TW202326841A - Ingot slicing method and wafer manufacturing method - Google Patents

Abstract

An ingot slicing method includes following steps. A laser impacts at least one portion of an outer surface of an ingot, so that the at least one portion of the outer surface changes to a softening layer, wherein hardness of the softening layer of the ingot is smaller than hardness of an inner layer of the ingot. Wires are contacted with the softening layer, and the wires are moved relative to the ingot to perform a sawing process. Moreover, a wafer manufacturing method is also provided.

Description

Wafer cutting method and wafer manufacturing method

The invention relates to a method for cutting a crystal anchor and a method for manufacturing a wafer.

Generally speaking, a method for manufacturing a silicon carbide wafer includes forming an ingot first, and then slicing the ingot to obtain a wafer. Crystal anchors are manufactured, for example, in a high-temperature environment. At present, the growth methods of crystal anchor include Physical Vapor Transport (Physical Vapor Transport, PVT), High Temperature Chemical Vapor Deposition (High Temperature Chemical Vapor Deposition, HT-CVD) and Liquid Phase Epitaxy (Liquid Phase Epitaxy, LPE) etc.

The seed crystal is placed in a high-temperature furnace, the seed crystal contacts gaseous or liquid raw materials, and forms semiconductor material on the surface of the seed crystal until a crystal anchor with a desired size is obtained. Crystal anchors can have different crystalline structures depending on the manufacturing method and raw materials. For example, silicon carbide anchors include 3C-silicon carbide, 4H-silicon carbide, 6H-silicon carbide, and the like. 3C-silicon carbide belongs to the cubic crystal system, while 4H-silicon carbide and 6H-silicon carbide belong to the hexagonal crystal system.

Slicing the anchor to obtain multiple wafers (Wafers). For example, the method of slicing the anchor includes cutting with a knife or a steel wire in combination with abrasive grains (such as diamond grains). In some cases, compressive stress and tensile stress remain inside the wafer as well as the anchor. In some processes, the corners of the wafers are ground into fillets to prevent the corners of the wafers from being cracked due to collisions.

Then, a grinding and polishing process is performed on the wafer to improve the surface quality of the wafer. Methods for performing lapping and polishing processes on wafers include, for example, physical lapping processes and chemical mechanical polishing processes. In the physical polishing process, for example, a polishing pad is used to polish the wafer surface with a polishing liquid containing diamond particles or other particles with relatively high hardness. The physical polishing process mainly treats the wafer surface by mechanical force. The chemical mechanical polishing process is to grind the surface of the wafer with a corrosive polishing liquid and abrasives together with a polishing pad. The corrosive polishing liquid in the chemical mechanical polishing process can chemically react with the wafer surface, turning the uneven part of the wafer surface into a less hard material, so that the abrasive can be removed more easily from the wafer surface Bumpy parts.

However, the hardness of the anchor and the wafer material makes the above-mentioned slicing, grinding and polishing processes difficult and time-consuming. Therefore, how to improve the above-mentioned slicing, grinding and polishing processes to reduce the time required for the above-mentioned processes and increase the yield is an important issue in the semiconductor material process.

The invention provides a crystal anchor cutting method, which can reduce the time required for cutting the crystal anchor. In one embodiment, the material of the diced anchor is silicon carbide.

The invention provides a method for manufacturing wafers, which can reduce the time required for manufacturing wafers and increase the yield of wafers.

The method for cutting a crystal anchor according to an embodiment of the present invention includes the following steps: irradiating laser light on at least a part of the outer surface layer of the crystal anchor, so that at least a part of the outer surface layer of the crystal anchor is converted into a softened layer, wherein the softened layer of the crystal anchor the hardness of the inner layer of the anchor is smaller than that of the inner layer of the anchor; and the plurality of wires are in contact with the softening layer of the anchor, and the plurality of wires are moved relative to the anchor to perform a slicing process.

The wafer manufacturing method of an embodiment of the present invention includes the following steps: providing a first quasi-wafer with a first outer layer; making the first laser irradiate the first outer layer of the first quasi-wafer, so that the first The first outer layer of the quasi-wafer is converted into a first softened layer; the first quasi-wafer is subjected to a grinding process to remove the first softened layer and form a second quasi-wafer, wherein the second quasi-wafer has a second outer layer the surface layer; and performing a polishing process on the second quasi-wafer to form a wafer.

A wafer manufacturing method according to an embodiment of the present invention includes the following steps: providing a first quasi-wafer; performing a grinding process on the first quasi-wafer to form a second quasi-wafer; irradiating the second quasi-wafer with a laser The outer layer of the circle, so that the outer layer of the second quasi-wafer is converted into a softened layer; and the second quasi-wafer is polished to remove the softened layer of the second quasi-wafer, and a wafer is formed.

