution in its focal plane. Based on the aforementioned light shaping process, the spot length of the linear flat-top light can be tens of microns. Compared with the traditional circular spot of 1 to 2 microns, the linear flat-top beam provided by the present application can have a larger operating range, thereby reducing the moving path and operating time of the crystal ingot during slicing, thereby significantly improving the operating efficiency of crystal ingot slicing. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 This is a system schematic diagram of an ingot slicing system provided in some embodiments of the present application.

[0012] Figure 2 This is a module schematic diagram of the ingot slicing device provided in some embodiments of the present application.

[0013] Figure 3 This is a schematic diagram of the internal optical path of a laser modulation module based on optical elements provided in some embodiments of the present application.

[0014] Figure 4It is a schematic diagram of a light spot at a focal plane provided in some embodiments of the present application.

[0015] Figure 5 It is an exemplary flow chart of the ingot slicing method provided in some embodiments of the present application.

[0016] Figure 6 This is a schematic diagram of a processing path based on a linear flat-top beam provided in some embodiments of the present application.

[0017] Figure 7 It is an exemplary flow chart of a processing path determination method provided in some embodiments of the present application.

[0018] Figure 8 It is an exemplary flow chart of a method for determining a linear flat-top beam shape provided in some embodiments of the present application. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] Application Overview:

[0021] In traditional processes, ingots can generally be sliced ​​by physical cutting to obtain chips (also called wafers, wafers, etc.) of a specific thickness. For example, a traditional diamond wire saw can be used to cut the ingot to separate the chips. However, physical cutting has process disadvantages such as high processing loss, low cutting efficiency, large surface damage, and low yield. In particular, as the substrate diameter continues to increase, traditional cutting processes are difficult to meet the needs of large-size ingots (such as the cutting needs of 8-inch SiC ingots).

[0022] In the related art, the ingot can be cut based on the laser stripping technology. The principle of the laser stripping technology is to use the laser to focus below the surface of the wafer, and scan layer by layer at different depths inside the silicon ingot to generate a single or multiple modified layers. Afterwards, under the action of external tension, the cracks in the modified layer extend in a direction perpendicular to the wafer surface, causing the wafer to split from the inside to the outside, thereby stripping the wafer from the silicon carbide ingot.

[0023] To further illustrate the actual operation process of the aforementioned laser lift-off technology, the present application also provides a system structure diagram of a crystal ingot slicing system ( Figure 1 ).

[0024] like Figure 1As shown, the ingot slicing system 100 may include a laser 110 , a laser modulation module 120 , an ingot stage 130 , and a wafer peeling mechanism 140 .

[0025] The laser 110 can be used as a light source of the ingot slicing system 100 to provide the laser required for ingot slicing. For example, laser cutting of silicon carbide generally uses a picosecond or femtosecond infrared laser as a light source, and the near-infrared wavelength can better penetrate silicon carbide and focus inside the material to form a modified zone.

[0026] The laser modulation module 120 can be used to adjust the laser generated by the laser 110 to meet the requirements of the ingot splitting. For example, the laser modulation module 120 can adjust the laser through the spatial light modulation technology to meet the requirements of the ingot splitting. In addition, the laser modulation module 120 can also be set toward the ingot carrier 130 to align the ingot to be processed on the ingot carrier 130.

[0027] The ingot carrier 130 may be a platform for placing an ingot. That is, after the ingot is placed on the carrier, the laser generated by the laser 110 is adjusted by the laser modulation module 120 and focused inside the ingot on the ingot carrier 130. Thus, a moving light spot can form a layer of microcracks inside the ingot.

[0028] Considering the high power of the laser 110, the aforementioned light spot moving process (also called scanning process) can be realized by the ingot stage 130, that is, the aforementioned ingot stage 130 can be a moving stage. Thus, when the light spot is focused in the ingot, the ingot is driven to move, thereby forming a layer of microcracks.

[0029] The wafer peeling mechanism 140 can be used to peel the wafer from the ingot based on the aforementioned microcracks. For example, after the laser modifies the inside of the ingot, the wafer is automatically separated by rapidly cooling the polymer and the ingot. The aforementioned wafer peeling mechanism 140 can be a collection of equipment for the process.

[0030] In practical applications, the laser light generated by the aforementioned laser 110 is generally adjusted to appear as a circular spot in the ingot. Considering the requirements for ingot stripping, the size of the circular spot is generally within 2 microns, and considering the size of the ingot (such as 6 inches, 8 inches), the circular spot of the aforementioned size requires a long time to process, which seriously affects the stripping efficiency of the wafer.

