TWI735924B - Incident radiation induced subsurface damage for controlled crack propagation in material cleavage - Google Patents

Abstract

A cleaving system employs a shaper, a positioner, an internal preparation system, an external preparation system, a cleaver, and a cropper to cleave a workpiece into cleaved pieces. The shaper shapes a workpiece into a defined geometric shape. The positioner then positions the workpiece such that the internal preparation system can generate a separation layer at the cleaving plane. The internal preparation system focuses a laser beam internal to the workpiece at a focal point and scans the focal point across the cleaving plane to create the separation layer. The external preparation system scores the external surface of the workpiece at a location coplanar to the separation layer. The cleaver cleaves the workpiece by propagating the crack on the external surface along the separation layer. The cropper shapes the cleaved piece into a geometric shape as needed.

Description

Subsurface damage caused by incident radiation for controlled crack propagation in material cracking

The present invention relates generally to material processing and more specifically to the use of incident radiation to prepare the workpiece for cracking and for cracking the workpiece.

Semiconductors are one of the important and valuable materials in the electronics and photovoltaic industries due to their unique properties, multi-purpose applications and widespread use now. Semiconductors are usually used in wafer form. However, current wafer fabrication methods are wasteful and can cause up to 50% material loss. It is an industry standard to saw large-scale semiconductor ingots/assembly mechanical wires into thin wafers, but the kerf loss caused by the saw wires is inevitable. Saw cutting also damages the surface of the resulting wafer, resulting in the need for damaged material removal and subsequent surface processing to achieve advanced wafers required for many applications. Polishing and mechanical grinding are commonly used to process the surface of the wafer, and these post-processing steps remove even more material from the wafer, thereby further increasing the overall material loss. The high material loss during the manufacturing of semiconductor wafers results in less semiconductor materials available for applications and higher cost per wafer. A similar argument can be made for advanced insulators used in a wide range of industries for diverse applications (for example, such as silica, alumina, zirconia, magnesia, etc.).

Cracking material workpieces through crack propagation is one of the promising alternatives to current wafer processing methods because it leads to very little material loss. In addition, it is seen that this type of cracking results in a higher quality wafer surface, which may reduce or eliminate the need for subsequent processing steps to achieve a high quality surface finish. However, it is challenging to efficiently produce wafers through these cracking methods.

The present invention describes a cracking system that uses a reduced amount of force to accurately crack a workpiece into one or more cracked parts compared with the traditional technology. The cracking system includes a shaper, a positioner, an internal preparation system, an external preparation system, a cracker and a cut-off device.

The cracking system can use various methods to produce cracked parts. For example, the shaper shapes a workpiece into a defined geometric shape (such as a cylinder). In this way, any one of the fragments produced by the cracking system can be a cross section of the defined geometric shape (for example, a circle). The cracking system determines the position of a cracking plane inside the workpiece. Then, the positioner positions the workpiece so that the internal preparation system can create a separation layer at the cracking plane.

To create the separation layer, the internal preparation system focuses a laser beam to a focal point inside the workpiece to create a local area ("coverage area") in the workpiece in which the mechanical properties have changed. The internal preparation system scans across the splitting plane with the laser beam to create the separation layer by generating many coverage areas. The separation layer is a material layer in the workpiece that is structurally different from the material around the separation layer. The structural difference between the separation layer and the surrounding materials facilitates the disintegration of the workpiece into disintegrated parts. More than one separation layer can be created inside the workpiece.

The external preparation system scribes the external surface of the workpiece at a position coplanar with the separation layer. Then, the cracker cracks the workpiece by expanding the crack on the outer surface along the separation layer. More specifically, the cracking system exerts a pulling force on the opposite end of the workpiece to cause the crack to expand along the different materials of the separation layer and thereby produce a cracked piece. The breaker shapes the disintegration piece into any geometric shape as needed.

Cross reference of related applications

This application claims the rights of U.S. Provisional Application No. 62/703,642 filed on July 26, 2018, and the entire content of the case is hereby incorporated by reference. System Overview

FIG. 1 illustrates a system environment 100 for cracking a workpiece 130 according to an embodiment. The environment 100 includes a system controller 120, a cracking system 110, and a workpiece 130. Within the environment 100, the system controller 120 determines a fragmentation plane 160 for the workpiece 130. The system controller 120 controls the cracking system 110 to generate a separation layer 140 along the cracking plane 160 in the workpiece 130. To this end, the cracking system 110 generates a coverage area 150 in the workpiece 130 to facilitate the cracking system 110 to crack the workpiece 130. Then, the system controller 120 controls the cracking system 110 to crack the workpiece along the separation layer 140. Cracking system

FIG. 2 shows a cracking system 110 in the environment 100. The cracking system 110 cracks a workpiece 130 into two or more pieces. When the workpiece 130 is a semiconductor ingot, the cracking system 110 can crack the semiconductor ingot into one or more semiconductor wafers.

The cracking system 110 includes a shaper 210, a positioner 220, an internal preparation system 230, an external preparation system 240, a cracker 250, and a cutoff 260.

The shaper 210 shapes the workpiece 130 so that the workpiece 130 can be cracked by the cracking system 110. Shaping the workpiece 130 may include forming the workpiece 130 into a known geometric shape, such as a cylinder, a rectangular prism, or some other shape. In some examples, shaping the workpiece 130 may include adding material or removing material from the workpiece 130. The removal of material from the workpiece 130 can be accomplished by a saw, a grinder, an etching process, or some other instrument or process that can remove material from the workpiece 130. Adding material to the workpiece 130 can be accomplished by chemical vapor deposition, thermal oxidation, atomic layer deposition, or any other method of adding material to the workpiece. In some cases, the shaped workpiece 130 may be received from an external source or supplier. In any case, the shaped workpiece 130 has a shape that can be cracked by the cracking system 110.