The method for manufacturing a quasi-wafer according to an embodiment of the present invention includes the following steps: providing a first quasi-wafer, wherein the first quasi-wafer has a first surface, a second surface opposite to the first surface, and a second surface connected to the first quasi-wafer. The side between the first surface and the second surface, the first surface and the side form the first corner of the first quasi-wafer, the second surface and the side form the second corner of the first quasi-wafer, the first quasi-wafer It also has an inner part, the inner part is located between the first surface part, the second surface part, the first corner part and the second corner part; the first corner part and the second corner part of the first quasi-wafer are irradiated with the laser at least one, so that at least one of the first corner portion and the second corner portion of the first quasi-wafer is converted into at least one corner softening portion, wherein the hardness of the at least one corner softening portion is less than that of the interior of the first quasi-wafer Hardness: performing a chamfering process on the first quasi-wafer to remove at least one corner softening portion and forming a second quasi-wafer.

Based on the above, in the cutting method of the anchor according to an embodiment of the present invention, at least a part of the outer surface layer of the anchor can be softened by laser first, so that at least a part of the outer surface layer of the anchor can be transformed into a softened layer. Due to the low hardness of the softening layer, when the wire rod contacts the softening layer to cut the crystal anchor, the wire rod can easily and quickly cut into the crystal anchor. Thereby, the time required for cutting the anchor can be reduced. In addition, when using laser to modify at least a part of the outer layer of the crystal anchor into a softening layer, no grooves will be formed on the outer layer of the crystal anchor. In the process of transforming into a softening layer, it will not cause the loss of crystal anchor material.

In the wafer manufacturing method according to an embodiment of the present invention, the laser softening process may be performed after the dicing process and before the grinding process, and/or after the grinding process and before the polishing process. Thereby, the time required for the grinding process and/or the polishing process can be reduced, which helps to increase the yield of wafers.

FIG. 1A to FIG. 1C are schematic diagrams of a method for cutting a crystal anchor according to an embodiment of the present invention. 1A to FIG. 1C are marked with a direction x, a direction y and a direction z which are perpendicular to each other, wherein the direction z is the axial direction of the crystal anchor 100 .

Please refer to FIG. 1A to FIG. 1C, the cutting method of the crystal anchor 100 includes the following steps: make the laser L0 irradiate at least a part of the outer surface layer 110 of the crystal anchor 100, so that at least a part of the outer surface layer 110 of the crystal anchor 100 is converted into a softening layer 112, wherein the hardness of the softening layer 112 of the anchor 100 is less than the hardness of the inner layer 114 of the anchor 100; Move to carry out the slicing process. After the slicing process is completed, the peg 100 is diced into a plurality of first quasi-wafers 116 . For example, in this embodiment, the hardness of at least a part of the outer layer 110 of the crystal anchor 100 is reduced to 95% or more of the original hardness after being softened; that is, the hardness of the softened layer 112 is equal to that of the crystal anchor. 95% or more of the hardness of at least a part of the outer surface layer 110 of the outer surface layer 110 of 100; but the present invention is not limited thereto.

It is worth mentioning that since the softening layer 112 of the crystal anchor 100 has a low hardness, when the wire 10 contacts the softening layer 112 to cut the crystal anchor 100 , the wire 10 can cut the crystal anchor 100 easily and quickly. In this way, the time required for dicing a plurality of first quasi-wafers 116 can be reduced. In addition, the softening layer 112 enables the wire 10 to be easily cut into the anchor 100 , thereby reducing the abrasion of the anchor 100 by the wire 10 during the slicing process, and improving the utilization rate of the anchor 100 .

1A, the crystal anchor 100 has a first end surface 100a and a second end surface 100b, the first end surface 100a and the second end surface 100b are arranged in the axial direction z of the crystal anchor 100, and the outer surface layer 110 of the crystal anchor 100 is formed by the first end surface 100b. The one end surface 100a extends to the second end surface 100b. 1A and FIG. 1B, for example, in this embodiment, laser L0 can be made to irradiate all parts of the outer surface layer 110 of the crystal anchor 100, so that all parts of the outer surface layer 110 of the crystal anchor 100 are turned into softening layer 112 . However, the present invention is not limited thereto. In other embodiments, a part of the surface layer 110 outside the anchor 100 may also be modified into a softening layer, but other parts of the surface layer 110 outside the anchor 100 may not be modified. The following It will be illustrated with examples in the following paragraphs with other figures.

