Crystal ingot processing method and crystal ingot processing equipment

Abstract

The invention discloses a crystal ingot processing method and crystal ingot processing equipment, and relates to the technical field of semiconductor processing, when cylindrical grinding machine processing is carried out on a cylindrical to-be-processed crystal ingot through a cylindrical grinding wheel, the side wall of the to-be-processed crystal ingot and the side wall of the grinding wheel are oppositely placed, the bottom surface of the to-be-processed crystal ingot is inclined by an angle alpha relative to the bottom surface of the grinding wheel, tan alpha = (h1-m) / z1, wherein h1 is the maximum depth of the defect, deepest from the side wall to the center shaft, on the to-be-machined crystal ingot, m is the minimum removal amount m of the bottom face where the maximum depth h1 is located, and the position where the maximum depth h1 is located is the tip position of the to-be-machined crystal ingot, so that oblique removal of the side wall of the crystal ingot is achieved, and the oblique cylindrical crystal ingot is obtained. Therefore, oblique growth defects or oblique areas needing to be removed on the crystal ingot are effectively removed, the effective thickness of the machined crystal ingot is increased, the machining breakage rate of the crystal ingot is reduced, the machining yield and output of the crystal ingot are increased, and the utilization rate of crystal ingot materials is increased.

Description

Technical Field

[0001] The present application relates to the field of semiconductor processing technology, and in particular to a crystal ingot processing method and a crystal ingot processing device. Background Art

[0002] The growth of silicon carbide crystals is difficult, and the temperature, pressure, growth rate, etc. during the growth process will affect the quality of silicon carbide crystals. At present, the growth of silicon carbide crystals mainly adopts physical vapor transport method (PVT method), high temperature chemical vapor deposition method (HTCVD method) and liquid phase method (Liquid Phase Method). After years of development, the PVT method is relatively mature and more suitable for industrial mass production. The principle of growing silicon carbide crystals is: carbon and silicon powders are placed at the bottom of the crucible as raw materials, and silicon carbide seed crystals are placed at the top of the crucible. Under the closed conditions of high temperature and low pressure, the sublimated powder is transferred upward to the vicinity of the seed crystal through the action of temperature gradient and concentration difference, and recrystallized after reaching the supersaturated state to achieve the growth of silicon carbide crystals.

[0003] The surface and sidewall of the silicon carbide embryo grown by the PVT method are irregular, and there are defects such as edge cracks and stray crystals on the circumference of the silicon carbide embryo. Generally, it is necessary to first process the original silicon carbide embryo into a silicon carbide ingot of a certain size through plane processing and external cylindrical rough processing, and then process the silicon carbide ingot into a cylindrical crystal of standard size through external cylindrical grinding. However, growth defects such as cracks and stray crystals may approach the central axis of the silicon carbide ingot as the growth process progresses, and most external cylindrical grinding machines can only remove the sidewalls of the silicon carbide ingot evenly. In this way, some obliquely grown defects in the silicon carbide ingot or the oblique areas that need to be removed will not be completely removed, resulting in the silicon carbide ingot having defects in some thicknesses, which reduces its effective thickness, or is damaged during processing, affecting the processing yield and output of the silicon carbide ingot. Of course, such problems are not limited to silicon carbide ingots. For ingots of other materials, if there are obliquely grown defects or oblique areas that need to be removed, such problems will also be faced. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the embodiments of the present application provide a crystal ingot processing method and a crystal ingot processing equipment to effectively remove obliquely grown defects on the crystal ingot or oblique areas that need to be removed, increase the effective thickness of the crystal ingot after processing, reduce the crystal ingot processing breakage rate, and improve the processing yield and output of the crystal ingot.

[0005] To achieve the above objectives, the present application provides the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a method for processing a crystal ingot, the method comprising:

[0007] Obtain a crystal ingot to be processed, wherein the crystal ingot to be processed is cylindrical, the diameter of the bottom surface of the crystal ingot to be processed is D1, and the thickness of the crystal ingot to be processed is z1;

[0008] Detect defects on the ingot to be processed, determine a maximum depth h1 of the defect that penetrates the deepest from the side wall to the central axis of the ingot to be processed, and determine a depth h2 of the defect that penetrates from the side wall to the central axis in a region opposite to the maximum depth h1 in the bottom surface where the maximum depth h1 is located, along the radial direction of the bottom surface, where 0≤h2

[0009] The maximum depth h1 is defined as the position of the maximum removal amount of the bottom surface where the maximum depth h1 is located, and based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, the minimum removal amount m of the bottom surface where the maximum depth h1 is located is determined, D1-D2≥h1+m, and the position where the minimum removal amount is located is opposite to the position where the maximum removal amount is located along the radial direction of the bottom surface where the maximum depth h1 is located;

[0010] The crystal ingot to be processed is subjected to external cylindrical grinding by means of a grinding wheel, wherein the grinding wheel is cylindrical, the side wall of the crystal ingot to be processed is placed opposite to the side wall of the grinding wheel, the bottom surface of the crystal ingot to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel, tanα=(h1-m) / z1, the maximum depth h1 is the top position of the crystal ingot to be processed, thereby obtaining an oblique cylindrical crystal ingot, the bottom surface of the oblique cylindrical crystal ingot is circular, and the side wall of the oblique cylindrical crystal ingot is inclined at an angle α relative to the height.

[0011] Optionally, based on h2 and a target diameter D2 of the bottom surface of the ingot to be processed, determining the minimum removal amount m of the bottom surface where the maximum depth h1 is located includes:

[0012] Compare the size of h2 with (D1-D2-h1);

[0013] If h2≤(D1-D2-h1), then determine the minimum removal amount m=h2 of the bottom surface where the maximum depth h1 is located;

[0014] If h2>(D1-D2-h1), then the minimum removal amount m=(D1-D2-h1) of the bottom surface where the maximum depth h1 is located is determined.