[0031] In order to solve the aforementioned technical problems, the present application provides an ingot slicing device, method and system, which relate to semiconductor processing. The present application creatively adopts a linear flat-top beam for ingot slicing, that is, the present application can convert the laser used for ingot slicing into a flat-top light and then into a linear flat-top beam, and the linear flat-top beam forms a linear light spot with uniform energy distribution in its focal plane. Based on the aforementioned light shaping process, the spot length of the linear flat-top light can be tens of microns. Compared with the traditional circular spot of 1 to 2 microns, the linear flat-top beam provided by the present application can have a larger operating range, thereby reducing the moving path and operating time of the ingot during slicing, thereby significantly improving the operating efficiency of ingot slicing.

[0032] In some embodiments, when the aforementioned ingot slicing system adopts the ingot slicing device provided in the present application, the ingot slicing device can be controlled by a controller to execute the ingot slicing method provided in the present application.

[0033] The following will be combined Figure 2-Figure 8 The present application provides a crystal ingot slicing device and method for further explanation.

[0034] Exemplary Ingot Slicing Apparatus:

[0035] To further illustrate the ingot slicing device provided by the present application, the present application provides a module schematic diagram of the ingot slicing device ( Figure 2 ). Among them, the ingot slicing device can be used as the main execution device of the aforementioned ingot slicing system. In addition to the ingot slicing device, the ingot slicing system can also include components such as a support structure and a controller.

[0036] like Figure 2 As shown, the ingot slicing device 200 provided in the present application may include a laser 210, a laser modulation module 220, and an ingot carrier 230. Different from the aforementioned ingot slicing system 100, the laser modulation module 220 may be used to modulate the laser light generated by the laser 210 into a linear flat-top beam and focus it on the inside of the ingot to be processed on the ingot carrier 230.

[0037] In practical applications, in the aforementioned ingot slicing device 200, the laser 210 can be selected according to the slicing requirements of the ingot. For example, for slicing of silicon carbide ingots, the laser 210 uses a picosecond or femtosecond infrared laser with a wavelength of 300nm to 1064nm and a pulse width of 200fs to 10ps. The pulse duration of a femtosecond or picosecond laser is less than the coupling time (picosecond order) between electrons and phonons in silicon carbide, and is therefore suitable for silicon carbide modification.

[0038] The laser generated by the aforementioned laser 210 is generally a Gaussian beam, that is, the intensity distribution of the beam presents a Gaussian function shape, that is, the light intensity decreases exponentially with the degree of deviation from the beam axis, the light intensity in the central area is the strongest, and the light intensity away from the central area decreases rapidly.

[0039] The laser modulation module 220 can transform the Gaussian beam into a linear flat-top beam, and the linear flat-top beam has two properties:

[0040] ① Flat-top beam properties: Flat-top beam is a type of laser beam whose light intensity distribution is uniform, that is, the light intensity distribution is flat on the cross section of the beam. The energy distribution of this beam is more uniform. Compared with Gaussian lasers directly released by lasers, flat-top beams have the advantages of high energy transfer and low heat-affected zone.

[0041] ② Linear form: The linear flat-top beam is approximately linear in its focal plane, that is, it has a longer length and a narrower width. Therefore, when the linear flat-top beam moves based on its long side direction (that is, it moves perpendicular to its long side direction and moves along the extension direction of the short side direction), the linear flat-top light sweeps a larger area. At the same time, considering its smaller width, the linear spot has a larger lateral length and a high-density output power compared to the circular spot after convergence, which effectively reduces the path length that the ingot cutting laser needs to run, thereby improving processing efficiency.

[0042] To realize the aforementioned linear flat-top beam, the aforementioned laser modulation module 220 may further include a beam expansion module 221, a flat-top light shaping module 222, a linear shaping module 223 and a focusing lens 224 which are sequentially arranged along the laser output optical path.

[0043] The beam expansion module 221 can be used to amplify the laser beam and reduce the divergence angle. The flat beam expansion module 221 can generally be implemented by a beam expander or other beam expansion system. Among them, the beam expander is an optical device, which is mainly used to change the diameter and divergence angle of the laser beam. The beam expander is usually composed of two or more lenses, which can enlarge or reduce the diameter of the input collimated beam. Based on the aforementioned design requirements, in the aforementioned beam expansion module 221, the beam expander can be used to amplify the laser and reduce the divergence angle of the laser.

[0044] In some embodiments, considering the actual needs, when slicing based on the laser generated by the laser 210, the light intensity of the laser can also be adjusted, so as to perform slicing with appropriate power. That is, the aforementioned beam expansion module 221 can also include a light intensity adjustment component. The light intensity adjustment component can be used to adjust the light intensity of the laser generated by the laser 210. Among them, the light intensity adjustment component can generally be implemented by an optical device that can adjust the light transmittance ratio. For example, the light intensity adjustment component can be presented as an electrically controlled liquid crystal lens, which adjusts the focus and refractive index of light by controlling the voltage, thereby achieving adjustment of the light intensity.

