Wafer cleaning defect trace lock system and method
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAN ESWIN MATERIAL TECHNOLOGY CO LTD
- Filing Date
- 2026-02-03
- Publication Date
- 2026-06-09
Smart Images
Figure CN122180366A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of wafer surface cleaning and defect control technology, and in particular to a wafer cleaning defect tracing and locking system and method. Background Technology
[0002] Wet cleaning processes play a central role in the manufacturing process of very large-scale integrated circuits (VLSI), involving numerous repetitions and having a crucial impact on device yield. As semiconductor manufacturing process nodes continue to advance towards smaller dimensions, the sensitivity of device structures to surface contaminants increases exponentially; even tiny particles, metal ions, or organic residues can lead to severe yield losses. Currently, mainstream cleaning equipment, whether tank-type or single-wafer cleaning systems, relies on complex mechanical structures to process wafers. These structures include wafer carriers (baskets) for carrying and transporting wafers, fixed combs to keep wafers upright within the process tank, and lifting mechanisms for raising and lowering wafers. Over long-term use, these internal components are highly susceptible to wear or the accumulation of chemical crystals, becoming systemic sources of contamination and forming fixed, recurring defects on the surfaces of subsequent batches of wafers.
[0003] Existing technologies for handling wafer surface defects suffer from inefficiency. When defect detection modules detect unique defect patterns with non-random characteristics, traditional engineering troubleshooting methods often employ blind testing and elimination. For example, this might involve shutting down individual process tanks for testing or performing full system maintenance to eliminate all possible sources of contamination. While full system maintenance can solve the problem, it results in prolonged equipment downtime, potentially lasting 24 to 48 hours, and consumes large quantities of electronic-grade chemicals, leading to extremely high maintenance costs and severely impacting overall equipment efficiency. Furthermore, existing technologies also employ wafer rotation to eliminate cleaning blind spots, such as rotating the wafer 180 degrees after a cleaning cycle and repeating the cleaning process to ensure adequate coverage of obscured areas. However, this rotation, designed to address "cleaning coverage," is implemented as a standard process step and does not address or teach how to use changes in defect coordinates before and after rotation to diagnose the specific physical location of contamination sources.
[0004] The core problem with existing operating methods is the difficulty in accurately identifying the physical location of contamination sources in a rapid, non-destructive manner. Specifically, it's difficult to distinguish whether the contamination source is located on a fixed component inside the wet cleaning equipment or originates from a carrier moving with the wafer or residue from upstream processes (i.e., accompanying contamination sources). When all wafers enter the target process tank in a standard orientation (e.g., notch facing down), the relative coordinates of defects on the wafer are always the same, regardless of whether the contamination source is fixed (e.g., the fixed comb teeth on the left side of the tank) or accompanying contamination source (e.g., particles attached to the left edge of the wafer). This consistency in defect patterns makes it difficult for engineers to determine which specific, fixed mechanical component the contamination originates from, hindering targeted repair and resulting in long troubleshooting times and high maintenance costs. Therefore, the industry urgently needs a diagnostic technology based on geometric coordinate logic deduction that can quickly pinpoint the physical location of specific defect patterns, thereby enabling refined equipment management. Summary of the Invention
[0005] This disclosure aims to overcome the shortcomings of the prior art and provide a wafer cleaning defect tracing and locking system and method. Through the principle of geometric coordinate transformation, it can accurately locate the source of contamination in special defect patterns and guide targeted removal and repair.
[0006] The technical problem to be solved by this disclosure is how to quickly and accurately distinguish the source of contamination of special defect patterns in wet cleaning processes based on coordinate logic, whether it comes from fixed components in the target process tank or from accompanying contamination sources on the upstream path or wafer carrier.