[0015] Optionally, performing cylindrical grinding on the ingot to be processed by a grinding wheel includes:

[0016] ​The clamping member clamps the crystal ingot to be processed through an auxiliary block, the auxiliary block comprises a bottom surface and an inclined surface with an inclination angle α relative to the bottom surface, the inclined surface of the auxiliary block is in contact with the bottom surface of the crystal ingot to be processed, the bottom surface of the auxiliary block is in contact with the clamping member, a line connecting the highest point and the lowest point of the inclined surface of the auxiliary block from its bottom surface is parallel to the radial direction of the bottom surface of the crystal ingot to be processed where the maximum depth h1 is located, the center of the inclined surface and the bottom surface of the auxiliary block, the center of the bottom surface of the crystal ingot to be processed and the central axis of the clamping member are aligned, so that the side wall of the crystal ingot to be processed is placed opposite to the side wall of the grinding wheel, the bottom surface of the crystal ingot to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel, and the maximum depth h1 is the top position of the crystal ingot to be processed;

[0017] By moving the grinding wheel and moving and rotating the ingot to be processed, the side wall of the grinding wheel obliquely removes the side wall of the ingot to be processed to obtain an oblique cylindrical ingot, the bottom surface of the oblique cylindrical ingot is circular, and the side wall of the oblique cylindrical ingot is inclined at an angle α relative to the height.

[0018] Optionally, before the crystal ingot to be processed is subjected to cylindrical grinding by a grinding wheel, the crystal ingot processing method further comprises:

[0019] Select the auxiliary block, wherein the elliptical inclined surface of the selected auxiliary block is inclined at an angle α relative to the circular bottom surface thereof, and the distance between the highest point and the lowest point of the inclined surface of the selected auxiliary block and the bottom surface thereof is r<D2;

[0020] When the clamping piece clamps the crystal ingot to be processed through the auxiliary block, the circular bottom surface of the auxiliary block is parallel to the bottom surface of the grinding wheel.

[0021] Optionally, the ingot processing method further includes:

[0022] The oblique cylindrical ingot is cut using a parallel wire mesh, wherein the extension direction of the parallel lines in the parallel wire mesh is parallel to the bottom surface of the oblique cylindrical ingot, and the arrangement direction of the parallel lines in the parallel wire mesh is perpendicular to the bottom surface of the oblique cylindrical ingot, to obtain a plurality of oblique cylindrical wafers.

[0023] Optionally, the ingot processing method further includes:

[0024] The oblique cylindrical wafer is chamfered to obtain a standard cylindrical wafer, wherein the thickness of the oblique cylindrical wafer is x, the diameter of the bottom surface of the oblique cylindrical wafer is D2, the deflection of the side wall of the oblique cylindrical wafer is y=xtanα, the diameter of the bottom surface of the standard cylindrical wafer is D3, and (D2-D3)≥y.

[0025] Optionally, the ingot processing method is applied to silicon carbide ingots.

[0026] In a second aspect, an embodiment of the present application provides a crystal ingot processing device, the crystal ingot processing device comprising:

[0027] A crystal ingot obtaining device, used for performing rough processing on the growing crystal embryo to obtain a crystal ingot to be processed, wherein the crystal ingot to be processed is cylindrical, the bottom surface of the crystal ingot to be processed has a diameter of D1, and the thickness of the crystal ingot to be processed is z1;

[0028] A defect detection device, used to detect defects on the ingot to be processed, determine the maximum depth h1 of the defect that penetrates the deepest from the side wall to the central axis on the ingot to be processed, and determine the depth h2 of the defect from the side wall to the central axis in the bottom surface where the maximum depth h1 is located and in the radial direction of the bottom surface, in the area opposite to the maximum depth h1, 0≤h2

[0029] The calculation device determines the maximum depth h1 as the position of the maximum removal amount of the bottom surface where the maximum depth h1 is located, and determines the minimum removal amount m of the bottom surface where the maximum depth h1 is located based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, D1-D2≥h1+m, and the position where the minimum removal amount is located is opposite to the position where the maximum removal amount is located in the radial direction of the bottom surface;

[0030] A cylindrical grinding machine processing device performs cylindrical grinding on the crystal ingot to be processed by a grinding wheel, wherein the grinding wheel is cylindrical, the side wall of the crystal ingot to be processed is placed opposite to the side wall of the grinding wheel, the bottom surface of the crystal ingot to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel, tanα=(h1-m) / z1, the maximum depth h1 is the top position of the crystal ingot to be processed, thereby obtaining an oblique cylindrical crystal ingot, the bottom surface of the oblique cylindrical crystal ingot is circular, and the side wall of the oblique cylindrical crystal ingot is inclined at an angle α relative to the height.

[0031] Optionally, the ingot processing equipment further includes:

[0032] A multi-wire cutting device uses a parallel wire network to cut the oblique cylindrical ingot, wherein the extension direction of the parallel lines in the parallel wire network is parallel to the bottom surface of the oblique cylindrical ingot, and the arrangement direction of the parallel lines in the parallel wire network is perpendicular to the bottom surface of the oblique cylindrical ingot, thereby obtaining multiple oblique cylindrical wafers.

[0033] Optionally, the ingot processing equipment further includes:

[0034] A chamfering device is used to perform chamfering on the oblique cylindrical wafer to obtain a standard cylindrical wafer, wherein the thickness of the oblique cylindrical wafer is x, the diameter of the bottom surface of the oblique cylindrical wafer is D2, the deflection of the side wall of the oblique cylindrical wafer is y=xtanα, the diameter of the bottom surface of the standard cylindrical wafer is D3, and (D2-D3)≥y.​

[0035] Compared with the prior art, the above technical solution has the following advantages:

[0036] Compared with the existing external cylindrical grinding machine processing that can only uniformly remove the side wall of the ingot, the ingot processing method provided in the embodiment of the present application, after obtaining the ingot to be processed with a bottom diameter of D1 and a thickness of z1, first detects the defects on the ingot to be processed, determines the maximum depth h1 of the defect that penetrates the deepest from the side wall to the central axis on the ingot to be processed, and determines the depth h2 of the defect from the side wall to the central axis in the area opposite to the maximum depth h1 along the radial direction of the bottom surface on the bottom surface where the maximum depth h1 is located, 0≤h2 BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 is a schematic side view of a crystal ingot 10 to be processed;

[0039] Figure 2 A schematic diagram of a perspective of processing on an existing cylindrical grinder;

[0040] Figure 3 Another perspective diagram of the existing cylindrical grinding machine processing; ​

[0041] Figure 4 It is a side view schematic diagram of uniformly removing the side wall of the crystal ingot 10 to be processed by an existing cylindrical grinder;

[0042] Figure 5 A schematic diagram of a perspective of performing oblique cylindrical grinding on a crystal ingot 10 to be processed by using the crystal ingot processing method provided in an embodiment of the present application;

