CN116408894A - Cutting method of crystal ingot and manufacturing method of wafer - Google Patents

Abstract

The invention provides a cutting method of a crystal ingot and a manufacturing method of a wafer, which comprises the following steps. And irradiating at least one part of the outer surface layer of the crystal ingot by laser so as to convert at least one part of the outer surface layer of the crystal ingot into a softened layer, wherein the softened layer of the crystal ingot has a hardness smaller than that of the inner layer of the crystal ingot. The wires are contacted with the softening layer of the crystal ingot, and the wires are moved relative to the crystal ingot so as to perform a slicing process. In addition, a method for manufacturing the wafer is also provided.

Description

Cutting method of crystal ingot and manufacturing method of wafer

Technical Field

The invention relates to a cutting method of a crystal ingot and a manufacturing method of a wafer.

Background

Generally, a method of manufacturing a silicon carbide wafer includes forming a Ingot (Ingot) first, and then slicing the Ingot to obtain a wafer. The ingot is manufactured, for example, in a high temperature environment. Currently, the growth methods of the ingot 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).

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

The ingot is sliced to obtain a plurality of wafers (Wafer). For example, the method of slicing the ingot includes cutting with a cutter or steel wire in combination with abrasive grains (e.g., diamond grains). In some cases, compressive and tensile stresses remain inside the wafer as well as the boule. In some processes, the corners of the wafer are rounded to avoid breakage of the corners of the wafer due to collisions.

Then, grinding and polishing processes are performed on the wafer to improve the surface quality of the wafer. Methods of performing polishing and polishing processes on wafers include, for example, physical polishing processes and chemical mechanical polishing processes. The physical polishing process is, for example, to polish the wafer surface with a polishing pad in combination with a polishing slurry containing diamond particles or other particles having a higher hardness. The physical polishing process is mainly to treat the wafer surface with mechanical force. The chemical mechanical polishing process is to polish the wafer surface by using corrosive polishing liquid and abrasive material in combination with a polishing pad. The corrosive polishing liquid in the chemical mechanical polishing process can chemically react with the surface of the wafer to convert the rugged portion of the surface of the wafer into a material with smaller hardness, so that the abrasive can more easily remove the rugged portion of the surface of the wafer.

However, the hardness of the ingot and wafer materials is so great that the slicing, grinding and polishing processes described above are not easy and time consuming. Therefore, how to improve the slicing, polishing and polishing processes to reduce the time required for the processes and to increase the yield is an important issue in the semiconductor material process.

Disclosure of Invention

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

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

The cutting method of the crystal ingot in one embodiment of the invention comprises the following steps: irradiating at least one part of the outer surface layer of the crystal ingot with laser so as to convert at least one part of the outer surface layer of the crystal ingot into a softened layer, wherein the softened layer of the crystal ingot has a hardness smaller than that of the inner layer of the crystal ingot; and making the plurality of wires contact with the softening layer of the ingot, and making the plurality of wires move relative to the ingot so as to perform a slicing process.

The manufacturing method of the wafer in one embodiment of the invention comprises the following steps: providing a first quasi-wafer with a first outer surface layer; irradiating the first outer surface layer of the first quasi-wafer with first laser so as to convert the first outer surface layer of the first quasi-wafer into a first softening layer; performing a grinding process on the first quasi-wafer to remove the first softening layer and form a second quasi-wafer, wherein the second quasi-wafer is provided with a second outer surface layer; and performing a polishing process on the second quasi-wafer to form a wafer.

The manufacturing method of the wafer in one embodiment of the invention comprises the following steps: providing a first quasi-wafer; performing a polishing process on the first quasi-wafer to form a second quasi-wafer; irradiating the outer surface layer of the second quasi-wafer with laser to convert the outer surface layer of the second quasi-wafer into a softening layer; and polishing the second quasi-wafer to remove the softening layer of the second quasi-wafer and form a wafer.