The shape of the workpiece 130 is selected based on the desired shape of the broken piece. Some examples include a workpiece 130 having a circular, rectangular, square, or pseudo-square cross-sectional area to produce a piece of the same shape. In other examples, the shape of the workpiece 130 is not the shape of the produced piece. In order to form commercially viable pieces (for example, wafers), compliance with industry standards may be preferable. For example, a 4-inch round wafer is a standardized, commonly used type of wafer, so the workpiece 130 used to form the wafer will have a cross-sectional area of a circle with a diameter of 4 inches (or 100 mm). Cylindrical. Other standard diameters of round wafers include 1 inch (25 mm), 2 inches (51 mm), 3 inches (76 mm), 5.9 inches (150 mm), 7.9 inches (200 mm), 11.8 inches (300 mm) And 17.7 inches (450 mm). The standard side lengths of quasi-square wafers include 125 mm and 156 mm, which are made from initial cylindrical pieces with diameters of 165 mm and 210 mm, respectively. In addition, according to industry standards, the workpiece 130 may include notches or flat portions. These characteristics can indicate the orientation of the crystal structure of the material (if it is single crystal). For example, an n-doped (100) silicon wafer has two flat portions parallel to each other, and can be made of a workpiece 130 having a cylindrical shape with two parallel flat portions cut on opposite sides of the length of the cylinder .

In addition, a cut-off device 260 can accurately cut the broken piece into a desired geometric shape after the breaker 250 has broken the workpiece 130. This allows the disintegration system 110 to disintegrate the workpiece 130 in one shape but produce a disintegrated part of a final geometry. For example, the cracker 250 is configured to crack the square workpiece 130. Thus, the shaper 210 shapes the workpiece 130 into a square and cracks the workpiece 130 into square wafers. However, in this case, the desired shape of the wafer is a circle. Therefore, the chopper 260 cuts the square wafer into a circular wafer of the desired geometric shape. The cutter 260 performs its function by any method of removing material from the wafer (including but not limited to laser cutting, wafer sawing, chemical etching, waterjet cutting, etc.).

In addition, the workpiece 130 can be shaped so that the two surfaces of the workpiece 130 are parallel to a cracking plane 160. The cracking plane 160 is a plane of the workpiece 130 defined in advance by the separation layer 140 and determined by the system controller 120 (the cracker 250 cracks along the plane). The two surfaces can be parallel to the cracking plane 160 so that the cracker 250 can crack the workpiece 130 more efficiently. An example of this procedure is described in more detail with respect to FIGS. 7A to 8C. Generally speaking, the two surfaces or faces are on opposite ends of the workpiece 130. For example, for a workpiece 130 in a cylindrical, single crystal silicon ingot (where the long axis of the ingot is perpendicular to the (100) crystal plane), the shaper 210 can shape the workpiece 130 so that it has the opposite end of the ingot On the two faces with the same (100) crystal orientation.

The outer surface of the shaped workpiece 130 may include residual surface roughness. Therefore, in some configurations, the shaper 210 prepares the surface of the workpiece 130 for cracking by reducing the surface roughness. In various embodiments, the shaper 210 uses a mechanical polishing, a chemical mechanical polishing, a wet etching process (for example, a chemical etching process), a dry etching process (for example, reactive ion etching), and a hot surface reflow process. The program or any other program that can prepare the surface of the workpiece 130 for cracking is used to prepare the surface.

The positioner 220 positions the workpiece 130 and/or the cracking system 110 during the cracking procedure. In one example, the positioner 220 positions the workpiece 130 while the cracking system 110 remains stationary. Alternatively, the positioner 220 positions the cracking system 110 while the workpiece 130 remains stationary. In some cases, the positioner 220 positions both the cracking system 110 and the workpiece 130 at the same time. More generally, the positioner 220 facilitates the cracking of the workpiece 130 by appropriately aligning the cracking system 110 and the workpiece 130. The positioner 220 can be any number of elements capable of positioning the workpiece 130 or the cracking system 110. For example, the positioner 220 may include components such as motors, positioning platforms, piezoelectric devices, and mounting accessories, together with appropriate sensing elements for detecting the position of the workpiece 130 and the cracking system 110, and accurately positioning the workpiece 130 and the cracking system 110 For the control system required for subsequent processing.

The internal preparation system 230 prepares the workpiece 130 for cracking by generating a separation layer 140. A separation layer 140 is a material layer in the workpiece 130 that is different from the surrounding materials and facilitates cleavage along the plane of the separation layer 140. Generally speaking, the separation layer 140 is coplanar with the cracking plane 160. To generate the separation layer 140, the internal preparation system 230 generates a laser beam and focuses the laser beam at a focal point (ie, a coverage area 150) inside the workpiece 130. In other configurations, the internal preparation system can generate any other type of incident radiation that can generate a coverage area 150 inside a workpiece 130. Generally speaking, the laser changes the structure of the workpiece 130 at the coverage area 150 to locally weaken the material, thereby creating a better location for crack propagation. The structure of the workpiece 130 has not been significantly modified at any location except the coverage area 150. As an example, the internal preparation system 230 may generate a certain amount of heat energy at the coverage area 150 to melt the material of the workpiece 130 in the area.