[0043] Figure 6 A schematic diagram showing another perspective of performing oblique cylindrical grinding on a crystal ingot 10 to be processed by using the crystal ingot processing method provided in an embodiment of the present application;

[0044] Figure 7 A schematic side view of the oblique removal of the side wall of the ingot 10 to be processed by the ingot processing method provided in an embodiment of the present application;

[0045] Figure 8 A schematic bottom view of the oblique removal of the side wall of the ingot 10 to be processed by the ingot processing method provided in an embodiment of the present application;

[0046] Fig. 9 A schematic diagram of a viewing angle of the auxiliary block 40;

[0047] Fig.10 is a schematic diagram of the auxiliary block 40 from another viewing angle;

[0048] Fig.11 A schematic diagram of performing parallel wire mesh cutting on an oblique cylindrical crystal ingot 11 using the crystal ingot processing method provided in an embodiment of the present application;

[0049] Fig.12 A schematic diagram of first pasting a standard cylindrical crystal ingot obtained by processing with an existing cylindrical grinder on a resin plate 60, and then pasting the resin plate 60 on a workbench fixture 70 of a multi-wire saw;

[0050] Fig.13 It is a schematic diagram of cutting a standard cylindrical ingot using a parallel wire network 50 of a multi-wire saw in the prior art;

[0051] Fig.14 It is a schematic diagram of cutting a standard cylindrical ingot processed by an existing cylindrical grinder using a parallel wire mesh 50 in the prior art;

[0052] Fig.15 A schematic side view of an oblique cylindrical wafer 12 obtained by performing parallel wire mesh cutting on an oblique cylindrical ingot 11 using the ingot processing method provided in an embodiment of the present application;

[0053] Fig.16 A schematic diagram of the process of a crystal ingot processing device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0055] As described in the background technology section, when oblique growth defects or oblique areas that need to be removed appear in silicon carbide ingots or ingots of other materials, the existing cylindrical grinding machine can only evenly remove the side walls of the ingot. Therefore, some oblique growth defects or oblique areas that need to be removed in the ingot cannot be completely removed, resulting in defects in part of the thickness of the ingot, which reduces its effective thickness, or causes damage during processing, affecting the processing yield and output of the ingot.

[0056] Figure 1 A schematic side view of a crystal ingot 10 to be processed is shown. Figure 1 As shown, the ingot 10 to be processed is cylindrical, and includes two opposite bottom surfaces and side walls connecting the two opposite bottom surfaces. Taking the ingot 10 to be processed as a silicon carbide ingot as an example, after the silicon carbide embryo is grown by the PVT method, the original silicon carbide embryo is first processed into a silicon carbide ingot of a certain size by plane processing and outer circle rough processing, that is, Figure 1 As shown in the cylindrical ingot, it can be seen that the ingot to be processed 10 has edge defects that approach the central axis of the ingot during the growth process.

[0057] Figure 2 A schematic diagram of a conventional cylindrical grinding machine is shown. Figure 3 Another perspective diagram of the existing cylindrical grinding machine processing is shown, combined with Figure 2 and Figure 3 As shown, when the crystal ingot 10 to be processed is processed by the existing cylindrical grinding machine, the crystal ingot 10 to be processed is clamped from the two bottom surfaces of the crystal ingot 10 to be processed by the clamping member 20, so that the side wall of the crystal ingot 10 to be processed is placed opposite to the side wall of the grinding wheel 30, and the bottom surface of the crystal ingot 10 to be processed is parallel to the bottom surface of the grinding wheel 30. In this way, by moving the grinding wheel 30 and moving and rotating the crystal ingot 10 to be processed, the side wall of the crystal ingot 10 to be processed is evenly removed to form a standard cylindrical crystal ingot. Figure 4 A schematic side view of the conventional cylindrical grinder for uniformly removing the side wall of the ingot 10 to be processed is shown. Figure 4 The parts outside the two dotted lines are removed by the cylindrical grinder.

[0058] contrast Figure 1 and Figure 4It can be known that the bottom diameter of the ingot 10 to be processed is D1, the thickness of the ingot 10 to be processed is z1, and the bottom diameter of the standard cylindrical ingot after processing by the existing cylindrical grinder needs to be at least the target diameter D2, that is, the diameter of the standard cylindrical ingot after processing by the cylindrical grinder needs to meet the requirements, then, along the radial direction of the bottom surface of the ingot 10 to be processed, the maximum removable amount of the diameter of the bottom surface of the ingot 10 to be processed is △D=D1-D2. Since the existing cylindrical grinder processing is to uniformly remove the side wall of the ingot 10 to be processed, therefore, along the radial direction of the bottom surface of the ingot 10 to be processed, the maximum removable amount of the radius of the bottom surface of the ingot 10 to be processed is △D / 2=(D1-D2) / 2.

[0059] If the maximum depth of the obliquely grown defects on the side wall of the ingot 10 to be processed is greater than △D / 2, then the effective thickness of the standard brick cylindrical ingot processed by the existing cylindrical grinder will be reduced due to defects in part of the thickness, or it will be damaged during processing, affecting the processing yield and output of the ingot. It should be noted that the effective thickness of the ingot refers to the thickness of the part of the ingot without defects.

[0060] In view of this, an embodiment of the present application provides a method for processing an ingot, which can be applied to a silicon carbide ingot or an ingot of other materials, which has obliquely grown defects or oblique areas that need to be removed, and the method for processing an ingot includes:

[0061] S100: Reference Figure 1 As shown, a crystal ingot 10 to be processed is obtained. The crystal ingot 10 to be processed is cylindrical, the diameter of the bottom surface of the crystal ingot 10 to be processed is D1, and the thickness of the crystal ingot to be processed is z1.

[0062] It is understandable that the grown crystal embryo can be processed into a cylindrical crystal ingot 10 to be processed by means of plane processing and outer circle rough processing.