The manufacturing method of the quasi-wafer in one embodiment of the invention comprises the following steps: providing a first quasi-wafer, wherein the first quasi-wafer is provided with a first surface, an opposite second surface positioned on the first surface and a side surface connected between the first surface and the second surface, the first surface and the side surface form a first corner part of the first quasi-wafer, the second surface and the side surface form a second corner part of the first quasi-wafer, the first quasi-wafer is also provided with an inner part, and the inner part is positioned among part of the first surface, part of the second surface, the first corner part and the second corner part; irradiating at least one of the first corner and the second corner of the first quasi-wafer with laser to convert the at least one of the first corner and the second corner of the first quasi-wafer into at least one corner softening part, wherein the hardness of the at least one corner softening part is smaller than that of the inside of the first quasi-wafer; and performing a chamfering process on the first quasi-wafer to remove at least one corner softening part and form a second quasi-wafer.

In view of the above, in the method for cutting a crystal according to an embodiment of the present invention, at least a portion of the outer surface layer of the crystal may be softened by laser light so as to convert at least a portion of the outer surface layer of the crystal into a softened layer. Because the hardness of the softened layer is low, when the wire is used to contact the softened layer and then cut the ingot, the wire can easily and quickly cut into the ingot. Thus, the time required for cutting the ingot can be reduced. In addition, when at least a part of the outer surface layer of the ingot is modified into a softened layer by using laser, a groove is not formed in the outer surface layer of the ingot, so that the loss of the material of the ingot is not caused in the process of modifying at least a part of the outer surface layer of the ingot into a softened layer by using laser.

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

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

Fig. 1A to 1C are schematic views of a method for cutting a ingot according to an embodiment of the invention;

fig. 2A to 2C are schematic views of a method for cutting a ingot according to another embodiment of the present invention;

fig. 3A to 3C are schematic views of a method for cutting a ingot according to still another embodiment of the present invention;

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

fig. 5A to 5C are schematic views illustrating a method for cutting a ingot according to still another embodiment of the present invention;

fig. 6A to 6C are schematic views of a method for cutting a ingot according to an embodiment of the present invention;

FIGS. 7A-7G are schematic diagrams illustrating a method of fabricating a wafer according to an embodiment of the invention;

fig. 8A to 8C are schematic views illustrating a method for manufacturing a quasi-wafer according to an embodiment of the invention.

Description of the reference numerals

10 wire rod

100 crystal ingot

100a first end face

100b second end face

100s1 first side

100x axis

110 outer surface layer

110r, 110rD, wire predetermined passing area

110r-1 first region

110r-2 second region

112. 112A, 112B, 112C, 112D softening layers

112A-1, 112B-1, 112C-1, 112D-1: softening pattern

112B-1a thick portion

112B-1B details

112C-1a first part

112C-1b second part

114 inner layer

116 first quasicrystal

116a first outer skin layer

116b first softening layer

116c first surface

116d second surface

116e side face

116f first corner

116g second corner portion

116h, interior

116i, 116j corner softening part

116k, 116l, chamfer surface

118. 118A second quasicrystal

118a second outer skin layer

118b second softening layer

119 wafer

L, l length of

L0, L3 laser

L1 first laser

L2:second laser

P112A-1, P10 spacing

Width of W112A-1, W2

W10 wire diameter

x, y, z, 100r direction

Detailed Description

Fig. 1A to 1C are schematic views of a method for cutting a crystal ingot according to an embodiment of the invention. Fig. 1A to 1C show directions x, y and z perpendicular to each other, wherein the direction z is the axial direction of the ingot 100.

Referring to fig. 1A to 1C, the method for cutting the ingot 100 includes the following steps: irradiating at least a portion of the outer surface layer 110 of the ingot 100 with laser light L0 to convert at least a portion of the outer surface layer 110 of the ingot 100 into a softened layer 112, wherein the softened layer 112 of the ingot 100 has a hardness less than that of the inner layer 114 of the ingot 100; and a slicing process of bringing the plurality of wires 10 into contact with the softening layer 112 of the ingot 100 and moving the plurality of wires 10 relative to the ingot 100. After the dicing process is completed, the ingot 100 is diced into a plurality of first quasicrystals 116. For example, in the present embodiment, the hardness of at least a portion of the outer surface layer 110 of the ingot 100 after being softened is reduced to 95% or more of the original hardness; that is, the hardness of the softening layer 112 is 95% or more of the hardness of at least a portion of the outer surface layer 110 of the ingot 100; however, the invention is not limited thereto.