[0045] The flat-top light shaping module 222 may be an optical device or a collection thereof for shaping the laser after beam expansion. The flat-top light shaping module 222 may be used to convert the laser light generated by the laser into a flat-top beam. The flat-top beam is a laser beam with uniform light intensity distribution. That is, on the cross section of the flat-top beam, the light intensity distribution presents a flat shape.

[0046] The flat top light shaping module 222 can be implemented based on a beam homogenization component that can shape Gaussian light into a flat top light. For example, the beam homogenization component can be implemented by a device such as an aspheric lens, a diffractive optical element (DOE), a microlens array, a liquid crystal spatial light modulator, etc. By setting a suitable shape / configuring suitable parameters, the beam homogenization component can modulate the aforementioned amplified Gaussian beam into a flat top beam.

[0047] In actual laser slicing, if the laser has wavefront aberration and spherical aberration, it will cause uneven focusing of the beam, thus affecting the quality of the processed surface. For example, spherical aberration will cause the size of the beam to change at the focus, which will affect the spatial resolution and processing efficiency of the system. In addition, wavefront aberration will cause the beam to be distorted, making the laser energy distribution uneven, thus causing surface damage.

[0048] In order to overcome the above phenomenon, a correction component for correcting the wavefront aberration of the flat top beam may be provided in the above flat top light shaping module 222. The correction component may be used to adjust the wavefront shape of the flat top beam, which may generally be achieved by a wavefront adjustment component. For example, the correction component may include a deformable mirror (DM), a liquid crystal spatial light modulator (SLM) and other devices.

[0049] Therefore, based on the aforementioned flat-top beam shaping module 222 , the Gaussian beam emitted by the laser 210 can be transformed into a flat-top beam, and the spherical aberration and wavefront thereof can be corrected.

[0050] The linear shaping module 223 can be used to transform the aforementioned flat-top beam into a linear flat-top beam, wherein the linear flat-top beam forms a linear light spot at the focal plane, and the linear light spot is in the shape of a straight line with uniform energy distribution.

[0051] In some embodiments, the linear shaping module 223 can be implemented based on components that can implement beam shaping. For example, the linear shaping module 223 can be implemented by components such as cylindrical mirrors, Powell prisms, diffractive optical elements (DOEs), and micro-optical lenses.

[0052] The focusing lens 224 can be arranged directly opposite to the ingot to be processed, so as to focus the linear flat-top beam in the ingot to be processed. The focusing lens 224 is generally implemented by a plurality of lens groups, so as to stably focus the focal plane at a specific position.

[0053] Considering that a high numerical aperture (NA) objective lens combined with a flat top light can improve the smoothness and uniformity of the material surface and reduce surface defects, that is, by controlling the laser energy and focusing characteristics, the quality of the material surface can be significantly improved and the generation of longitudinal cracks can be reduced, the aforementioned focusing objective lens 224 can be set as a high numerical control objective lens.

[0054] However, high NA can lead to increased spherical aberration. Spherical aberration refers to the image blur caused by the uneven curvature of the lens surface. Especially when using high NA lenses, spherical aberration is more likely to occur due to the large incident angle of light, thus affecting the quality of the light spot.

[0055] Therefore, a spherical aberration compensation structure may be included in the aforementioned focusing objective lens 224. The spherical aberration compensation structure is used to compensate for the spherical aberration of the beam of the laser modulation module and can improve the numerical aperture of the focusing objective lens. Among them, being able to improve the numerical aperture of the focusing objective lens does not mean that the numerical aperture of the focusing objective lens 224 is improved based on the design, but allows the use of an objective lens design with a higher numerical aperture.

[0056] The spherical aberration compensation structure can be used to eliminate spherical aberration. Considering that the focusing objective 224 is generally a lens group, the aforementioned spherical aberration compensation structure can be a combination of optical elements. For example, the spherical aberration compensation structure can include a lens combination (such as a doublet lens), an aspherical lens, and other structures. For another example, the spherical aberration compensation structure can also be characterized as an immersion medium. That is, in some cases, using an immersion medium (such as oil or water) with a refractive index similar to that of the sample protection glass can significantly increase the numerical aperture and eliminate spherical aberration.

[0057] Therefore, based on the aforementioned laser modulation module 220 , it is possible to modulate the laser light generated by the laser 210 into a linear flat-top beam and focus it inside the ingot to be processed on the ingot carrier 230 .

[0058] The ingot carrier 230 can carry the ingot to be processed and move when the linear flat-top beam is focused inside the ingot to be processed. The linear spot focused inside the ingot to be processed will cause cracks to form inside the ingot to be processed, and the movement of the ingot carrier 230 can extend the cracks to the entire plane to form a micro-crack layer.

[0059] After the microcrack layer of the wafer is formed, the wafer can be peeled off from the ingot based on the auxiliary peeling process. In order to reduce the damage to the wafer surface, the aforementioned auxiliary peeling process can be implemented based on ultrasonic vibration. That is, the ingot slicing device 200 can also include an ultrasonic vibration device. The ultrasonic vibration device is used to perform an auxiliary peeling process based on ultrasonic vibration on the ingot to be processed after the microcrack layer is formed in the ingot to be processed, and the wafer is peeled off from the ingot to be processed based on the microcrack layer.