[0007] The technical solution disclosed herein is implemented as follows:
[0008] In a first aspect, this disclosure provides a wafer cleaning defect tracing and locking system, the system comprising: The wafer sorting module is configured to identify the location of the wafer notch and, based on the notch, control the wafer to be sent out at a test angle different from the standard orientation. A wet cleaning module includes at least one target process tank, the target process tank including internal components for maintaining the wafer position during the cleaning process; A defect detection module is used to acquire coordinate data of a special defect pattern on the surface of the wafer after processing in the target process tank, wherein the coordinate data uses the wafer notch as a position reference point; and The processing unit is configured to receive a first relative coordinate of a special defect pattern corresponding to a first wafer under the standard orientation, receive a second relative coordinate of a special defect pattern corresponding to a second wafer under the test angle, and determine, based on the angular offset relationship between the first and second relative coordinates, whether the contamination source of the special defect pattern is located on an internal component of the target process tank or in an upstream path before entering the target process tank.
[0009] Secondly, this disclosure provides a method for tracing and locking the source of defects in wafer cleaning, the method comprising: Obtain the first defect distribution map of the first wafer after it has been processed by the target process tank in a standard orientation, identify special defect patterns and determine the first relative coordinates of the special defect patterns with respect to the wafer notch; The notch angle of the second wafer is adjusted to the test angle, so that the second wafer enters the target process tank for processing. The test angle is different from the standard orientation. Obtain a second defect distribution map after the second wafer is processed, and determine the second relative coordinates of the special defect pattern relative to the wafer notch; Based on the angular offset relationship between the first relative coordinate and the second relative coordinate, it is determined whether the contamination source of the special defect pattern is located on the internal components of the target process tank or in the upstream path before entering the target process tank.
[0010] This disclosure provides a wafer cleaning defect tracing and locking system and method, which can use geometric logic to accurately lock the source of contamination from "a certain cleaning machine" to "a specific part of a certain internal component of a certain process tank", completely solving the blindness in traditional inspection; it realizes repair, allowing the maintenance and repair module to directly perform fixed-point high-pressure flushing or mechanical tolerance adjustment on the locked contamination source location, reducing equipment downtime from several days to several hours; the diagnostic process mainly relies on the existing wafer sorting module and defect detection module, as well as the software algorithm of the processing unit, without consuming a large number of fake wafers and expensive chemical solutions. Attached Figure Description
[0011] Figure 1 This is a schematic diagram showing a wafer and its notch, used to indicate the geometric center of the wafer and the notch as a positional reference.
[0012] Figure 2 This is a schematic block diagram illustrating the structure of a wafer cleaning defect tracing and locking system according to an embodiment of the present disclosure. The system includes a wafer sorting module, a wet cleaning module (including a target process tank), a defect detection module, a processing unit, and a maintenance and repair module.
[0013] Figure 3This is a schematic diagram illustrating the process flow of a wafer from a wafer carrier container to a wet cleaning module according to an embodiment of the present disclosure, showing the standard orientation transfer path of the wafer.
[0014] Figure 4 This is a schematic diagram illustrating the structure of a wafer sorting module according to an embodiment of the present disclosure. The module includes a rotating stage, an angle detection system, and a servo drive unit for precisely controlling the rotation and positioning of the wafer.
[0015] Figure 5 This is a schematic diagram of the internal component structure of the target process tank according to an embodiment of the present disclosure, which mainly includes wafer fixing combs, lifting mechanism, mechanical adjustment mechanism and fluid spray nozzles.
[0016] Figure 6 This is a schematic diagram illustrating the structure of the maintenance and repair module according to an embodiment of the present disclosure. The core of the module is a fluid jetting device mounted on a multi-axis robotic arm, used for targeted flushing of locked pollution sources.
[0017] Figure 7 This is a flowchart illustrating a wafer cleaning defect tracing and locking method according to an embodiment of the present disclosure, including the steps of obtaining a defect distribution map, adjusting the wafer angle, obtaining the defect distribution map again, and determining the source of contamination. Detailed Implementation
[0018] The technical solutions in this disclosure will now be clearly and completely described with reference to the accompanying drawings.