The internal preparation system 230 cooperates with the positioner 220 to generate a coverage area 150 along the cracking plane 160 within the workpiece 130. Therefore, the coverage area 150 changes the structure of the workpiece 130 in the cleavage plane 160 as a whole to produce a separation layer 140. Because the structure of the workpiece 130 in the separation layer 140 is different from the structure around the separation layer 140, the workpiece 130 is more likely to be split along the plane of the separation layer 140. The process of generating a separation layer 140 is described in more detail with respect to FIG. 6.

FIG. 3 shows the internal preparation system 230 in more detail. The internal preparation system 230 includes a laser source 310, a beam shaper 320, a coverage area positioning element 330, and a workpiece geometry compensation optical device 340.

The laser source 310 generates pulses of radiation at a repetition rate. The laser pulse forms a collimated symmetrical laser beam. The laser beam has a wavelength that is longer than the electronic band gap of the material of the workpiece 130, so that when the laser enters the workpiece 130, the material of the workpiece 130 is not excited by electrons. Generally speaking, the laser source 310 has a wavelength between 0.2 µm and 20 µm, for example. This allows the internal preparation system 230 to create a separation layer 140 for a workpiece 130 having an electronic band gap between 0.1 eV and 10 eV, for example.

In one embodiment, a beam shaper 320 generates an asymmetric laser beam. The optics of the beam shaper 320 can be operated as a cylindrical telescope that generates an asymmetric laser beam. The asymmetric laser beam allows a larger coverage area 150 when focused in the workpiece 130. Generating a larger coverage area 150 from a single pulse allows the separation layer 140 to be fabricated faster for the same laser repetition rate. Asymmetrical beams can also produce a thinner separation layer 140. The thinner separation layer 140 allows the cracker 250 to crack a workpiece 130 with lower force and provides less roughness on the resulting separation surface. In one embodiment, the main axis of the asymmetric laser beam is parallel to the long axis of the workpiece 130. In another embodiment, the main axis of the laser beam is perpendicular to the long axis of the workpiece 130. The laser beam can be re-collimated after the beam shaper 320. For some workpiece shapes, an asymmetric laser beam may not be necessary.

A coverage area positioning element 330 focuses the laser beam to a coverage area 150 inside the workpiece 130. Generally speaking, the geometry of the coverage area 150 in the cleavage plane 160 is configurable, and the thickness of the coverage area 150 for determining the thickness of the separation layer 140 is less than, for example, 20 μm but can be any other size. In one embodiment, the coverage area positioning element 330 is a rotationally symmetric, positive focal length optical device. The coverage area positioning element 330 can move along the propagation axis of the laser beam. The movement of the coverage area positioning element 330 along this axis allows the depth of the coverage area 150 in the workpiece 130 to vary along the same axis.

In an embodiment, the workpiece 130 and the workpiece geometry compensation optical device 340 can move in unison with the coverage area positioning element 330 to also change the depth of the coverage area 150 in the workpiece 130. In some cases, the depth of the coverage area 150 within the workpiece 130 may far exceed, for example, 1 mm. The depth of the coverage area 150 within the workpiece 130 is only limited by the optical transmission of the workpiece 130 material and the laser parameters (such as average power, peak power, and wavelength). The material properties of the workpiece 130 affect the laser parameters (ie, wavelength, peak power, average power) that can produce a coverage area 150 in the workpiece 130. For example, a laser having a first wavelength can be used to generate a coverage area in a workpiece of a first material, and a laser having a second wavelength can be used to generate a coverage area in a workpiece of a second material. Similar coverage area. Other examples are also possible.

A workpiece geometry compensation optics 340 compensates for the shape of the workpiece 130 surface and reduces aberration (such as astigmatism) effects to change the position of the coverage area positioning element 330 and maintain the flux required to generate a coverage area 150 in the workpiece 130 . The workpiece geometry compensation optics 340 may include more than one element that compensates for a single aberration or many aberrations. For some workpiece shapes, this optical device may be unnecessary.

In summary, the internal preparation system 230 and the positioner 220 are configured to generate a coverage area 150 at any location within the workpiece 130. In addition, the configuration of the internal preparation system 230 controls the shape and size of the coverage area 150. For example, one configuration of the internal preparation system 230 produces a coverage area 150 in the separation layer 140 that is a 4-μm×20-μm ellipse, and another configuration produces a 20-μm diameter circle in the separation layer 140 One covers area 150. As previously discussed, the thickness of the coverage area 150 will be determined mainly by the configuration of the beam shaper 320 and the coverage area positioning element 330, but generally will be less than 20 μm.

The internal preparation system 230 may have several other optical device combinations that function similarly. For example, refractive optical elements can be replaced by reflective optical devices (curved mirrors). The beam shaper 320 can be a deformed pair of beams instead of a cylindrical telescope. The workpiece geometry compensation optics 340 can be replaced by a free-form optics, which in addition to compensating the shape of the workpiece 130 will also help compensate for any aberrations caused by the previous optics.

The external preparation system 240 prepares the workpiece 130 for lysis by scoring the outer surface of the workpiece 130. Scribing the outer surface of the workpiece 130 introduces a crack into the workpiece 130. The cracker 250 spreads the crack along the separation layer 140 throughout the workpiece 130 to crack the workpiece 130 into multiple pieces. Generally speaking, the external preparation system 240 scores the workpiece 130 at the same position as the separation layer 140 (desirably along which it is split), but can score the workpiece 130 in other positions as needed. In one embodiment, the functions of the external preparation system 240 are performed by some or all of the components of the internal preparation system 230.

