Grinding method of monocrystalline silicon

Abstract

The invention relates to the technical field of semiconductor silicon material processing, and discloses a monocrystalline silicon grinding method, which is used for grinding monocrystalline silicon wafers, and mainly comprises the following steps: cutting a silicon rod into a plurality of silicon wafer samples, setting the thickness of the silicon wafers according to different application fields, and taking the cutting surfaces of the silicon wafer samples as grinding surfaces; grinding stages including grinding preparation, machining and post-treatment stages are set, illumination analysis is conducted on a grinding surface, an illumination analysis chart is obtained through different projection modes, convex and concave areas on the grinding surface are recognized, and defect positions on the grinding surface are determined through a shadow area obtaining strategy and a shadow area matching strategy; and according to the identified convex and concave areas, a grinding strategy is executed, and the grinding strategy comprises determination of grinding point positions and grinding of the convex areas.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor silicon material processing, in particular to a method for grinding single crystal silicon. Background Art

[0002] With the continuous advancement of semiconductor technology, single-crystal silicon, as a key electronic material, plays a vital role in the manufacture of integrated circuits and photovoltaic cells. The grinding quality of single-crystal silicon wafers is directly related to the performance and production cost of electronic devices. However, traditional single-crystal silicon grinding methods suffer from low efficiency and uneven surface quality, making them difficult to meet the requirements of high-precision and high-efficiency processing.

[0003] In existing technologies, the grinding of single-crystal silicon wafers relies heavily on empirical parameters and qualitative judgments, lacking precise quantitative analysis. Furthermore, the grinding process lacks precise identification of raised and recessed areas on the wafer surface, resulting in uneven surface treatment and impacting device performance and lifespan.

[0004] To improve the processing quality of single-crystal silicon wafers, a more advanced and precise grinding method is needed. This method should be able to identify and address surface defects on the silicon wafer surface to meet the needs of high-precision electronic device manufacturing. Summary of the Invention

[0005] The present invention provides a method for grinding single crystal silicon, which is used to promote the solution of the problems mentioned in the above background technology.

[0006] The present invention provides the following technical solutions: a method for grinding single crystal silicon, optionally cutting a silicon rod into a plurality of silicon wafer samples; Set the grinding stages of silicon wafer samples, which are divided into grinding preparation stage, grinding process stage and grinding post-processing stage; Get n silicon wafer samples, number them, and generate a silicon wafer sample set E, expressed as E={ , ,..., },in It is represented as the i-th silicon wafer sample, and n is the number of silicon wafer samples; The cut surface of the silicon wafer sample is marked as the grinding surface, and the grinding surface is circular; Set the projection time interval, denoted as Q; Set the angle range of the projection light source on the grinding surface to [0°, 180°]; Two mutually perpendicular reference lines are set on the grinding surface, which are respectively marked as reference line P and reference line I; The intersection point of the reference lines is set at the center of the grinding surface; Mark the reference line P as the longitudinal line and the reference line I as the transverse line; On the grinding surface, make a semicircular section perpendicular to the longitudinal line, marked as section Z, and make a semicircular section perpendicular to the transverse line, marked as section X; Projecting along the semicircular cross section by projecting a light source, the projection method is divided into a first projection method and a second projection method; The first projection method is that the projection light source is projected onto the grinding surface along the edge of the cross section Z; The second projection method is that the projection light source is projected onto the grinding surface along the edge of the cross section X; According to the two projection methods, the grinding surface is projected by a projection light source to obtain a set of illumination analysis graphs generated by the first projection method and the second projection method, which are respectively recorded as illumination analysis graph set U and illumination analysis graph set Y; The illumination analysis diagram is an illumination area formed by projecting a light source onto the grinding surface at a certain angle, and the illumination area is used to obtain the convex areas and concave areas of the grinding surface; According to the illumination analysis graph set U and set Y, the convex area and concave area on the grinding surface are obtained; At the beginning of the grinding process, grinding strategies are implemented for both raised and recessed areas.

