Wafer electroplating conductive ring contact finger online closed loop detection device and method

Abstract

The application provides a wafer electroplating conductive ring contact finger on-line closed loop detection device and method, which can realize high-precision and full-coverage resistance detection of the conductive ring contact finger under non-stop working condition, and improves equipment utilization rate and production efficiency; the device comprises an electroplating chuck body and a conductive ring assembly arranged in the electroplating chuck body; an on-line resistance collection assembly is arranged on the electroplating chuck body; the conductive ring assembly comprises a conductive ring and a rotating mechanism for driving the conductive ring to rotate circumferentially in the electroplating chuck body; a plurality of contact fingers are distributed along the circumference on the inner side of the conductive ring, and each contact finger does not interfere with each other in electrical property; the on-line resistance collection assembly comprises a detection finger and a reciprocating driving mechanism; the detection finger is provided with a resistance collection loop; the detection finger is driven by the reciprocating driving mechanism to produce reciprocating motion towards the contact finger, so as to contact or disconnect with the contact finger, and realize dynamic resistance data collection of the contact finger under non-stop state.

Description

Technical Field

[0001] This invention relates to the field of semiconductor wafer manufacturing equipment technology, specifically to an online closed-loop detection device and method for wafer electroplated conductive ring contact fingers. Background Technology

[0002] In wafer electroplating processes, the plating chuck is a core component for both bearing and power supply. The conductive ring contact finger inside the chuck is the key component for enabling wafer power supply. It directly contacts the conductive area at the wafer edge and is the only conductive carrier for transmitting plating current from the external power source to the wafer. Furthermore, the stability of its contact resistance directly determines the uniformity of the plating layer on the wafer surface, the plating yield, and device performance. However, the conductive ring contact finger operates under harsh conditions of electroplating solution corrosion, high-frequency switching, mechanical friction, and repeated clamping. This makes it highly susceptible to problems such as surface metal adhesion, elastic fatigue, contact pressure attenuation, increased contact resistance, and localized conductivity failure. These issues can lead to defects such as abnormal plating at the wafer edge, localized missed plating, and unexpected metal deposition.

[0003] Currently, the maintenance and inspection methods for the conductive ring contact fingers of electroplating chucks are limited, relying entirely on manual shutdown and visual inspection upon opening the cavity. However, this method has the following drawbacks: (1) The equipment must be stopped and the cavity opened. Then, manual inspection is required to check for lip seal leakage and electroplating adhesion on the surface of the contact finger. The operation is time-consuming and seriously affects the equipment utilization rate and production efficiency. (2) Only obvious surface faults can be observed, and the actual resistance of the contact finger cannot be quantified, so the electrical performance of the contact finger cannot be evaluated. (3) Unable to identify defects that are not visible to the naked eye, such as contact finger elastic decay, poor latent contact, and premature aging; (4) Shutdown testing significantly reduces equipment uptime, and missed testing can easily lead to batch wafer scrapping.

[0004] (5) There is no automatic detection, automatic retesting and early warning closed-loop mechanism.

[0005] Based on the aforementioned shortcomings, the industry urgently needs a non-stop, online, fully automatic, and high-precision conductive ring contact finger resistance detection solution to achieve early warning of latent faults. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides an online closed-loop detection device and method for conductive ring contact fingers on wafers, which can achieve high-precision, full-coverage resistance detection of conductive ring contact fingers under non-stop operating conditions, thereby improving equipment uptime and production efficiency.

[0007] This invention adopts the following technical solution: an online closed-loop detection device for conductive ring contact fingers in wafer electroplating, comprising an electroplating chuck body and a conductive ring assembly disposed within the electroplating chuck body. An online resistance acquisition component is mounted on the electroplating chuck body. The conductive ring assembly includes a conductive ring and a rotation mechanism for driving the conductive ring to rotate circumferentially within the electroplating chuck body. A plurality of contact fingers are distributed circumferentially along the inner side of the conductive ring, and each contact finger does not electrically interfere with the others. The online resistance acquisition component includes a detection finger and a reciprocating drive mechanism. A resistance acquisition circuit is configured in the detection finger. The detection finger is driven by the reciprocating drive mechanism to reciprocate towards the contact finger, thereby contacting or disconnecting from the contact finger, and realizing the acquisition of dynamic resistance data of the contact finger in a non-stop state.