The external preparation system 240 can score the workpiece 130 in several ways. For example, the external preparation system 240 can use a laser to ablate the material of the workpiece 130, physically remove the material of the workpiece 130 (using a mechanical scribing, sawing, chiseling, etc.), and etching the workpiece 130 (using a gas , Chemicals, plasma, etc.) or any other process that can score the workpiece 130 to score the workpiece 130.

In an example in which the external preparation system 240 scribes the workpiece 130 at the same position as the separation layer 140, scribing the surface may partially expand a crack at the periphery of the separation layer 140. The partially expanded cracks further expand throughout the separation layer 140 when the workpiece 130 is cracked. For example, the internal preparation system 230 generates a separation layer 140 on one (100) plane of the silicon workpiece 130. The external preparation system 240 scribes the silicon workpiece 130 along the periphery of the separation layer 140 and introduces a crack on the (100) plane. Therefore, when the cracker 250 cracks the silicon workpiece 130, the crack spreads over the entire separation layer 140 along the (100) plane. The extent to which the cracks extend along the separation layer 140 depends on the characteristics of the separation layer 140 (for example, thickness, uniformity, etc.), the method of scribing the workpiece 130 (for example, ablation, physical removal, etc.), and the material of the workpiece 130 And orientation (e.g., crystal orientation, composition, etc.).

The cracker 250 cracks the workpiece 130 into one or more pieces. In one example, the cracker 250 applies a mechanical pulling force 440 normal to the separation layer 140 to crack the workpiece 130. In one embodiment, the mechanical pulling force 440 is applied to the workpiece 130 through an electrostatic clamp 410 attached to the opposite end of the workpiece 130. A voltage 416 between the electrostatic clamp 410 and the workpiece 130 is applied to make them adhere firmly together. When a mechanical pulling force 440 is applied to pull the electrostatic clamp 410 apart in a controlled manner, the workpiece 130 is broken.

FIG. 4 shows an exemplary procedure for cracking a workpiece 130 with a cracker 250 (for example, a capacitive clamp 410). A capacitive clamp 410 includes a non-conductive layer 414 and a conductive body 412. The non-conductive layer 414 is close to one surface of the conductive body 412. In some embodiments, the non-conductive layer 414 is directly deposited on the surface of the conductive body 412 so that it is chemically adhered. In many embodiments, the other side of the conductive body 412 is fixed to some kind of support 430. This can be done by any suitable means for fastening or attaching the two materials mechanically or chemically. If the support 430 is made of metal or another conductive material, a non-conductive attachment method is used to prevent the voltage 416 applied to the conductive body 412 from being applied to the support 430 and may cause a short circuit or some other hazards. In one embodiment, the workpiece 130 can be attached to the clamp 420 using epoxy resin or other types of adhesive, and the clamp 420 will remain permanent when the clamp 410 splits multiple pieces from the workpiece 130 in a repeated manner. Attached to the workpiece 130. In some embodiments, the shape of the capacitive clamp 410 matches the cross-sectional geometry of the workpiece 130.

The capacitive clamp 410 fixes the workpiece 130 by generating an electrostatic force such as the electrostatic force experienced by the plates of a parallel plate capacitor. A voltage supply 416 is used to energize the conductive body 412 to a high voltage, and the workpiece 130 is energized to the opposite polarity or grounded. In addition, the non-conductive layer 414 prevents any charge from being transferred from the conductive body 412 to the workpiece 130, and vice versa. Therefore, the charges are accumulated at the nearest surfaces of both the conductive body 412 and the workpiece 130. Because these charges are opposite and therefore attractive, an electric field is generated in the non-conductive layer 414 and an associated electrostatic force is also generated.

Although the strength of the electrostatic force required to fix the workpiece 130 to the capacitive clamp 410 can vary, the compressive stress applied is usually about 10 ⁶ Pa to 10 ⁸ Pa. This stress is usually generated by applying a voltage 416 from (including but not limited to) the range of 100 V to 500 kV (which depends on the thickness and dielectric properties of the non-conductive layer 414). For example, a 100-nm ₂ across the non-conductive layer thick HfO 414 100-V bias voltage is applied to produce about one-one 10 ⁸ Pa compressive stress. Similarly, applying a 500-kV bias across a 500-µm thick non-conductive layer 414 of quartz will produce a compressive stress of ^{approximately 10 7 Pa.} Fracture mechanics analysis indicates that the stress required to propagate the crack 404 mainly depends on the initial crack depth and the sharpness of the crack tip. For example, if the crack 404 extends along the part of the separation layer 140 generated by the internal preparation system 230, the amount of force required to crack the workpiece 130 will be reduced. The flexibility of the depth of the initial crack 404 results in the electrostatic force required for expansion and therefore the flexibility of the voltage 416 required.

The surface finish of the capacitive clamp 410 can affect the strength and uniformity of the electrostatic force between the capacitive clamp 410 and the workpiece 130. Because air has a lower dielectric constant than the material used for the non-conductive layer 414, the air gap between the workpiece 130 and the non-conductive layer 414 can reduce the electric field existing between the workpiece 130 and the conductive body 412 and therefore reduce Small resulting electrostatic force. In addition, the random placement of the air gap can affect the uniformity of the electric field between the conductive body 412 and the workpiece 130, resulting in a less uniform electrostatic force. In order to reduce these effects, the contact surface of the non-conductive layer 414 can be made atomically flat as much as possible (for example, using a method such as polishing) to reduce the existence of air between the capacitive clamp 410 and the workpiece 130. If the material used for the non-conductive layer 414 is harder than the workpiece 130, polishing can also be used to prevent damage to the workpiece 130. In some embodiments, the surface finish depends on the materials used for the conductive body 412 and the non-conductive layer 414. In some embodiments, the conductive body 412 is made of a semi-conductive material.

