Automatic silicon wafer cutting direction morphology detection method based on coordinate transformation

Abstract

The invention relates to the technical field of semiconductor silicon wafer manufacturing, in particular to an automatic silicon wafer cutting direction morphology detection method based on coordinate transformation, which comprises the following steps of: S1, automatically measuring and recording a deflection angle phi of a Notch mark relative to a set datum line by bonding equipment; uploading the deflection angle phi and the corresponding crystal ingot batch identification to an MES system database; s2, after a control system of the testing machine obtains the batch identification of the silicon wafers, a request is automatically initiated to an MES system, and the Notch deflection angle phi corresponding to the batch identification is inquired; s3, the control system of the testing machine automatically calculates a corresponding silicon wafer front scanning datum line angle theta under the coordinate system of the testing machine according to the bonding angle phi fed back by the MES system, and the testing machine controls a scanning mechanism of the testing machine to automatically rotate to the angle theta by taking Notch as 0 degree for positioning; and S4, the testing machine automatically completes flatness and morphology measurement of the front surface of the silicon wafer along the set scanning path.

Description

Technical Field

[0001] This invention relates to the field of semiconductor silicon wafer manufacturing technology, and in particular to a method for automatically positioning and detecting the morphology in the cutting direction by integrating bonding and testing process coordinate data through a manufacturing execution system (MES). This method is applicable to the detection of the flatness and morphology of silicon wafers after wire cutting. Background Technology

[0002] In the manufacturing process of 12-inch monocrystalline silicon wafers, the wafers after wire cutting need to undergo flatness testing to evaluate the cutting quality and guide process optimization. Currently, the industry commonly uses flatness testers such as Tokyo Seimitsu LBW (capacitive method) or Nanjing Zhong'an (optical method) for testing. To accurately reflect the changes in silicon wafer morphology from the entry point to the exit point during wire cutting and to evaluate process variations, the test scanning path must be kept consistent with the cutting direction.

[0003] Current technologies generally rely on manual operation: engineers must first obtain the notch deflection angle φ of the ingot from the previous bonding process, and then manually input this angle into the testing machine interface to set the scanning baseline. This mode has significant drawbacks: firstly, it is inefficient, as repetitive manual operations consume engineers' valuable working time; secondly, it introduces the risk of human error, as incorrect angle input will cause the scanning direction to deviate from the actual cutting direction, and the obtained morphology data cannot accurately reflect the cutting process status, which may mislead process adjustments and, in severe cases, cause batch quality accidents. Therefore, there is an urgent need for an automated and highly reliable solution. Summary of the Invention

[0004] The purpose of this invention is to overcome the inefficiency and risk of human error caused by the reliance on manual operation in the prior art, and in particular to solve the problem of having to manually convert angles due to the inconsistency between the coordinate systems of the bonding and testing equipment. This invention provides a detection method that can automatically and accurately align the scanning direction of silicon wafer flatness testing with the wire cutting direction.

[0005] The technical objective of this invention is achieved as follows: an automatic detection method for silicon wafer cutting orientation topography based on coordinate transformation, comprising the following steps: S1. Measurement and Reporting of Bonding Angle Data: In the ingot bonding process, with the ingot tail as the viewing angle, the bonding equipment automatically measures and records the deflection angle φ of the Notch mark relative to the set baseline; the deflection angle φ and its corresponding ingot batch identifier are uploaded to the MES system database to realize the association between the deflection angle φ and the ingot batch identifier. S2. Test command triggering and data acquisition: When the silicon wafer is cut and transferred to the flatness test station, the control system of the test machine obtains the batch identifier of the silicon wafer and automatically sends a request to the MES system to query the Notch deflection angle φ corresponding to the batch identifier. S3. Automatic Coordinate System Mirroring Transformation and Scanning Path Setting: Based on the bonding angle φ fed back by the MES system and the predefined coordinate mirroring transformation relationship, the control system of the test machine automatically calculates the corresponding silicon wafer front scanning baseline angle θ in the coordinate system of the test machine. The test machine controls its scanning mechanism to automatically rotate from Notch 0° to angle θ for positioning. S4. Automatic testing and data association: The testing machine automatically completes the flatness and morphology measurement of the front side of the silicon wafer along the set scanning path, and automatically associates and stores the measurement results with the scanning angle θ, bonding angle φ, and batch identifier.

