CN-119871106-B - Ingot processing method and ingot processing apparatus

CN119871106BCN 119871106 BCN119871106 BCN 119871106BCN-119871106-B

Abstract

The application discloses an ingot processing method and ingot processing equipment, which relate to the technical field of semiconductor processing, and are characterized in that when a cylindrical ingot to be processed is processed by a cylindrical grinding wheel through a cylindrical grinding wheel, the side wall of the ingot to be processed and the side wall of the grinding wheel are oppositely placed, the bottom surface of the ingot to be processed is inclined by an angle alpha, tan alpha= (h 1-m)/z 1 relative to the bottom surface of the grinding wheel, wherein h1 is the maximum depth of a defect deepened from the side wall to a central shaft on the ingot to be processed, m is the minimum removal amount m of the bottom surface where the maximum depth h1 is positioned, and the position of the top of the ingot to be processed is set at the maximum depth h1, so that the inclined removal of the side wall of the ingot is realized, and an inclined cylindrical ingot is obtained, so that the inclined grown defect or the inclined area of the ingot to be removed is effectively removed, the effective thickness of the ingot after processing is improved, the processing breakage rate is reduced, the processing yield and the yield of the ingot are improved, and the utilization rate of ingot materials is also improved.

Inventors

ZHANG WEN
SUN JIANJIAN
ZHU XIAOSONG
WANG DONG
ZHANG JINGRU
LOU YANFANG
LIU CHUNJUN
PENG TONGHUA
YANG JIAN

Assignees

北京天科合达半导体股份有限公司
江苏天科合达半导体有限公司

Dates

Publication Date: 20260512
Application Date: 20250305

Claims (10)