The material used for the non-conductive layer 414 can affect the operation of the capacitive clamp 410 due to the magnitude of the electrostatic force required to crack the workpiece 130. For the capacitive clamp 410 to function like a capacitor, the non-conductive layer 414 must be a dielectric material. The electric field at which these materials decompose or lose their insulating properties is called the dielectric strength. Since the electric field experienced by the non-conductive layer 414 is proportional to the electrostatic force generated by the capacitive clamping, it is advantageous to use a material with a high dielectric strength. It has been found that the materials that can withstand the necessary electric field are diamond, cubic boron nitride, aluminum nitride, hafnium oxide, silicon oxide, silicon nitride, niobium oxide, barium titanate, strontium titanate, lithium niobate, aluminum oxide, Calcium fluoride, silicon carbide and any combination thereof. However, this list is not restrictive, as other materials with similar high dielectric strength can also be used for this purpose. The primary consideration for dielectric materials is the dielectric constant. Higher dielectric constant values result in lower voltages and therefore electric fields that need to be applied to achieve the same magnitude of electrostatic force. Therefore, the ideal material for the non-conductive layer 414 is a material with both high dielectric strength and high dielectric constant.

In some embodiments, the dielectric material used for the non-conductive layer 414 is coated with a thin layer of a different material. If the dielectric material is too hard and causes damage to the workpiece 130 during clamping, the thin layer coating can be a softer dielectric material that does not damage the workpiece 130. If the dielectric is too soft and suffers damage during clamping, the thin layer coating can be a harder dielectric material that better withstands the forces associated with the clamping. Artifact

Although this system is particularly suitable for semiconductor manufacturing, the workpiece 130 can be made of materials other than semi-conductive materials. In various embodiments, the workpiece 130 should be conductive or semi-conductive so that the charge can flow to the surface of the workpiece 130 that is mated with the capacitive clamp 410 when the voltage 416 is applied between the workpiece 130 and the conductive body 412 . Examples of workpiece 130 materials that meet these requirements include many semiconductors, such as silicon, silicon carbide, indium phosphide, gallium phosphide, germanium, gallium arsenide, and gallium nitride. If the material used for the workpiece 130 is not sufficiently conductive to meet these requirements, a small electrostatic force will be generated, and the capacitive clamp 410 may not be able to secure the workpiece 130 as strongly as required by the cracking process. However, these properties can still be achieved with a workpiece 130 made of an insulating material such as silicon oxide, aluminum oxide, zirconium oxide, and magnesium oxide. For example, in one embodiment, the shaper 210 may apply a thin conductive coating that is strongly bonded to the surface of the insulating material. To be considered a strong bond, the thin conductive coating must be able to remain bonded to the surface of the insulating material during the application of the electrostatic and tensile forces used in the cracking process.

Positioning the separation layer 140 in the workpiece 130 can determine the crystal orientation of the resulting wafer. In many embodiments, the separation layer 140 is aligned with a specific crystal plane in the workpiece 130. Therefore, the crystal orientation of the obtained wafer is the same as the selected crystal plane. The standard crystal orientations of crystalline silicon include (100), (111) and (110). System controller

In various embodiments, the system controller 120 controls various components of the cracking system 110 to crack the workpiece 130.

The system controller 120 determines the shape of one of the workpieces 130 based on the desired shape of the disintegrated part. For example, if the desired shape of the disintegrated part is circular, the controller 120 controls the shaper 210 to shape the workpiece 130 into a cylindrical shape. In one embodiment, the system controller 120 additionally controls an optional cut-off 260 subsystem to cut a broken piece into a final desired geometric shape. Generally speaking, controlling the shaper 210 includes: generating electrical signals to control various elements of the shaper 210 that can shape the workpiece 130. Similarly, controlling the cutoff 260 includes various elements that generate electrical signals to control the cutoff 260 that can cut the disintegrating element into a specified, final geometric shape.

The system controller 120 determines the positions of the workpiece 130, the external preparation system 240, and the internal preparation system 230 when the workpiece 130 is ready for cracking and being cracked. The determining position may include determining a spatial position of the workpiece 130 or a component of the cracking system 110 so that the cracking plane 160 of the workpiece 130 is irradiated by the internal preparation system 230. Once the position is determined, the system controller 120 can generate a control signal for the positioner 220 to position the workpiece 130 or the components of the cracking system 110. Similarly, the system controller 120 can generate control signals to enable the positioner 220 to position any other components or workpieces 130 of the cracking system 110.

The system controller 120 determines and adjusts the operating characteristics of the internal preparation system 230. In one example, the system controller 120 determines and adjusts the characteristics of the laser beam emitted by the laser source 310. One or more laser beam characteristics can be determined based on the characteristics of the workpiece 130, the position of the separation layer 140, and the like, for example. The characteristics of the laser source 310 and the laser beam may include wavelength, power, pulse rate, and so on. In addition, the system controller 120 can determine and adjust the appropriate positions of various optical elements to generate a coverage area 150 and a separation layer 140 inside the workpiece 130. The optical element can be further configured to control the size, shape and position of the coverage area 150.

