Spliced silicon rod processing method and silicon wafer processing method

Abstract

The invention provides a spliced silicon rod processing method and a silicon wafer processing method, and the method comprises the steps: bonding at least two short round silicon rods in the axial direction of the short round silicon rods through a first glue layer, and forming a spliced round silicon rod; squaring the spliced round silicon rod to form a spliced silicon rod; and before the wire cutting process is carried out, at least part of the first adhesive layer in the spliced silicon rod is removed to form a spacer region. Before the wafer cutting procedure is carried out, at least part of the first adhesive layer in the spliced silicon rod is removed to form the interval area, the interval area can provide an expansion space for the first adhesive layer which absorbs water to expand due to cutting heat, wafer spalling caused by the fact that the first adhesive layer is heated and absorbs water to expand when the spliced silicon rod is cut is reduced, and the yield of wafer cutting is improved.

Description

Technical Field

[0001] This disclosure relates to the field of silicon rod cutting technology, and in particular to a method for processing spliced ​​silicon rods and a method for processing silicon wafers. Background Technology

[0002] Some square bars used for wafer cutting need to undergo a gluing process during the crystal process. That is, after the round bar cutting process and before the squaring process, the axial end faces of two short round bars need to be glued together before the squaring process is carried out to form a square bar. This type of square bar will form a layer of adhesive between the two bar sections.

[0003] In the current wire cutting process, wafers near the original ingot splicing adhesive area may break during cutting. Research has found that this is because the adhesive layer absorbs water and expands when heated during cutting, causing the wafer in that area to crack.

[0004] Therefore, how to reduce wafer cracking caused by the expansion of the adhesive layer due to heat absorption of water during silicon rod cutting has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned technical problems, this disclosure provides a method for processing spliced ​​silicon rods and a method for processing silicon wafers, which reduces wafer cracking caused by the expansion of the adhesive layer due to heat absorption of water during silicon rod cutting.

[0006] This disclosure provides a method for processing spliced ​​silicon rods, comprising: bonding at least two short round silicon rods together along the axial direction of the short round silicon rods through a first adhesive layer to form spliced ​​round silicon rods; A squaring process is performed on spliced ​​round silicon rods to form spliced ​​silicon rods; Before the wire cutting process, at least part of the first adhesive layer in the spliced ​​silicon rod is removed to form a gap region.

[0007] Optionally, removing at least a portion of the first adhesive layer in the spliced ​​silicon rod to form a gap region specifically involves: using a wire cutting process to insert the blade along a first direction and feed it a first distance along the first direction, such that at least a portion of the first adhesive layer within the depth range of the first distance is removed, forming a portion of the gap region; the first direction is perpendicular to the axial direction of the spliced ​​silicon rod.

[0008] Optionally, the removal of at least a portion of the first adhesive layer in the splicing silicon rod to form a gap region specifically involves: using a wire cutting process to insert the blade along a first direction and feed it a first distance along the first direction, such that at least a portion of the first adhesive layer within the depth range of the first distance is removed to form the gap region; the first direction is perpendicular to the outer surface of the splicing silicon rod extending in the axial direction.

[0009] Optionally, the wire cutting process includes: a first stage and a second stage, wherein the first stage includes a first cutting stage, the second stage includes a second cutting stage, and the second stage is performed after the first stage is completed; the feed rate of the second cutting stage is less than the feed rate of the first cutting stage.

[0010] Optionally, the feed depth of the second cutting stage is less than the feed depth of the first cutting stage.

[0011] Optionally, the first stage further includes a reverse cutting stage, which is performed after the first cutting stage is completed, and the feed direction of the reverse cutting stage is opposite to the first direction.

[0012] Optionally, the first cutting stage feeds along the first direction to a preset cutting depth of the first stage, and the reverse cutting stage feeds along a second distance depth in a direction opposite to the first direction, the second distance depth being less than the preset cutting depth of the first stage.

[0013] Optionally, the feed rate of the reverse cutting stage is greater than the feed rate of the first cutting stage and the feed rate of the second cutting stage.

[0014] Optionally, the ratio of the feed rate of the first cutting stage to the feed rate of the second cutting stage is greater than or equal to 3:1 and less than or equal to 4:1.

[0015] Based on the same inventive concept, this disclosure provides a silicon wafer processing method, which uses a spliced ​​silicon rod formed by the splicing silicon rod processing method described above for processing. After the interval area is cut, the material plate is bonded to the first side of the spliced ​​silicon rod. Along the axial direction perpendicular to the spliced ​​silicon rod, the first side is the outer side of the first adhesive layer in the spliced ​​silicon rod that is away from the interval area.