[0019] First, the term "special defect pattern" in this disclosure will be explained. In the inspection pattern of a wafer surface defect scanner, defects usually appear to be randomly distributed. However, when equipment failure or process abnormalities occur on the production line, defects often exhibit clustered patterns with obvious geometric characteristics. These non-randomly distributed defects are called "special patterns." Common forms of special defect patterns include: arc-shaped scratches at the edges, usually caused by gripping deviations of the robotic arm or excessive clamping of the comb teeth; localized haze, which may originate from dead zones in the flow field caused by nozzle blockage or water marks during the drying process; and periodic dot arrays, which usually correspond strictly to the support points or contact positions of the comb teeth on the back side of the wafer.
[0020] The appearance of special defect patterns signifies systemic risk. If not eliminated in time, it will continue to contaminate all subsequent batches of wafers, causing huge economic losses. However, in the complex process of multi-tank continuous cleaning, accurately locating which tank or specific mechanical component (such as the left or right comb tooth) caused the contamination is extremely challenging.
[0021] This disclosure will be as follows Figure 1 The geometric rotation of wafer 101 shown is introduced into the field of defect investigation. Utilizing the dialectical relationship between "relative coordinate change" and "absolute coordinate invariance," a mathematical fault location model is established, thereby enabling rapid tracing of the source of contamination in special defect patterns. To more clearly illustrate the technical solution of this disclosure, the structure and operation process of this disclosure will be described in detail below.
[0022] Reference Figure 2 The wafer cleaning defect tracing and locking system 100 is based on existing tank-type wet cleaning equipment, integrating a wafer sorting module 200, a wet cleaning module (including the target process tank 300), a defect detection module 400, a processing unit 500, and a maintenance and repair module 600. In a normal wafer 101 production process, such as in... Figure 3 As shown, wafer 101 is placed in wafer carrier container 103 and removed by wafer sorting module 200 or robotic arm. It is then fed into a series of process tanks in a wet cleaning module in a standard orientation (e.g., wafer notch 102 facing 0 degrees or 180 degrees) for cleaning. After cleaning, wafer 101 is scanned by defect detection module 400 to obtain a defect distribution map. When processing unit 500 detects special defect patterns with fixed geometric features on the surface of multiple consecutive batches of wafers 101 through yield management system, it initiates the diagnostic program provided in this disclosure. Processing unit 500 first retrieves the initial defect distribution map of the contaminated wafer 101, performs overlay analysis using software to filter out random noise, identifies special defect patterns with a certain regularity and fixed shape, and records the first relative coordinates of the special defect pattern relative to wafer notch 102.
[0023] In one embodiment, the processing unit 500 performs a process segment isolation test before entering the core angle-changing diagnostic process. Since the wet cleaning process may include multiple process tanks such as SC1, SC2, and DHF, the isolation test reduces the workload of subsequent angle-changing tests. The processing unit 500 controls the wet cleaning module to break down the complete cleaning process into several sub-processes, processing the test pieces by adding process tanks one by one and using the transfer tank as a node. The defect detection module 400 inspects the test pieces at each stage; once a specific defect pattern is detected for the first time, the contamination area can be pinpointed to a specific process tank. This diagnostic method is applicable to all tank-type cleaning machines, i.e., those models that clean sequentially from front to back.
[0024] The wafer sorting module 200 plays a crucial role in enabling core variable-angle incident radiation tracing and diagnosis. (Refer to...) Figure 4The wafer sorting module 200 includes a rotating stage 210, an angle detection system 220, and a servo drive unit 230. The processing unit 500 instructs the wafer sorting module 200 to retrieve a group of clean test wafers, at least one of which is designated as the second wafer (experimental group). The rotating stage 210 is responsible for precisely carrying and rotating this second wafer. The rotating stage 210 is preferably made of a high-rigidity, low-thermal-expansion-coefficient material (such as high-purity silicon carbide or alumina ceramic), and its surface flatness is strictly controlled within the micrometer tolerance range to eliminate mechanical deformation during rotation. The upper surface of the rotating stage 210 integrates multiple micro-vacuum chucks, which, through distributed air pressure control, achieve uniform and stress-free clamping of the wafer 101, ensuring the stability of the wafer 101 during high-speed rotation and angle adjustment.