The system controller 120 determines and adjusts the operating characteristics of the external preparation system 240. In one example, when scribing the outside of the workpiece 130, the system controller 120 determines and adjusts the positions of the workpiece 130 and the external preparation system 240. The system controller 120 can also determine and adjust the depth, width and overall shape of the introduced cracks.

The system controller 120 controls the operation of the cracker 250. That is, the system controller generates the voltage and signals required for the cracker 250 to crack the workpiece 130. In one embodiment, the system controller 120 controls a cracker 250 based on the capacitive clamp design shown in FIG. 4. Cracking procedure

FIG. 5 is a flow chart of a process 500 of using a cracking system 110 to crack a workpiece 130.

The system controller 120 determines the shape of one of the workpieces 130 based on the desired shape of the disintegrated part. Based on the determined shape, the shaper 210 shapes 510 the workpiece 130 into the desired shape. For example, if the formed workpiece 130 will be square, the shaper 210 shapes 510 the workpiece 130 into a square prism with the necessary geometric specifications and tolerances required to successfully complete the rest of the splitting process.

The system controller 120 determines a position of a fragmentation plane 160 in the workpiece 130. The internal preparation system 230 prepares 520 the workpiece 130 internally by generating a separation layer 140 at the desired cracking plane 160 in the workpiece 130. In some cases, the internal preparation system 230 creates multiple separation layers 140 within the workpiece 130. These procedures are described in more detail with respect to FIG. 6.

The system controller 120 determines a position to introduce a crack to the workpiece 130. The external preparation system 240 prepares 530 the workpiece 130 externally by creating a crack 404 on an outer surface that will expand along the separation layer 140 throughout the workpiece 130 when the workpiece 130 is cracked. Generally speaking, the crack 404 is along the periphery or part of the periphery of the separation layer 140 prepared by the internal preparation system 230. In some cases, the external preparation system 240 introduces a number of cracks 404 along the outer surface of the workpiece 130.

The system controller 120 generates a signal to cause the cracker 250 to crack 540 the workpiece 130. In one embodiment, the cracked workpiece 130 expands the crack 404 along the separation layer 140 by generating a mechanical pulling force 440 on the opposite end of the workpiece 130. That is, the workpiece 130 is split by pulling the workpiece 130 apart at the separation layer 140 into two pieces. Generally speaking, the workpiece 130 is cracked so that the cracking surface is orthogonal to the long axis of the workpiece 130. In another embodiment, the cracked workpiece 130 generates a stress in the workpiece 130 by applying a controlled shearing force to the workpiece 130 so that the crack 404 preferentially expands along the separation layer 140 and the crack 404 expands. In another embodiment, the cracked workpiece 130 generates a general mechanical stress composed of a variable combination of a compressive stress, a tensile stress, a shear stress, a bending stress, a torsional stress, or a fatigue stress in the workpiece 130 to cause cracks. 404 preferentially expands along the separation layer 140 so that the crack 404 expands. In another embodiment, cracking 540 of the workpiece 130 causes the crack 404 to expand along the separation layer 140 by applying a thermal stress that can be achieved by rapidly heating or cooling the workpiece 130. In another embodiment, cracking 540 of the workpiece 130 is achieved by applying a powerful vibration through a piezoelectric actuator, magnetostrictive actuator, or similar device that generates a strong sound wave in the workpiece 130, so that the crack 404 is moved along. The separation layer 140 expands. In another embodiment, cracking 540 of the workpiece 130 can be achieved by any combination of the above methods.

The system can split 540 workpieces 130 any number of times. In various embodiments, this may include preparing 520 workpieces 130 internally, preparing 530 workpieces externally, and cracking 540 workpieces 130 any number of times. These steps can occur in different arrangements based on the configuration of the cracking system 110 and repeated any number of times. Internal preparation

FIG. 6 is a flowchart of a procedure 600 for preparing a workpiece 130 internally by an internal preparation system 230.

Here, the system controller 120 has determined that one of the cleavage planes 160 of the workpiece 130 is used. Thus, the system controller 120 configures 610 the internal preparation system 230 to generate a separation layer 140 at the desired cleavage plane 160 within the workpiece 130. Configuring the internal preparation system 230 may include positioning optics, positioning the workpiece 130, configuring the parameters of the laser source 310, etc., so that the internal preparation system 230 generates an appropriate coverage area 150 within the workpiece 130.

Then, the system controller 120 controls the laser source 310 to project a laser beam 620 toward the workpiece 130. The laser beam is focused into the workpiece 130 by various optical devices of the internal preparation system 230. The laser beam creates 630 a coverage area 150 inside the workpiece 130 that changes the structure of the workpiece 130 in the region along the desired split plane 160.

FIGS. 7A and 7B show an example of preparing a workpiece 130 internally for cracking by generating 630 a coverage area 150. FIG. 7A is an isometric view of the workpiece 130 during internal preparation, and FIG. 7B is a cross-sectional view of the workpiece 130 during internal preparation.

In this example, because the disintegration piece will be circular, the workpiece 130 is a cylindrical ingot. The cracking plane 160 is orthogonal to the long axis of the workpiece 130. The laser beam 710 is incident on the surface of the workpiece 130 and focused to a coverage area 150. The coverage area 150 is coplanar with the cracking plane 160.

Returning to FIG. 6, the system controller 120 configures 610 the internal preparation system 230 again. In this example, the internal preparation system 230 is configured to reposition the optics so that the coverage area 150 inside the workpiece 130 is at a different position on the cracking plane 160. After configuring the internal preparation system 230 again, the system controller 120 projects 620 a light beam, which is focused to produce 630 a new coverage area 150. This procedure is shown in Figure 7C and Figure 7D.