In addition, in this embodiment, the slicing process can be started after all parts of the outer layer 110 have been transformed into the softened layer 112 . However, the present invention is not limited thereto. In other embodiments, the softened part of the outer layer 110 can also be sliced while using a laser to soften other parts of the outer layer 110. The time required to cut out the plurality of first quasi-wafers 116 is shortened.

In this embodiment, when at least a part of the outer surface layer 110 of the crystal anchor 100 is converted into the softening layer 112 by using the laser L0 (that is, when the laser softening operation is performed), the power of the laser L0 can be greater than 700mW (for example, but not Limited to: greater than 700mW and less than or equal to 750mW), the penetration depth of the laser L0 to the crystal anchor 100 can be greater than 1 μm (for example but not limited to: greater than 1 μm and less than or equal to 10 μm), the laser L0 relative to the crystal anchor 100 The moving speed can be greater than 0.1mm/s (such as but not limited to: greater than 0.1mm/s and less than or equal to 0.8mm/s), and the pulse width of the laser L0 can be greater than 120fs (such as but not limited to: greater than 120fs and less than or equal to 150fs). Specifically, in this embodiment, various parameters of the laser softening process performed before or during slicing are shown in Table 1 below, but the present invention is not limited thereto. Laser parameters Processing Department At least a part of the outer surface of the crystal anchor Power of laser L0 (mW) 700 Penetration depth of laser L0 (μm) 1 Relative velocity of laser L0 (mm/sec) 0.1 Pulse width of laser L0 (fs) 120 [Table I]

It must be noted here that the following embodiments use the component numbers and part of the content of the previous embodiments, wherein the same numbers are used to denote the same or similar components, and descriptions of the same technical content are omitted. For the description of omitted parts, reference may be made to the aforementioned embodiments, and the following embodiments will not be repeated.

FIG. 2A to FIG. 2C are schematic diagrams of a method for cutting a crystal anchor according to another embodiment of the present invention. The cutting method of the anchor shown in FIGS. 2A to 2C is similar to the cutting method of the anchor shown in FIGS. 1A to 1C , the difference between them is that the softening layers 112 and 112A are formed at different positions.

Please refer to FIG. 2A and FIG. 2C. Specifically, in this embodiment, the outer layer 110 of the crystal anchor 100 has a plurality of predetermined wire passage regions 110r, each wire predetermined passage region 110r surrounds the axis 100x of the crystal anchor 100, and Let the laser L0 irradiate at least a part of the outer surface layer 110 of the crystal anchor 100, so that at least a part of the outer surface layer 110 of the crystal anchor 100 is converted into a softening layer 112A. The plurality of wires are scheduled to pass through the regions 110r, so that the plurality of wires are expected to pass through the regions 110r of the outer surface layer 110 of the crystal anchor 100 into a plurality of softening patterns 112A-1 of the softening layer 112A.

During the slicing process, a plurality of wires 10 will pass through a plurality of softening patterns 112A- 1 formed by softening the predetermined passing regions 110 r of the outer layer 110 . In other words, in this embodiment, the laser L0 will soften the part of the outer layer 110 that is passed by the wire 10 , but will not soften the part of the outer layer 110 that does not need to be passed by the wire 10 . Thereby, the time for using the laser L0 to soften the outer surface layer 110 of the anchor 100 can be shortened, and the time required for cutting out a plurality of first quasi-wafers 116 can be further reduced.

In this embodiment, the plurality of softening patterns 112A-1 are respectively used for passing the plurality of wires 10, and the pitch P112A-1 of the plurality of softening patterns 112A-1 in the axial direction z of the crystal anchor 100 is substantially equal to The pitch P10 of the wires 10 in the axial direction z. In addition, in this embodiment, the width W112A-1 of each softening pattern 112A-1 in the axial direction z of the crystal anchor 100 can be greater than the wire diameter W10 of a corresponding wire 10, so that the wire 10 can be easily and quickly cut into the location of the softening pattern 112A-1, but the present invention is not limited thereto.

FIG. 3A to FIG. 3C are schematic diagrams of a method for cutting a crystal anchor according to another embodiment of the present invention. The cutting method of the anchor shown in FIGS. 3A to 3C is similar to the cutting method of the anchor shown in FIGS. 2A to 2C , the difference between them is that the patterns of the softening layers 112A and 112B are different.

Please refer to FIG. 3A and FIG. 3B , in this embodiment, the softening layer 112B also includes a plurality of softening patterns 112B- 1 , which are respectively used for a plurality of wires 10 to pass through. The difference is that in this embodiment, each softening pattern 112B-1 has a thick portion 112B-1a and a thin portion 112B-1b, the thick portion 112B-1a is disposed on the first side 100s1 of the crystal anchor 100, and the thick portion The width W1 of 112B- 1 a in the axial direction z of the crystal anchor 100 is greater than the width W2 of the thin portion 112B- 1 b in the axial direction z of the crystal anchor 100 .