[0016] Compared with the prior art, the technical solution provided in this disclosure has the following advantages: This disclosure provides a method for processing spliced ​​silicon rods and a method for processing silicon wafers, for manufacturing spliced ​​silicon rods, including: bonding at least two short round silicon rods together along the axial direction of the short round silicon rods through a first adhesive layer; performing a squaring process on the spliced ​​round silicon rods to form spliced ​​silicon rods; and before performing a wire cutting process, at least partially removing the first adhesive layer in the spliced ​​silicon rods to form a gap region. Before performing a wafer cutting process, by at least partially removing the first adhesive layer in the spliced ​​silicon rods to form a gap region, the gap region can provide expansion space for the first adhesive layer to absorb water and expand due to the heat of cutting, reducing wafer cracking caused by the expansion of the first adhesive layer spliced ​​silicon rods due to heat absorption of water during cutting, and improving the yield of wafer cutting. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0018] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 The diagram shown is a flowchart of a method for processing spliced ​​silicon rods according to an embodiment of this disclosure; Figure 2 The image shown is a side view of a first adhesive layer after it has been cut, according to an embodiment of this disclosure. Figure 3 The diagram shown is a schematic representation of the relative positional relationship between a cutting line and a splicing silicon rod according to an embodiment of this disclosure. Figure 4 As shown Figure 3 A planar schematic diagram of a spaced region obtained by cutting; Figure 5 As shown Figure 3 A planar schematic diagram of another type of interval region obtained by cutting; Figure 6 As shown Figure 3 A planar schematic diagram of another type of interval region obtained by cutting; Figure 7 The diagram shown illustrates another relative positional relationship between the cutting line and the splicing silicon rod provided in an embodiment of this disclosure. Figure 8 As shown Figure 7 A planar schematic diagram of the cut interval region; Figure 9 The image shown is a cross-sectional view of a first adhesive layer after cutting, according to an embodiment of this disclosure. Figure 10 The diagram shows the relative positional relationship between a spliced ​​silicon rod and a substrate according to an embodiment of this disclosure. Detailed Implementation

[0020] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0021] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0022] Figure 1 The diagram shown is a flowchart of a method for processing spliced ​​silicon rods according to an embodiment of this disclosure. Figure 2 The image shown is a side view of a first adhesive layer after cutting, according to an embodiment of this disclosure. Please refer to... Figure 1 and Figure 2 This disclosure provides a method for processing spliced ​​silicon rods to manufacture spliced ​​silicon rods 100, including: step S1, bonding at least two short round silicon rods together along the axial direction D0 of the short round silicon rods through a first adhesive layer 11 to form a spliced ​​round silicon rod; step S2, performing a squaring process on the spliced ​​round silicon rods to form the spliced ​​silicon rod 100; step S3, before performing a wire cutting process, at least partially removing the first adhesive layer 11 in the spliced ​​silicon rod 100 to form a gap region 12.

[0023] Specifically, in step S1, the axial direction D0 of the short round silicon rod is the same as the extension direction of the short round silicon rod. Bonding at least two short round silicon rods along the axial direction D0 forms a spliced ​​round silicon rod with a flexible and adjustable length, which is beneficial for the subsequent squaring process. In step S2, the bonded spliced ​​round silicon rod is subjected to a squaring process to form a spliced ​​silicon rod 100. At this time, the spliced ​​silicon rod 100 includes at least two first silicon rods 10, and adjacent first silicon rods 10 are bonded along the axial direction D0 of the first silicon rod 10 through a first adhesive layer 11. Figure 2 This illustration only uses the example of a spliced ​​silicon rod 100 comprising two first silicon rods 10, and does not represent the actual number of first silicon rods 10 contained in the spliced ​​silicon rod 100. For example, the cross-section of each first silicon rod 10 facing the first adhesive layer 11 in the spliced ​​silicon rod 100 is a square with a side length of 210 mm; or, the cross-section of each first silicon rod 10 facing the first adhesive layer 11 in the spliced ​​silicon rod 100 is a rectangle, wherein the first side length along the axial direction D0 perpendicular to the first silicon rod 10 is 210 mm, and the second side length along the axial direction D0 parallel to the first silicon rod 10 is 105 mm. The above are merely examples, and this disclosure does not limit the size of the first silicon rod 10; the specific dimensions depend on actual process requirements. In step S3, before the wire cutting process, at least a portion of the first adhesive layer 11 in the spliced ​​silicon rod 100 is removed to form a gap region 12. That is, there is a gap region 12 between adjacent first silicon rods 10 in the splicing silicon rod 100. During the wafer wire cutting process, the heat generated by the cutting process may cause the first adhesive layer 11 to absorb water and expand. The gap region 12 between adjacent first silicon rods 10 can provide a certain expansion space for the first adhesive layer 11 to absorb water and expand, thereby reducing the wafer cracking caused by the expansion of the first adhesive layer 11.

[0024] Thus, by removing at least part of the first adhesive layer 11 in the splicing silicon rod 100, a gap region 12 can be formed between adjacent first silicon rods 10. During the wafer wire cutting process, the gap region 12 can provide expansion space for the first adhesive layer 11, which absorbs water and expands due to the heat of cutting, thereby reducing wafer cracking caused by the expansion of the first adhesive layer 11 and improving the wafer cutting yield.