[0025] Furthermore, the angle detection system 220 is used to accurately detect the position of the wafer notch 102 and convert it into a digital signal. The angle detection system 220 typically consists of a high-resolution CCD vision system, an optical sensor, or a laser triangulation device, used to locate the geometric center of the wafer 101 and the precise orientation of the V-groove at the wafer notch 102 in real time. The angle detection system 220 works in conjunction with a high-resolution grating encoder to form a high-precision closed-loop feedback control system. In one embodiment, the angular resolution of the grating encoder needs to reach 0.001 degrees or even higher to ensure that the control error of the test angle during geometric coordinate analysis by the processing unit 500 is much smaller than the pixel resolution of the defect detection module 400. The servo drive unit 230 receives instructions from the processing unit 500 and drives the rotating stage 210 via a high-response DC servo motor (e.g., a voice coil motor or a direct drive motor) to rotate the wafer notch 102 of the second wafer to a preset test angle, such as 90 degrees, 180 degrees, or 270 degrees. The processing unit 500 can set the wafer 101 to enter different target process tanks 300 at different test angles in order to quickly pinpoint specific problems.
[0026] After the second wafer is precisely rotated to the test angle, the robotic arm of the wafer sorting module 200, while maintaining the relative angle of the wafer 101, delivers the second wafer into the locked target process tank 300 for processing. At this time, the second wafer is in an unconventional angle relative to the internal components (e.g., ...) within the target process tank 300. Figure 5 The wafer fixing comb 310 or lifting mechanism 320 shown in the figure are in contact.
[0027] Regarding the internal structure of the target process tank 300, refer to... Figure 5The internal components mainly include wafer fixing combs 310 (or baffles), typically made of high-purity, chemically resistant non-metallic materials such as polytetrafluoroethylene (PTFE) or perfluoroalkoxy copolymers (PFA). The wafer fixing combs 310 are installed in pairs on both sides of the target process tank 300 to vertically fix the wafers 101 and prevent them from colliding with each other during chemical flow or lifting. The teeth of each wafer fixing comb 310 are precision-machined, for example, using etching techniques to form smooth arcs or chamfers, to minimize the contact area and contact stress with the edge of the wafer 101. The tooth gap width is precisely designed, typically providing a margin of 0.5 mm to 1.0 mm to reduce mechanical pressure on the edge of the wafer 101, thereby avoiding edge arc scratches.
[0028] A mechanical adjustment mechanism 330 is provided on the bottom or side of the wafer fixing comb teeth 310. This mechanical adjustment mechanism 330 is implemented by a precision adjusting screw or a linear guide rail integrated on the side wall. When the processing unit 500 diagnoses mechanical contact (scratching) contamination, it uses the mechanical adjustment mechanism 330 to fine-tune the clamping distance between the two wafer fixing comb teeth 310, for example, by increasing the gap by 0.2 mm to 0.5 mm, to eliminate physical scratches caused by thermal expansion or mechanical fatigue.
[0029] The lifting mechanism 320, also an internal component, is used to smoothly place and remove the wafer 101 into the target process tank 300. The lifting mechanism 320 includes a support rod supporting the bottom of the wafer 101, with its contact points designed to minimize contact area. The drive assembly of the lifting mechanism 320 employs a high-precision servo system to ensure minimal deviation in its vertical movement trajectory. The installation of the lifting mechanism 320 requires strict concentricity; its centerline must deviate from the centerline of the target process tank 300 by less than 0.5 mm to prevent the bottom of the wafer 101 from contacting the bottom guide rails or supports of the target process tank 300 during lifting. Furthermore, the target process tank 300 is equipped with fixed fluid spray nozzles 340 for providing chemicals or rinsing water. If these nozzles 340 become clogged or exhibit abnormal jet flow, defects will occur at fixed locations, thus being considered a potential source of stationary contamination by the processing unit 500.