[0060] Therefore, based on the aforementioned ingot slicing device, a linear flat-top light is creatively used for ingot slicing, that is, the present application can convert the laser used for ingot slicing into a flat-top light and then into a linear flat-top light, and the linear flat-top light forms a linear light spot with uniform energy distribution in its focal plane. Based on the aforementioned light shaping process, the spot length of the linear flat-top light can be tens of microns. Compared with the traditional circular spot of 1 to 2 microns, the linear flat-top light provided by the present application can have a larger operating range, thereby reducing the moving path and operating time of the ingot during slicing, thereby significantly improving the operating efficiency of ingot slicing.

[0061] In some embodiments, considering that some of the modules in the above modules may need to be implemented by electronic control components, and further considering that electronic control components have usage restrictions and are relatively expensive. For example, although spatial light modulation technology can modulate light beams in time and space, it is not suitable for large-scale, high-energy, and long-term operation requirements due to the low damage threshold of liquid crystals, and there is a high threshold for industrial application due to price and cost restrictions.

[0062] Considering the above situation, in order to further reduce the operation requirements and reduce the cost. The aforementioned laser modulation module 220 can be implemented based on optical elements. Among them, optical elements are devices used to control, adjust or convert light, and are widely used in optical systems and instruments, including lenses, prisms, filters, beam splitters, etc. These elements realize the effective control of light based on the physical properties of light by focusing, diverging, splitting, reflecting, refracting, etc.

[0063] To further illustrate the laser modulation module based on optical elements, the present application also provides a schematic diagram of the internal optical path of the laser modulation module ( Figure 3 ).

[0064] like Figure 3As shown, the laser modulation module 220 still includes the aforementioned beam expansion module 221, flat-top light shaping module 222, linear shaping module 223 and focusing lens 224 which are sequentially arranged along the laser output optical path, and each module can be constructed based on optical elements.

[0065] like Figure 3 As shown, the beam expansion module 221 may include a 1 / 2 wave plate 2211, a polarization beam splitter 2212, and a beam expander 2213. The beam expander 2213 is generally composed of a lens group, which is used as the main functional component of the beam expansion module 221 to amplify the laser and reduce the divergence angle of the laser. The 1 / 2 wave plate 2211 and the polarization beam splitter 2212 can be combined as a light intensity adjustment component to adjust the intensity of the laser.

[0066] Among them, the 1 / 2 wave plate 2211 can be used to change the polarization direction of the incident light. When the linear polarized light passes through the 1 / 2 wave plate 2211, its polarization direction will rotate 90 degrees, but the light intensity will not change. The polarization beam splitter 2212 is used to split the incident light beam into two beams according to its polarization direction, respectively transmitted and reflected. For example, horizontally polarized light is usually transmitted by the polarization beam splitter 2212, while vertically polarized light is reflected.

[0067] When the 1 / 2 wave plate 2211 and the polarization beam splitter 2212 are combined to form a light intensity adjustment component, the laser can first pass through the 1 / 2 wave plate 2211 and then pass through the polarization beam splitter 2212, and the ratio of transmitted light and reflected light can be adjusted by rotating the 1 / 2 wave plate 2211, thereby adjusting the laser intensity.

[0068] like Figure 3 As shown, the aforementioned flat top light shaping module 222 can be formed by an aspheric lens group, that is, the flat top light shaping module 222 includes a first aspheric lens 2221 and a second aspheric lens 2222. Among them, the first aspheric lens 2221 is used as the aforementioned beam homogenization component, which is used to change the deflection angle of the Gaussian beam, and form a flat top beam at the focal position of the first aspheric lens 2221. The second aspheric lens 2222 is set at the focal position of the first aspheric lens 2221 and is configured as a correction component, which is used to shape the beam so that the wavefront shape of the flat top beam is adjusted to a plane.

[0069] In the modulation process, the first aspheric lens 2221 introduces wave aberration to redistribute the light beam energy, and the second aspheric lens 2222 compensates for the wave aberration generated by the first aspheric lens 2221 and collimates the outgoing light beam.

[0070] It should be noted that, considering the overall wavefront problem of the optical system, when designing the second aspheric lens 2222, it is also possible to design based on the wavelength aberration and spherical aberration generated by other optical elements (such as the beam expander 2213) to further collimate the flat-top beam.

[0071] like Figure 3 As shown, the linear shaping module 223 includes a cylindrical mirror 2231. The cylindrical mirror 2231 can be composed of a curved surface and a flat surface, and the curved surface is drawn along an axis to form a curved surface with a rectangular cross section. When the light beam is irradiated to the curved surface of the cylindrical mirror 2231, it will be focused by the curved surface, and the light beam perpendicular to the curved surface will directly pass through the cylindrical mirror 2231.