During the slicing process, the plurality of wires 10 contact the plurality of softened patterns 112B- 1 of the anchor 100 from the first side 100s1 of the anchor 100 . In other words, in the slicing process, the wire 10 first contacts the thick portion 112B- 1 a of the softening pattern 112B- 1 and then contacts the thin portion 112B- 1 b of the softening pattern 112B- 1 . By softening the thick portion 112B-1a of the pattern 112B-1, the wire 10 can be easily cut into the crystal anchor 100 at the beginning of the slicing process; By softening the detail 112B- 1b of the pattern 112B- 1 , the wire 10 can continue to cut the anchor 100 smoothly and reduce the abrasion of the anchor 100 .

FIG. 4 shows a vertical projection of a crystal anchor and its softening pattern on a reference plane according to an embodiment of the present invention.

Please refer to FIG. 3B and FIG. 4, the axis 100x of the crystal anchor 100 is set on a reference plane (such as the yz plane), and the vertical projection of the outer diameter of the crystal anchor 100 on the reference plane (such as the yz plane) has a length L, softening the pattern The vertical projection of the thick portion 112B-1a of 112B-1 on the reference plane has a length l. In this embodiment, 1%≤(l/L)≤10%. Furthermore, 5%≤(l/L)≤8%, but the present invention is not limited thereto.

FIG. 5A to FIG. 5C are schematic diagrams of a method for cutting a crystal anchor according to yet another embodiment of the present invention. The cutting method of the anchor shown in FIGS. 5A to 5C is similar to the cutting method of the anchor shown in FIGS. 2A to 2C , the difference between them is that the softening layers 112A and 112C are formed in different ways.

Please refer to FIG. 5A and FIG. 5B. In this embodiment, each wire predetermined passage area 110r of the outer surface layer 110 of the crystal anchor 100 includes a first area 110r-1 and a second area 110r-2, and the first area 110r- 1 is located on the first side 100s1 of the crystal anchor 100 which is in contact with the wire 10 first. In this embodiment, the laser L0 is used to irradiate the predetermined passage regions 110r of the outer surface layer 110 of the crystal anchor 100, so that the predetermined passage regions 110r of the outer surface layer 110 of the crystal anchor 100 are transformed into a plurality of softening patterns. The step 112C-1 includes: making the laser L0 irradiate the first region 110r-1 and the second region 110r-2 of the wire material predetermined passage region 110r on the outer surface layer 110 of the crystal anchor 100 with the first power and the second power respectively, so as to Make the first region 110r-1 and the second region 110r-2 of the wire rod predetermined passage region 110r on the outer surface layer 110 of the crystal anchor 100 respectively transform into the first part 112C-1a and the second part 112C-1b of the softening pattern 112C-1 . In particular, the first power is greater than the second power, so that the hardness of the first portion 112C-1a of the softening pattern 112C-1 is smaller than the hardness of the second portion 112C-1b of the softening pattern 112C-1.

In other words, in this embodiment, by adjusting the power of the laser L0 irradiating different regions of the crystal anchor 100, the first part 112C-1a of the softening pattern 112C-1 of the wire 10 is contacted first, and then the softening pattern 112C of the wire 10 is contacted. -1's second part 112C-1b soft. In this way, without excessively increasing the complexity of the laser softening process, the wire 10 can cut the anchor 100 more quickly, and further reduce the abrasion of the anchor 100 .

FIG. 6A to FIG. 6C are schematic diagrams of a method for cutting a crystal anchor according to an embodiment of the present invention. The cutting method of the anchor shown in FIGS. 6A to 6C is similar to the cutting method of the anchor shown in FIGS. 1A to 1C , the difference between them is that the patterns of the softening layers 112 and 112D are different.

Referring to FIG. 6A and FIG. 6B , the arc direction 100r of the anchor 100 is substantially parallel to the outer layer 110 of the anchor 100 and substantially perpendicular to the axis 100x of the anchor 100 . In this embodiment, the outer layer 110 of the anchor 100 has a plurality of predetermined softening regions 110rD, and the plurality of predetermined softening regions 110rD are arranged along the arc direction 100r of the anchor 100 .