[0007] Furthermore, according to the two projection methods, the grinding surface is projected by a projection light source to obtain a set of illumination analysis graphs generated by the first projection method and the second projection method, which are respectively recorded as illumination analysis graph set U and illumination analysis graph set Y, including: According to the projection time interval and angle range, set the projection angle change value, recorded as W°; Set the angle change rule of the projected light source; The projection light source angle change rule is as follows: after each projection time interval, the projection light source angle is increased according to the projection angle change value; At the beginning of the grinding preparation stage, the projection light source angle is set to 0°, and the grinding surface is projected by the projection light source in a first projection mode; Obtain a set of illumination analysis graphs generated by the first projection method, forming a set U; After the projection light source finishes executing the first projection mode, the projection light source angle is set to 0°, and the grinding surface is projected in the second projection mode; A set of illumination analysis graphs generated by the second projection method is obtained and formed into a set Y.

[0008] Optionally, obtaining the raised areas and recessed areas on the grinding surface according to the illumination analysis graph set U and the set Y includes: According to the angle range of the projected light source, it is divided into two intervals: [0°, 90°] and [90°, 180°]. Mark the divided intervals as the first angle range interval and the second angle range interval respectively; According to the illumination analysis diagram set U and the set Y, the illumination analysis diagrams formed by the projection light source on the grinding surface in the first angle range according to the law of the projection light source angle change are obtained, and the illumination analysis diagrams are formed into sets, which are recorded as set A and set B respectively; and obtaining illumination analysis diagrams of the grinding surface formed by the projection light source according to the variation law of the projection light source angle within the second angle range, and forming sets thereof, which are respectively recorded as set C and set D; Execute the shadow area acquisition strategy based on the elements in set A, set B, set C, and set D.

[0009] Furthermore, based on the elements in set A, set B, set C, and set D, a shadow area acquisition strategy is executed, including: For a certain set, obtain a random set of adjacent elements, mark them, and record them as the first element and the second element; The random group is represented by randomly selecting two adjacent illumination analysis images from the set; Get all the shadow areas in the first element and the second element to form the first set and the second set; According to the first set and the second set, the shadow area matching strategy is executed to obtain the position information of the same edges in set A, set B, set C, and set D respectively.

[0010] Optionally, the shadow area matching strategy includes: S1: In the illumination analysis diagram, a plane rectangular coordinate system is established to obtain the position information of the edge of the shadow area; S2: Get two shadow areas of adjacent elements, and group the shadow patterns in these two shadow areas into sets, which are respectively recorded as set V and set B; S3: Screen the shadow areas of set V and set B; The pattern screening is to screen out shadow areas with the same edges for the patterns in the two sets, and obtain the position information of the same edges to form a set; The screening steps are: According to the shaded areas in set V and set B, obtain two shaded areas with the same edges. If these two shaded areas do not belong to the same set, then group these two shaded areas together and mark them as edge similarity group. If, in the edge similarity group, the area with a larger shadow area covers the area with a smaller shadow area, the position information of the same edge is obtained; According to set A, set B, set C, and set D, the position information of all the same edges in each set is obtained respectively to form a set, which is recorded as set F.

[0011] Furthermore, according to the illumination analysis graph set U and the set Y, the raised area and the recessed area on the grinding surface are obtained, including: Match the same edge position information in set F; The matching rule is that if there are four identical edges that can form a closed region, then these four edges are removed from the set F and grouped together, marked as a closed region group. Mark the closed area formed by four identical edges in the closed area group as a convex area; Obtain the brightness of the elements in set A, set B, set C, and set D through a photosensitive sensor device, and obtain the edge with the highest brightness value, which is recorded as the high-brightness edge; The area surrounded by the high-brightness edge is marked as the concave area, and the point with the lowest brightness value near the edge is obtained and recorded as the grinding point.

[0012] Optionally, at the beginning of the grinding process, a grinding strategy is executed for the raised areas and the recessed areas, including: If there are concave areas and convex areas on the grinding surface, the grinding point position is obtained; Grind the entire grinding surface with the grinding point as the bottom surface; If there are raised areas on the grinding surface and no recessed areas, all raised areas are acquired and ground.

[0013] The present invention has the following beneficial effects: 1. The single crystal silicon grinding method generates a silicon wafer sample set E by cutting a silicon rod into multiple silicon wafer samples, providing each silicon wafer sample with a unique identifier, facilitating tracking during the grinding process and ensuring the traceability of the processing. The projection time interval Q and the angle range interval [0°, 180°] are set, and a comprehensive illumination analysis of the grinding surface can be performed. Light sources at different angles can be projected. Mutually perpendicular reference lines P and I are set on the grinding surface, and semicircular cross sections Z and X are projected. The grinding surface is projected from two orthogonal directions, thereby improving the protrusion and The accuracy of recessed area detection is improved by obtaining the illumination analysis graph sets U and Y using the first and second projection methods, which capture illumination changes on the grinding surface from different directions and provide a data basis for defect analysis of the grinding surface. The raised and recessed areas on the grinding surface are obtained based on the illumination analysis graph sets U and Y, and the unevenness of the silicon wafer surface is identified, providing a target for subsequent grinding processing. During the grinding processing stage, grinding strategies are implemented for the raised and recessed areas, and grinding operations are performed to eliminate the unevenness of the silicon wafer surface and improve the surface quality of the silicon wafer.