[0008] Furthermore, the detection finger forks at its end, forming a first contact portion and a second contact portion, which respectively come into contact with different contact fingers; Furthermore, both the first contact portion and the second contact portion have two probe portions, which are divided into a first probe portion, a second probe portion, a third probe portion, and a fourth probe portion. The first probe portion and the fourth probe portion are connected to the power supply through a power line to form a power supply circuit, and the second probe portion and the third probe portion are connected to the measuring instrument through a measuring line to form the resistance acquisition circuit. Furthermore, the reciprocating drive mechanism includes a front plate and a rotating cylinder mounted on the front plate. The front plate is mounted on the electroplating chuck body. The rotating cylinder is connected to the detection finger via a rotating shaft to drive the detection finger to reciprocate. A limiting guide plate is mounted on the front plate. The limiting guide plate has a fan-shaped structure. A guide strip is provided at the top of the limiting guide plate to form a cavity with the limiting guide plate. The detection finger is located in the cavity. A notch is opened at the top of the electroplating chuck body, and the detection finger contacts the contact finger through the notch. Furthermore, the guide bar has an inverted U-shaped structure, the detection finger is shaped like a "7", and the horizontal parts of the guide bar and the detection finger are both arc-shaped; an opening is provided on the vertical part of the guide bar near the electroplating chuck body, and after the end of the horizontal part of the detection finger passes through the opening, it is limited and guided by the guide bar to achieve reciprocating rotation in the cavity; Furthermore, the device also includes a main control module and an early warning module. The main control module is connected to the rotating mechanism, the reciprocating drive mechanism, the resistance acquisition circuit, and the early warning module. It is used to acquire dynamic resistance data, control the operation of the rotating mechanism and the reciprocating drive mechanism to achieve full-coverage resistance detection of the contact finger, and realize early warning. A method for online closed-loop detection of conductive ring contact fingers on wafers includes the following steps: S1. Obtain the initial contact resistance of all contact fingers, take the average value as the initial reference threshold, and enter it into the main control module; S2. The reciprocating drive mechanism moves, causing the detection finger to rotate and extend until it contacts the contact finger, thereby obtaining the dynamic resistance value of the current contact. S3. After the test is completed, the test finger is retracted. Then, the conductive ring is driven by the rotating mechanism to rotate circumferentially within the electroplating chuck body at a fixed angle. The test finger is then extended again to contact the next set of contact fingers to obtain the dynamic resistance value of the next set. S4. Repeat step S3 until the conductive ring rotates one full circle to complete the 360° full coverage detection of all contact fingers. S5. All obtained resistance data are transmitted to the main control module. The main control module compares the real-time resistance detection data with the initial reference threshold to determine the contact finger fault type and fault level. S6. The main control module executes the corresponding closed-loop linkage handling strategy to complete the online closed-loop detection of the contact finger; wherein, the closed-loop linkage handling strategy includes triggering abnormal retesting, graded early warning, and production lockout operation according to the fault level.

[0009] Furthermore, in step S2, the formula for calculating the current dynamic resistance value is: in, This represents the current dynamic resistance value at contact. The resistance on the contact finger that is in contact with the first contact portion; The resistance on the contact finger that comes into contact with the second contact portion; The resistance of the wire; The resistance on the conductive ring; The voltage is measured by a measuring instrument; This refers to the current in the circuit where the power supply circuit is located; Furthermore, in step S5, the logic for determining the contact fault type and fault level includes: When the real-time resistance detection data exceeds the initial reference threshold by 5% to 15%, it is determined to be a mild fouling fault. When the real-time resistance detection data exceeds the initial reference threshold by 15% to 30%, it is determined to be a moderate contact failure type. When the real-time resistance detection data exceeds the initial reference threshold by more than 30%, it is determined to be a high-aging fault type; When the real-time resistance detection data reaches the scrapping threshold, it is determined to be a complete failure fault type. Furthermore, in step S6, the execution logic of the closed-loop linkage handling strategy includes: When the fault is identified as a minor fouling fault, a minor fault warning is triggered. After cleaning the test finger, return to step S2 and perform an abnormal retest. If the retested resistance test data is qualified, the minor fault warning flag is removed. If the retested resistance test data is unqualified, the fault is upgraded to a moderate contact failure fault. When the fault is identified as a moderate contact failure, a moderate fault warning is triggered, and production is reduced in load. When the fault is identified as a high-age fault, a high-fault warning is triggered to alert maintenance personnel to shut down the system and replace the aging contact fingers. When a complete failure is identified, an emergency fault alarm is triggered, and production is locked to prevent production.