[0063] S200: Reference Figure 1 and Figure 5 As shown, defects on the crystal ingot 10 to be processed are detected, and the maximum depth h1 of the defect that penetrates the deepest from the side wall to the central axis on the crystal ingot 10 to be processed is determined, and the depth h2 of the defect from the side wall to the central axis in the area opposite to the maximum depth h1 in the bottom surface where the maximum depth h1 is located and along the radial direction of the bottom surface is determined, 0≤h2

[0064] Take the ingot 10 to be processed as a silicon carbide ingot as an example. Figure 1 As shown, since growth defects such as cracks and impurity crystals will approach the central axis of the silicon carbide ingot as the growth process progresses, the maximum depth h1 of the deepest defect from the side wall to the central axis on the ingot 10 to be processed is usually located on the upper bottom surface of the ingot 10 to be processed (i.e., the bottom surface after growth). ​

[0065] It can be understood that after determining the deepest defect from the side wall to the central axis on the ingot 10 to be processed and the maximum depth h1 of the defect, the depth h2 of the defect from the side wall to the central axis in the area opposite to the maximum depth h1 along the radial direction of the bottom surface where the maximum depth h1 is located can be determined. Figure 1 As shown, the maximum depth h1 is located on the upper bottom surface of the ingot 10 to be processed. Along the radial direction of the upper bottom surface of the ingot 10 to be processed, there is no defect in the area opposite to the maximum depth h1, that is, h2=0; another option, as Figure 5 As shown, in the bottom surface where the maximum depth h1 is located, there is a defect in the area opposite to the maximum depth h1 along the radial direction of the bottom surface, and the depth of the defect from the side wall to the central axis is h2, and h2>0.

[0066] S300: Reference Figure 5 As shown, the maximum depth h1 is defined as the position of the maximum removal amount of the bottom surface at the maximum depth h1, and based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, the minimum removal amount m of the bottom surface at the maximum depth h1 is determined, D1-D2≥h1+m, and the position of the minimum removal amount is opposite to the position of the maximum removal amount along the radial direction of the bottom surface at the maximum depth h1.

[0067] It can be understood that, in order to remove the defects at the maximum depth h1, the maximum depth h1 can be defined as the position of the maximum removal amount at the bottom surface where the maximum depth h1 is located.

[0068] It can also be understood that the diameter of the ingot after being processed by the cylindrical grinder needs to be at least the target diameter D2. Then, along the radial direction of the bottom surface of the ingot 10 to be processed, the maximum removable amount of the diameter of the bottom surface of the ingot 10 to be processed is △D=D1-D2, and △D>h1. Since the maximum depth h1 has been determined as the position of the maximum removal amount of the bottom surface where the maximum depth h1 is located, the maximum removable amount of the position opposite to the position of the maximum removal amount (i.e., the maximum depth h1) in the bottom surface where the maximum depth h1 is located along the radial direction (i.e., the position of the minimum removal amount) is (D1-D2-h1). And, as known above, in the bottom surface where the maximum depth h1 is located, along the radial direction, the depth h2 of the defect from the side wall to the central axis in the area opposite to the maximum depth h1, 0≤h2

[0069] Compare the size of h2 with (D1-D2-h1);

[0070] If h2≤(D1-D2-h1), then determine the minimum removal amount m=h2 of the bottom surface where the maximum depth h1 is located;​

[0071] If h2>(D1-D2-h1), then determine the minimum removal amount m=(D1-D2-h1)of the bottom surface where the maximum depth h1 is located.

[0072] That is to say, when the maximum removable amount △D of the diameter of the bottom surface of the crystal ingot 10 to be processed is constant, and the maximum depth h1 is set as the position of the maximum removal amount of the bottom surface where the maximum depth h1 is located, in the bottom surface where the maximum depth h1 is located, along the radial direction, the maximum removable amount at the position opposite to the position where the maximum removal amount is located (i.e., the position where the minimum removal amount is located) is (D1-D2-h1). If in the bottom surface where the maximum depth h1 is located, along the radial direction, the depth h2 of the defect from the side wall to the center axis in the area opposite to the maximum depth h1 is ≤ (D1-D2-h1), then the minimum removal amount m=h2 of the bottom surface where the maximum depth h1 is directly determined, otherwise, m=(D1-D2-h1).

[0073] S400: Reference Figure 5 and Figure 6 As shown, the crystal ingot 10 to be processed is subjected to external cylindrical grinding by means of a grinding wheel 30, wherein the grinding wheel 30 is cylindrical, the side walls of the crystal ingot 10 to be processed are placed opposite to the side walls of the grinding wheel 30, the bottom surface of the crystal ingot 10 to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel 30, tanα=(h1-m) / z1, and the maximum depth h1 is the top position of the crystal ingot 10 to be processed, thereby obtaining an oblique cylindrical crystal ingot, the bottom surface of the oblique cylindrical crystal ingot is circular, and the side walls of the oblique cylindrical crystal ingot are inclined at an angle α relative to the height.

[0074] It is understandable that, combined with Figure 5 and Figure 6 As shown, when the crystal ingot 10 to be processed is subjected to cylindrical grinding by the grinding wheel 30, the side wall of the crystal ingot 10 to be processed is placed opposite to the side wall of the grinding wheel 30, and the bottom surface of the crystal ingot 10 to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel 30, tanα=(h1-m) / z1, and the maximum depth h1 is the top position of the crystal ingot 10 to be processed, thereby achieving oblique removal of the side wall of the crystal ingot 10 to be processed and removing the deepest defects from the side wall to the center axis on the crystal ingot 10 to be processed.

[0075] Figure 7 FIG. 1 is a side view schematic diagram showing the oblique removal of the side wall of the ingot 10 to be processed by the ingot processing method provided in the embodiment of the present application, compared with FIG. Figure 4 and Figure 7 It can be seen that compared with the existing cylindrical grinding machine processing which can only uniformly remove the side wall of the ingot, the ingot processing method provided in the embodiment of the present application can realize the oblique removal of the side wall of the ingot 10 to be processed, so that:

[0076] On the one hand, since the ingot processing method provided in the embodiment of the present application is to obliquely remove the side wall of the ingot 10 to be processed, the removal amount on the bottom surface of the ingot 10 to be processed can be more distributed to the maximum depth h1 of the defect that penetrates the deepest from the side wall to the central axis of the ingot 10 to be processed. Along the radial direction of the bottom surface, the removal amount at the position on the bottom surface opposite to the maximum depth h1 is the minimum removal amount m, m