It should be noted that, because the hardness of the softening layer 112 of the ingot 100 is low, when the wire 10 contacts the softening layer 112 to cut the ingot 100, the wire 10 can easily and rapidly cut the ingot 100. Thus, the time required for dicing the plurality of first quasicrystals 116 can be reduced. In addition, the softening layer 112 can easily cut the wire rod 10 into the ingot 100, thereby reducing the amount of abrasion of the ingot 100 by the wire rod 10 in the slicing process and improving the utilization rate of the ingot 100.

Referring to fig. 1A, the ingot 100 has a first end face 100a and a second end face 100b, the first end face 100a and the second end face 100b are disposed in an axial direction z of the ingot 100, and an outer surface layer 110 of the ingot 100 extends from the first end face 100a to the second end face 100b. Referring to fig. 1A and 1B, for example, in the present embodiment, the laser L0 irradiates all portions of the outer surface layer 110 of the ingot 100, so that all portions of the outer surface layer 110 of the ingot 100 are transformed into the softened layer 112. However, the present invention is not limited thereto, and in other embodiments, a portion of the outer surface layer 110 of the ingot 100 may be modified into a softened layer, but other portions of the outer surface layer 110 of the ingot 100 are not modified, and the following paragraphs are exemplified in conjunction with other drawings.

In addition, in the present embodiment, the slicing process may be started after all portions of the outer surface layer 110 have been converted into the softened layer 112. However, the present invention is not limited thereto, and in other embodiments, the dicing process may be performed from a softened portion of the outer surface layer 110, and the other portion of the outer surface layer 110 may be softened by using a laser, so that the time required for dicing the plurality of first quasi-wafers 116 may be further shortened.

In the present embodiment, when at least a portion of the outer surface layer 110 of the ingot 100 is converted into the softened layer 112 by the laser L0 (i.e., when the laser softening operation is performed), the power of the laser L0 may be greater than 700mW (e.g., but not limited to, greater than 700mW and less than or equal to 750 mW), the penetration depth of the laser L0 into the ingot 100 may be greater than 1 μm (e.g., but not limited to, greater than 1 μm and less than or equal to 10 μm), the moving speed of the laser L0 relative to the ingot 100 may be greater than 0.1mm/s (e.g., but not limited to, greater than 0.1mm/s and less than or equal to 0.8 mm/s), and the pulse width of the laser L0 may be greater than 120fs (e.g., but not limited to, greater than 120fs and less than or equal to 150 fs). Specifically, in the present embodiment, the parameters of the laser softening process performed before or during dicing are as shown in the following table, but the present invention is not limited thereto.

TABLE one

It should be noted that the following embodiments use component numbers and part of the content of the foregoing embodiments, where the same numbers are used to denote the same or similar components, and descriptions of the same technical content are omitted. Reference is made to the foregoing embodiments for an explanation of omitted parts, which will not be repeated.

Fig. 2A to 2C are schematic views of a method for cutting a ingot according to another embodiment of the present invention. The cutting method of the ingot shown in fig. 2A to 2C is similar to the cutting method of the ingot shown in fig. 1A to 1C, and the difference between them is that: the formation positions of the softening layers 112 and 112A are different.

Referring to fig. 2A and 2C, specifically, in the present embodiment, the outer surface layer 110 of the ingot 100 has a plurality of wire predetermined passing areas 110r, each wire predetermined passing area 110r surrounds an axis 100x of the ingot 100, and the step of irradiating at least a portion of the outer surface layer 110 of the ingot 100 with laser light L0 to convert at least a portion of the outer surface layer 110 of the ingot 100 into a softened layer 112A includes: the laser L0 is irradiated to the predetermined passing areas 110r of the plurality of wires of the outer surface layer 110 of the ingot 100 so that the predetermined passing areas 110r of the plurality of wires of the outer surface layer 110 of the ingot 100 are converted into the plurality of softening patterns 112A-1 of the softening layer 112A.