[0010] The beneficial effects of this invention are that, through the coordinated operation of the online resistance acquisition component and the conductive ring component, it can achieve high-precision, full-coverage acquisition of dynamic resistance data of the contact fingers without stopping the machine or opening the cavity. The detection operation can be interspersed in the production gaps without occupying dedicated downtime, completely eliminating the downtime loss of traditional detection modes, reducing the missed detection rate, and thus preventing batch wafer scrapping accidents caused by contact finger failure. It has good economic value. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the assembled three-dimensional structure of the present invention; Figure 2 yes Figure 1 Enlarged structural diagram at point C; Figure 3 This is the assembly front view of the present invention; Figure 4 yes Figure 2 Enlarged structural diagram at point D in the diagram; Figure 5 This is a schematic diagram of the online resistance acquisition component in this invention; Figure 6 This is a schematic diagram of the detection finger structure in this invention; Figure 7 This is a partial structural diagram of the detection finger in this invention; Figure 8 yes Figure 7 Enlarged cross-sectional view of point E in the diagram; Figure 9 This is a structural block diagram of the present invention; Figure 10 This is a schematic diagram of the circuit formed after the contact finger and the detection finger come into contact in this invention. Detailed Implementation

[0012] like Figures 1-10 As shown, the present invention discloses an online closed-loop detection device for conductive ring contact fingers in wafer electroplating, comprising an electroplating chuck body 1 and a conductive ring assembly disposed within the electroplating chuck body 1. An online resistance acquisition component 20 is mounted on the electroplating chuck body 1. The conductive ring assembly includes a conductive ring 2 and a rotating mechanism (not shown) for driving the conductive ring 2 to rotate circumferentially within the electroplating chuck body 1. The main control module drives the rotating mechanism to rotate, which, in conjunction with the detection finger 4, achieves 360° full-circumference detection, ensuring that all contact fingers 3 are detected. Several contact fingers 3 are distributed circumferentially along the inner side of the conductive ring 2 to clamp the wafer (not shown) and complete power supply conduction, and each contact finger 3 is electrically independent. The online resistance acquisition component includes a detection finger 4 and a reciprocating drive mechanism. The detection finger 4 is configured with a resistance acquisition circuit. The detection finger 4 is driven by the reciprocating drive mechanism to reciprocate towards the contact finger 3, thereby contacting or disconnecting from the contact finger 3, and realizing the acquisition of dynamic resistance data of the contact finger 3 in a non-stop state.

[0013] The detection finger 4 has a forked end at the horizontal part, which branches into a first contact part 5 and a second contact part 6. The first contact part 5 and the second contact part 6 respectively contact different contact fingers 3. The first contact part 5 and the second contact part 6 each have two probe parts, which are divided into a first probe part 7, a second probe part 8, a third probe part 9, and a fourth probe part 10. The first probe part 7 and the fourth probe part 10 are connected to the power supply through the power line 11 to form a power supply circuit. The second probe part 8 and the third probe part 9 are connected to the measuring instrument through the measuring line 12 to form a resistance acquisition circuit.

[0014] The material of the detection finger 4 is tungsten, rhenium tungsten, or gold-plated, which has low contact resistance, resistance to electroplating solution corrosion, and wear resistance. As a contact carrier with the contact finger 3, it can achieve a stable electrical connection with the contact finger 3.

[0015] Existing components used in measuring instruments, such as high-precision differential voltmeters, have high input impedance (≥10). 12 (Ω), mV / µV level resolution, suppressing common-mode interference.