[0077] Secondly, assuming that the maximum removable amount of the diameter of the bottom surface of the crystal ingot 10 to be processed (△D=D1-D2) allows the existing external cylindrical grinder to remove the maximum depth h1 of the deepest defect from the side wall to the center axis on the crystal ingot 10 to be processed, then, since the existing external cylindrical grinder uniformly removes the side wall of the crystal ingot 10 to be processed, the removal amount of the diameter of the bottom surface of the crystal ingot 10 to be processed is 2h1, and the diameter of the bottom surface of the standard cylindrical crystal ingot after processing is D2''=D1-2h1. The diameter of the bottom surface of the oblique cylindrical crystal ingot obtained after processing the crystal ingot 10 to be processed by the ingot processing method provided in the embodiment of the present application becomes D2'=D1-h1-m. Since m D2'' is beneficial to improving the utilization rate of ingot materials.<h1>

[0078] In order to better understand this application,​ Figure 8 The bottom schematic diagram of the side wall of the ingot 10 to be processed by the ingot processing method provided in the embodiment of the present application is shown, combined with Figure 5-Figure 8 As shown, it can be understood that, since the oblique external cylindrical grinding machine is performed on the ingot 10 to be processed by the grinding wheel 30, the bottom surface of the oblique cylindrical ingot obtained after processing is still circular, but the side wall of the oblique cylindrical ingot obtained after processing is inclined at an angle α relative to its height, and it can be understood that in step S300, the maximum depth h1 is determined as the position of the maximum removal amount of the bottom surface where the maximum depth h1 is located, and h2 or (D1-D2-h1) is determined as the minimum removal amount m of the bottom surface where the maximum depth h1 is located. , and the position of the minimum removal amount is opposite to the position of the maximum removal amount along the radial direction of the bottom surface where the maximum depth h1 is located, so that in step S400, the side wall of the crystal ingot 10 to be processed is placed opposite to the side wall of the grinding wheel 30, and the bottom surface of the crystal ingot 10 to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel 30, tanα=(h1-m) / z1, and when the maximum depth h1 is the top position of the crystal ingot 10 to be processed, the deepest defects on the crystal ingot 10 to be processed that penetrate from the side wall to the center axis can be removed obliquely.

[0079] It is also understandable that, combined with Figure 5-Figure 8 As shown, since the ingot processing method provided in the embodiment of the present application is to obliquely remove the side wall of the ingot 10 to be processed, the removal conditions on the two bottom surfaces of the ingot 10 to be processed are the same. However, on the other bottom surface opposite to the bottom surface where the maximum depth h1 is located, the removal amount corresponding to the maximum depth h1 is m, and the removal amount corresponding to m on the bottom surface where the maximum depth h1 is located on the other bottom surface is h1.

[0080] Based on the above embodiments, optionally, in some embodiments of the present application, step S400 of performing cylindrical grinding on the ingot 10 to be processed by the grinding wheel 30 may include:

[0081] S410: Reference Figure 5 and Figure 6 As shown, the clamping member 20 clamps the ingot 10 to be processed through the auxiliary block 40, and refers to Fig. 9 and Fig.10As shown, the auxiliary block 40 includes a bottom surface and an inclined surface inclined relative to the bottom surface, the inclined surface of the auxiliary block 40 is in contact with the bottom surface of the crystal ingot 10 to be processed, the bottom surface of the auxiliary block 40 is in contact with the clamping piece 20, the line connecting the highest point A1 and the lowest point A2 of the inclined surface of the auxiliary block 40 from its bottom surface is parallel to the radial direction of the bottom surface of the crystal ingot 10 to be processed where the maximum depth h1 is located, the center of the inclined surface and the bottom surface of the auxiliary block 40, the center of the bottom surface of the crystal ingot 10 to be processed and the center axis of the clamping piece 20 are aligned, so that the side wall of the crystal ingot 10 to be processed is placed opposite to the side wall of the grinding wheel 30, the bottom surface of the crystal ingot 10 to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel 30, and the maximum depth h1 is the top position of the crystal ingot to be processed.

[0082] S420: By moving the grinding wheel 30 and moving and rotating the ingot 10 to be processed, the side wall of the grinding wheel 30 is obliquely removed from the side wall of the ingot 10 to be processed, so as to obtain an oblique cylindrical ingot, the bottom surface of which is circular, and the side wall of the oblique cylindrical ingot is inclined at an angle α relative to its height.

[0083] It can be understood that when the crystal ingot 10 to be processed is subjected to external cylindrical grinding by the grinding wheel 30, in order to make the bottom surface of the crystal ingot 10 to be processed tilt at an angle α relative to the bottom surface of the grinding wheel 30, an auxiliary block 40 can be arranged between the clamp 20 and the crystal ingot 10 to be processed, and the side wall of the crystal ingot 10 to be processed is placed opposite to the side wall of the grinding wheel 30 by the clamp 20 and the auxiliary block 40, and the bottom surface of the crystal ingot 10 to be processed tilts at an angle α relative to the bottom surface of the grinding wheel 30, and the maximum depth h1 is the top of the crystal ingot to be processed. Fig. 9 and Fig.10 As shown, the auxiliary block 40 includes a bottom surface and a slope inclined relative to its bottom surface, the slope of the auxiliary block 40 is fitted with the bottom surface of the crystal ingot 10 to be processed, the bottom surface of the auxiliary block 40 is fitted with the clamping member 20, and the line connecting the highest point and the lowest point of the slope of the auxiliary block 40 from its bottom surface is parallel to the radial direction of the bottom surface of the crystal ingot 10 to be processed where the maximum depth h1 is located, and the center of the slope and bottom surface of the auxiliary block 40, the center of the bottom surface of the crystal ingot 10 to be processed and the center axis of the clamping member 20 are aligned.

[0084] It can also be understood that, optionally, the inclined surface of the auxiliary block 40 is inclined at an angle α relative to its bottom surface, so that the bottom surface of the auxiliary block 40 can be parallel to the bottom surface of the grinding wheel 30, but the present application is not limited thereto. Alternatively, the inclined surface of the auxiliary block 40 may not be inclined at an angle α relative to its bottom surface, for example, the inclined angle is less than α. In this case, the bottom surface of the ingot 10 to be processed may be inclined at an angle α relative to the bottom surface of the grinding wheel 30 by tilting the clamp 20 together with the auxiliary block 40.

[0085] Alternatively, the auxiliary block 40 may not be provided, but the clamp 20 or the grinding wheel 30 may be tilted so that the bottom surface of the ingot 10 to be processed is tilted at an angle α relative to the bottom surface of the grinding wheel 30 , depending on the specific situation.