[0072] As a result, part of the beam tube in the flat top beam along the curved surface direction (focusing direction of the cylindrical mirror) will be converged by the cylindrical mirror 2231, while the beam in the flat top beam perpendicular to the curved surface direction will directly pass through the cylindrical mirror 2231. As a result, the light spot of the flat top beam will be compressed in the curved surface direction to form a linear flat top beam.

[0073] Considering that in the process of generating the linear flat top beam, the shape of the linear flat top beam is related to the flat top beam, in order to further modulate its shape, the linear shaping module 223 may further include an adjustment lens 2232. The adjustment lens 2232 may be disposed between the cylindrical mirror 2231 and the focusing objective lens 224 to adjust the shape (width and length) of the linear flat top beam.

[0074] In addition to the aforementioned adjustment lens 2232, the aforementioned focusing lens 224 can also adjust the shape of the linear flat top beam. In order to adjust the shape of the appropriate linear flat top beam, at least one of the aforementioned cylindrical mirror 2231, the adjustment lens 2232 and the focusing lens 224 is detachably connected to the main structure (such as a bracket) where the laser modulation module 220 is located.

[0075] The aforementioned detachable connection refers to that at least one of the cylindrical mirror 2231, the adjustment lens 2232, and the focusing lens 224 can be removed and replaced with other components in the main structure to change the device parameters, rather than not requiring the corresponding optical device. Therefore, based on the detachable structure, a suitable cylindrical mirror 2231, the adjustment lens 2232, and the focusing lens 224 can be selected and installed in the main structure to change the combination relationship of the cylindrical mirror 2231, the adjustment lens 2232, and the focusing lens 224 in the laser modulation module 220, thereby adjusting the shape of the linear flat-top beam to meet the needs of slicing.

[0076] In some embodiments, in order to adapt to the actual working space, one or more reflectors can be set in the aforementioned light path to adjust the distribution of the light path in space to match the application scenario. Figure 3In the embodiment, a 45° reflector is arranged between the flat-top light shaping module and the linear light shaping module to change the direction of the light path.

[0077] In some embodiments, a scanning galvanometer can also be set in the aforementioned optical path (the reflector between the aforementioned flat-top light shaping module and the linear shaping module can be configured as a scanning galvanometer) to directly realize the position change of the light spot in the focal plane in the laser modulation module without the need for the ingot carrier to drive the ingot to be processed to move.

[0078] To further illustrate the changes of the light spot in the above process, the present application also provides a schematic diagram of the light spot at the focal plane ( Figure 4 ).

[0079] Figure 4 There are four types of light spots. 4a can present a Gaussian light spot released by a laser. 4b can reflect a flat-top light spot of a flat-top beam. 4c can reflect a linear light spot after being processed by a cylindrical mirror. 4d can reflect a linear light spot focused in a silicon ingot.

[0080] As shown in 4a, the brightness of the Gaussian spot can be distributed in space according to the Gaussian law, that is, the center energy is higher and the edge energy gradually decreases. As shown in 4b, the size of the flat-top beam spot is larger than the aforementioned Gaussian spot and the energy is evenly distributed in the spot. As shown in 4c, a linear spot can be formed based on the flat-top spot of 4b, so that the length is consistent with the aforementioned flat-top spot, and the thickness is compressed by the cylindrical mirror. As shown in 4d, the linear spot is still linear (i.e., a narrower rectangle), but its size changes due to the influence of the adjustment lens and the focusing objective.

[0081] Exemplary Ingot Slicing Method:

[0082] To further illustrate the slicing process based on the aforementioned ingot slicing device, the present application also provides an exemplary flow chart of an ingot slicing method ( Figure 5 ).

[0083] Figure 5 The process P500 shown can be executed by a controller in the ingot slicing system, that is, the controller can control the electronic control device in the ingot slicing device to execute the aforementioned P500. When the laser modulation module of the aforementioned ingot slicing device is constructed by optical elements, the controller can control the laser and the ingot carrier to execute the following method:

[0084] S510, loading the ingot to be processed onto the ingot carrier.

[0085] S520, driving the laser to emit laser.

[0086] S530, focusing the focal plane of the linear flat-top beam on the inside of the ingot to be processed.

[0087] S540, driving the ingot carrier to move with the ingot to be processed, and forming a micro-crack layer inside the ingot to be processed.

[0088] S550, peeling a wafer from the ingot to be processed based on the micro-crack layer at the target focus position.

[0089] In the aforementioned S510, the ingot to be processed may be the ingot sliced ​​in the aforementioned P500. In some embodiments, the ingot posture may be provided with an ingot stopper to fix the ingot at a specific position of the ingot carrier. In addition, considering the different sizes of the ingots, the size of the ingot may be input into the ingot slice system by the staff or sensed by the sensor in the ingot slice system. The size of the general ingot is 6 inches or 8 inches.