[0016] The power supply can be a constant current power supply to achieve constant current output, with stable current, low noise, high output impedance, and a wide range covering nA to A.

[0017] The reciprocating drive mechanism includes a front plate 13 and a rotating cylinder 14 mounted on the front plate 13. The front plate 13 is mounted on the electroplating chuck body 1. The rotating cylinder 14 is connected to the detection finger 4 via a rotating shaft 21 to drive the detection finger 4 to reciprocate. A limiting guide plate 15 is mounted on the front plate 13. The limiting guide plate 15 has a fan-shaped structure. A guide strip 16 is provided at the top of the limiting guide plate 15 to form a cavity 17 with the limiting guide plate 15. The detection finger 4 is located in the cavity 17. A notch 18 is opened at the top of the electroplating chuck body 1. The detection finger 4 contacts the contact finger 3 through the notch 18. The guide strip 16 has an inverted U-shaped structure. The detection finger 4 is in the shape of a "7". The horizontal parts of the guide strip 16 and the detection finger 4 are both arc-shaped. An opening 19 is provided on the vertical part of the guide strip 16 near the electroplating chuck body 1. After the end of the horizontal part of the detection finger 4 passes through the opening 19, it is limited and guided by the guide strip 16 to achieve reciprocating rotation in the cavity 17.

[0018] The device also includes a main control module and an early warning module. The main control module can be a PLC / host computer to realize process control, data calculation, threshold judgment, and early warning output. The main control module is connected to the rotating mechanism, the reciprocating drive mechanism, the resistance acquisition circuit, and the early warning module. It is used to acquire dynamic resistance data, control the operation of the rotating mechanism and the reciprocating drive mechanism to realize full-coverage resistance detection of contact finger 3, and realize graded early warning.

[0019] A method for online closed-loop detection of conductive ring contact fingers on wafers includes the following steps: S1. Obtain the initial contact resistance of all contact fingers 3, take the average value as the initial reference threshold, and enter it into the main control module together with the scrap critical threshold. S2. The main control module drives the rotating cylinder 14 to rotate and extend the detection finger 4 until it contacts the contact finger 3. At this time, the first probe part 7 and the second probe part 8 of the first contact part 5 contact one of the contact fingers 3, and the third probe part 9 and the fourth probe part 10 of the second contact part 6 contact the other contact finger 3, forming a power supply circuit and a resistance acquisition circuit. The constant current power supply outputs a constant current, and the measuring instrument (i.e., voltmeter) acquires the voltage signal. The main control module obtains the dynamic resistance value of the current contact based on the data signal fed back by the resistance acquisition circuit. Furthermore, in step S2, the formula for calculating the current dynamic resistance value is: in, This represents the current dynamic resistance value at contact. The resistance on the contact finger 3 that is in contact with the first contact part 5; The resistance on the contact finger 3 that contacts the second contact portion 6; The resistance of the wire; The resistance on conductive ring 2; The voltage is measured by a measuring instrument; This refers to the current in the circuit where the power supply circuit is located; S3. After the test is completed, the test finger 4 is retracted. Then, the conductive ring 2 is driven to rotate circumferentially within the electroplating chuck body 1 by the rotating mechanism to fix the angle. The test finger 4 is extended again to contact the next set of contact fingers 3 to obtain the dynamic resistance value of the next set. S4. Repeat step S3 until conductive ring 2 rotates one full circle to complete the 360° full coverage detection of all contact fingers. S5. All obtained resistance data are transmitted to the main control module. The main control module compares the real-time resistance detection data with the initial reference threshold to determine the fault type and fault level of contact finger 3. Furthermore, in step S5, the logic for determining the fault type and fault level of contact finger 3 includes: When the real-time resistance detection data exceeds the initial reference threshold by 5% to 15%, it is determined to be a mild fouling fault. When the real-time resistance detection data exceeds the initial reference threshold by 15% to 30%, it is determined to be a moderate contact failure type. When the real-time resistance detection data exceeds the initial reference threshold by more than 30%, it is determined to be a high-aging fault type; When the real-time resistance detection data reaches the scrapping threshold, it is determined to be a complete failure fault type. S6. The main control module executes the corresponding closed-loop linkage handling strategy to complete the online closed-loop detection of contact finger 3; the closed-loop linkage handling strategy includes triggering abnormal retesting, graded early warning, and production lockout operation according to the fault level. Furthermore, in step S6, the execution logic of the closed-loop linkage handling strategy includes: When the fault is identified as a minor fouling fault, a minor fault warning is triggered. After cleaning the fouling on the detection index 4, the process returns to step S2 to perform an abnormal retest. If the retested resistance data is qualified, meaning the retested resistance data returns to the allowable error range of the initial reference threshold, the fault is considered repaired, and the minor fault warning flag is removed. Normal production then resumes after the test is completed. If the retested resistance data is unqualified, meaning the retested resistance data still exceeds the allowable error range of the initial reference threshold, the fault is considered unrepaired and is upgraded to a moderate contact failure fault. When the fault is identified as a moderate contact failure, a moderate fault warning is triggered to remind the user to reduce the load for production. Through active load reduction protection, the fault can be prevented from escalating, equipment damage can be reduced, and downtime can be shortened. When the fault is identified as a high-aging fault, a high-fault warning is triggered to alert maintenance personnel to shut down the machine and replace the aging conductive ring 2 or contact finger 3. When a complete failure is identified, an emergency fault alarm is triggered, and production is locked to prevent production.