[0006] Preferably, in S1, the baseline is set as follows: Notch is vertically upward at 0°, counterclockwise rotation is negative, clockwise rotation is positive, and φ∈[-90°, 90°].

[0007] Preferably, in S3, the coordinate mirror transformation relationship is θ = -φ.

[0008] Another technical solution of the present invention is: a detection system applying the aforementioned automatic detection method for silicon wafer cutting orientation topography based on coordinate transformation, comprising: The measuring device of the bonding equipment is used to obtain bonding angle data and batch identification of the crystal ingot; Flatness testing equipment, used for measuring the flatness and morphology of the front side of silicon wafers; The MES system is used to receive bonding angle data and batch identifiers reported by the measuring device of the bonding equipment, and to provide feedback when the flatness testing machine requests a query.

[0009] The beneficial effects of this invention are: 1. Improved testing efficiency and automation level: The MES system realizes the automatic flow and coordinate transformation of bonding angle data from bonding equipment to testing station, reducing the angle setting time required before testing each batch of silicon wafers from about 30 seconds of manual operation to milliseconds, eliminating manual intervention in this step, and realizing the automation of the testing process; 2. Ensures the consistency and accuracy of test data: The program automatically executes the coordinate transformation formula (θ = -φ), replacing the error-prone manual conversion and input operations, fundamentally avoiding test direction errors caused by human error, and ensuring that the morphology data of all batches of silicon wafers can accurately and consistently reflect the true situation of the cutting direction; 3. Enhanced traceability of the production process: This invention automatically and forcibly correlates the morphology detection data of silicon wafers with their bonding angle and batch information, establishing a complete and accurate data chain, which provides reliable data support for the precise analysis and continuous optimization of the cutting process; 4. This invention provides a specific technical means to solve the problem of inconsistent coordinate systems between bonding and testing equipment in existing production lines. By using an automated solution based on MES system integration and a specific algorithm (coordinate mirroring transformation), it solves the problem of data incompatibility or lack of communication between bonding equipment (front end) and testing equipment (back end), providing a useful reference for peers to solve similar problems.

[0010] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the bonding machine (adhesion equipment) bonding crystal ingots in an embodiment of the present invention.

[0013] Figure 2 This is a schematic diagram of the process of a wire cutter cutting a crystal ingot in an embodiment of the present invention.

[0014] Figure 3 This is a schematic diagram of the scanning direction during testing by the testing machine (flatness measuring instrument) in an embodiment of the present invention.

[0015] Figure 4 This is a flowchart of a method according to an embodiment of the present invention.

[0016] Figure reference numerals: 1. Fixing iron plate; 2. Adhesive resin board; 3. Silicon wafer; 4. Notch mark. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0018] like Figure 4 As shown, this embodiment provides an automatic detection method for silicon wafer cutting orientation morphology based on coordinate transformation. This method constructs an automated data flow closed loop from bonding to testing and defines key coordinate transformation rules to achieve automatic positioning and detection of silicon wafer cutting orientation morphology. It includes the following steps: Step S1, Measurement and Reporting of Bonding Angle Data: (e.g.) Figure 1As shown, in the ingot bonding process, with the ingot tail as the viewing angle, the bonding equipment (bonding machine) measures and records the deflection angle φ of the Notch mark relative to the vertical direction (0°). 0° is defined as the Notch pointing vertically upwards, counter-clockwise rotation is negative, and clockwise rotation is positive, with φ ∈ [-90°, 90°]. The bonding equipment uploads this deflection angle φ and its corresponding ingot batch identifier to the MES system database, automatically associating the deflection angle φ with the ingot batch identifier. S2. Test command triggering and data acquisition: such as Figure 2 As shown, when entering the wire cutting process, the ingot rotates 180°, with the blade entering directly below. After the wire cutter cuts the silicon wafer off the ingot, when the silicon wafer flows to the flatness testing station, the control system of the testing machine (such as Nanjing Zhong'an Equipment) automatically obtains the ingot batch identifier and automatically sends a request to the MES system through its integrated communication interface to query and obtain the Notch deflection angle φ corresponding to the batch identifier. S3. Coordinate system mirroring transformation and automatic scan path setting: such as Figure 3 As shown, the control system of the testing machine automatically calculates the corresponding scanning baseline angle θ in the testing machine coordinate system based on the acquired bonding angle φ and a predefined coordinate mirror transformation relationship. The testing machine then controls its scanning mechanism to automatically rotate to angle θ for positioning. This coordinate mirror transformation relationship stems from the opposite viewing angles of the bonding equipment and the testing machine: the bonding machine uses the tail of the ingot as its viewing angle, while the flatness testing machine uses the front of the silicon wafer (the head of the ingot) as its viewing angle. To align the scanning path with the cutting direction, the preferred coordinate mirror transformation formula is: θ = -φ. For example, when the bonding angle φ returned by the MES system is -73°, the control system of the testing machine automatically calculates θ = -(-73°) = 73° and controls the scanning mechanism to position itself at 73°. It should be noted that 73° here is the angle in the testing machine coordinate system. S4. Automatic testing and data association: The testing machine scans along angle θ to obtain the cutting direction morphology. This scanning path is the cutting direction from the inlet to the outlet, ensuring the accuracy of the cutting direction morphology data. The measurement results are automatically associated and stored with the scanning angle θ, bonding angle φ, and batch identifier. Subsequently, the scanning path set by the testing equipment automatically completes the flatness and morphology measurement of the silicon wafer, such as... Figure 3 As shown, the detection of silicon wafer surface morphology is based on four scanning paths in four scanning directions (0°, 45°, 90°, and 135°) to synthesize the entire silicon wafer surface morphology.