[0030] After the second wafer completes the angle-changing cleaning, the defect detection module 400 scans and acquires its second defect distribution map, and determines the position of the special defect pattern relative to the wafer notch 102 as the second relative coordinate. The processing unit 500 and its coordinate analysis module receive the first relative coordinate, the second relative coordinate, and the test angle, and perform geometric logic interpretation. The logic basis of this interpretation lies in distinguishing whether the contamination source is stationary in the physical space coordinate system (fixed source) or moves with the wafer 101 (moving source).
[0031] If the processing unit 500 detects that the second relative coordinate has shifted relative to the first relative coordinate by a magnitude equal to but opposite in direction to the test angle (i.e., a negative test angle offset), it indicates that the relative position of the defect on the surface of wafer 101 has changed, but its absolute physical contact point inside the target process tank 300 remains stationary. For example, if the contamination source is a wafer fixed comb tooth 310 located at a physical 90-degree position, when the wafer notch 102 of wafer 101 rotates 90 degrees (i.e., test angle = 90 degrees), causing the defect at the first relative coordinate (180 degrees relative to the notch) to become a defect at the second relative coordinate (270 degrees relative to the notch), the processing unit 500 determines that the contamination source is located on an internal component of the target process tank 300, and calculates which specific comb tooth gap or lifting mechanism 320 contact point caused the contamination based on the absolute physical orientation of the first relative coordinate. This geometric diagnostic model completely solves the problem of locking fixed contamination sources.
[0032] Conversely, if the processing unit 500 finds that the relative positions of the second relative coordinate and the first relative coordinate with respect to the wafer notch 102 are substantially the same, meaning the defect rotates along with the wafer 101, it indicates that the contamination source had already adhered to a specific location on the wafer 101 before entering the target process tank 300. In this case, the processing unit 500 determines that the contamination source is located in the upstream path before entering the target process tank 300, such as residue from an upstream cleaning tank, or originates from a carrier or wafer support container 103 that moves with the wafer 101.
[0033] After the processing unit 500 determines that the contamination source is an upstream path or a follow-up source on the wafer carrier 103, the system 100 further performs slot change diagnosis. If a special defect pattern exhibits a pattern related to a specific slot index within the batch (e.g., slots 1 and 25 are always damaged), the processing unit 500 controls the wafer sorting module 200 to change the slot index of the test wafer in the wafer carrier 103. For example, the damaged wafer is moved to a new slot, while a clean wafer is placed in the originally damaged slot. After cleaning, the defect detection module 400 scans again, and the processing unit 500 accurately distinguishes whether the contamination source originates from upstream process residues on the wafer 101 itself or from the corresponding slot guide rail of the wafer carrier 103, based on whether the defect follows the wafer to the new slot or appears on the wafer newly placed in the damaged slot.
[0034] Once the processing unit 500 has pinpointed the precise physical location and attribution of the pollution source through the aforementioned geometric logic and slot diagnosis, the maintenance and repair module 600 is activated to implement a targeted remediation strategy. (Refer to...) Figure 6 The core of the maintenance and repair module 600 is the fluid jet device 610 (i.e., high-pressure water gun), which is used to perform non-disassembly fixed-point flushing of the locked fixed pollution source location.
[0035] The fluid jetting device 610 is mounted on a high-precision multi-axis robotic arm, enabling it to precisely move the nozzle to specific coordinates within the target process tank 300, such as the third tooth of the left wafer fixing comb 310, under the control of the processing unit 500. The fluid jetting device 610 uses a micro-aperture nozzle with a diameter of 1mm to 2mm, is connected to an ultrapure water (DIW) pipeline, and is equipped with a high-precision pressure regulator. The processing unit 500 controls its output pressure within the range of 30PSI to 100PSI, generating a high-energy microjet. The fluid jetting device 610 employs a pulsed or intermittent jetting mode, alternating between vertical and 45-degree angled flushing, utilizing fluid shear force to peel away hard chemical crystals or particles deeply embedded in the wafer fixing comb 310 or the contacts of the lifting mechanism 320, thereby achieving efficient repair.