[0086] On the basis of the above-mentioned setting of the auxiliary block 40, optionally, in some embodiments of the present application, as Fig. 9 and Fig.10 As shown, the auxiliary block 40 can be in the shape of a truncated cylinder, which can be regarded as a shape obtained by cutting a cylinder at an angle. The bottom surface of the auxiliary block 40 is a circular bottom surface, and the inclined surface of the auxiliary block 40 is an elliptical inclined surface. The line connecting the highest point A1 and the lowest point A2 of the inclined surface of the auxiliary block 40 relative to its bottom surface is the major axis of the elliptical inclined surface of the auxiliary block 40.

[0087] Optionally, in some embodiments of the present application, before the crystal ingot 10 to be processed is subjected to cylindrical grinding by the grinding wheel 30, the crystal ingot processing method may further include:

[0088] S500: Select an auxiliary block 40, wherein the inclined surface of the selected auxiliary block 40 is inclined at an angle α relative to the bottom surface thereof, and the distance between the highest point and the lowest point of the inclined surface of the selected auxiliary block 40 and the bottom surface thereof is r<D2.

[0089] In this embodiment, when the clamping member 20 clamps the ingot 10 to be processed through the auxiliary block 40 , the bottom surface of the auxiliary block 40 may be parallel to the bottom surface of the grinding wheel 30 .

[0090] In this embodiment, the distance r between the highest point and the lowest point of the bottom surface of the auxiliary block 40 is selected to be less than D2 in order to prevent the grinding wheel 30 from wearing the auxiliary block 40 .

[0091] Further optionally, in some embodiments of the present application, the ingot processing method further includes:

[0092] S600: Fig.11 As shown, the oblique cylindrical ingot 11 is cut using a parallel wire mesh 50, the extension direction of the parallel lines in the parallel wire mesh 50 is parallel to the bottom surface of the oblique cylindrical ingot 11, and the arrangement direction of the parallel lines in the parallel wire mesh is perpendicular to the bottom surface of the oblique cylindrical ingot, thereby obtaining multiple oblique cylindrical wafers.

[0093] In the prior art, Fig.12 As shown, the standard cylindrical ingot obtained after the cylindrical grinder is first pasted on the resin plate 60, and then the resin plate 60 is pasted on the workbench fixture 70 of the multi-wire sawing machine; then refer to Fig.13 As shown, the standard cylindrical ingot is cut using the parallel wire net 50 of the multi-wire saw to obtain a plurality of standard cylindrical wafers. Fig.14As shown, when the standard cylindrical ingot processed by the existing external cylindrical grinder is cut using the parallel wire mesh 50, the extension direction of the parallel lines in the parallel wire mesh 50 is parallel to the bottom surface of the standard cylindrical ingot, and the arrangement direction of the parallel lines in the parallel wire mesh is perpendicular to the bottom surface of the standard cylindrical ingot.

[0094] In this application, reference is made to Fig.11 As shown, the oblique cylindrical ingot 11 is first pasted on the resin plate 60, and then the resin plate 60 is pasted on the workbench fixture 70 of the multi-wire sawing machine, and then the parallel wire net 50 of the multi-wire sawing machine is used to cut the oblique cylindrical ingot 11. Different from the prior art, the extension direction of the parallel lines in the parallel wire net 50 is parallel to the bottom surface of the oblique cylindrical ingot 11, and the arrangement direction of the parallel lines in the parallel wire net 50 is perpendicular to the bottom surface of the oblique cylindrical ingot, so as to obtain multiple oblique cylindrical wafers. It can be understood that the obtained multiple oblique cylindrical wafers are similar to the oblique cylindrical ingot 11, and the bottom surface is also circular, and the side wall is relatively inclined at a high angle α, but the thickness of the oblique cylindrical wafer is thinner than that of the oblique cylindrical ingot 11.

[0095] If the oblique cylindrical ingot 11 processed by the external cylindrical grinder is a silicon carbide ingot, the oblique cylindrical ingot 11 can be pasted on the resin plate 60 according to the calibration accuracy of the Si surface and the C surface, and then the resin plate 60 can be pasted on the workbench fixture 70 of the multi-wire cutting machine, and the oblique cylindrical ingot 11 can be cut using the parallel wire network 50.

[0096] Further optionally, in some embodiments of the present application, the ingot processing method further includes:

[0097] S700: Chamfering the oblique cylindrical wafer to obtain a standard cylindrical wafer, wherein the thickness of the oblique cylindrical wafer is x, the diameter of the bottom surface of the oblique cylindrical wafer is D2, the deflection amount of the side wall of the oblique cylindrical wafer is y=x tanα, the diameter of the bottom surface of the standard cylindrical wafer is D3, and (D2-D3)≥y.

[0098] It is understandable that if Fig.15 The oblique cylindrical wafer 12 shown in the figure has a diameter that is unchanged relative to the oblique cylindrical ingot 11, that is, the diameter of the bottom surface of the oblique cylindrical wafer 12 is also D2, and the thickness of the oblique cylindrical wafer 12 is reduced to x relative to the oblique cylindrical ingot 11. Since the side wall of the oblique cylindrical wafer 12 is tilted at an angle α relative to the height, the deflection of the side wall of the oblique cylindrical wafer is y=x tanα.

[0099] It is also understandable that when the oblique cylindrical wafer 12 is chamfered, the deflection of the side wall of the oblique cylindrical wafer 12 (i.e., the edge bevel) can be removed to obtain a cylindrical wafer of standard size and specification. Fig.15As shown, the diameter removal amount of the bottom surface of the oblique cylindrical wafer 12 after chamfering is n, n=(D2-D3)=y+2b, b≥0. In order to ensure that the chamfering process removes the deflection of the side wall of the oblique cylindrical wafer 12, it is necessary to satisfy n≥y, that is, (D2-D3)≥y.

[0100] It should be noted that, through the above analysis, it can be seen that the ingot processing method provided in the embodiment of the present application can completely use existing processing equipment, such as a cylindrical grinding machine processing device, a multi-wire cutting device, and a chamfering processing device, etc., except that when the obtained ingot 10 to be processed is subjected to cylindrical grinding, the ingot 10 to be processed is subjected to oblique external cylindrical processing to obtain an oblique cylindrical ingot 11; accordingly, when the processed oblique cylindrical ingot 11 is subjected to multi-wire cutting, the oblique cylindrical ingot 11 is cut into multiple oblique cylindrical chips 12 in a form parallel to the bottom surface of the oblique cylindrical ingot 11; finally, the oblique cylindrical chips 12 are subjected to normal chamfering processing to obtain chips of standard size and specification.

