A method for grinding single crystal silicon

Abstract

The invention relates to the technical field of semiconductor silicon material processing, and discloses a single crystal silicon grinding method. The method is aimed at the grinding processing of single crystal silicon wafers, and the main steps include: cutting a silicon rod into a plurality of silicon wafer samples, setting the silicon wafer thickness according to different application fields, using the cut surface of the silicon wafer sample as the grinding surface, and setting the grinding stage, including grinding preparation, processing and post-processing stages, performing light analysis on the grinding surface, obtaining light analysis diagrams through different projection methods, identifying raised and recessed areas on the grinding surface, using a shadow area acquisition strategy and a shadow area matching strategy to determine the defect position on the grinding surface, and executing a grinding strategy according to the identified raised and recessed areas, including determining the grinding point and grinding the raised area.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor silicon material processing, in particular to a single crystal silicon grinding method. 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 have problems such as low efficiency and uneven surface quality, which makes it difficult to meet the requirements of high-precision and high-efficiency processing.

[0003] In the existing technology, the grinding process of single crystal silicon wafers mostly relies on empirical parameters and qualitative judgments, lacking accurate quantitative analysis methods. In addition, the identification of raised and recessed areas on the surface of the silicon wafer during the grinding process is not accurate enough, resulting in uneven surface treatment of the silicon wafer, affecting the performance and life of the device.

[0004] In order 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 process 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 solving the problems mentioned in the above background technology.

[0006] The present invention provides the following technical solution: a method for grinding single crystal silicon, optionally, cutting a silicon rod into a plurality of silicon wafer samples;

[0007] Setting the grinding stages of silicon wafer samples, which are divided into grinding preparation stage, grinding process stage and grinding post-processing stage;

[0008] 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;

[0009] The cut surface of the silicon wafer sample is marked as the grinding surface, and the surface of the grinding surface is circular;

[0010] Set the projection time interval, denoted as Q;

[0011] Set the angle range of the projection light source on the grinding surface to [0°, 180°];

[0012] Two mutually perpendicular reference lines are set on the grinding surface, which are respectively denoted as reference line P and reference line I;

[0013] The intersection point of the reference lines is set at the center of the grinding surface;

[0014] Mark the reference line P as the longitudinal line and the reference line I as the transverse line;

[0015] 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;

[0016] 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;

[0017] The first projection method is that the projection light source is projected onto the grinding surface along the edge on the section Z;

[0018] The second projection method is that the projection light source is projected onto the grinding surface along the edge on the section X;

[0019] 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;

[0020] 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;

[0021] According to the illumination analysis graph set U and set Y, the raised area and the recessed area on the grinding surface are obtained;

[0022] 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:

[0024] According to the projection time interval and angle range, set the projection angle change value, recorded as W°;

[0025] Set the angle change rule of the projected light source;

[0026] 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;

[0027] 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;

[0028] Obtain a set of illumination analysis graphs generated by the first projection method, forming a set U;

[0029] 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;

[0030] A set of illumination analysis graphs generated by the second projection method is obtained, and the sets are formed into a set Y.

[0031] Optionally, 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:

[0032] According to the angle range of the projected light source, it is divided into two intervals: [0°, 90°] and [90°, 180°];

[0033] Mark the divided intervals as a first angle range interval and a second angle range interval respectively;

[0034] 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;

[0035] 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;

[0036] According to the elements in set A, set B, set C and set D, a shadow area acquisition strategy is executed.

[0037] Furthermore, according to the elements in set A, set B, set C, and set D, a shadow area acquisition strategy is executed, including:

[0038] For a certain set, obtain a random set of adjacent elements, mark them, and record them as the first element and the second element;

[0039] The random group is represented by randomly selecting two adjacent illumination analysis images in the set;

[0040] Get all the shadow areas in the first element and the second element to form the first set and the second set;

[0041] 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.

[0042] Optionally, the shadow area matching strategy includes:

[0043] 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;

[0044] 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;

[0045] S3: Screen the shadow areas of set V and set B;

[0046] 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;

[0047] The screening steps are:

[0048] 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;

[0049] 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;

[0050] 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.