[0036] If the processing unit 500 diagnoses mechanical interference contamination, the maintenance and repair module 600 will instruct engineers to dynamically adjust the mechanical tolerances using the mechanical adjustment mechanism 330. This includes fine-tuning the clamping width of the wafer fixing comb 310, or calibrating the concentricity of the lifting mechanism 320 using a center calibration tool to ensure that the deviation of the lifting mechanism 320 is less than 0.5 mm, thereby eliminating physical scratching. If the diagnosis confirms local redeposition (e.g., cloud-like aggregation) caused by solution aging or dead zones in the flow field, the processing unit 500 can instruct the performance of solution replacement or filter replacement for that single target process tank 300 without requiring maintenance of the entire system. Through the above detailed structural and operational supplements, this disclosure provides a complete wafer cleaning defect tracing and locking system 100.
[0037] Accordingly, see Figure 7 This disclosure also provides a method for tracing and locking the source of defects in wafer cleaning, the method including the following steps S701, S702, S703 and S704: S701: Obtain the first defect distribution map of the first wafer after it has been processed by the target process tank in a standard orientation, identify special defect patterns and determine the first relative coordinates of the special defect patterns with respect to the wafer notch; S702: Adjust the notch angle of the second wafer to the test angle so that the second wafer can enter the target process tank for processing. The test angle is different from the standard orientation. S703: Obtain the second defect distribution map after the second wafer processing, and determine the second relative coordinates of the special defect pattern with respect to the wafer notch; S704: Based on the angular offset relationship between the first relative coordinate and the second relative coordinate, determine whether the contamination source of the special defect pattern is located on the internal components of the target process tank or in the upstream path before entering the target process tank.
[0038] More specifically, in the detailed operation of the wafer cleaning defect tracing and locking system, the first step is to capture and define the characteristics of special defect patterns. Specifically, when the yield management system alarms and indicates that multiple consecutive batches have high-density defects in the same coordinate area, engineers will intervene. At this stage, defect distribution maps from the most recent batches need to be retrieved, and overlay analysis is performed using automatic defect classification software. By overlaying multiple defect maps with the wafer notch as a reference, random noise is filtered out, while fixed special defect patterns will show clear outlines, such as a distinct arc or a dense cloud of points. Subsequently, the center coordinates and morphological characteristics of the pattern are recorded, laying the foundation for subsequent analysis.
[0039] Next, to narrow down the problem area, isolation testing is required. Since wet cleaning stations typically contain multiple chemical tanks, this step aims to initially identify the suspected tank. During the operation, two sets of test wafers are prepared and guided through different paths: the first set passes through only one specific chemical tank before entering the drying unit; the second set passes through that tank and another chemical tank before drying. By comparing the defects in the two sets of wafers, it is possible to determine which specific chemical tank the problem originates from, thus significantly reducing the complexity of subsequent testing.
[0040] After initially identifying the suspected process tank, further angle verification is performed to confirm the nature of the contamination source. For example, if the problem is suspected to originate from a particular cleaning tank, several clean test wafers are prepared, and a program is set on the wafer sorter to feed these wafers into the tank for cleaning at different notch angles (e.g., 0 degrees, 90 degrees, 180 degrees), while the robotic arm must maintain the set angle of the wafers throughout the process. After cleaning, each wafer is scanned and the defect location is recorded. By analyzing the angular relationship of these defect locations, a key judgment can be made: if the defect location shifts systematically in the same amount and opposite direction with the wafer rotation angle, the contamination source is confirmed to be located on a fixed component inside the tank, such as a specific comb or guide rail; otherwise, it indicates that the contamination may originate upstream.
[0041] If the angle change test indicates that the contamination source originates from upstream or accompanying items (i.e., it is determined to be a non-fixed contamination source), a slot change diagnosis is required for further differentiation. In this case, the test wafer is cleaned after changing the slot order in the wafer carrier basket (wafer carrier container), and then the defect pattern is inspected. If the defect pattern moves with the original wafer to the new slot, the contamination source is determined to be upstream process residue carried by the wafer itself; if the defect pattern appears on a clean wafer newly placed in the original problematic slot, the contamination source is determined to be the structure of that specific slot in the wafer carrier container.