[0090] In the aforementioned S520, after the driving laser emits laser light, it is processed by the aforementioned laser modulation module to form a linear flat-top beam.

[0091] In the aforementioned S530, considering that the aforementioned laser and the ingot carrier are fixedly arranged in space, the position of the focal plane of the aforementioned linear flat-top beam in space is fixed. Therefore, the position of the ingot to be processed can be adjusted so that the focal plane is focused inside the ingot to be processed. Among them, the silicon ingot at the position of the linear light spot inside the ingot to be processed will be modified by the linear flat-top beam, thereby forming microcracks.

[0092] In some embodiments, considering that the ingot is generally sliced ​​longitudinally, that is, the slicing direction is horizontal. When focusing, the focal plane position can be focused to the target focusing position of the ingot to be processed in the vertical direction. Among them, the target focusing position can refer to the position where the ingot needs to be sliced. Among them, the target focusing position is generally determined based on the thickness of the wafer. That is, the distance from the target focusing position to the top surface can be the wafer thickness or an integer multiple thereof. The specific position can be determined according to the actual preparation process.

[0093] Specifically, if only one wafer is separated each time, the distance from the target focus position to the top surface of the ingot can be the wafer thickness to separate one wafer. If multiple wafers can be separated each time, the distance from the target focus position to the top surface of the ingot can be the wafer thickness and its integer multiple, thereby forming multiple microcrack layers to separate multiple wafers.

[0094] In some embodiments, the aforementioned S530 can be implemented by aligning the target focus position with the focal plane, wherein, to ensure the stability of the optical system, the target focus position is generally aligned with the focal plane by longitudinally moving the ingot to be processed.

[0095] In some embodiments, the alignment process may be triggered based on the detection results of the target focal position and the focal plane, that is, when executing the aforementioned S530, the focal plane position of the linear flat-top beam may be determined first. Then, the target focal position of the ingot to be processed is determined based on the wafer slice thickness. Finally, in response to the inconsistency between the focal plane position and the target focal position, the ingot to be processed is driven to move in the vertical direction to align the target focal position with the focal plane position.

[0096] Among them, in the aforementioned ingot slicing system, the laser and the laser modulation module are fixedly set, and their focal plane positions can be directly determined based on their device parameters. When the ingot to be processed is loaded on the ingot carrier, the top surface of the ingot to be processed will be sensed by the ingot slicing system, and thus, the target focus position based on the top surface of the ingot will also be sensed by the controller. When the two positions are converted to the same coordinate system, it can be determined whether they coincide (such as whether the Z-axis coordinates are consistent). Alignment is performed when they are inconsistent.

[0097] In particular, the inconsistency between the focal plane position and the target focus position can reflect three situations: the ingot has just been placed, the ingot has been sliced, and the target focus position has been changed. The alignment based on this condition can reflect the alignment operation of subsequent slicing after completing some operations during the entire processing of the ingot.

[0098] In the aforementioned S540, considering that microcracks will form in the area where the linear light spot at the target focusing position of the ingot to be processed is located, the microcracks can be spread throughout the target focusing position by moving the plane position of the linear light spot at the target focusing position in a horizontal plane, thereby forming a microcrack layer.

[0099] This process can be achieved through the relative movement of the crystal ingot and the linear flat-top beam in a horizontal plane. In order to ensure the stability of the optical system, the relative movement of the crystal ingot and the linear flat-top beam can be achieved by the crystal ingot carrier.

[0100] To ensure that the microcracks are distributed throughout the target focus position, when the ingot carrier moves, a suitable processing path can be determined based on the spot length of the linear spot and the size of the ingot to be processed. Then the wafer carrier is driven to move along the processing path. This ensures that the linear spot covers the cross section of the ingot to be processed at the target focus position along the processing path, so that the microcracks are distributed throughout the target focus position to form a microcrack layer.

[0101] In some embodiments, the aforementioned processing path generally includes two types: linear reciprocating motion and rotation. Considering that the distance from the axis is different during rotation, the area to be processed is different, so the moving speed also needs to be considered when executing the aforementioned processing path. That is, the moving speed of the processing path can be determined first. Then the wafer carrier is driven to move along the processing path based on the moving speed. Among them, the linear spot moving along the processing path based on the moving speed moves the same area per unit time to ensure that the aforementioned microcracks are evenly distributed at the target focusing position.

[0102] In the aforementioned S550, after the aforementioned microcrack layer is formed, the wafer can be peeled off based on the microcrack layer. The specific peeling method can be selected according to actual needs, and the present application can use ultrasonic vibration to perform peeling.