[0101] It should also be noted that the ingot processing method provided in the embodiment of the present application is applicable to ingots 10 to be processed of various sizes. For example, the diameter of the bottom surface of the ingot 10 to be processed can be 2 inches, 3 inches, 4 inches, 6 inches or 8 inches, etc.

[0102] Based on the same inventive concept, the embodiment of the present application also provides a crystal ingot processing device, Fig.16 A schematic diagram of a process flow of a crystal ingot processing device provided in an embodiment of the present application is shown, and the crystal ingot processing device includes:

[0103] The ingot obtaining device 100 is used to perform rough processing on the growing crystal embryo to obtain the ingot 10 to be processed. The ingot 10 to be processed is cylindrical, the bottom surface of the ingot 10 to be processed has a diameter D1, and the thickness of the ingot 10 to be processed is z1;

[0104] The defect detection device 200 is used to detect defects on the ingot 10 to be processed, determine the maximum depth h1 of the defect that penetrates the deepest from the side wall to the central axis on the ingot 10 to be processed, and determine the depth h2 of the defect from the side wall to the central axis in the area opposite to the maximum depth h1 along the radial direction of the bottom surface where the maximum depth h1 is located, 0≤h2

[0105] The computing device 300 determines the maximum depth h1 as the position of the maximum removal amount of the bottom surface where the maximum depth h1 is located, and determines the minimum removal amount m of the bottom surface where the maximum depth h1 is located based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, D1-D2≥h1+m, and the position of the minimum removal amount is opposite to the position of the maximum removal amount along the radial direction of the bottom surface;

[0106] ​The external cylindrical grinding machine processing device 400 performs external cylindrical grinding on the crystal ingot 10 to be processed by means of a grinding wheel 30, wherein the grinding wheel 30 is cylindrical, and the side wall of the crystal ingot 10 to be processed is placed opposite to the side wall of the grinding wheel 30, and the bottom surface of the crystal ingot 10 to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel 30, tanα=(h1-m) / z1, and the maximum depth h1 is the top position of the crystal ingot to be processed, thereby obtaining an oblique cylindrical crystal ingot 11, the bottom surface of the oblique cylindrical crystal ingot 11 is circular, and the side wall of the oblique cylindrical crystal ingot is inclined at an angle α relative to the height.

[0107] Optionally, the crystal ingot acquisition device 100 and the cylindrical grinding machine processing device 400 can be the same cylindrical grinding machine processing device, that is, the cylindrical grinding machine processing device first performs cylindrical rough processing on the grown crystal embryo to obtain the crystal ingot 10 to be processed, and then performs cylindrical fine processing on the crystal ingot 10 to be processed to obtain an oblique cylindrical crystal ingot 11.

[0108] Further optionally, in some embodiments of the present application, such as Fig.16 As shown, the ingot processing equipment may also include:

[0109] The multi-wire cutting device 500 uses a parallel wire network 50 to cut the oblique cylindrical ingot 11. The extension direction of the parallel lines in the parallel wire network 50 is parallel to the bottom surface of the oblique cylindrical ingot 11, and the arrangement direction of the parallel lines in the parallel wire network 11 is perpendicular to the bottom surface of the oblique cylindrical ingot 11, thereby obtaining multiple oblique cylindrical wafers 12.

[0110] It can be understood that the multi-wire cutting device 500 can be a multi-wire cutting machine.

[0111] Further optionally, in some embodiments of the present application, such as Fig.16 As shown, the ingot processing equipment may also include:

[0112] The chamfering processing device 600 performs chamfering processing on the oblique cylindrical wafer 12 to obtain a standard cylindrical wafer, wherein the thickness of the oblique cylindrical wafer 12 is x, the diameter of the bottom surface of the oblique cylindrical wafer 12 is D2, the deflection of the side wall of the oblique cylindrical wafer 12 is y=x tanα, the diameter of the bottom surface of the standard cylindrical wafer 12 is D3, and (D2-D3)≥y.

[0113] Since the ingot processing equipment provided in the embodiments of the present application corresponds to the ingot processing method provided in the embodiments of the present application, and the ingot processing method provided in the embodiments of the present application has been described in detail in the aforementioned embodiments, the ingot processing equipment provided in the embodiments of the present application can refer to the aforementioned analysis and will not be repeated here.

[0114] The various parts in this manual are described in a combination of parallel and progressive ways. Each part focuses on the differences from other parts, and the same or similar parts between the various parts can be referenced to each other.

[0115] With respect to the above description of the disclosed embodiments, the features described in the embodiments in this specification may be replaced or combined with each other, so that professionals in the field can implement or use the present application. Various modifications to these embodiments will be apparent to professionals in the field, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for processing a crystal ingot, characterized in that: The ingot processing method comprises: Obtain a crystal ingot to be processed, wherein the crystal ingot to be processed is cylindrical, the diameter of the bottom surface of the crystal ingot to be processed is D1, and the thickness of the crystal ingot to be processed is z1; Detect defects on the ingot to be processed, determine a maximum depth h1 of the defect that penetrates the deepest from the side wall to the central axis of the ingot to be processed, and determine a depth h2 of the defect that penetrates from the side wall to the central axis in a region opposite to the maximum depth h1 in the bottom surface where the maximum depth h1 is located, along the radial direction of the bottom surface, where 0≤h2<h1; The maximum depth h1 is defined as the position of the maximum removal amount of the bottom surface where the maximum depth h1 is located, and based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, the minimum removal amount m of the bottom surface where the maximum depth h1 is located is determined, D1-D2≥h1+m, and the position where the minimum removal amount is located is opposite to the position where the maximum removal amount is located along the radial direction of the bottom surface where the maximum depth h1 is located; The crystal ingot to be processed is subjected to external cylindrical grinding by means of a grinding wheel, wherein the grinding wheel is cylindrical, the side wall of the crystal ingot to be processed is placed opposite to the side wall of the grinding wheel, the bottom surface of the crystal ingot to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel, tanα=(h1-m) / z1, the maximum depth h1 is the top position of the crystal ingot to be processed, thereby obtaining an oblique cylindrical crystal ingot, the bottom surface of the oblique cylindrical crystal ingot is circular, and the side wall of the oblique cylindrical crystal ingot is inclined at an angle α relative to the height.