[0014] 2. This method for grinding single-crystal silicon sets the projection angle change value W° and the projection light source angle change law, utilizes the first projection method and the second projection method to perform illumination analysis on the grinding surface from different directions, captures the geometric features of the grinding surface, and enhances the recognition of the surface condition of the silicon wafer. At the beginning of the grinding preparation stage, by initializing the projection light source angle to 0° and adjusting the light source angle according to the set projection time interval and angle change value, continuous and orderly illumination analysis of the grinding surface is achieved. By obtaining the illumination analysis graph sets U and Y, a basis is provided for the subsequent shadow area acquisition strategy.

[0015] 3. The single crystal silicon grinding method divides the angle range of the projected light source into two intervals, namely [0°, 90°] and [90°, 180°], thereby realizing the analysis of the lighting effects in different directions on the grinding surface and enhancing the recognition ability of the grinding surface features. The lighting analysis diagrams are obtained within different angle ranges and respectively formed into sets A, B, C and D, which provide comprehensive lighting data for the accurate identification of raised and recessed areas on the grinding surface. The shadow area acquisition strategy is implemented to identify the shadow areas on the grinding surface formed by changes in the lighting angle according to the elements in the sets A, B, C and D. These shadow areas are useful for determining whether the grinding surface is flat. By analyzing the shadow changes under lighting at different angles, the tiny protrusions and recesses on the grinding surface can be distinguished, providing a data basis for subsequent grinding processing.

[0016] 4. This single-crystal silicon grinding method analyzes the illumination analysis images in sets A, B, C, and D by implementing a shadow region acquisition strategy. This identifies shadow regions in adjacent illumination analysis images, providing a basis for locating raised and recessed areas on the grinding surface. By randomly selecting adjacent elements in the set and marking them as first and second elements, the method captures shadow changes on the grinding surface from different angles, classifying shadow regions within the same set. This provides a basic data set for the subsequent shadow region matching strategy, improving the efficiency of shadow region identification. The shadow region matching strategy is then implemented to obtain the position information of the same edges of shadow regions in each set, laying the foundation for the subsequent determination of raised areas.

[0017] 5. This single-crystal silicon grinding method establishes a rectangular coordinate system within an illumination analysis image to determine the edge position of shadow regions. Two shadow regions of adjacent elements are obtained and grouped into sets V and B. Shadow regions with identical edges are then compared and screened, improving the recognition of raised regions. Shadow region screening is performed to identify similar shadow patterns in different illumination analysis images and group them into edge-similar groups. The areas of similar shadow regions within these edge-similar groups are then compared.