In this embodiment, the step of letting the laser L0 irradiate at least a part of the outer surface layer 110 of the crystal anchor 100 so that at least a part of the outer surface layer 110 of the crystal anchor 100 is converted into a softening layer 112D includes: letting the laser L0 irradiate the crystal anchor The plurality of predetermined softening regions 110rD of the outer surface layer 110 of the 100 are transformed into a plurality of softening patterns 112D- 1 of the softening layer 112D respectively. Please refer to FIG. 6A , in this embodiment, the plurality of softening patterns 112D-1 may be a plurality of patterns extending in the axial direction z of the crystal anchor 100, and the plurality of patterns are spaced apart from each other and along the direction of the crystal anchor 100. Arranged in the arc direction 100r.

7A to 7G are schematic diagrams of a wafer manufacturing method according to an embodiment of the present invention. The method for manufacturing a wafer according to an embodiment of the present invention is illustrated below with reference to FIGS. 7A to 7G .

Referring to FIG. 7A , firstly, a first quasi-wafer 116 cut from a wafer anchor (not shown) is provided. The first quasi-wafer 116 can also be called a freshly cut wafer. The first quasi-wafer 116 has an uneven first outer layer 116a.

Please refer to FIG. 7A and FIG. 7B, then, the first laser L1 is made to irradiate the first outer layer 116a of the first quasi-wafer 116, so that the first outer layer 116a of the first quasi-wafer 116 is converted into a first softening layer 116b. Referring to FIG. 7C and FIG. 7D , then, a grinding process is performed on the first quasi-wafer 116 to remove the first softening layer 116 b and form the second quasi-wafer 118 . The second quasi-wafer 118 may also be called a ground wafer. The surface roughness of the second outer layer 118 a of the second quasi-wafer 118 is smaller than the surface roughness of the first outer layer 116 a of the first quasi-wafer 116 . In this embodiment, the grinding process is, for example, a physical grinding process, but the invention is not limited thereto.

Please refer to FIG. 7D and FIG. 7E, then, the second laser L2 is made to irradiate the second outer layer 118a of the second quasi-wafer 118, so that the second outer layer 118a of the second quasi-wafer 118 is converted into a second softening layer 118b. Referring to FIG. 7F and FIG. 7G , then, a polishing process is performed on the second quasi-wafer 118 to remove the second softening layer 118 b and form a wafer 119 . The surface roughness of the wafer 119 is smaller than the surface roughness of the second outer layer 118 a of the second quasi-wafer 118 . In this embodiment, the polishing process is, for example, a chemical mechanical polishing process, but the invention is not limited thereto.

It is worth mentioning that, in this embodiment, before the grinding process, a laser softening process will be performed on the first quasi-wafer 116, so that the first quasi-wafer 116 has a first softening process with a lower hardness. layer 116b. The first softening layer 116 b with lower hardness helps the first quasi-wafer 116 to be ground quickly and forms the second outer layer 118 a of the second quasi-wafer 118 which is flatter. In addition, in this embodiment, a laser softening process is performed on the second quasi-wafer 118 before the polishing process, so that the second quasi-wafer 118 has a second softening layer 118 b with a lower hardness. The second softening layer 118 b with lower hardness helps the second quasi-wafer 118 to be polished quickly and form a flatter wafer 119 .

In this embodiment, during the laser softening process after dicing and before grinding, the power of the first laser L1 can be greater than 700 mW, and the penetration depth of the first laser L1 to the first quasi-wafer 116 can be greater than 5 μm The moving speed of the first laser L1 relative to the first quasi-wafer 116 may be greater than 0.1 mm/s, and the pulse width of the first laser L1 is greater than 120 fs. Furthermore, in this embodiment, the power of the first laser L1 may be greater than 700 mW and less than or equal to 780 mW, and the penetration depth of the first laser L1 to the first quasi-wafer 116 may be greater than or equal to 40 μm and Less than or equal to 70 μm, the moving speed of the first laser L1 relative to the first quasi-wafer 116 can be greater than or equal to 5 mm/s and less than or equal to 15 mm/s (mm/sec.), and the pulse of the first laser L1 The width can be greater than 120fs and less than or equal to 150fs.

In this embodiment, when performing the laser softening process after grinding and before polishing, the power of the second laser L2 can be greater than 700 mW, and the penetration depth of the second laser L2 to the second quasi-wafer 118 can be greater than 1 μm , the moving speed of the second laser L2 relative to the second quasi-wafer 118 may be greater than 0.1 mm/s, and the pulse width of the second laser L2 may be greater than 120 fs. Furthermore, in this embodiment, the power of the second laser L2 may be greater than 700 mW and less than or equal to 780 mW, and the penetration depth of the second laser L2 to the second quasi-wafer 118 may be greater than or equal to 40 μm and Less than or equal to 70 μm, the moving speed of the second laser L2 relative to the second quasi-wafer 118 can be greater than or equal to 5 mm/s and less than or equal to 15 mm/s (mm/sec.), and the pulse of the second laser L2 The width can be greater than 120fs and less than or equal to 150fs.