1. A method of processing an ingot, the method comprising: acquiring an ingot to be processed, wherein the ingot to be processed is cylindrical, the diameter of the bottom surface of the ingot to be processed is D1, and the thickness of the ingot to be processed is z1; Detecting defects on the ingot to be processed, determining the maximum depth h1 of the defects which deepen to the central axis from the side wall on the ingot to be processed, and determining the depth h2 of the defects which deepen to the central axis from the side wall in the region opposite to the maximum depth h1 along the radial direction of the bottom surface in the bottom surface where the maximum depth h1 is located, wherein h2 is more than or equal to 0 and less than or equal to h2< h1; The position of the maximum depth h1 is defined as the position of the maximum removal amount of the bottom surface of the maximum depth h1, the minimum removal amount m of the bottom surface of the maximum depth h1 is determined based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, D1-D2 is more than or equal to 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 of the maximum depth h 1; And processing the ingot to be processed by a cylindrical grinding machine through a grinding wheel, wherein the grinding wheel is cylindrical, the side wall of the ingot to be processed is opposite to the side wall of the grinding wheel, the bottom surface of the ingot to be processed is inclined by an angle alpha, tan alpha= (h 1-m)/z 1 relative to the bottom surface of the grinding wheel, the maximum depth h1 is the top position of the ingot to be processed, so that an inclined cylindrical ingot is obtained, the bottom surface of the inclined cylindrical ingot is circular, and the side wall of the inclined cylindrical ingot is inclined by an angle alpha relative to the high inclination angle.
2. The ingot processing method of claim 1, wherein determining a minimum removal amount m of the bottom surface where the maximum depth h1 is located based on h2 and a target diameter D2 of the bottom surface of the ingot to be processed comprises: comparing the sizes of h2 and (D1-D2-h 1); If h2 is less than or equal to (D1-D2-h 1), determining the minimum removal amount m=h2 of the bottom surface where the maximum depth h1 is located; if h2> (D1-D2-h 1), determining a minimum removal m= (D1-D2-h 1) of the bottom surface where the maximum depth h1 is located.
3. An ingot processing method as set forth in claim 1, wherein cylindrical grinding of the ingot to be processed by a grinding wheel comprises: The method comprises the steps that a clamping piece clamps an ingot to be processed through an auxiliary block, the auxiliary block comprises a bottom surface and an inclined surface inclined by an angle alpha relative to the bottom surface, the inclined surface of the auxiliary block is attached to the bottom surface attached to the ingot to be processed, the bottom surface of the auxiliary block is attached to the clamping piece, a connecting line of the inclined surface of the auxiliary block, which is the highest point and the lowest point of the bottom surface of the auxiliary block, is parallel to the radial direction of the bottom surface of the ingot to be processed, where the maximum depth h1 is located, the inclined surface of the auxiliary block, the center of the bottom surface of the ingot to be processed and the center axis of the clamping piece are aligned, so that the side wall of the ingot to be processed is placed opposite to the side wall of the grinding wheel, the bottom surface of the ingot to be processed is inclined by the angle alpha relative to the bottom surface of the grinding wheel, and the maximum depth h1 is the top position of the ingot to be processed. And moving the grinding wheel and moving and rotating the ingot to be processed, so that 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 relative to a high inclination angle alpha.
4. An ingot processing method as set forth in claim 3, wherein prior to cylindrical grinding of the ingot to be processed by a grinding wheel, the ingot processing method further comprises: Selecting the auxiliary block, wherein the inclination angle alpha of the elliptic inclined plane of the selected auxiliary block relative to the circular bottom surface of the auxiliary block is equal to or smaller than the distance r < D2 between the highest point and the lowest point of the inclined plane of the selected auxiliary block from the bottom surface of the auxiliary block; When the clamping piece clamps the 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 of claim 1, the ingot processing method is characterized by further comprising the following steps: And cutting the inclined cylindrical crystal ingot by using a parallel wire mesh, wherein the extending direction of parallel wires in the parallel wire mesh is parallel to the bottom surface of the inclined cylindrical crystal ingot, and the arrangement direction of the parallel wires in the parallel wire mesh is perpendicular to the bottom surface of the inclined cylindrical crystal ingot, so as to obtain a plurality of inclined cylindrical wafers.
6. An ingot processing method as set forth in claim 5 further comprising: Chamfering is carried out on the inclined cylindrical wafer to obtain a standard cylindrical wafer, wherein the thickness of the inclined cylindrical wafer is x, the diameter of the bottom surface of the inclined cylindrical wafer is D2, the deflection amount of the side wall of the inclined cylindrical wafer is y= xtan α, and the diameter of the bottom surface of the standard cylindrical wafer is D3, (D2-D3) is more than or equal to y.
7. An ingot processing method as set forth in any one of claims 1 to 6 wherein the ingot processing method is applied to a silicon carbide ingot.
8. An ingot processing apparatus, characterized in that the ingot processing apparatus comprises: The ingot obtaining device is used for carrying out rough machining on the grown crystal blank to obtain an ingot to be machined, the ingot to be machined is cylindrical, the diameter of the bottom surface of the ingot to be machined is D1, and the thickness of the ingot to be machined is z1; The defect detection device is used for detecting defects on the ingot to be processed, determining the maximum depth h1 of the defects which are deepest from the side wall to the central axis on the ingot to be processed, and determining the depth h2 of the defects which are deepest from the side wall to the central axis in the region opposite to the maximum depth h1 along the radial direction of the bottom surface in the bottom surface, wherein h2 is more than or equal to 0 and less than or equal to h2< h1; The computing device is used for determining the position of the maximum depth h1 as the position of the maximum removal amount of the bottom surface of the maximum depth h1, determining the minimum removal amount m of the bottom surface of the maximum depth h1 based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, wherein D1-D2 is more than or equal to 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; The cylindrical grinding machine processing device is used for processing the ingot to be processed through the grinding wheel, wherein the grinding wheel is cylindrical, the side wall of the ingot to be processed is opposite to the side wall of the grinding wheel, the bottom surface of the ingot to be processed is inclined by an angle alpha, tan alpha= (h 1-m)/z 1 relative to the bottom surface of the grinding wheel, the maximum depth h1 is the top position of the ingot to be processed, so that an inclined cylindrical ingot is obtained, the bottom surface of the inclined cylindrical ingot is circular, and the side wall of the inclined cylindrical ingot is inclined by an angle alpha relative to the high inclination angle.
9. An ingot processing apparatus as set forth in claim 8, further comprising: The multi-wire cutting device is used for cutting the inclined cylindrical crystal ingot by utilizing a parallel wire mesh, the extending direction of parallel wires in the parallel wire mesh is parallel to the bottom surface of the inclined cylindrical crystal ingot, and the arrangement direction of the parallel wires in the parallel wire mesh is perpendicular to the bottom surface of the inclined cylindrical crystal ingot, so that a plurality of inclined cylindrical wafers are obtained.
10. An ingot processing apparatus as set forth in claim 9, further comprising: And chamfering the inclined cylindrical wafer to obtain a standard cylindrical wafer, wherein the thickness of the inclined cylindrical wafer is x, the diameter of the bottom surface of the inclined cylindrical wafer is D2, the deflection of the side wall of the inclined cylindrical wafer is y= xtan α, and the diameter of the bottom surface of the standard cylindrical wafer is D3, (D2-D3) is more than or equal to y.