[0018] 6. The single crystal silicon grinding method identifies closed areas on the grinding surface by matching the position information of the same edges in the set F. These areas are marked as raised areas, providing targets for grinding processing, and eliminating the four same edges that can form a closed area. The remaining same edges in the set are screened, and the brightness of the elements in the light analysis image is obtained using a photosensitive sensing device to identify the edge with the highest brightness value, i.e., the high-brightness edge. This helps to determine the concave area on the grinding surface, and identify the area surrounded by the high-brightness edge as the concave area. Specific grinding strategies are performed on these areas to eliminate surface unevenness, and determine the grinding point, i.e., the point with the lowest brightness value near the high-brightness edge, for grinding the concave area. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flow chart of the steps of the present invention. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] In the first embodiment, a silicon rod is cut into a plurality of silicon wafer samples; The grinding area of ​​the silicon wafer sample is circular, and the cutting thickness is determined by the standard of the manufacturing industry. If the thickness of the silicon wafer is 75 between 100 microns; In photovoltaic manufacturing, the thickness of silicon wafers ranges from 150 to 200 microns (0.15 to 0.2 mm). Set the grinding stages of silicon wafer samples, which are divided into grinding preparation stage, grinding process stage and grinding post-processing stage; Get n silicon wafer samples, number them, and generate a silicon wafer sample set E, expressed as E={ , ,..., },in It is represented as the i-th silicon wafer sample, and n is the number of silicon wafer samples; The cut surface of the silicon wafer sample is marked as the grinding surface, and the grinding surface is circular; Set the projection time interval, denoted as Q; Set the angle range of the projection light source on the grinding surface to [0°, 180°]; Two mutually perpendicular reference lines are set on the grinding surface, which are respectively marked as reference line P and reference line I; The intersection point of the reference lines is set at the center of the grinding surface; Mark the reference line P as the longitudinal line and the reference line I as the transverse line; On the grinding surface, make a semicircular section perpendicular to the longitudinal line, marked as section Z, and make a semicircular section perpendicular to the transverse line, marked as section X; Projecting along the semicircular cross section by projecting a light source, the projection method is divided into a first projection method and a second projection method; The first projection method is that the projection light source is projected onto the grinding surface along the edge of the cross section Z; The second projection method is that the projection light source is projected onto the grinding surface along the edge of the cross section X; According to the two projection methods, the grinding surface is projected by a projection light source to obtain a set of illumination analysis graphs generated by the first projection method and the second projection method, which are respectively recorded as illumination analysis graph set U and illumination analysis graph set Y; The illumination analysis diagram is an illumination area formed by projecting a light source onto the grinding surface at a certain angle, and the illumination area is used to obtain the convex areas and concave areas of the grinding surface; Since the concave area is lower than the surrounding surface, the bottom of the concave area cannot be directly illuminated when the projected light source is illuminated, resulting in a deeper shadow area. The edge of the concave area is steep, and the projected light source will focus at the edge, resulting in a bright highlight area at the edge of the concave area.

[0022] According to the illumination analysis graph set U and set Y, the convex area and concave area on the grinding surface are obtained; At the beginning of the grinding process, grinding strategies are implemented for both raised and recessed areas.

[0023] Furthermore, according to the two projection methods, the grinding surface is projected by a projection light source to obtain a set of illumination analysis graphs generated by the first projection method and the second projection method, which are respectively recorded as illumination analysis graph set U and illumination analysis graph set Y, including: According to the projection time interval and angle range, set the projection angle change value, recorded as W°; Set the angle change rule of the projected light source; The projection light source angle change rule is as follows: after each projection time interval, the projection light source angle is increased according to the projection angle change value; At the beginning of the grinding preparation stage, the projection light source angle is set to 0°, and the grinding surface is projected by the projection light source in a first projection mode; Obtain a set of illumination analysis graphs generated by the first projection method, forming a set U; After the projection light source finishes executing the first projection mode, the projection light source angle is set to 0°, and the grinding surface is projected in the second projection mode; A set of illumination analysis graphs generated by the second projection method is obtained and formed into a set Y.

[0024] Furthermore, according to the illumination analysis graph set U and the set Y, the raised area and the recessed area on the grinding surface are obtained, including: According to the angle range of the projected light source, it is divided into two intervals: [0°, 90°] and [90°, 180°]. Mark the divided intervals as the first angle range interval and the second angle range interval respectively; According to the illumination analysis diagram set U and the set Y, the illumination analysis diagrams formed by the projection light source on the grinding surface in the first angle range according to the law of the projection light source angle change are obtained, and the illumination analysis diagrams are formed into sets, which are recorded as set A and set B respectively; and obtaining illumination analysis diagrams of the grinding surface formed by the projection light source according to the variation law of the projection light source angle within the second angle range, and forming sets thereof, which are respectively recorded as set C and set D; Execute the shadow area acquisition strategy based on the elements in set A, set B, set C, and set D.

[0025] Optionally, based on the elements in Set A, Set B, Set C, and Set D, a shadow area acquisition strategy is executed, including: For a certain set, obtain a random set of adjacent elements, mark them, and record them as the first element and the second element; The random group is represented by randomly selecting two adjacent illumination analysis images from the set; Get all the shadow areas in the first element and the second element to form the first set and the second set; According to the first set and the second set, the shadow area matching strategy is executed to obtain the position information of the same edges in set A, set B, set C, and set D respectively.