[0025] Figure 3 The diagram shown is a schematic representation of the relative positional relationship between a cutting line and a splicing silicon rod according to an embodiment of this disclosure. Figure 4 As shown Figure 3 A planar schematic diagram of a segmented region obtained by cutting. Figure 5 As shown Figure 3 A planar schematic diagram of another type of interval region obtained by cutting. Figure 6 As shown Figure 3 A planar schematic diagram of another type of interval region obtained by cutting. Figure 7 The diagram shows another schematic representation of the relative positional relationship between the cutting line and the splicing silicon rod according to an embodiment of this disclosure. Figure 8 As shown Figure 7 Please refer to the planar schematic diagram of the cut interval region. Figures 3 to 8 In a processing method for spliced ​​silicon rods provided in this disclosure, at least a portion of the first adhesive layer 11 in the spliced ​​silicon rod 100 is removed to form a gap region 12. Specifically, a wire cutting process is used to insert the tool along a first direction D1 and feed it along the first direction D1 for a first distance H1, so that at least a portion of the first adhesive layer 11 within the depth range of the first distance H1 is removed, forming a partial gap region 12; the first direction D1 is perpendicular to the axial direction D0 of the spliced ​​silicon rod 100. It should be noted that the "perpendicular" in "the first direction D1 is perpendicular to the axial direction D0 of the spliced ​​silicon rod 100" is allowed to have a certain range of included angles, such as ±1° or ±2°. This disclosure does not specifically limit the value of the included angle. It can be understood that within this included angle range, the first direction D1 can be regarded as perpendicular to the axial direction D0 of the spliced ​​silicon rod 100.

[0026] Specifically, the method for removing at least a portion of the first adhesive layer 11 from the spliced ​​silicon rods 100 provided in this disclosure embodiment can be implemented using a wire cutting process. Along the axial direction D0 perpendicular to the first silicon rods 10, a cutting line 00 cuts the first adhesive layer 11 between adjacent first silicon rods 10. Please refer to... Figure 3 and Figure 4In one optional embodiment provided in this disclosure, the first direction D1 is perpendicular to the outer surface of the splicing silicon rod 100 extending along the axial direction D0. That is, the cutting line 00 enters from the outer surface of the splicing silicon rod 100 perpendicular to the axial direction D0 and advances a first distance H1 along the axial direction D0 of the splicing silicon rod 100 to remove at least a portion of the adhesive layer within the first distance H1. It should be noted that the "outer surface" in "the first direction D1 is perpendicular to the outer surface of the splicing silicon rod 100 extending along the axial direction D0" refers to the non-beveled surface of the first silicon rod 10. A gap region 12 is formed between adjacent first silicon rods 10. At this time, the gap region 12 includes an opening 16, which is connected to the outside of the splicing silicon rod 100. At this time, in the same opening 16, at least a portion of opening 16 is located in the plane where the first outer side 14 of the splicing silicon rod 100 is located, at least a portion of opening 16 is located in the plane where the second outer side 13 of the splicing silicon rod 100 is located, and at least a portion of opening 16 is located in the plane where the third outer side 15 of the splicing silicon rod 100 is located. The first outer side 14, the second outer side 13, and the third outer side 15 are all parallel to the axial direction D0 of the first silicon rod 10, and the first outer side 14 is adjacent to the second outer side 13, and the third outer side 15 is adjacent to the second outer side 13. That is, the opening 16 formed by cutting in the first direction D1 in this embodiment, located on the three outer sides parallel to the axial direction D0 of the first silicon rod 10, can provide effective expansion space for the thermal expansion of the first adhesive layer 11 during the wafer cutting process, reducing the probability of wafer cracking.

[0027] Please refer to Figure 5 In some embodiments, the cross-section of the spliced ​​silicon rod 100 formed after cutting the spliced ​​circular silicon rod is hexagonal, and not... Figure 4 The square shape shown here refers to a surface perpendicular to the axial direction of the splicing silicon rod 100. In this embodiment, the cutting line is fed a first distance H1 along the axial direction D0 perpendicular to the splicing silicon rod 100 to remove at least a portion of the adhesive layer within the first distance H1, forming a spacer region 12. The spacer region 12 includes an opening 16, the shape of which is related to the cross-sectional shape of the splicing silicon rod 100.

[0028] Please refer to Figure 6 In some embodiments, the cross-section of the spliced ​​silicon rod 100 formed after cutting the spliced ​​circular silicon rod is hexagonal, and not... Figure 4 The square shape shown here refers to a surface perpendicular to the axial direction of the splicing silicon rod 100. In this embodiment, the cutting line is fed a first distance H1 along the axial direction D0 perpendicular to the splicing silicon rod 100 to remove at least a portion of the adhesive layer within the first distance H1, forming a spacer region 12. The spacer region 12 includes an opening 16, the shape of which is related to the cross-sectional shape of the splicing silicon rod 100.