In the slicing process, the plurality of wires 10 pass through the plurality of softening patterns 112A-1 softened by the plurality of wire predetermined passing areas 110r of the outer surface layer 110. In other words, in the present embodiment, the laser light L0 softens a portion of the outer surface layer 110 through which the wire 10 passes, but does not soften a portion of the outer surface layer 110 through which the wire 10 does not pass. Thus, the time required for softening the outer surface layer 110 of the ingot 100 by the laser light L0 can be shortened, and the time required for dicing the plurality of first quasi-wafers 116 can be further reduced.

In the present embodiment, the plurality of softening patterns 112A-1 are respectively used for the plurality of wires 10 to pass through, and the pitch P112A-1 of the plurality of softening patterns 112A-1 in the axial direction z of the ingot 100 is substantially equal to the pitch P10 of the plurality of wires 10 in the axial direction z. In addition, in the present embodiment, the width W112A-1 of each softening pattern 112A-1 in the axial direction z of the ingot 100 may be larger than the wire diameter W10 of the corresponding wire 10, so that the wire 10 can easily and rapidly cut into the softening pattern 112A-1, but the invention is not limited thereto.

Fig. 3A to 3C are schematic views of a method for cutting a ingot according to still another embodiment of the present invention. The method of cutting the ingot shown in fig. 3A to 3C is similar to the method of cutting the ingot shown in fig. 2A to 2C, and the difference between them is that: the softening layers 112A, 112B are different in pattern.

Referring to fig. 3A and 3B, in the present embodiment, the softening layer 112B also includes a plurality of softening patterns 112B-1 for respectively passing through the plurality of wires 10. In contrast, in the present embodiment, each of the softening patterns 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 ingot 100, and the width W1 of the thick portion 112B-1a in the axial direction z of the ingot 100 is larger than the width W2 of the thin portion 112B-1B in the axial direction z of the ingot 100.

In the slicing process, the plurality of wires 10 are brought into contact with the plurality of softening patterns 112B-1 of the ingot 100 from the first side 100s1 of the ingot 100. In other words, in the slicing process, the wire 10 is contacted with the thick portion 112B-1a of the softened pattern 112B-1 and then contacted with the thin portion 112B-1B of the softened pattern 112B-1. By softening the thick portion 112B-1a of the pattern 112B-1, the wire 10 can be easily cut into the ingot 100 at the beginning of the slicing process; when the wire 10 has contacted the thick portion 112B-1a and cut into the ingot 100, the wire 10 can smoothly continue cutting the ingot 100 and reduce the abrasion of the ingot 100 by softening the thin portion 112B-1B of the pattern 112B-1.

Fig. 4 shows a vertical projection of the ingot and its softened pattern on a reference plane according to an embodiment of the present invention.

Referring to fig. 3B and 4, an axis 100x of the ingot 100 is disposed on a reference plane (e.g., yz plane), a vertical projection of an outer diameter of the ingot 100 on the reference plane (e.g., yz plane) has a length L, and a vertical projection of the thick portion 112B-1a of the softened pattern 112B-1 on the reference plane has a length L. In this example, 1% or less (L/L) or less than 10%. Further, the content of (L/L) is not more than 5% and not more than 8%, but the invention is not limited thereto.

Fig. 5A to 5C are schematic views illustrating a method for cutting a ingot according to still another embodiment of the present invention. The cutting method of the ingot shown in fig. 5A to 5C is similar to the cutting method of the ingot shown in fig. 2A to 2C, and the difference between them is that: the softening layers 112A and 112C are formed in different ways.

Referring to fig. 5A and 5B, in the present embodiment, each wire predetermined passing area 110r of the outer surface layer 110 of the ingot 100 includes a first area 110r-1 and a second area 110r-2, and the first area 110r-1 is located at a first side 100s1 of the ingot 100 that is first contacted with the wire 10. In the present embodiment, the step of causing the laser L0 to irradiate the predetermined passing areas 110r of the plurality of wires of the outer surface layer 110 of the ingot 100 so that the predetermined passing areas 110r of the plurality of wires of the outer surface layer 110 of the ingot 100 are converted into the plurality of softening patterns 112C-1 includes: the laser L0 irradiates the first region 110r-1 and the second region 110r-2 of the wire predetermined passing region 110r of the outer surface layer 110 of the ingot 100 with the first power and the second power, respectively, so that the first region 110r-1 and the second region 110r-2 of the wire predetermined passing region 110r of the outer surface layer 110 of the ingot 100 are respectively converted into the first portion 112C-1a and the second portion 112C-1b of the softened pattern 112C-1. In particular, the first power is greater than the second power such that the hardness of the first portion 112C-1a of the softening pattern 112C-1 is less than the hardness of the second portion 112C-1b of the softening pattern 112C-1.