For example, in this embodiment, the parameters of a laser softening process after cutting and before grinding and another laser softening process after grinding and before polishing are shown in Table 2 and Table 3 below, respectively , but the present invention is not limited thereto. Processing laser parameters small facet Silicon surface carbon surface First quasi-wafer (wafer just cut out) Power of the first laser (mW) 750 700 700 700 Penetration depth of the first laser (μm) >40 >40 >40 >40 Relative moving speed of the first laser (mm/sec) 5 10 10 10 Pulse width of the first laser (fs) 140 120 120 120 [Table II] Processing laser parameters small facet Silicon surface carbon surface Second quasi-wafer (polished wafer) Power of the second laser (mW) 750 700 700 700 Penetration depth of the second laser (μm) >10 >10 >10 <3 Relative moving speed of the second laser (mm/sec) 3 5 5 5 Pulse width of the second laser (fs) 140 120 120 120 [Table 3]

In addition, it should be noted that, in this embodiment, the laser softening process is performed before grinding and polishing respectively. However, the present invention is not limited thereto. In another embodiment of the wafer manufacturing method, the laser softening process may be performed after dicing and before grinding, but the laser softening process is not performed after grinding and before polishing. In the manufacturing method of the wafer of another embodiment, also can not carry out laser softening process after cutting and before grinding, but after grinding and before polishing, carry out laser softening process; The manufacture of these wafers The method is also within the scope of protection of the present invention.

8A to 8C are schematic diagrams of a quasi-wafer manufacturing method according to an embodiment of the present invention. The method for manufacturing the second quasi-wafer according to another embodiment of the present invention will be described below with reference to FIG. 8A to FIG. 8C .

Referring to FIG. 8A , firstly, a first quasi-wafer 116 cut out from a wafer anchor (not shown) is provided. The first quasi-wafer 116 has a first surface 116c, a second surface 116d opposite to the first surface 116c, and a side surface 116e connected between the first surface 116c and the second surface 116d, wherein the first surface 116c and the side surface 116 e forms a first corner portion 116 f of the first quasi-wafer 116 , and the second surface 116 d and the side surface 116 e form a second corner portion 116 g of the first quasi-wafer 116 . The first quasi-wafer 116 also has an interior 116h located between a portion of the first surface 116c, a portion of the second surface 116d, a first corner portion 116f, and a second corner portion 116g.

Please refer to FIG. 8A and FIG. 8B, then, laser L3 is made to irradiate at least one of the first corner portion 116f and the second corner portion 116g of the first quasi-wafer 116, so that the first corner portion of the first quasi-wafer 116 At least one of the portion 116f and the second corner portion 116g is transformed into at least one corner softened portion 116i , 116j , wherein at least one corner softened portion 116i , 116j has a hardness less than the hardness of the interior 116h of the first quasi-wafer 116 . For example, in this embodiment, the laser L3 can be made to irradiate the first corner portion 116f and the second corner portion 116g of the first quasi-wafer 116, so that the first corner portion 116f and the second corner portion 116g of the first quasi-wafer 116 The second corner portion 116g is transformed into the first softened corner portion 116i and the second softened corner portion 116j respectively, but the present invention is not limited thereto.

The mechanism of transforming the first corner portion 116f and the second corner portion 116g of the first quasi-wafer 116 into the first corner softening portion 116i and the second corner softening portion 116j is the same as the aforementioned modification of a part of the outer surface layer 110 of the wafer 100 The mechanism for the softening layer and/or the aforementioned mechanism for transforming the first outer layer 116 a of the first quasi-wafer 116 into the first softening layer 116 b is similar and will not be repeated here.

Referring to FIG. 8B and FIG. 8C , then, a chamfering process is performed on the first quasi-wafer 116 to remove at least one corner softening portion 116i, 116j and form a second quasi-wafer 118A. The second quasi-wafer 118A has at least one chamfered surface 116k, 116l, which is connected between part of the first surface 116c and part of the side 116e, between part of the second surface 116d and part of the side 116e, or part of the first surface 116c. Between the first surface 116c and part of the side 116e and between part of the second surface 116d and part of the side 116e. The second quasi-wafer 118A can also be called a wafer after chamfering and before grinding. The chamfered second quasi-wafer 118A has chamfered surfaces 116k, 116l and is less likely to be damaged by impact. For example, in this embodiment, at least one chamfered surface 116k, 116l of the second quasi-wafer 118A may include the first chamfered surface 116k and The second chamfer surface 116l is connected between the second surface 116d of the part and the side surface 116e of the part, but the invention is not limited thereto. In this embodiment, at least one chamfered surface 116k, 116l of the second quasi-wafer 118A is, for example, a convex arc surface, but the invention is not limited thereto.