[0029] Please refer to Figure 7 and Figure 8 In another optional embodiment provided in this disclosure, the first direction D1 is perpendicular to the axial direction D0 of the splicing silicon rod 100, but the first direction D1 is not perpendicular to the outer side of the splicing silicon rod 100 extending along the axial direction D0. That is, the cutting line 00 enters from a direction perpendicular to the axial direction D0 of the splicing silicon rod 100 but not perpendicular to the outer side of the splicing silicon rod 100 extending along the axial direction D0, and advances a first distance H1 to remove at least a portion of the adhesive layer within the first distance H1, forming a gap region 12 between adjacent first silicon rods 10. The gap region 12 includes an opening 16, which is V-shaped. At least a portion of the opening 16 is located in the plane of the first outer side 14, and at least a portion of the opening 16 is located in the plane of the second outer side 13. Both the first outer side 14 and the second outer side 13 are parallel to the axial direction D0 of the first silicon rod 10, and the first outer side 14 and the second outer side 13 are adjacent to each other. That is, the opening 16 formed by cutting in the first direction D1 in this embodiment is located on two adjacent outer surfaces parallel to the axial direction D0 of the first silicon rod 10, which can provide effective expansion space for the thermal expansion of the first adhesive layer 11 in the wafer cutting process and reduce the probability of wafer cracking.

[0030] Thus, by employing a wire cutting process to insert the die along the first direction D1 and feed it a first distance H1 along the first direction D1, at least a portion of the first adhesive layer 11 within the depth range of the first distance H1 can be removed, forming a partial gap region 12. This provides effective expansion space for the first adhesive layer 11, which expands due to heat during wafer cutting, reducing the probability of wafer cracking. Simultaneously, different forms of cutting can be achieved for the first adhesive layer 11 in the spliced ​​silicon rod 100 along the first direction D1, providing a variety of different options for the actual process.

[0031] Figures 4 to 6 as well as Figure 8 This illustration only shows an example of cutting the first adhesive layer 11 between adjacent first silicon rods 10 at a certain point in the spliced ​​silicon rod 100. It is understood that the first adhesive layer 11 at different positions of the spliced ​​silicon rod 100 can be cut according to actual process needs, and this disclosure is not limited thereto.

[0032] Figure 9 The image shown is a cross-sectional view of the first adhesive layer after cutting, according to an embodiment of this disclosure. Please refer to it. Figure 9In some embodiments, a second adhesive layer 20 is provided on at least one side of the spacer region 12 along the axial direction D0 of the first silicon rod 10. Optionally, the spacer region 12 may include the second adhesive layer 20 on one side along the axial direction D0 of the first silicon rod 10, or the spacer region 12 may include the second adhesive layer 20 on opposite sides along the axial direction D0 of the first silicon rod 10; this disclosure does not limit this. It can be understood that the second adhesive layer 20 may be formed by cutting the first adhesive layer 11 along the first direction D1 by the cutting line 00, that is, the second adhesive layer 20 is actually the residue on the side of the first silicon rod 10 after the first adhesive layer 11 is cut.

[0033] In some embodiments, along the axial direction of the first silicon rod 10, a second adhesive layer 20 is respectively provided on both sides of the spacer region 12, and the second adhesive layer 20 completely covers the surface of the first silicon rod 10 facing the spacer region 12. The second adhesive layer 20 is made of the same material as the first adhesive layer 11, except that the first adhesive layer 11 exists only on one side of the spacer region 12 along the first direction D1, while the second adhesive layer 20 can be located on one side or both sides of the spacer region 12 along the direction parallel to the axial direction D0. Please refer to... Figure 3 and Figure 4 As can be seen from the different cutting references in the first direction D1, when the first direction D1 is perpendicular to the axial direction D0 of the first silicon rod 10, and the first direction D1 is perpendicular to the outer surface of the splicing silicon rod 100 extending along the axial direction D0, the second adhesive layer 20 can intersect with the first outer surface 14, the second outer surface 13, and the third outer surface 15. The shape of the second adhesive layer 20 is rectangular or square. Please refer to... Figure 7 and Figure 8 When the first direction D1 is perpendicular to the axial direction D0 of the first silicon rod 10, but the first direction D1 is not located on the outer side of the splicing silicon rod 100 extending along the axial direction D0, the second adhesive layer 20 only intersects with the first outer side 14 and the second outer side 13 of the first silicon rod 10. In this case, the shape of the second adhesive layer 20 can be triangular. When the spacer region 12 has the second adhesive layer 20 on at least one side along the axial direction D0 of the first silicon rod 10, the second adhesive layer 20, due to its material properties, can mitigate vibration. The second adhesive layer 20 covers the side of the first silicon rod 10 facing the spacer region 12, ensuring that during subsequent slicing processes, the silicon wafer on this side will not vibrate and break during cutting because there is no connected medium (such as adhesive layer or silicon material) on the side facing the spacer region 12. This embodiment can reduce the impact of vibration on the first silicon rod 10 and ensure the smooth progress of subsequent wafer cutting.