In other words, in the present embodiment, the power of the laser light L0 irradiating different regions of the ingot 100 is adjusted so that the first portion 112C-1a of the softening pattern 112C-1 of the wire 10 is contacted first and then the second portion 112C-1b of the softening pattern 112C-1 of the wire 10 is contacted second. Thus, the wire 10 can cut the ingot 100 more rapidly and further reduce the abrasion amount of the ingot 100 without excessively increasing the complexity of the laser softening process.

Fig. 6A to 6C are schematic views of a method for cutting a ingot according to an embodiment of the present invention. The cutting method of the ingot shown in fig. 6A to 6C is similar to the cutting method of the ingot shown in fig. 1A to 1C, and the difference between them is that: the softening layers 112, 112D are different in pattern.

Referring to fig. 6A and 6B, the arc direction 100r of the ingot 100 is substantially parallel to the outer surface 110 of the ingot 100 and substantially perpendicular to the axis 100x of the ingot 100. In the present embodiment, the outer surface layer 110 of the ingot 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 ingot 100.

In the present embodiment, the step of causing the laser light L0 to irradiate at least a portion of the outer surface layer 110 of the ingot 100 so as to convert at least a portion of the outer surface layer 110 of the ingot 100 into the softened layer 112D includes: the laser light L0 is irradiated to a plurality of predetermined softened regions 110rD of the outer surface layer 110 of the ingot 100 so that the plurality of predetermined softened regions 110rD are respectively converted into a plurality of softened patterns 112D-1 of the softened layer 112D. Referring to fig. 6A, in the present embodiment, the plurality of softening patterns 112D-1 may be a plurality of patterns extending in the axial direction z of the ingot 100, the plurality of patterns being spaced apart from each other and arranged along the arc direction 100r of the ingot 100.

Fig. 7A to 7G are schematic views illustrating a method for manufacturing a wafer according to an embodiment of the invention. The following describes a method for manufacturing a wafer according to an embodiment of the present invention with reference to fig. 7A to 7G.

Referring to fig. 7A, first, a first quasi-wafer 116 cut from a wafer (not shown) is provided. The first quasi-wafer 116 may also be referred to as a freshly cut wafer. The first quasi-wafer 116 has an uneven first outer surface layer 116a.

Referring to fig. 7A and 7B, the first laser L1 is then irradiated onto the first outer surface layer 116a of the first quasi-wafer 116, so that the first outer surface layer 116a of the first quasi-wafer 116 is converted into the first softened layer 116B. Referring to fig. 7C and 7D, a polishing process is performed on the first quasi-wafer 116 to remove the first softened layer 116b and form a second quasi-wafer 118. The second quasi-wafer 118 may also be referred to as a polished wafer. The surface roughness of the second outer surface layer 118a of the second quasicrystal 118 is less than the surface roughness of the first outer surface layer 116a of the first quasicrystal 116. In the present embodiment, the polishing process is, for example, a physical polishing process, but the present invention is not limited thereto.

Referring to fig. 7D and 7E, a second laser beam L2 is then irradiated onto the second outer surface layer 118a of the second quasi-wafer 118, so that the second outer surface layer 118a of the second quasi-wafer 118 is converted into a second softened layer 118b. Referring to fig. 7F and 7G, a polishing process is performed on the second quasi-wafer 118 to remove the second softening layer 118b and form a wafer 119. The surface roughness of the wafer 119 is less than the surface roughness of the second outer surface layer 118a of the second quasicrystal 118. In the present embodiment, the polishing process is, for example, a chemical mechanical polishing process, but the invention is not limited thereto.