[0042] Finally, after accurately locating the specific source of contamination through the above steps, such as a specific tooth groove on the left side of a cleaning tank, targeted repairs can be carried out. The system can activate the maintenance and repair module to perform point-to-point rinsing or adjustment of the locked location, thereby effectively removing contaminants and restoring the process to a clean state without disassembling the entire equipment.
[0043] It should be noted that the technical solutions described in this disclosure can be combined arbitrarily as long as they do not conflict.
[0044] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.
Claims
1. A wafer cleaning defect tracing and locking system, characterized in that, include: The wafer sorting module is configured to identify the location of the wafer notch and, based on the notch, control the wafer to be sent out at a test angle different from the standard orientation. A wet cleaning module includes at least one target process tank, the target process tank including internal components for maintaining the wafer position during the cleaning process; The defect detection module is used to acquire coordinate data of a special defect pattern on the surface of the wafer after it has been processed by the target process tank, with the wafer notch as the position reference point. as well as The processing unit is configured to receive a first relative coordinate of a special defect pattern corresponding to a first wafer under the standard orientation, receive a second relative coordinate of a special defect pattern corresponding to a second wafer under the test angle, and determine, based on the angular offset relationship between the first and second relative coordinates, whether the contamination source of the special defect pattern is located on an internal component of the target process tank or in an upstream path before entering the target process tank.
2. The wafer cleaning defect tracing and locking system according to claim 1, characterized in that, The processing unit is configured such that if the second relative coordinate has undergone a displacement relative to the first relative coordinate that is equal in magnitude but opposite in direction to the test angle, it determines that the pollution source is located on an internal component of the target process tank.
3. The wafer cleaning defect tracing and locking system according to claim 2, characterized in that, The internal components include wafer fixing combs, lifting mechanisms, and fluid spray nozzles.
4. The wafer cleaning defect tracing and locking system according to claim 1, characterized in that, The processing unit is configured to determine that the contamination source is located in the upstream path or in the wafer carrier if the second relative coordinate and the first relative coordinate are in the same relative position with respect to the wafer notch.
5. The wafer cleaning defect tracing and locking system according to claim 1, characterized in that, The system also includes a maintenance and repair module, which includes a fluid jetting device configured to perform targeted flushing of the locked pollution source location.
6. The wafer cleaning defect tracing and locking system according to claim 3, characterized in that, The wafer fixing comb is equipped with a mechanical adjustment mechanism for adjusting the clamping width between the wafer fixing comb teeth.
7. The wafer cleaning defect tracing and locking system according to claim 3, characterized in that, The lifting mechanism is equipped with a calibration mechanism for calibrating concentricity, and the processing unit can control the concentricity deviation of the lifting mechanism to within 0.5mm through the calibration mechanism.
8. The wafer cleaning defect tracing and locking system according to claim 1, characterized in that, The wafer sorting module includes a rotating stage and an angle detection system for detecting wafer notch positions.
9. The wafer cleaning defect tracing and locking system according to claim 4, characterized in that, The processing unit is further configured to perform a slot change diagnosis after determining that the contamination source is located in the upstream path or the wafer carrier container. The diagnosis is made by changing the slot index of the third wafer in the wafer carrier container and determining whether the contamination source originates from the slot structure of the wafer carrier container or from upstream process residues attached to the wafer surface, based on whether the special defect pattern moves with the wafer to the new slot.
10. A method for tracing and locking the source of defects in wafer cleaning, characterized in that, include: Obtain the first defect distribution map of the first wafer after it has been processed by the target process tank in a standard orientation, identify special defect patterns and determine the first relative coordinates of the special defect patterns with respect to the wafer notch; The notch angle of the second wafer is adjusted to the test angle so that the second wafer enters the target process tank for processing. The test angle is different from the standard orientation. Obtain a second defect distribution map after the second wafer is processed, and determine the second relative coordinates of the special defect pattern relative to the wafer notch; Based on the angular offset relationship between the first relative coordinate and the second relative coordinate, it is determined whether the contamination source of the special defect pattern is located on the internal components of the target process tank or in the upstream path before entering the target process tank.