[0034] Thus, by providing a second adhesive layer 20 on at least one side of the spacer region 12 along the axial direction D0 of the first silicon rod 10, vibrations during the cutting process can be mitigated, reducing the impact on the first silicon rod 10.

[0035] Please refer to Figure 9 Along the axial direction D0 perpendicular to the first silicon rod 10, at least a portion of the second adhesive layer 20 is in contact with the first adhesive layer 11. That is, during the cutting process of the first adhesive layer 11, the second adhesive layer 20 inevitably remains on the side of the first silicon rod 10 facing the spacing region 12. The second adhesive layer 20 and the first adhesive layer 11 are made of the same material and are in contact. When the first adhesive layer 11 expands due to heat, the second adhesive layer 20 in contact with it can disperse some of the heat or deformation of the first adhesive layer 11, further reducing the impact of the thermal expansion of the first adhesive layer 11 on the first silicon rod 10. When the second adhesive layer 20 is subjected to vibration, the first adhesive layer 11 in contact with it is located below the second adhesive layer 20 and can withstand the descent or deformation of the second adhesive layer 20 under gravity, reducing the overflow of the second adhesive layer 20.

[0036] Thus, the second adhesive layer 20, which is in contact with the first adhesive layer 11, can expand the heat dissipation area of ​​the first adhesive layer 11 and reduce the impact of the first adhesive layer 11 on the first silicon rod 10 due to thermal expansion. The first adhesive layer 11, which is in contact with the second adhesive layer 20, can support the descent or deformation of the second adhesive layer 20 and reduce the overflow of the second adhesive layer 20 under vibration or external force.

[0037] In some embodiments, within the same second adhesive layer 20, the width of the second adhesive layer 20 at different locations along the axial direction D0 of the first silicon rod 10 is equal. It can be understood that the width of the spacer region 12 along the axial direction D0 of the first silicon rod 10 is approximately the same as the diameter of the cutting line 00, and the width of the second adhesive layer 20 on at least one side of the spacer region 12 formed by the cutting along the axial direction D0 of the first silicon rod 10 is uniform.

[0038] Along the axial direction D0 perpendicular to the first silicon rod 10, the depth ratio H1:H2 of the spacer region 12 to the depth of the first adhesive layer 11 is greater than or equal to 1:1 and less than or equal to 4:1. Optionally, the depth ratio H1:H2 of the spacer region 12 to the first adhesive layer 11 can be 1:1, or the depth ratio H1:H2 of the spacer region 12 to the first adhesive layer 11 can be 2:1, or the depth ratio H1:H2 of the spacer region 12 to the first adhesive layer 11 can be 3:1, etc. This disclosure does not specifically limit the depth ratio H1:H2 of the spacer region 12 to the first adhesive layer 11 in the axial direction D0 perpendicular to the first silicon rod 10, as long as the depth of the cut first adhesive layer 11 in the axial direction D0 perpendicular to the first silicon rod 10 is between 20% and 30% of the original depth of the first adhesive layer 11. Along the axial direction D0 perpendicular to the first silicon rod 10, when the depth ratio H1:H2 between the spacer region 12 and the first adhesive layer 11 is less than 1:1, the cutting depth of the first adhesive layer 11 is insufficient, and the spacer region 12 provides insufficient space for thermal expansion of the first adhesive layer 11, easily leading to adhesive overflow. When the depth ratio H1:H2 between the spacer region 12 and the first adhesive layer 11 is greater than 4:1, the cutting depth of the first adhesive layer 11 is too large, resulting in a smaller depth of the first adhesive layer 11 after cutting, which is detrimental to the bonding stability between adjacent first silicon rods 10. Therefore, by setting the depth ratio H1:H2 between the spacer region 12 and the first adhesive layer 11 in the axial direction D0 perpendicular to the first silicon rod 10 to be greater than or equal to 1:1 and less than or equal to 4:1, sufficient expansion space can be provided for the thermal expansion of the first adhesive layer 11 while ensuring effective bonding between adjacent first silicon rods 10, reducing adhesive overflow.

[0039] In some embodiments, along the axial direction perpendicular to the first silicon rod 10, the depth ratio of the second adhesive layer 20 to the depth of the first adhesive layer 11 is greater than or equal to 1:1 and less than or equal to 4:1. It is understood that the second adhesive layer 20 is formed simultaneously with the cutting of the first adhesive layer 11 to form the spacer region 12. The second adhesive layer 20 is located on the surface of the first silicon rod 10 facing the spacer region 12; that is, the depth of the spacer region 12 formed after cutting is the same as the depth of the second adhesive layer 20. Therefore, along the axial direction perpendicular to the first silicon rod 10, when the depth ratio of the spacer region 12 to the depth of the first adhesive layer 11 is greater than or equal to 1:1 and less than or equal to 4:1, the depth ratio of the second adhesive layer 20 to the depth of the first adhesive layer 11 is also greater than or equal to 1:1 and less than or equal to 4:1.