It should be noted that, in the present embodiment, before the polishing process, a laser softening process is performed on the first quasi-wafer 116, so that the first quasi-wafer 116 has the first softened layer 116b with a lower hardness. The lower hardness of the first softening layer 116b helps the first quasicrystal 116 to be polished quickly and forms a second outer surface layer 118a of the second quasicrystal 118 that is flatter. In addition, in the present embodiment, a laser softening process is performed on the second quasicrystal wafer 118 before the polishing process, so that the second quasicrystal wafer 118 has a second softened layer 118b with a lower hardness. The lower hardness of second softening layer 118b helps 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 polishing, the power of the first laser beam L1 may be greater than 700mW, the penetration depth of the first laser beam L1 to the first quasi-wafer 116 may be greater than 5 μm, the moving speed of the first laser beam L1 relative to the first quasi-wafer 116 may be greater than 0.1mm/s, and the pulse width of the first laser beam L1 may be greater than 120fs. Further, in the present embodiment, the power of the first laser light L1 may be greater than 700mW and less than or equal to 780mW, the penetration depth of the first laser light L1 into the first quasicrystal 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 light L1 relative to the first quasicrystal 116 may be greater than or equal to 5mm/s and less than or equal to 15mm/s (mm/sec.), and the pulse width of the first laser light L1 may be greater than 120fs and less than or equal to 150fs.

In the present embodiment, the power of the second laser beam L2 may be greater than 700mW, the penetration depth of the second laser beam L2 to the second quasi-wafer 118 may be greater than 1 μm, the moving speed of the second laser beam L2 relative to the second quasi-wafer 118 may be greater than 0.1mm/s, and the pulse width of the second laser beam L2 may be greater than 120fs during the laser softening process after polishing and before polishing. Further, in the present embodiment, the power of the second laser light L2 may be greater than 700mW and less than or equal to 780mW, the penetration depth of the second laser light L2 into the second quasicrystal 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 light L2 relative to the second quasicrystal 118 may be greater than or equal to 5mm/s and less than or equal to 15mm/s (mm/sec.), and the pulse width of the second laser light L2 may be greater than 120fs and less than or equal to 150fs.

For example, in the present embodiment, the parameters of one laser softening process after cutting and before polishing and the other laser softening process after polishing and before polishing are shown in the following table two and the following table three, respectively, but the invention is not limited thereto.

TABLE II

TABLE III

In the present embodiment, the laser softening step is performed before polishing and before lapping, respectively. However, the present invention is not limited thereto, and in the method for manufacturing a wafer according to another embodiment, the laser softening process may be performed after dicing and before polishing, but the laser softening process may not be performed after polishing and before polishing; in the method for manufacturing a wafer according to the still another embodiment, the laser softening step may not be performed after dicing and before polishing, but the laser softening step may be performed after polishing and before polishing; methods of fabricating such wafers are also within the scope of the invention.

Fig. 8A to 8C are schematic views illustrating a method for manufacturing a quasi-wafer according to an embodiment of the invention. The following illustrates a method for manufacturing a second quasi-wafer according to another embodiment of the present invention with reference to fig. 8A to 8C.

Referring to fig. 8A, first, a first quasi-wafer 116 cut from a wafer (not shown) is provided. The first quasi-wafer 116 has a first surface 116c, an opposite second surface 116d located on 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 116e form a first corner 116f of the first quasi-wafer 116, and the second surface 116d and the side surface 116e form a second corner 116g of the first quasi-wafer 116. The first quasi-wafer 116 further has an interior 116h located between a portion of the first surface 116c, a portion of the second surface 116d, the first corner 116f, and the second corner 116g.

Referring to fig. 8A and 8B, the laser beam L3 irradiates at least one of the first corner 116f and the second corner 116g of the first quasi-wafer 116, so that at least one of the first corner 116f and the second corner 116g of the first quasi-wafer 116 is converted into at least one corner softening portion 116i, 116j, wherein the hardness of the at least one corner softening portion 116i, 116j is smaller than the hardness of the inner portion 116h of the first quasi-wafer 116. For example, in the present embodiment, the laser light L3 may be irradiated on the first corner 116f and the second corner 116g of the first quasi-wafer 116, so that the first corner 116f and the second corner 116g of the first quasi-wafer 116 are respectively converted into the first corner softening portion 116i and the second corner softening portion 116j, but the invention is not limited thereto.