It is worth mentioning that, in this embodiment, after cutting the first quasi-wafer 116 from the wafer (not shown) and before performing the grinding process, the first quasi-wafer 116 can be subjected to a laser The corner softening process is performed so that the first quasi-wafer 116 has corner softening portions 116h, 116i with lower hardness. The corner softening portions 116h and 116i with lower hardness help the first quasi-wafer 116 to be chamfered quickly, reducing the loss of devices used for chamfering the first quasi-wafer 116 .

10: wire 100: crystal anchor 100a: first end face 100b: second end face 100s1: First side 100x: axis 110: Outer layer 110r, 110rD: wire rod scheduled passing area 110r-1: The first area 110r-2: Second area 112, 112A, 112B, 112C, 112D: softening layer 112A-1, 112B-1, 112C-1, 112D-1: softening pattern 112B-1a: Coarse part 112B-1b: Details 112C-1a: Part I 112C-1b: Part Two 114: inner layer 116: The first quasi-wafer 116a: first outer skin 116b: the first softening layer 116c: first surface 116d: second surface 116e: side 116f: the first corner 116g: second corner 116h: internal 116i, 116j: corner softening part 116k, 116l: chamfering surface 118, 118A: the second quasi-wafer 118a: second outer skin 118b: second softening layer 119: Wafer L, l: length L0, L3: Laser L1: the first laser L2: second laser P112A-1, P10: Spacing W112A-1, W1, W2: Width W10: wire diameter x, y, z, 100r: direction

FIG. 1A to FIG. 1C are schematic diagrams of a method for cutting a crystal anchor according to an embodiment of the present invention. FIG. 2A to FIG. 2C are schematic diagrams of a method for cutting a crystal anchor according to another embodiment of the present invention. FIG. 3A to FIG. 3C are schematic diagrams of a method for cutting a crystal anchor according to another embodiment of the present invention. FIG. 4 shows a vertical projection of a crystal anchor and its softening pattern on a reference plane according to an embodiment of the present invention. FIG. 5A to FIG. 5C are schematic diagrams of a method for cutting a crystal anchor according to yet another embodiment of the present invention. FIG. 6A to FIG. 6C are schematic diagrams of a method for cutting a crystal anchor according to an embodiment of the present invention. 7A to 7G are schematic diagrams of a wafer manufacturing method according to an embodiment of the present invention. 8A to 8C are schematic diagrams of a quasi-wafer manufacturing method according to an embodiment of the present invention.

10: wire

100: crystal anchor

112: softening layer

114: inner layer

L0: laser

x, y, z: direction

Claims (15)