[0040] Please combine Figures 1 to 9In the processing method of spliced ​​silicon rods provided in this disclosure, the wire cutting process includes: a first stage and a second stage. The first stage includes a first cutting stage, and the second stage includes a second cutting stage. The second stage is performed after the first stage is completed. The feed rate of the second cutting stage is less than the feed rate of the first cutting stage.

[0041] Specifically, the cutting of the first adhesive layer 11 includes a first stage and a second stage, wherein the cutting speed of the first cutting stage is a first cutting speed, the feed depth of the first cutting stage is a first feed depth, the cutting speed of the second cutting stage is a second cutting speed, the feed depth of the second cutting stage is a second feed depth, the first cutting speed is greater than the second cutting speed, and the first feed depth is greater than the second feed depth.

[0042] In some embodiments, the feed depth of the second cutting stage is less than the feed depth of the first cutting stage. The second cutting stage is performed after the first cutting stage is completed. Since the second feed depth is closer to the first distance H1 of the cutting depth along the first direction D1 of the cutting line 00, in order to prevent over-cutting, the second cutting speed must be less than the first cutting speed, and the second feed depth is less than the first feed depth.

[0043] The first stage also includes a reverse cutting stage, that is, the first stage includes a first cutting stage and a reverse cutting stage, and the reverse cutting stage is performed after the first cutting stage is completed. The feed direction of the reverse cutting stage is opposite to the first direction D1. During the cutting process, the greater the cutting depth along the first direction D1, the greater the resistance of the first adhesive layer 11 on the cutting line 00, resulting in a greater degree of deformation when the cutting line 00 continues to cut downwards along the first direction D1, and an uneven cut surface of the first adhesive layer 11. By setting a reverse cutting stage after the first cutting stage in the first stage, that is, the cutting line 00 retreats in the opposite direction to the first direction D1, the cutting line 00 can be restored to its original shape, which is beneficial to the second cutting stage.

[0044] Furthermore, in the first cutting stage, the feed proceeds along the first direction D1 to a preset cutting depth, which is the first feed depth mentioned above. In the reverse cutting stage, the feed proceeds along the opposite direction to the first direction D1 to a second distance depth, which is less than the preset cutting depth of the first stage. That is to say, in the first stage, the second distance depth of the reverse cutting stage following the first cutting stage is less than the first feed depth. This avoids the cutting line 00 from exiting the first interval due to excessive retraction, thus preventing the second cutting stage from being affected.

[0045] In the processing method for splicing silicon rods provided in this disclosure, the feed speed of the reverse cutting stage is greater than the feed speed of the first cutting stage and the feed speed of the second cutting stage. That is, the feed speed of the reverse cutting stage is the highest among the first and second stages. Since the feed direction of the reverse cutting stage is opposite to that of the first and second cutting stages, setting the feed speed of the reverse cutting stage to be larger can effectively shorten the reverse cutting stage time, thereby effectively shortening the cutting time of the first adhesive layer 11 and improving production efficiency.

[0046] Thus, by setting the feed speed of the reverse cutting stage to be greater than the feed speed of the first cutting stage and the feed speed of the second cutting stage, the overall cutting time of the first adhesive layer 11 can be effectively shortened, thereby improving production efficiency.

[0047] Table 1 shows the wire cutting process parameters for one type of spliced ​​silicon rod 100 provided in this embodiment, and Table 2 shows the wire cutting process parameters for another type of spliced ​​silicon rod 100 provided in this embodiment. Referring to Tables 1 and 2, when cutting the first adhesive layer 11 in the spliced ​​silicon rod 100 using the wire cutting process, the adhesive seam (original first adhesive layer 11) between adjacent first silicon rods 10 in the spliced ​​silicon rod 100 must be aligned with the diamond wire (i.e., the cutting line 00). During the cutting of the first adhesive layer 11, the cooling water spray device is continuously turned on, with the water flow rate uniformly sprayed onto the diamond wire and the cutting position to reduce the accumulation of debris in the interval area 12 after cutting. The water flow rate is greater than or equal to 24 L / min. The diameter of the diamond wire is less than or equal to 0.3 mm, and there is no shedding of diamond abrasive.

[0048] Table 1

[0049] Table 2

[0050] As shown in Tables 1 and 2, the first cutting stage in the first phase can be divided into three segments according to the different cutting depths. Including the 5mm tool setting distance, the final distance of the first segment is 10mm, so the actual cutting depth of the first segment is 5mm; the final distance of the second segment is 80mm, so the actual cutting depth of the second segment is 75mm; and the final distance of the third segment is 170mm, so the actual cutting depth of the third segment is 165mm. In Table 1, the initial feed speed of the first, second, and third segments is 90mm / min, and the final feed speed of the first, second, and third segments is 90mm / min. In Table 2, the initial feed speed of the first, second, and third segments is 110mm / min, and the final feed speed of the first, second, and third segments is 110mm / min. It can be seen that in the first cutting stage, the diamond wire feeds towards the original first adhesive layer 11 at a constant speed.