The mechanism for converting 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 similar to the mechanism for modifying a portion of the outer surface layer 110 of the ingot 100 into a softened layer and/or the mechanism for converting the first outer surface layer 116a of the first quasi-wafer 116 into the first softened layer 116b described above, and will not be repeated here.

Referring to fig. 8B and 8C, 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 corner-guiding surface 116k, 116l connected between a portion of the first surface 116c and a portion of the side surface 116e, a portion of the second surface 116d and a portion of the side surface 116e, or a portion of the first surface 116c and a portion of the side surface 116e and a portion of the second surface 116d and a portion of the side surface 116 e. The second quasi-wafer 118A may also be referred to as a wafer after chamfering and before polishing. The chamfered second quasi-wafer 118A has chamfer faces 116k, 116l and is not easily damaged by impact. For example, in the present embodiment, the at least one corner guide surface 116k, 116l of the second quasi-wafer 118A may include a first corner guide surface 116k connected between the portion of the first surface 116c and the portion of the side surface 116f and a second corner guide surface 116l connected between the portion of the second surface 116d and the portion of the side surface 116e, but the invention is not limited thereto. In the present embodiment, at least one of the chamfer surfaces 116k, 116l of the second quasi-wafer 118A is, for example, a convex arc surface, but the invention is not limited thereto.

It should be noted that, in the present embodiment, after the first quasi-wafer 116 is cut from the ingot (not shown) and before the polishing process, a laser corner softening process may be performed on the first quasi-wafer 116, so that the first quasi-wafer 116 has corner softening portions 116h and 116i with lower hardness. The lower hardness of the corner softeners 116h, 116i helps the first quasicrystal 116 to be chamfered quickly, reducing the loss of devices used to chamfer the first quasicrystal 116.

Claims (15)

1. The cutting method of the ingot is characterized by comprising the following steps:

irradiating at least a portion of an outer surface layer of the ingot with laser light to convert the at least a portion of the outer surface layer of the ingot into a softened layer, wherein the softened layer of the ingot has a hardness less than that of an inner layer of the ingot; and

and enabling the plurality of wires to be in contact with the softening layer of the crystal ingot, and enabling the plurality of wires to move relative to the crystal ingot so as to carry out a slicing process.

2. The method of cutting a crystal according to claim 1, wherein the crystal has a first end face and a second end face, the first end face and the second end face being disposed in an axial direction of the crystal, the outer surface layer of the crystal extending from the first end face to the second end face, and causing the laser to irradiate the at least a portion of the outer surface layer of the crystal so that the at least a portion of the outer surface layer of the crystal is converted into the softened layer comprises:

and irradiating all parts of the outer surface layer of the crystal by the laser so as to convert all parts of the outer surface layer of the crystal into the softening layer.

3. The method of cutting an ingot of claim 1, wherein the outer surface layer of the ingot has a plurality of wire predetermined pass-through regions, each wire predetermined pass-through region surrounding an axis of the ingot, and causing the laser to irradiate the at least a portion of the outer surface layer of the ingot to convert the at least a portion of the outer surface layer of the ingot to the softened layer comprises:

and irradiating the laser on the preset passing areas of the wires on the outer surface layer of the crystal ingot to convert the preset passing areas of the wires on the outer surface layer of the crystal ingot into a plurality of softening patterns of the softening layer.

4. The cutting method of the ingot according to claim 3, wherein a width of the softened pattern in an axial direction of the ingot is larger than a wire diameter of the wire.

5. The cutting method of the ingot of claim 3, wherein the pitch of the plurality of softening patterns in the axial direction of the ingot is substantially equal to the pitch of the plurality of wires in the axial direction.

6. The cutting method of the ingot according to claim 3, wherein the plurality of wires are brought into contact with the plurality of softened patterns of the ingot from a first side of the ingot, the softened patterns have thick portions and thin portions, the thick portions of the softened patterns are provided at the first side of the ingot, and a width of the thick portions in an axial direction of the ingot is larger than a width of the thin portions in the axial direction of the ingot.