[0019] This embodiment also provides a detection system that applies the above-described automatic detection method for silicon wafer cutting orientation topography based on coordinate transformation, including: The measuring device of the bonding equipment is used to obtain bonding angle data and batch identification of the crystal ingot; Flatness testing equipment, used for measuring the flatness and morphology of the front side of silicon wafers; The MES system is used to receive bonding angle data and batch identifiers reported by the measuring device of the bonding equipment, and to provide feedback when the flatness testing machine requests a query.

[0020] The above description is merely a preferred embodiment of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An automatic detection method for silicon wafer cutting direction topography based on coordinate transformation, characterized in that, Includes the following steps: S1. Measurement and Reporting of Bonding Angle Data: In the ingot bonding process, with the ingot tail as the viewing angle, the bonding equipment automatically measures and records the deflection angle φ of the Notch mark relative to the set baseline; the deflection angle φ and its corresponding ingot batch identifier are uploaded to the MES system database to realize the association between the deflection angle φ and the ingot batch identifier. S2. Test command triggering and data acquisition: When the silicon wafer is cut and transferred to the flatness test station, the control system of the test machine obtains the batch identifier of the silicon wafer and automatically sends a request to the MES system to query the Notch deflection angle φ corresponding to the batch identifier. S3. Automatic Coordinate System Mirroring Transformation and Scanning Path Setting: Based on the bonding angle φ fed back by the MES system and the predefined coordinate mirroring transformation relationship, the control system of the test machine automatically calculates the corresponding silicon wafer front scanning baseline angle θ in the coordinate system of the test machine. The test machine controls its scanning mechanism to automatically rotate from Notch 0° to angle θ for positioning. S4. Automatic testing and data association: The testing machine automatically completes the flatness and morphology measurement of the front side of the silicon wafer along the set scanning path, and automatically associates and stores the measurement results with the scanning angle θ, bonding angle φ, and batch identifier.

2. The automatic detection method for silicon wafer cutting direction topography based on coordinate transformation according to claim 1, characterized in that, In S1, the baseline is set as follows: Notch is vertically upward at 0°, counterclockwise rotation is negative, and clockwise rotation is positive, φ∈[-90°,90°].

3. The automatic detection method for silicon wafer cutting direction topography based on coordinate transformation according to claim 1, characterized in that, In S3, the coordinate mirror transformation relationship is θ = -φ.

4. A detection system applying the automatic detection method for silicon wafer dicing orientation topography based on coordinate transformation as described in any one of claims 1-3, characterized in that, include: The measuring device of the bonding equipment is used to obtain bonding angle data and batch identification of the crystal ingot; Flatness testing equipment, used for measuring the flatness and morphology of the front side of silicon wafers; The MES system is used to receive bonding angle data and batch identifiers reported by the measuring device of the bonding equipment, and to provide feedback when the flatness testing machine requests a query.

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