[0051] During the reverse cutting stage, the initial position of the diamond wire is 170mm, and the final position of the diamond wire is 160mm. It can be seen that during the reverse cutting stage, the diamond wire retreats 5mm in the opposite direction to the first direction D1. The above is only an example. In some other embodiments, the retreat distance during the reverse cutting stage may be other values. This disclosure does not limit this, as long as the retreat distance during the reverse cutting stage is within the range of 5mm ± 0.5mm.

[0052] In the second cutting stage, including a 5mm tool setting distance, the initial distance of the second cutting stage is 165mm, and the final distance is 172mm. Therefore, the actual cutting depth in the second cutting stage is 7mm. Table 1 shows that the initial and final speeds of the second cutting stage are both 30mm / min, indicating that the feed rate of the second cutting stage is much lower than that of the first cutting stage. Table 2 shows that the initial and final speeds of the second cutting stage are both 35mm / min, again indicating that the feed rate of the second cutting stage is much lower than that of the first cutting stage. By setting the feed rate of the second cutting stage to be much lower than that of the first cutting stage, the feed depth can be controlled, thereby controlling the depth of the interval region 12 in the axial direction D0 perpendicular to the splicing silicon rod 100. Furthermore, the initial and final speeds of the reverse cutting stage in Table 1 are both 450 mm / min, which is greater than the feed speeds of the first and second cutting stages in Table 1; the initial and final speeds of the reverse cutting stage in Table 2 are both 550 mm / min, which is greater than the feed speeds of the first and second cutting stages in Table 2. This is beneficial for shortening the overall cutting time and improving process efficiency.

[0053] In the processing method for splicing silicon rods provided in this disclosure, the ratio of the feed speed of the first cutting stage to the feed speed of the second cutting stage is greater than or equal to 3:1 and less than or equal to 4:1. Referring to Table 1, the feed speed of the first cutting stage is 90 mm / min, and the feed speed of the second cutting stage is 30 mm / min, with a ratio of 3:1. Referring to Table 2, the feed speed of the first cutting stage is 110 mm / min, and the feed speed of the second cutting stage is 35 mm / min, with a ratio of 3.1:1. Both of these ratios satisfy the range of 3:1 and 4:1. Of course, the ratio of the feed speed of the first cutting stage to the feed speed of the second cutting stage can also be other values, and this disclosure does not specifically limit it.

[0054] When the first adhesive layer 11 is cut using a wire cutting process, the cutting tool can be a wire cutter used in wafer cutting processes. The wire cutter includes a cutting line 00, which maintains a basically uniform speed throughout the entire wire cutting process. Referring to Tables 1 and 2, the linear speed of the cutting line 00 is greater than or equal to 20 mm / min and less than or equal to 50 mm / min. Optionally, the linear speed of the cutting line 00 is 31 mm / min, or 32 mm / min, or 33 mm / min, or 34 mm / min, or the linear speed of the cutting line 00 may vary slightly during the cutting process, but generally remains between greater than or equal to 20 mm / min and less than or equal to 50 mm / min... This disclosure does not specifically limit this. When the linear speed of the cutting wire 00 is less than 20 mm / min, the cutting resistance of the first adhesive layer 11 may be too high, resulting in a low feed speed of the cutting wire 00 along the first direction D1 and a longer cutting time, which is not conducive to improving production efficiency. When the linear speed of the cutting wire 00 is greater than 50 mm / min, the cutting speed of the cutting wire 00 is too high, which may cause the cutting wire 00 to remove the first adhesive layer 11 too quickly, making it impossible to match with the feed speed along the first direction D1 during the cutting stage, resulting in the cutting machine running idle. Therefore, by setting the linear speed of the wire cutting process within the range of greater than or equal to 20 mm / min and less than or equal to 50 mm / min, the linear speed of the cutting wire 00 can be matched with the feed speed of the cutting wire 00 along the first direction D1, so as to achieve effective cutting of the first adhesive layer 11 and ensure normal production.