[0026] Furthermore, the shadow area matching strategy includes: S1: In the illumination analysis diagram, a plane rectangular coordinate system is established to obtain the position information of the edge of the shadow area; S2: Get two shadow areas of adjacent elements, and group the shadow patterns in these two shadow areas into sets, which are respectively recorded as set V and set B; S3: Screen the shadow areas of set V and set B; The pattern screening is to screen out shadow areas with the same edges for the patterns in the two sets, and obtain the position information of the same edges to form a set; The screening steps are: According to the shaded areas in set V and set B, two shaded areas with the same edges are obtained. If these two shaded areas do not belong to the same set, these two shaded areas are grouped together and marked as an edge similarity group. If, in the edge similarity group, the area with a larger shadow area covers the area with a smaller shadow area, the position information of the same edge is obtained; According to set A, set B, set C, and set D, the position information of all the same edges in each set is obtained respectively to form a set, which is recorded as set F.

[0027] Optionally, obtaining the raised areas and recessed areas on the grinding surface according to the illumination analysis graph set U and the set Y includes: Match the same edge position information in set F; The matching rule is that if there are four identical edges that can form a closed region, then these four edges are removed from the set F and grouped together, marked as a closed region group. Mark the closed area formed by four identical edges in the closed area group as a convex area; Obtain the brightness of the elements in set A, set B, set C, and set D through a photosensitive sensor device, and obtain the edge with the highest brightness value, which is recorded as the high-brightness edge; The area surrounded by the high-brightness edge is marked as the concave area, and the point with the lowest brightness value near the edge is obtained and recorded as the grinding point.

[0028] Furthermore, at the beginning of the grinding process, a grinding strategy is executed for the raised and recessed areas, including: If there are concave areas and convex areas on the grinding surface, the grinding point position is obtained; Grind the entire grinding surface with the grinding point as the bottom surface; If there are raised areas on the grinding surface and no recessed areas, all raised areas are acquired and ground.

[0029] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0030] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for grinding single crystal silicon, characterized in that: include, Cutting the silicon rod into multiple silicon wafer samples; The grinding area of ​​the silicon wafer sample is circular, and the thickness of the cut is determined by the standard of the manufacturing industry. In the manufacture of integrated circuits, the thickness of the silicon wafer is 75 Between 100 microns; In photovoltaic manufacturing, the thickness of silicon wafers is between 150 microns and 200 microns (0.15 mm to 0.2 mm). Setting the grinding stages of silicon wafer samples, which are divided into grinding preparation stage, grinding process stage and grinding post-processing stage; Get n silicon wafer samples, number them, and generate a silicon wafer sample set E, expressed as E={ , , ..., },in It is represented as the i-th silicon wafer sample, and n is the number of silicon wafer samples; The cut surface of the silicon wafer sample is marked as the grinding surface, and the surface of the grinding surface is circular; Set the projection time interval, denoted as Q; Set the angle range of the projection light source on the grinding surface to [0°, 180°]; Two mutually perpendicular reference lines are set on the grinding surface, which are respectively denoted as reference line P and reference line I; The intersection point of the reference lines is set at the center of the grinding surface; Mark the reference line P as the longitudinal line and the reference line I as the transverse line; On the grinding surface, make a semicircular section perpendicular to the longitudinal line, marked as section Z, and make a semicircular section perpendicular to the transverse line, marked as section X; The projection is performed along a semicircular cross section by projecting a light source, and the projection method is divided into a first projection method and a second projection method; The first projection method is that the projection light source is projected onto the grinding surface along the edge on the section Z; The second projection method is that the projection light source is projected onto the grinding surface along the edge on the section X; According to the two projection methods, the grinding surface is projected by a projection light source to obtain a set of illumination analysis graphs generated by the first projection method and the second projection method, which are respectively recorded as an illumination analysis graph set U and an illumination analysis graph set Y; The illumination analysis diagram is an illumination area formed by projecting a light source onto the grinding surface at a certain angle, and the illumination area is used to obtain the convex area and the concave area of ​​the grinding surface; Since the concave area is lower than the surrounding surface, the bottom of the concave cannot be directly illuminated when the projected light source is illuminated, resulting in a deepening of the shadow area. The edge of the concave area is steeper, and the projected light source will focus at the edge, resulting in a bright highlight area at the edge of the concave area.

2. Obtain the raised area and the depressed area on the grinding surface according to the illumination analysis graph set U and the set Y; At the beginning of the grinding process, grinding strategies are implemented for both raised and recessed areas.