Description

Ingot processing method and ingot processing apparatus Technical Field The application relates to the technical field of semiconductor processing, in particular to an ingot processing method and ingot processing equipment. Background The silicon carbide crystal has high growth difficulty, the quality of the silicon carbide crystal can be influenced by temperature, pressure, growth speed and the like in the growth process, and the silicon carbide crystal is mainly grown by a physical vapor transport method (PVT method), a high-temperature chemical vapor deposition method (HTCVD method), a liquid phase method (Liquid Phase Method) and the like at present. The PVT method is developed for many years, the process is relatively mature, and the method is more suitable for industrialized mass production, and the principle of growing silicon carbide crystals is that carbon and silicon powder are used as raw materials to be placed at the bottom of a crucible, silicon carbide seed crystals are placed at the top of the crucible, sublimated powder is upwards transmitted to the vicinity of the seed crystals under the action of temperature gradient and concentration difference under the airtight condition of high temperature and low pressure, and the silicon carbide crystals are recrystallized after reaching a supersaturated state. The surface and the side wall of the silicon carbide crystal embryo grown by the PVT method are irregular, the circumference of the silicon carbide crystal embryo has defects such as edge cracks, mixed crystals and the like, the original silicon carbide crystal embryo is generally processed into a silicon carbide crystal ingot with a certain size by adopting a plane processing mode and an outer circle rough processing mode, and then the silicon carbide crystal ingot is processed into a cylindrical crystal with a standard size by adopting a cylindrical grinding machine. However, growth defects such as cracks and miscellaneous crystals may approach the central axis of the silicon carbide ingot along with the growth process, and most cylindrical grinding machines only can uniformly remove the side wall of the silicon carbide ingot, so that the partial oblique growth defects or the oblique areas needing to be removed in the silicon carbide ingot cannot be completely removed, resulting in the reduction of the effective thickness of the silicon carbide ingot due to the defect left in the partial thickness, or the damage of the silicon carbide ingot, which affects the processing yield and output of the silicon carbide ingot. Of course, such problems are not limited to silicon carbide ingots, and may also be encountered with ingots of other materials if defects that grow obliquely or areas that need to be removed obliquely occur. Disclosure of Invention In order to solve the technical problems, the embodiment of the application provides an ingot processing method and ingot processing equipment, which are used for effectively removing defects of obliquely grown ingots or areas to be removed in an oblique direction, improving the effective thickness of the processed ingots, reducing the processing breakage rate of the ingots and improving the processing yield and output of the ingots. In order to achieve the above purpose, the embodiment of the present application provides the following technical solutions: In a first aspect, an embodiment of the present application provides a method for processing an ingot, the method comprising: acquiring an ingot to be processed, wherein the ingot to be processed is cylindrical, the diameter of the bottom surface of the ingot to be processed is D1, and the thickness of the ingot to be processed is z1; Detecting defects on the ingot to be processed, determining the maximum depth h1 of the defects which deepen to the central axis from the side wall on the ingot to be processed, and determining the depth h2 of the defects which deepen to the central axis from the side wall in the region opposite to the maximum depth h1 along the radial direction of the bottom surface in the bottom surface where the maximum depth h1 is located, wherein h2 is more than or equal to 0 and less than or equal to h2< h1; The position of the maximum depth h1 is defined as the position of the maximum removal amount of the bottom surface of the maximum depth h1, the minimum removal amount m of the bottom surface of the maximum depth h1 is determined based on h2 and the target diameter D2 of the bottom surface of the ingot to be processed, D1-D2 is more than or equal to 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 of the maximum depth h 1; And processing the ingot to be processed by a cylindrical grinding machine through a grinding wheel, wherein the grinding wheel is cylindrical, the side wall of the ingot to be processed is opposite to the side wall of the grinding wheel, the bottom