[0055] Figure 10 The diagram shown illustrates the relative positions of a spliced ​​silicon rod and a substrate according to an embodiment of this disclosure. Please refer to it. Figure 10Based on the same inventive concept, this disclosure also provides a silicon wafer processing method. The method involves processing a spliced ​​silicon rod 100 formed using the previously described splicing silicon rod processing method. After the spacer region 12 is cut, a material plate 30 is bonded to the first side surface 17 of the spliced ​​silicon rod 100. Along the axial direction D0 perpendicular to the spliced ​​silicon rod 100, the first side surface 17 is the outer side of the first adhesive layer 11 in the spliced ​​silicon rod 100 facing away from the spacer region 12. That is, after at least a portion of the first adhesive layer 11 in the spliced ​​silicon rod 100 is cut, the material plate 30 needs to be bonded to the spliced ​​silicon rod 100 along the first side surface 17 to facilitate the subsequent wafer cutting process. Understandably, along the axial direction D0 perpendicular to the spliced ​​silicon rod 100, the first side surface 17 is located on the side of the first adhesive layer 11 facing away from the spacer region 12, and the first side surface 17 is in contact with the first adhesive layer 11. In the wafer dicing process, the dicing line 00 travels in a direction perpendicular to the axial direction D0 of the splicing silicon rod 100. By bonding the first side 17 of the splicing silicon rod 100 to the material plate 30, good support can be provided for the splicing silicon rod 100, which facilitates the smooth progress of wafer dicing.

[0056] This disclosure, by placing the cutting process of the first adhesive layer 11 after the squaring process of the short round silicon rod and before the wafer cutting process of the spliced ​​silicon rod 100, avoids affecting the squaring process of the short round silicon rods connected by the original first adhesive layer 11. If the first adhesive layer 11 is cut before squaring, the adjacent short round silicon rods may become loosely connected due to the partial removal of the first adhesive layer 11, leading to squaring failure. If the first adhesive layer 11 is removed after the wafer cutting process, the wafer cutting has already taken place, and the first adhesive layer 11 will undergo thermal expansion during the wafer cutting process, making removal after wafer cutting meaningless. Therefore, by placing the wire cutting process of the first adhesive layer 11 after the squaring process of the short round silicon rod and before the wafer cutting process of the spliced ​​silicon rod 100, this disclosure effectively mitigates the risk of wafer cracking due to thermal expansion of the first adhesive layer 11 in the spliced ​​silicon rod 100 during the wafer cutting process, thereby improving the yield of the wafer cutting process.

[0057] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for processing spliced ​​silicon rods, characterized in that, include: At least two short round silicon rods are bonded together along the axial direction of the short round silicon rods through a first adhesive layer to form spliced ​​round silicon rods; A squaring process is performed on spliced ​​round silicon rods to form spliced ​​silicon rods; Before the wire cutting process, at least part of the first adhesive layer in the spliced ​​silicon rod is removed to form a gap region.

2. The processing method for splicing silicon rods as described in claim 1, characterized in that, The removal of at least part of the first adhesive layer in the spliced ​​silicon rod to form a gap region specifically involves: using a wire cutting process to insert the blade along a first direction and feed it a first distance along the first direction, so that at least part of the first adhesive layer within the depth range of the first distance is removed, forming part of the gap region; The first direction is perpendicular to the axial direction of the spliced ​​silicon rod.

3. The processing method for splicing silicon rods as described in claim 1, characterized in that, The removal of at least part of the first adhesive layer in the spliced ​​silicon rod to form a gap region specifically involves: using a wire cutting process to insert the blade along a first direction and feed it a first distance along the first direction, so that at least part of the first adhesive layer within the depth range of the first distance is removed to form the gap region; The first direction is perpendicular to the outer surface of the spliced ​​silicon rod extending in the axial direction.

4. The processing method for splicing silicon rods as described in any one of claims 2 or 3, characterized in that, The wire cutting process includes: a first stage and a second stage, wherein the first stage includes a first cutting stage, the second stage includes a second cutting stage, and the second stage is performed after the first stage is completed; The feed rate in the second cutting stage is less than the feed rate in the first cutting stage.

5. The processing method for splicing silicon rods as described in claim 4, characterized in that, The feed depth of the second cutting stage is less than the feed depth of the first cutting stage.

6. The processing method for splicing silicon rods as described in claim 4, characterized in that, The first stage also includes a reverse cutting stage, which is performed after the first cutting stage is completed, and the feed direction of the reverse cutting stage is opposite to that of the first direction.

7. The processing method for splicing silicon rods as described in claim 6, characterized in that, The first cutting stage feeds along the first direction to a preset cutting depth of the first stage, and the reverse cutting stage feeds along the opposite direction to the first direction to a second distance depth, the second distance depth being less than the preset cutting depth of the first stage.

8. The processing method for splicing silicon rods as described in claim 6, characterized in that, The feed rate of the reverse cutting stage is greater than the feed rate of the first cutting stage and the feed rate of the second cutting stage.

9. The processing method for splicing silicon rods as described in claim 5, characterized in that, The ratio of the feed rate of the first cutting stage to the feed rate of the second cutting stage is greater than or equal to 3:1 and less than or equal to 4:

1.

10. A silicon wafer processing method, comprising processing a spliced ​​silicon rod formed by the splicing silicon rod processing method as described in any one of claims 1-9, characterized in that, After the interval area is cut, the material plate is bonded to the first side of the spliced ​​silicon rod. Along the axial direction perpendicular to the spliced ​​silicon rod, the first side is the outer side of the first adhesive layer in the spliced ​​silicon rod that faces away from the interval area.

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