[0103] Therefore, the ingot slicing method provided in the present application can be based on the aforementioned linear flat-top beam for slicing, and when slicing, a suitable processing path can be configured based on the spot shape of the linear flat-top beam to form a uniformly distributed microcrack layer, thereby ensuring the slicing effect.

[0104] To further illustrate the processing path based on the linear flat-top beam, the present application also provides a schematic diagram of the processing path based on the linear flat-top beam ( Figure 6 ) and an exemplary flowchart of a method for determining a machining path ( Figure 7 ).

[0105] Considering that the ingot is generally cylindrical, Figure 6 In the embodiment, a circular wafer can be used as an example for explanation.

[0106] like Figure 6 As shown, reciprocating motion can be used to implement the slicing, thereby executing Boustrophedon path planning. That is, multiple sets of parallel paths can be planned based on their coverage, and the distance between each parallel path is ensured to be the working range (i.e. the length of the aforementioned linear spot), thereby forming a processing path.

[0107] That is Figure 7 As shown, process P700 may include:

[0108] S710 , forming a plurality of parallel paths on a cross section of the ingot to be processed based on the spot length.

[0109] S720 , connecting various parallel paths based on the cross-sectional edge of the ingot to be processed to determine a processing path.

[0110] In the aforementioned S710, the direction of the parallel paths may be perpendicular to the length direction of the linear light spot. In addition, to ensure that the linear light spot can completely cover the cross section, the distance between any two adjacent parallel paths in the aforementioned parallel paths is less than or equal to the light spot length.

[0111] In addition, when planning the aforementioned parallel paths, planning can be performed based on the edge of the cross section so that the parallel path closest to the edge is half the length of the linear spot from the edge. Then, parallel paths are generated as much as possible within the range of the cross section based on the length of the linear spot.

[0112] In the aforementioned S720, in order to further reduce the processing path, the connection between each parallel path can be set based on the edge of the cross section, so that the processing path is as short as possible while ensuring that the processing path completely covers the cross section.

[0113] Thus, based on the aforementioned P700, a processing path that can completely cover the cross section of the ingot can be generated, so that based on the processing path, a uniform microcrack layer covering the entire cross section can be formed at the target focusing position.

[0114] In some embodiments, considering that the cylindrical mirror, adjustment lens and focusing lens in the aforementioned laser modulation module can be adjusted, when performing crystal ingot slicing, the shape of the linear flat-top light of this slicing can also be determined first, and then the laser modulation module can be modulated.

[0115] To further illustrate the process, the present application also provides an exemplary flow chart of a method for determining a linear flat-top beam shape ( Figure 8 ).

[0116] like Figure 8 As shown, process P800 may include the following steps:

[0117] S810, determining the spot power requirement of the ingot to be processed.

[0118] S820: Determine an expected length of the linear light spot that meets the light spot power requirement based on the total power of the linear light spot.

[0119] S830, adjusting the laser modulation module based on the expected length so that the spot length of the linear spot is smaller than the expected length.

[0120] In the aforementioned S810, the spot power requirement may reflect the spot power required to generate microcracks under the execution process parameters of the ingot to be processed (such as the average moving speed of the processing path). The actual spot power should be greater than or equal to this value to ensure the normal generation of microcracks.

[0121] In the aforementioned S820, the total power may refer to the total power of the light beam focused on the focal plane after the aforementioned laser modulation module is lost. That is, considering the properties of the flat-top beam, when the light intensity is evenly distributed at the spot, the distribution of the total power may be determined based on its spot size. After determining the aforementioned spot power requirement, its shape may be reversely calculated to determine the desired shape.

[0122] Therefore, after determining the desired shape of the linear flat-top light spot, the parameters of the laser modulation module can be adjusted accordingly to make the shape of the actual light spot consistent with the aforementioned desired shape (such as the actual light spot length is less than or equal to the aforementioned expected length to increase the energy distribution density), so that its light spot power meets the aforementioned requirements.

[0123] In some embodiments, considering that the cylindrical mirror, the adjustment lens and the focusing lens can be adjusted (such as disassembled and matched), the aforementioned S830 can also be implemented by matching appropriate components, that is, the aforementioned S830 can also include the following steps:

[0124] S831. Determine a target beam reduction system for the linear flat-top beam based on a desired length.

[0125] S832, installing the adjustment lens and focusing objective lens of the target beam reduction system in the laser modulation module.

[0126] In some embodiments, the candidate adjustment lenses and focusing lenses can be combined, and the shapes of the linear light spots formed by the combinations can be calibrated. Based on the aforementioned expected length, a combination that can meet the expected length is selected as a target beam reduction system, and the adjustment lens and focusing lens of the target beam reduction system are installed in the laser modulation module.

[0127] In addition, a cylindrical mirror can also be used as a part of the aforementioned combination, so that a suitable cylindrical mirror is selected and placed in the laser modulation module.

[0128] Therefore, the laser modulation module provided in the present application can select suitable devices to adjust the light spot shape according to actual work needs, so that the light spot under the shape can complete the corresponding work task.