[0051] 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:

[0052] Match the same edge position information in set F;

[0053] 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;

[0054] Mark the closed area formed by four identical edges in the closed area group as a convex area;

[0055] 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;

[0056] 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.

[0057] Optionally, at the beginning of the grinding process, a grinding strategy is executed for the raised area and the recessed area, including:

[0058] If there are concave areas and convex areas on the grinding surface, the grinding point position is obtained;

[0059] Grind the entire grinding surface with the grinding point as the bottom surface;

[0060] If there are raised areas on the grinding surface and no recessed areas, all the raised areas are acquired and ground.

[0061] The present invention has the following beneficial effects:

[0062] 1. The single crystal silicon grinding method generates a silicon wafer sample set E by cutting a silicon rod into multiple silicon wafer samples, provides a unique identifier for each silicon wafer sample, facilitates tracking during the grinding process, ensures the traceability of the processing, sets the projection time interval Q and the angle range interval [0°, 180°], and performs comprehensive illumination analysis on the grinding surface. It can project light sources at different angles, sets mutually perpendicular reference lines P and I on the grinding surface, and projects semicircular sections Z and X. The grinding surface is projected from two orthogonal directions, thereby improving the projection and The accuracy of recessed area detection is improved by obtaining the illumination analysis diagram sets U and Y using the first projection method and the second projection method, which capture illumination changes on the grinding surface from different directions, and provide a data basis for defect analysis on the grinding surface. The raised and recessed areas on the grinding surface are obtained based on the illumination analysis diagram sets U and Y, and the unevenness of the silicon wafer surface is identified, providing a target for subsequent grinding processing. In the grinding processing stage, grinding strategies are implemented for the raised and recessed areas, and grinding operations are performed, thereby eliminating the unevenness on the silicon wafer surface and improving the surface quality of the silicon wafer.

[0063] 2. The single crystal silicon grinding method sets the projection angle change value W° and the projection light source angle change law, utilizes the first projection mode and the second projection mode 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, the projection light source angle is initialized to 0°, and the light source angle is adjusted according to the set projection time interval and angle change value, thereby realizing continuous and orderly illumination analysis of the grinding surface. By obtaining the illumination analysis graph sets U and Y, a basis is provided for the subsequent shadow area acquisition strategy.

[0064] 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, and the shadow areas formed on the grinding surface due to changes in lighting angles are identified according to the elements in 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.

[0065] 4. The single crystal silicon grinding method analyzes the illumination analysis diagrams in the sets A, B, C and D by executing the shadow area acquisition strategy, identifies the shadow areas in the adjacent illumination analysis diagrams, and provides a basis for positioning the raised and recessed areas on the grinding surface. By randomly selecting adjacent elements in the set and marking them as the first element and the second element, the shadow changes on the grinding surface are captured from different angles, and the shadow areas in the same set are classified, providing a basic data set for the subsequent shadow area matching strategy, improving the efficiency of shadow area identification, executing the shadow area matching strategy, and obtaining the position information of the same edges of the shadow areas in each set. This lays the foundation for determining the raised area later.

[0066] 5. The single crystal silicon grinding method determines the edge position information of the shadow area by establishing a plane rectangular coordinate system in the illumination analysis diagram, obtains two shadow areas of adjacent elements and forms sets V and B, compares and screens out shadow areas with the same edges, and improves the recognition of raised areas. Perform shadow area screening, identify similar shadow patterns in different illumination analysis diagrams, and classify them into edge similarity groups, and compare the areas of similar areas of the shadow areas in the edge similarity groups.

[0067] 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, which provide targets for grinding processing, and removes four identical edges that can form closed areas. The remaining identical edges in the set are screened, and the brightness of the elements in the light analysis diagram is obtained using a photosensitive sensor device to identify the edge with the highest brightness value, i.e., the high-brightness edge, which helps to determine the recessed area on the grinding surface, and identify the area surrounded by the high-brightness edge as the recessed area. Specific grinding strategies are performed on these areas to eliminate surface unevenness, and the grinding point, i.e., the point with the lowest brightness value near the high-brightness edge, is determined for grinding the recessed area. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a flow chart of the steps of the present invention. DETAILED DESCRIPTION

[0069] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0070] In the first embodiment, a silicon rod is cut into a plurality of silicon wafer samples;

[0071] 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;

[0072] In photovoltaic manufacturing, the thickness of silicon wafers is between 150 microns and 200 microns (0.15 mm to 0.2 mm).