A method for cutting crystal anchors, comprising: directing a laser to at least a portion of an outer layer of a crystal anchor to convert the at least a portion of the outer layer of the crystal anchor into a softened layer, wherein the softened layer of the crystal anchor has a hardness less than that of the crystal anchor the hardness of the inner layer; and A plurality of wires are brought into contact with the softening layer of the anchor, and the wires are moved relative to the anchor to perform a slicing process. The method for cutting a crystal anchor as described in Claim 1, wherein the crystal anchor has a first end surface and a second end surface, the first end surface and the second end surface are arranged in an axial direction of the crystal anchor, the The outer layer of the crystal anchor extends from the first end face to the second end face, and the laser is irradiated on the at least a part of the outer layer of the crystal anchor, so that the at least part of the outer layer of the crystal anchor turns The steps for this softening layer include: making the laser irradiate all parts of the outer layer of the crystal anchor, so that all parts of the outer layer of the crystal anchor are transformed into the softening layer. The method for cutting a crystal anchor as claimed in item 1, wherein the outer layer of the crystal anchor has a plurality of predetermined wire passing areas, each wire predetermined passing area surrounds an axis of the crystal anchor, and the crystal is irradiated by the laser Anchoring the at least a portion of the outer layer so that the at least a portion of the anchored outer layer becomes the softened layer comprises: Make the laser irradiate the predetermined passing areas of the wires on the outer layer of the crystal anchor, so that the predetermined passing areas of the wires on the outer layer of the crystal anchor are transformed into a plurality of softening patterns of the softening layer. The method for cutting a crystal anchor according to claim 3, wherein a width of a softening pattern in an axial direction of the crystal anchor is greater than a diameter of a wire. The method for cutting a crystal anchor as claimed in claim 3, wherein a pitch of the softening patterns in an axial direction of the crystal anchor is substantially equal to a pitch of the wires in the axial direction. The method for cutting a crystal anchor as claimed in claim 3, wherein the wires are in contact with the softened patterns of the crystal anchor from a first side of the crystal anchor, a softened pattern has a thick portion and a thin portion, the The thick portion of the softening pattern is disposed on the first side of the anchor, and a width of the thick portion in an axial direction of the anchor is greater than a width of the thin portion in the axial direction of the anchor . The cutting method of crystal anchor as described in claim 6, wherein an axis of the crystal anchor is set on a reference plane, a vertical projection of an outer diameter of the crystal anchor on the reference plane has a length L, and the softening pattern A vertical projection of the thick portion on the reference plane has a length l, and 1%≤(l/L)≤10%. The crystal anchor cutting method as described in Claim 7, wherein 5%≤(l/L)≤8%. The cutting method of the crystal anchor as claimed in item 3, wherein the wires are in contact with the softened patterns of the crystal anchor from a first side of the crystal anchor, and each wire of the outer layer of the crystal anchor is predetermined The passage area includes a first area and a second area, and the first area is located on the first side of the crystal anchor; the laser is irradiated to the predetermined passage area of the wires on the outer layer of the crystal anchor, so that The step of converting the wires of the outer layer of the crystal anchor into the softening patterns through the predetermined passing regions includes: Let the laser irradiate the first area and the second area of the wire rod predetermined passage area of the outer layer of the crystal anchor with a first power and a second power, so that the outer layer of the crystal anchor The first area and the second area of the wire-rod intended to pass through are respectively transformed into a first part and a second part of a softening pattern; Wherein, the first power is greater than the second power, so that the hardness of the first portion of the softening pattern is smaller than the hardness of the second portion of the softening pattern. The method for cutting a crystal anchor as claimed in item 1, wherein an arc direction of the crystal anchor is substantially parallel to the outer layer of the crystal anchor and is substantially perpendicular to an axis of the crystal anchor, and the outer surface of the crystal anchor The surface layer has a plurality of predetermined softening regions, and the predetermined softening regions are arranged along the arc direction of the crystal anchor; the laser is irradiated on at least a part of the outer layer of the crystal anchor, so that the outer surface of the crystal anchor The step of converting at least a part of the surface layer into the softened layer comprises: The laser is irradiated to the predetermined softened regions of the outer layer of the crystal anchor, so that the predetermined softened regions of the outer layer of the crystal anchor are respectively transformed into a plurality of softened patterns of the softened layer. A method of manufacturing a wafer, comprising: providing a first quasi-wafer having a first outer layer; irradiating the first outer layer of the first quasi-wafer with a first laser to convert the first outer layer of the first quasi-wafer into a first softened layer; performing a grinding process on the first quasi-wafer to remove the first softened layer and form a second quasi-wafer, wherein the second quasi-wafer has a second outer layer; and A polishing process is performed on the second quasi-wafer to form a wafer. The wafer manufacturing method as described in claim 11, further comprising: Before performing the polishing process on the second quasi-wafer, causing a second laser to irradiate the second outer layer of the second quasi-wafer, so that the second outer layer of the second quasi-wafer is transformed into a second softening layer. The method for manufacturing a wafer as claimed in claim 12, wherein performing the polishing process on the second quasi-wafer to form the wafer includes: The polishing process is performed on the second quasi-wafer to remove the second softening layer and form the wafer. A method of manufacturing a wafer, comprising: providing a first quasi-wafer; performing a grinding process on the first quasi-wafer to form a second quasi-wafer; exposing a laser to an outer layer of the second quasi-wafer to convert the outer layer of the second quasi-wafer into a softened layer; and performing a polishing process on the second quasi-wafer to remove the softened layer of the second quasi-wafer to form a wafer A method of manufacturing a quasi-wafer, comprising: A first quasi-wafer is provided, wherein the first quasi-wafer has a first surface, a second surface opposite to the first surface, and a connection between the first surface and the second surface side, the first surface and the side form a first corner of the first quasi-wafer, the second surface and the side form a second corner of the first quasi-wafer, the first quasi-wafer also having an interior located between a portion of the first surface, a portion of the second surface, the first corner portion, and the second corner portion; directing a laser to at least one of the first corner and the second corner of the first quasi-wafer such that at least one of the first corner and the second corner of the first quasi-wafer one transforms into at least one corner softening portion, wherein the hardness of the at least one corner softening portion is less than the hardness of the interior of the first quasi-wafer; and A corner chamfering process is performed on the first quasi-wafer to remove the at least one corner softening portion and form a second quasi-wafer.

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