2. The ingot processing method according to claim 1, characterized in that: Based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, determining the minimum removal amount m of the bottom surface where the maximum depth h1 is located includes: Compare the size of h2 with (D1-D2-h1); If h2≤(D1-D2-h1), then determine the minimum removal amount m=h2 of the bottom surface where the maximum depth h1 is located; If h2>(D1-D2-h1), then the minimum removal amount m=(D1-D2-h1) of the bottom surface where the maximum depth h1 is located is determined.

3. The ingot processing method according to claim 1, characterized in that: Cylindrical grinding of the ingot to be processed by a grinding wheel comprises: The clamping member clamps the crystal ingot to be processed through an auxiliary block, the auxiliary block comprises a bottom surface and an inclined surface with an inclination angle α relative to the bottom surface, the inclined surface of the auxiliary block is in contact with the bottom surface of the crystal ingot to be processed, the bottom surface of the auxiliary block is in contact with the clamping member, a line connecting the highest point and the lowest point of the inclined surface of the auxiliary block from its bottom surface is parallel to the radial direction of the bottom surface of the crystal ingot to be processed where the maximum depth h1 is located, the center of the inclined surface and the bottom surface of the auxiliary block, the center of the bottom surface of the crystal ingot to be processed and the central axis of the clamping member are aligned, so that the side wall of the crystal ingot to be processed is placed opposite to the side wall of the grinding wheel, the bottom surface of the crystal ingot to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel, and the maximum depth h1 is the top position of the crystal ingot to be processed; By moving the grinding wheel and moving and rotating the ingot to be processed, the side wall of the grinding wheel obliquely removes the side wall of the ingot to be processed to obtain an oblique cylindrical ingot, the bottom surface of the oblique cylindrical ingot is circular, and the side wall of the oblique cylindrical ingot is inclined at an angle α relative to the height.

4. The ingot processing method according to claim 3, characterized in that: Before the crystal ingot to be processed is subjected to cylindrical grinding by a grinding wheel, the crystal ingot processing method further comprises: Select the auxiliary block, wherein the elliptical inclined surface of the selected auxiliary block is inclined at an angle α relative to the circular bottom surface thereof, and the distance between the highest point and the lowest point of the inclined surface of the selected auxiliary block and the bottom surface thereof is r<D2; When the clamping piece clamps the crystal ingot to be processed through the auxiliary block, the circular bottom surface of the auxiliary block is parallel to the bottom surface of the grinding wheel.

5. The ingot processing method according to claim 1, characterized in that: The ingot processing method further comprises: The oblique cylindrical ingot is cut using a parallel wire mesh, wherein the extension direction of the parallel lines in the parallel wire mesh is parallel to the bottom surface of the oblique cylindrical ingot, and the arrangement direction of the parallel lines in the parallel wire mesh is perpendicular to the bottom surface of the oblique cylindrical ingot, to obtain a plurality of oblique cylindrical wafers.

6. The ingot processing method according to claim 5, characterized in that: The ingot processing method further comprises: The oblique cylindrical wafer is chamfered to obtain a standard cylindrical wafer, wherein the thickness of the oblique cylindrical wafer is x, the diameter of the bottom surface of the oblique cylindrical wafer is D2, the deflection of the side wall of the oblique cylindrical wafer is y=xtanα, the diameter of the bottom surface of the standard cylindrical wafer is D3, and (D2-D3)≥y.

7. The ingot processing method according to any one of claims 1 to 6, characterized in that: The ingot processing method is applied to silicon carbide ingots.

8. A crystal ingot processing device, characterized in that: The ingot processing equipment comprises: A crystal ingot obtaining device, used for performing rough processing on the growing crystal embryo to obtain a crystal ingot to be processed, wherein the crystal ingot to be processed is cylindrical, the bottom surface of the crystal ingot to be processed has a diameter of D1, and the thickness of the crystal ingot to be processed is z1; A defect detection device, used to detect defects on the ingot to be processed, determine the maximum depth h1 of the defect that penetrates the deepest from the side wall to the central axis on the ingot to be processed, and determine the depth h2 of the defect from the side wall to the central axis in the bottom surface where the maximum depth h1 is located and in the radial direction of the bottom surface, in the area opposite to the maximum depth h1, 0≤h2<h1; The calculation device determines the maximum depth h1 as the position of the maximum removal amount of the bottom surface where the maximum depth h1 is located, and determines the minimum removal amount m of the bottom surface where the maximum depth h1 is located based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, D1-D2≥h1+m, and the position where the minimum removal amount is located is opposite to the position where the maximum removal amount is located in the radial direction of the bottom surface; A cylindrical grinding machine processing device performs cylindrical grinding on the crystal ingot to be processed by a grinding wheel, wherein the grinding wheel is cylindrical, the side wall of the crystal ingot to be processed is placed opposite to the side wall of the grinding wheel, the bottom surface of the crystal ingot to be processed is inclined at an angle α relative to the bottom surface of the grinding wheel, tanα=(h1-m) / z1, the maximum depth h1 is the top position of the crystal ingot to be processed, thereby obtaining an oblique cylindrical crystal ingot, the bottom surface of the oblique cylindrical crystal ingot is circular, and the side wall of the oblique cylindrical crystal ingot is inclined at an angle α relative to the height.

9. The ingot processing equipment according to claim 8, characterized in that: The ingot processing equipment also includes: A multi-wire cutting device uses a parallel wire network to cut the oblique cylindrical ingot, wherein the extension direction of the parallel lines in the parallel wire network is parallel to the bottom surface of the oblique cylindrical ingot, and the arrangement direction of the parallel lines in the parallel wire network is perpendicular to the bottom surface of the oblique cylindrical ingot, thereby obtaining multiple oblique cylindrical wafers.

10. The ingot processing equipment according to claim 9, characterized in that: The ingot processing equipment also includes: A chamfering device is used to perform chamfering on the oblique cylindrical wafer to obtain a standard cylindrical wafer, wherein the thickness of the oblique cylindrical wafer is x, the diameter of the bottom surface of the oblique cylindrical wafer is D2, the deflection of the side wall of the oblique cylindrical wafer is y=xtanα, the diameter of the bottom surface of the standard cylindrical wafer is D3, and (D2-D3)≥y.

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