[0073] Setting the grinding stages of silicon wafer samples, which are divided into grinding preparation stage, grinding process stage and grinding post-processing stage;

[0074] 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;

[0075] The cut surface of the silicon wafer sample is marked as the grinding surface, and the surface of the grinding surface is circular;

[0076] Set the projection time interval, denoted as Q;

[0077] Set the angle range of the projection light source on the grinding surface to [0°, 180°];

[0078] Two mutually perpendicular reference lines are set on the grinding surface, which are respectively denoted as reference line P and reference line I;

[0079] The intersection point of the reference lines is set at the center of the grinding surface;

[0080] Mark the reference line P as the longitudinal line and the reference line I as the transverse line;

[0081] 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;

[0082] 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;

[0083] The first projection method is that the projection light source is projected onto the grinding surface along the edge on the section Z;

[0084] The second projection method is that the projection light source is projected onto the grinding surface along the edge on the section X;

[0085] 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;

[0086] 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;

[0087] 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.

[0088] According to the illumination analysis graph set U and set Y, the raised area and the recessed area on the grinding surface are obtained;

[0089] At the beginning of the grinding process, grinding strategies are implemented for both raised and recessed areas.

[0090] 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:

[0091] According to the projection time interval and angle range, set the projection angle change value, recorded as W°;

[0092] Set the angle change rule of the projected light source;

[0093] 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;

[0094] 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;

[0095] Obtain a set of illumination analysis graphs generated by the first projection method, forming a set U;

[0096] 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;

[0097] A set of illumination analysis graphs generated by the second projection method is obtained, and the sets are formed into a set Y.

[0098] 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:

[0099] According to the angle range of the projected light source, it is divided into two intervals: [0°, 90°] and [90°, 180°];

[0100] Mark the divided intervals as a first angle range interval and a second angle range interval respectively;

[0101] 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;

[0102] 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;

[0103] According to the elements in set A, set B, set C and set D, a shadow area acquisition strategy is executed.

[0104] Optionally, a shadow area acquisition strategy is executed according to the elements in set A, set B, set C, and set D, including:

[0105] For a certain set, obtain a random set of adjacent elements, mark them, and record them as the first element and the second element;

[0106] The random group is represented by randomly selecting two adjacent illumination analysis images in the set;

[0107] Get all the shadow areas in the first element and the second element to form the first set and the second set;

[0108] 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.

[0109] Further, the shadow area matching strategy includes:

[0110] 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;

[0111] 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;

[0112] S3: Screen the shadow areas of set V and set B;

[0113] 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;

[0114] The screening steps are:

[0115] 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;

[0116] 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;

[0117] 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.

[0118] Optionally, 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:

[0119] Match the same edge position information in set F;

[0120] 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;

[0121] Mark the closed area formed by four identical edges in the closed area group as a convex area;

[0122] 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;

[0123] 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.

[0124] Furthermore, at the beginning of the grinding process, a grinding strategy is executed for the raised area and the recessed area, including:

[0125] If there are concave areas and convex areas on the grinding surface, the grinding point position is obtained;

[0126] Grind the entire grinding surface with the grinding point as the bottom surface;

[0127] If there are raised areas on the grinding surface and no recessed areas, all the raised areas are acquired and ground.

[0128] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0129] 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 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 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. According to the illumination analysis graph set U and set Y, the raised area and the recessed area on the grinding surface are obtained; At the beginning of the grinding process, grinding strategies are implemented for both raised and recessed areas.

2. 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.

3. 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°]; The divided intervals are marked 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.

4. 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 the set A, the set B, the set C and the 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.

5. 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.

6. 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.

7. 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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