7. The cutting method of the ingot according to claim 6, wherein an axis of the ingot is disposed on a reference plane, a perpendicular projection of an outer diameter of the ingot on the reference plane has a length L, and a perpendicular projection of the thick portion of the softened pattern on the reference plane has a length L, and 1% +.ltoreq.l/l+.10%.

8. The method for cutting a crystal ingot according to claim 7, wherein 5% or less (L/L) or less than 8%.

9. The method of cutting a crystal of claim 3, wherein the plurality of wires are in contact with the plurality of softening patterns of the crystal from a first side of the crystal, each wire predetermined pass of the outer surface layer of the crystal comprises a first region and a second region, and the first region is located at the first side of the crystal; the step of causing the laser to irradiate the plurality of wire predetermined passing areas of the outer surface layer of the ingot so as to convert the plurality of wire predetermined passing areas of the outer surface layer of the ingot into the plurality of softening patterns includes:

irradiating the first area and the second area of the wire scheduled passing area of the outer surface layer of the ingot with the laser at a first power and a second power respectively, so that the first area and the second area of the wire scheduled passing area of the outer surface layer of the ingot are respectively converted into a first part and a second part of a softened pattern;

wherein the first power is greater than the second power such that the hardness of the first portion of the softening pattern is less than the hardness of the second portion of the softening pattern.

10. The method of slicing a crystal according to claim 1, wherein an arced direction of the crystal is substantially parallel to the outer surface layer of the crystal and substantially perpendicular to an axis of the crystal, the outer surface layer of the crystal has a plurality of predetermined softened regions, and the plurality of predetermined softened regions are aligned along the arced direction of the crystal; the step of causing the laser to irradiate the at least a portion of the outer surface layer of the ingot to convert the at least a portion of the outer surface layer of the ingot to the softened layer includes:

and irradiating the laser on the plurality of preset softening areas of the outer surface layer of the crystal so as to respectively convert the plurality of preset softening areas of the outer surface layer of the crystal into a plurality of softening patterns of the softening layer.

11. A method of manufacturing a wafer, comprising:

providing a first quasi-wafer with a first outer surface layer;

irradiating the first outer surface layer of the first quasi-wafer with a first laser to convert the first outer surface layer of the first quasi-wafer into a first softened layer;

performing a grinding process on the first quasi-wafer to remove the first softening layer and form a second quasi-wafer, wherein the second quasi-wafer is provided with a second outer surface layer; and

and performing a polishing process on the second quasi-wafer to form a wafer.

12. The method of manufacturing a wafer according to claim 11, further comprising:

before the polishing process is performed on the second quasi-wafer, a second laser is irradiated on the second outer surface layer of the second quasi-wafer so as to convert the second outer surface layer of the second quasi-wafer into a second softening layer.

13. The method of manufacturing a wafer according to claim 12, wherein the step of performing the polishing process on the second quasi-wafer to form the wafer comprises:

and performing the polishing process on the second quasi-wafer to remove the second softening layer and form the wafer.

14. 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;

irradiating an outer surface layer of the second quasi-wafer with laser so as to convert the outer surface layer of the second quasi-wafer into a softening layer; and

and performing a polishing process on the second quasi-wafer to remove the softening layer of the second quasi-wafer and form a wafer.

15. A method of manufacturing a quasi-wafer, comprising:

providing a first quasicrystal, wherein the first quasicrystal has a first surface, a second surface opposite to the first surface, and a side surface connected between the first surface and the second surface, the first surface and the side surface forming a first corner of the first quasicrystal, the second surface and the side surface forming a second corner of the first quasicrystal, the first quasicrystal further having an interior located between a portion of the first surface, a portion of the second surface, the first corner, and the second corner;

causing laser to irradiate at least one of the first corner and the second corner of the first quasi-wafer to convert the at least one of the first corner and the second corner of the first quasi-wafer into at least one corner softening portion, wherein the at least one corner softening portion has a hardness less than a hardness of the interior of the first quasi-wafer; and

and conducting a chamfering process on the first quasi-wafer to remove the at least one corner softening part and form a second quasi-wafer.

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