[0020] This invention integrates a complete closed loop of resistance detection, data judgment, anomaly retesting, and graded early warning, reducing manual intervention and achieving full coverage detection of contact fingers 3 and early warning of faults. It has no missed detections and no blind spots, and can detect conductivity abnormalities caused by contact finger 3 aging and slight contamination that cannot be detected by traditional visual inspection. It can detect hidden faults in advance, avoid batch wafer defects, significantly improve electroplating yield, and transform passive maintenance into preventive maintenance. It also greatly reduces the workload of manual maintenance and lowers the enterprise's operation and maintenance labor costs. Moreover, it is a non-stop online detection, which can save the time of manual inspection by opening the cavity during shutdown, and significantly improve the uptime.

[0021] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0022] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A wafer electroplating conductive ring contact finger online closed-loop detection device, comprising an electroplating chuck body and a conductive ring assembly disposed within the electroplating chuck body, characterized in that: The electroplating chuck body is equipped with an online resistance acquisition component. The conductive ring component includes a conductive ring and a rotating mechanism for driving the conductive ring to rotate circumferentially within the electroplating chuck body. Several contact fingers are distributed circumferentially on the inner side of the conductive ring, and each contact finger does not electrically interfere with the others. The online resistance acquisition component includes a detection finger and a reciprocating drive mechanism. The detection finger is configured with a resistance acquisition circuit. The detection finger is driven by the reciprocating drive mechanism to reciprocate towards the contact finger, so as to contact or disconnect with the contact finger, and realize the acquisition of dynamic resistance data of the contact finger in a non-stop state.

2. The wafer electroplated conductive ring contact finger online closed-loop detection device according to claim 1, characterized in that: The detection finger forks at its end, forming a first contact portion and a second contact portion, which respectively come into contact with different contact fingers.

3. The wafer electroplated conductive ring contact finger online closed-loop detection device according to claim 2, characterized in that: Both the first contact portion and the second contact portion have two probe portions, which are further divided into a first probe portion, a second probe portion, a third probe portion, and a fourth probe portion. The first probe portion and the fourth probe portion are connected to the power supply via a power line to form a power supply circuit, and the second probe portion and the third probe portion are connected to the measuring instrument via a measuring line to form the resistance acquisition circuit.

4. The wafer electroplated conductive ring contact finger online closed-loop detection device according to claim 1, characterized in that: The reciprocating drive mechanism includes a front plate and a rotating cylinder mounted on the front plate. The front plate is mounted on the electroplating chuck body. The rotating cylinder is connected to the detection finger via a rotating shaft to drive the detection finger to reciprocate. A limiting guide plate is mounted on the front plate. The limiting guide plate has a fan-shaped structure and a guide strip at its top to form a cavity with the limiting guide plate. The detection finger is located in the cavity. A notch is opened at the top of the electroplating chuck body, and the detection finger contacts the contact finger through the notch.