3. The method for grinding single crystal silicon according to claim 1, characterized in that: According to the two projection methods, the grinding surface is projected by a projection light source to obtain a set of illumination analysis graphs generated by the first projection method and the second projection method, which are respectively recorded as an illumination analysis graph set U and an illumination analysis graph set Y, including: According to the projection time interval and angle range, set the projection angle change value, recorded as W°; Set the angle change rule of the projected light source; The projection light source angle variation rule is as follows: after each projection time interval, the angle of the projection light source is increased according to the projection angle variation value; At the beginning of the grinding preparation stage, the projection light source angle is set to 0°, and the grinding surface is projected by the projection light source in a first projection mode; Obtain a set of illumination analysis graphs generated by the first projection method, forming a set U; After the projection light source finishes executing the first projection mode, the projection light source angle is set to 0°, and the grinding surface is projected in the second projection mode; A set of illumination analysis graphs generated by the second projection method is obtained, and the sets are formed into a set Y.

4. The method for grinding single crystal silicon according to claim 1, characterized in that: The step of obtaining the raised area and the recessed area on the grinding surface according to the illumination analysis graph set U and the set Y includes: According to the angle range of the projected light source, it is divided into two intervals: [0°, 90°] and [90°, 180°]; Mark the divided intervals as a first angle range interval and a second angle range interval respectively; According to the illumination analysis diagram set U and the set Y, an illumination analysis diagram formed by the projection light source on the grinding surface in the first angle range according to the projection light source angle change law is obtained, and the illumination analysis diagrams are formed into sets, which are respectively recorded as set A and set B; And obtaining the illumination analysis diagram formed by the projection light source on the grinding surface according to the projection light source angle variation law in the second angle range, and forming a set, which are respectively recorded as set C and set D; According to the elements in set A, set B, set C and set D, a shadow area acquisition strategy is executed.

5. The method for grinding single crystal silicon according to claim 3, characterized in that: The shadow area acquisition strategy is executed according to the elements in set A, set B, set C, and set D, including: For a certain set, obtain a random set of adjacent elements, mark them, and record them as the first element and the second element; The random group is represented by randomly selecting two adjacent illumination analysis images in the set; Get all the shadow areas in the first element and the second element to form the first set and the second set; According to the first set and the second set, the shadow area matching strategy is executed to obtain the position information of the same edges in set A, set B, set C, and set D respectively.

6. The method for grinding single crystal silicon according to claim 4, characterized in that: The shadow area matching strategy includes: S1: In the illumination analysis diagram, a plane rectangular coordinate system is established to obtain the position information of the edge of the shadow area; S2: Get two shadow areas of adjacent elements, and group the shadow patterns in the two shadow areas into sets, which are recorded as set V and set B respectively; S3: Screen the shadow areas of set V and set B; The pattern screening is to screen out shadow areas with the same edges for the patterns in the two sets, and obtain position information of the same edges to form sets; The screening steps are: According to the shaded areas in set V and set B, two shaded areas with the same edges are obtained, and the two shaded areas do not belong to the same set, then the two shaded areas are grouped together and marked as an edge similarity group; If in the edge similarity group, the area with a larger shadow area covers the area with a smaller shadow area, then the position information of the same edge is obtained; According to set A, set B, set C, and set D, the position information of all the same edges in each set is obtained respectively to form a set, which is recorded as set F.

7. The method for grinding single crystal silicon according to claim 1, characterized in that: The step of obtaining the raised area and the recessed area on the grinding surface according to the illumination analysis graph set U and the set Y includes: Match the same edge position information in set F; The matching rule is that if there are four identical edges that can form a closed area, then the four edges are removed from the set F and grouped together, marked as a closed area group; Mark the closed area formed by four identical edges in the closed area group as a convex area; The brightness of the elements in set A, set B, set C, and set D is obtained through a photosensitive sensor device, and the edge with the highest brightness value is obtained and recorded as a high-brightness edge; The area surrounded by the high-brightness edge is obtained and marked as the concave area, and the point with the lowest brightness value near the edge is obtained and recorded as the grinding point.

8. The method for grinding single crystal silicon according to claim 6, characterized in that: At the beginning of the grinding process, a grinding strategy is executed for the raised area and the recessed area, including: If there are concave areas and convex areas on the grinding surface, the grinding point position is obtained; Grind the entire grinding surface with the grinding point as the bottom surface; If there are raised areas on the grinding surface and no recessed areas, all the raised areas are acquired and ground.

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