In particular, FIGS. 7A to 7D show an example in which the main axis of the laser beam used to prepare a workpiece 130 internally is perpendicular to the long axis of the workpiece 130, but other examples of laser beam orientation are also possible. For example, the laser beam can be perpendicular to the long axis of the workpiece. In this case, the laser beam will enter the workpiece from the top surface of the workpiece instead of one of the side surfaces of the workpiece.

The process of generating the coverage area 150 continues repeatedly until the coverage area 150 generates a separation layer 140 as a whole. FIG. 8A shows an example of the coverage area 150 where a separation layer 140 is formed on a cracking plane 160 of the workpiece 130. The split plane 160 is the plane of the page. In other embodiments, the separation layer 140 may have various coverage area 150 densities. That is, in some examples, the coverage areas 150 may have a certain overlap or may have additional spacing between the coverage areas 150. In addition, the system controller 120 may use a specific coverage area 150 pattern to generate the separation layer 140. For example, the system controller 120 may generate the coverage area 150 using a grating pattern from one side to the other, a pattern starting at the center and spiraling outward, a pattern of concentric rings forming the coverage area 150, and the like. Regardless of the pattern and density, a separation layer 140 is generated in the coverage area 150. 8B and 8C show an isometric representation and a cross-sectional representation of the separation layer 140.

Returning to FIG. 6, the system controller 120 determines the position of another separation layer 140. Thus, the system controller 120 causes the positioner 220 to reposition the workpiece 130 and/or the internal preparation system 230 to generate another separation layer 140. Generally speaking, the positioner 220 positions 640 the workpiece 130 by moving the workpiece 130 along its long axis to generate another separation layer 140 parallel to the first separation layer 140. Once the workpiece 130 and the internal preparation system 230 are properly positioned, the internal preparation system 230 generates another separation layer 140. FIG. 9 shows an example of a workpiece 130 after a plurality of separation layers 140 are generated. The distance between the separation layers 140 specifies the thickness of the cracked piece produced after cracking. The distance between the separation layers can be limited by the thickness of a separation layer 140. For example, the separation layer may have a minimum thickness t ′ , and the distance between two adjacent separation layers in the workpiece is greater than, for example, t ′/2 . Generally speaking, the thickness of the produced wafer is greater than 10 µm but can be less than 10 µm. In another embodiment, a plurality of separation layers 140 are made in parallel in a way that the previous coverage area 150 does not cause interference when the new coverage area 150 is generated.

FIG. 10A shows an example of a workpiece 130 that has been cracked along a separation layer 140. The workpiece 130 is broken into a top part 1010 and a bottom part 1030 along the separation layer 140 (in this example, it is coplanar with the cracking plane 160). Here, the bottom surface 1020 of the top part 1010 is at the separation layer 140, and similarly, the top surface 1040 of the bottom part 1030 is at the separation layer 140.

FIG. 10B shows an example of a workpiece 130 that has been cracked along several separation layers 140. In this example, the workpiece is split into a top part 1050, a middle part 1060, and a bottom part 1070. The previously joined surface is the location of the cleavage plane 160 and the coplanar separation layer 140. In various embodiments, the cracking system 110 can crack the workpiece 130 into any number of pieces. Each piece can have any desired thickness based on the proximity of the separation layer 140 to the cracking plane 160.

The previous description of the embodiments of the invention has been presented for illustrative purposes; it is not intended to be exhaustive or to limit the invention to the precise form disclosed. Those who are familiar with the relevant technology can understand that in view of the above disclosure, many modifications and changes are feasible.

Finally, the language used in this specification has been chosen mainly for readability and guidance purposes, and it may not be chosen to describe or limit the subject matter of the present invention. Therefore, the scope of the present invention is not intended to be limited by this [embodiment], but is limited by the scope of any invention application that is discussed based on this application. Therefore, the disclosure of the embodiments of the present invention is intended to illustrate rather than limit the scope of the present invention described in the following patent applications.

100: system environment 110: Cracking system 120: System Controller 130: Workpiece 140: Separation layer 150: coverage area 160: Fragmentation plane 210: Former 220: locator 230: internal preparation system 240: External preparation system 250: Cracker 260: Cutter 310: Laser source 320: beam shaper 330: Coverage area positioning element 340: Workpiece geometry compensation optics 404: Crack 410: Electrostatic clamp/capacitive clamp 412: Conductive body 414: Non-conductive layer 416: Voltage/Voltage Supply 420: Clamp 440: mechanical pull 500: program 510: forming 520: preparation 530: preparation 540: Crack 600: program 610: configuration 620: projection 630: produce 640: Positioning 710: Laser beam 1010: Top part 1020: bottom surface 1030: bottom part 1040: top surface 1050: Top part 1060: middleware 1070: bottom part

Figure 1 illustrates a system for cracking a workpiece according to an example embodiment.

Figure 2 illustrates a cracking system for cracking a workpiece according to an example embodiment.

Figure 3 illustrates an internal preparation system according to an example embodiment.

Figure 4 shows a cracker according to an example embodiment.

Figure 5 is a program flow for cracking a workpiece according to an example embodiment.

FIG. 6 is a program flow for generating a separation layer inside a workpiece according to an example embodiment.

7A to 7D illustrate the generation of a separation layer inside a workpiece according to an example embodiment.

FIG. 8A illustrates the footprint of a separation layer produced in a workpiece according to an example embodiment.

8B and 8C illustrate a separation layer inside a workpiece according to an example embodiment.