[0129] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present application, and will not be described one by one here.

[0130] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0131] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0132] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0133] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0134] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0135] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program check codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0136] It should be noted that, in the description of this application, the terms "first", "second", "third", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0137] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A crystal ingot slicing device, characterized in that: include: A laser, a laser modulation module and an ingot carrier, wherein the laser modulation module is used to modulate the laser light generated by the laser into a linear flat-top beam and focus the beam inside the ingot to be processed on the ingot carrier, and the ingot carrier is used to carry and move the ingot to be processed; The laser modulation module comprises a beam expansion module, a flat-top light shaping module, a linear shaping module and a focusing objective lens which are sequentially arranged along the output optical path of the laser; The beam expansion module and the flat-top light shaping module are used to convert the laser generated by the laser into a flat-top beam, the linear shaping module is used to convert the flat-top beam into the linear flat-top beam, the focusing objective is arranged facing the crystal ingot to be processed and is used to focus the focal plane of the linear flat-top beam inside the crystal ingot to be processed on the crystal ingot carrier, wherein the linear flat-top beam forms a linear light spot at the focal plane, and the linear light spot is in the shape of a straight line with uniform energy distribution.

2. The ingot slicing device according to claim 1, characterized in that: The flat-top light shaping module includes a beam homogenization component and / or a correction component; the beam homogenization component is used to homogenize the laser light generated by the laser to form the flat-top beam; the correction component is used to adjust the wavefront shape of the flat-top beam.

3. The ingot slicing device according to claim 2, characterized in that: The beam homogenization component is a first aspheric lens, and the correction component is a second aspheric lens, wherein the second aspheric lens is arranged at the focal position of the first aspheric lens; The first aspheric lens is used to change the deflection angle of the laser light generated by the laser, and form the flat-top beam at the focal position of the first aspheric lens; The second aspheric lens is used to shape the light beam so that the wavefront shape of the flat-top light beam is adjusted to a plane.

4. The ingot slicing device according to claim 1, characterized in that: The focusing objective lens comprises a spherical aberration compensation structure, and the spherical aberration compensation structure is used to compensate for the spherical aberration of the light beam of the laser modulation module.

5. The ingot slicing device according to claim 1, characterized in that: The linear shaping module includes a cylindrical mirror and an adjusting lens, and the adjusting lens is arranged between the cylindrical mirror and the focusing objective lens; The component of the flat top beam along the curved surface direction of the cylindrical mirror is converged by the curved surface of the cylindrical mirror to form the linear flat top beam, and the adjustment lens is used to adjust the shape of the linear flat top beam; At least one of the cylindrical mirror, the adjusting lens and the focusing objective lens is detachably connected.

6. A method for slicing a crystal ingot, characterized in that: include: Loading the ingot to be processed on the ingot carrier; Driving the laser to emit laser, wherein the laser generated by the laser is modulated into a linear flat-top beam by a laser modulation module, and the linear flat-top beam forms a linear light spot at a focal plane, and the linear light spot is in the shape of a straight line with uniform energy distribution; Focusing the focal plane of the linear flat-top beam on the inside of the ingot to be processed, wherein microcracks are formed in the ingot to be processed in the area where the linear light spot is located; Driving the ingot carrier to move with the ingot to be processed, and forming a micro-crack layer inside the ingot to be processed; A wafer is peeled off from the ingot to be processed based on the microcrack layer.

7. The ingot slicing method according to claim 6, characterized in that: The step of driving the ingot carrier to carry the ingot to be processed to move comprises: Determining a processing path based on the spot length of the linear spot and the size of the ingot to be processed; The ingot carrier is driven to move along the processing path, wherein the linear light spot covers a cross section of the ingot to be processed along the processing path.

8. The ingot slicing method according to claim 6, characterized in that: The method further comprises: Determining the spot power requirement of the ingot to be processed; Determining an expected length of the linear light spot that meets the light spot power requirement based on the total power of the linear light spot; The laser modulation module is adjusted based on the expected length so that the spot power of the linear spot meets the spot power requirement.

9. The ingot slicing method according to claim 6, characterized in that: The step of focusing the focal plane of the linear flat-top beam on the inside of the ingot to be processed comprises: determining a focal plane position of the linear flat-top beam; Determining a target focusing position of the ingot to be processed based on the wafer slice thickness; In response to the inconsistency between the focal plane position and the target focal position, the ingot to be processed is driven to move in a vertical direction to align the target focal position with the focal plane position.

10. A crystal ingot slicing system, characterized in that: The ingot slicing system comprises: An ingot slicing device, wherein the ingot slicing device comprises a laser, a laser modulation module and an ingot carrier; and A controller is communicatively connected to the ingot slicing system, and the controller is used to control the ingot slicing device to execute the ingot slicing method according to any one of claims 6 to 9.

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