FIG. 9 illustrates a workpiece having multiple separation layers according to an example embodiment.

FIGS. 10A to 10B illustrate examples of cracking a workpiece along one or more separation layers 140.

The figures depict various embodiments of the invention for illustrative purposes only. Those familiar with the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated in this document can be used without departing from the principles of the invention described in this document.

100: system environment

110: Cracking system

120: System Controller

130: Workpiece

140: Separation layer

150: coverage area

160: Fragmentation plane

Claims (20)

A method for cleaving a workpiece of a material, comprising: using a laser generated by an internal preparation system to produce a separation layer in the workpiece with material properties different from the rest of the workpiece; using a The controller determines a position of a cleavage plane in the workpiece; uses a locator to position the workpiece so that the cleavage plane coincides with the separation layer; and uses an external preparation system to score the workpiece to coincide with the separation layer A crack is generated on an external surface of the workpiece at at least one point; and a cracker is used to crack the workpiece to generate a cracked piece by generating a pulling force on the workpiece perpendicular to at least a part of the separation layer, the pulling force The crack is extended along the separation layer. The method of claim 1, further comprising: forming the workpiece into a defined geometric shape with a forming system, so that the disintegrated piece has a periphery as a cross section of the defined geometric shape. The method of claim 1, wherein generating the separation layer further comprises: focusing the pulse laser to a coverage area inside the workpiece, wherein a pulse of the laser locally changes the workpieces at the coverage area Material properties. The method of claim 1, wherein generating the separation layer further comprises: moving a focus of the laser within the workpiece to generate the separation layer, when the separation layer is When moving within the workpiece, the separation layer is formed as a collection of one of the locally modified materials at the focal point. The method of claim 1, wherein cracking the workpiece further comprises: attaching the cracker to the opposite end of the workpiece; and generating the tensile force that causes the crack to expand along the separation layer, the tensile force being generated on the opposite end of the workpiece Between the ends and perpendicular to at least the part of the separation layer. The method of claim 5, wherein the splitter is electrostatically attached to the opposite end of the workpiece. The method of claim 1, further comprising: using the laser to generate another separation layer with different material properties in the workpiece. The method of claim 7, further comprising: using the cracker to crack the workpiece along the other separating layer to produce another cracked piece. The method of claim 1, wherein: the laser is a pulse laser and the internal preparation system generates laser pulses at a repetition rate of at least 100 kHz. A method for cleaving a workpiece of a material, comprising: using a laser generated by an internal preparation system to produce a separation layer in the workpiece with material properties different from the rest of the workpiece; using a The external preparation system scores the workpiece so as to overlap with the separation layer at least A crack is generated on an external surface of the workpiece at one point; and a cracker is used to crack the workpiece to produce a cracked piece by generating a pulling force on the workpiece perpendicular to at least a part of the separation layer, the pulling force causing The crack expands along the separation layer; and a cut-off device is used to cut the cracked piece into a specific geometric shape. A system for splitting a workpiece of a material, comprising: an internal preparation system configured to generate a laser beam for generating a separation layer in the workpiece, the separation layer having a different shape from the workpiece The material properties of the remaining materials; a controller configured to determine a position of a cracking plane in the workpiece; a locator configured to position the workpiece so that the cracking plane coincides with the separation layer; An external preparation system configured to scribe the workpiece to produce a crack on the surface of the workpiece at least at one point coincident with the separation layer; and a cracker configured to A tensile force perpendicular to at least a part of the separation layer is generated on the workpiece to generate a broken piece of the workpiece, and the tensile force causes the crack to expand along the separation layer. Such as the system of claim 11, further comprising: a shaper configured to shape the workpiece into a defined geometric shape, so that the disintegrated piece has a periphery as a cross section of the defined geometric shape. Such as the system of claim 11, wherein the internal preparation system further includes: A focusing system configured to focus the laser to a coverage area inside the workpiece, wherein a pulse of the laser locally changes the material properties of the workpiece at the coverage area. Such as the system of claim 11, wherein the internal preparation system further comprises: a focusing system configured to move the focus of the lasers within the workpiece to generate the separation layer, when the separation layer is on the workpiece When moving inside, the separation layer is formed as a collection of one of the locally modified materials at the focal point. Such as the system of claim 11, wherein: the splitter is further configured to be attached to the opposite end of the workpiece and generate the tensile force that causes the crack to expand along the separation layer, and the tensile force is generated on the workpiece Between opposite ends and perpendicular to at least the part of the separation layer. Such as the system of claim 15, wherein the cracker is configured to be electrostatically attached to the opposite end of the workpiece. Such as the system of claim 11, wherein the internal preparation system is further configured to use the pulse laser to generate another separation layer with different material properties in the workpiece. Such as the system of claim 17, wherein the cracker is further configured to crack the workpiece along the other separating layer to produce another cracked piece. Such as the system of claim 11, wherein the laser beam generated by the internal preparation system is a pulsed laser beam, which generates pulses at a repetition rate of at least 100 kHz. A system for splitting a workpiece of a material, comprising: an internal preparation system configured to generate a laser beam for generating a separation layer in the workpiece, the separation layer having a different shape from the workpiece The material properties of the remaining materials; an external preparation system configured to score the workpiece to produce a crack on the surface of the workpiece at least at one point coincident with the separation layer; and a cracker, which It is configured to generate a broken piece of the workpiece by generating a tensile force on the workpiece perpendicular to at least a portion of the separation layer, the tensile force causing the crack to expand along the separation layer; and a cutter, which Configure to cut the broken piece into a specific geometric shape.

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