5. The wafer electroplated conductive ring contact finger online closed-loop detection device according to claim 4, characterized in that: The guide bar has an inverted U-shaped structure, and the detection finger is shaped like a "7". The horizontal parts of both the guide bar and the detection finger are arc-shaped. An opening is provided on the vertical part of the guide bar near the electroplating chuck body. After the end of the horizontal part of the detection finger passes through the opening, it is limited and guided by the guide bar to achieve reciprocating rotation in the cavity.

6. The wafer electroplated conductive ring contact finger online closed-loop detection device according to claim 1, characterized in that: The device also includes a main control module and an early warning module. The main control module is connected to the rotating mechanism, the reciprocating drive mechanism, the resistance acquisition circuit, and the early warning module. It is used to acquire dynamic resistance data, control the rotating mechanism and the reciprocating drive mechanism to achieve full-coverage resistance detection of the contact finger, and provide early warning.

7. A method for online closed-loop detection of contact fingers of electroplated conductive rings on wafers, characterized in that: Includes the following steps: S1. Obtain the initial contact resistance of all contact fingers, take the average value as the initial reference threshold, and enter it into the main control module; S2. The reciprocating drive mechanism moves, causing the detection finger to rotate and extend until it contacts the contact finger, thereby obtaining the dynamic resistance value of the current contact. S3. After the test is completed, the test finger is retracted. Then, the conductive ring is driven by the rotating mechanism to rotate circumferentially within the electroplating chuck body at a fixed angle. The test finger is then extended again to contact the next set of contact fingers to obtain the dynamic resistance value of the next set. S4. Repeat step S3 until the conductive ring rotates one full circle to complete the 360° full coverage detection of all contact fingers. S5. All obtained resistance data are transmitted to the main control module. The main control module compares the real-time resistance detection data with the initial reference threshold to determine the contact finger fault type and fault level. S6. The main control module executes the corresponding closed-loop linkage handling strategy to complete the online closed-loop detection of the contact finger; wherein, the closed-loop linkage handling strategy includes triggering abnormal retesting, graded early warning, and production lockout operation according to the fault level.

8. The method for online closed-loop detection of contact fingers of a wafer electroplated conductive ring according to claim 7, characterized in that: In step S2, the formula for calculating the current dynamic resistance value is: in, This represents the current dynamic resistance value at contact. The resistance on the contact finger that is in contact with the first contact portion; The resistance on the contact finger that comes into contact with the second contact portion; The resistance of the wire; The resistance on the conductive ring; The voltage is measured by a measuring instrument; This refers to the current in the circuit where the power supply circuit is located.

9. The method for online closed-loop detection of contact fingers of a wafer electroplated conductive ring according to claim 7, characterized in that: In step S5, the logic for determining the contact fault type and fault level includes: When the real-time resistance detection data exceeds the initial reference threshold by 5% to 15%, it is determined to be a mild fouling fault. When the real-time resistance detection data exceeds the initial reference threshold by 15%~30%, it is determined to be a moderate contact failure type. When the real-time resistance detection data exceeds the initial reference threshold by more than 30%, it is determined to be a high-aging fault type; When the real-time resistance detection data reaches the critical threshold for scrapping, it is determined to be a complete failure fault type.

10. The method for online closed-loop detection of contact fingers of a wafer electroplated conductive ring according to claim 7, characterized in that: In step S6, the execution logic of the closed-loop linkage handling strategy includes: When the fault is identified as a minor fouling fault, a minor fault warning is triggered. After cleaning the test finger, return to step S2 and perform an abnormal retest. If the retested resistance test data is qualified, the minor fault warning flag is removed. If the retested resistance test data is unqualified, the fault is upgraded to a moderate contact failure fault. When the fault is identified as a moderate contact failure, a moderate fault warning is triggered, and production is reduced in load. When the fault is identified as a high-age fault, a high-fault warning is triggered to alert maintenance personnel to shut down the system and replace the aging contact fingers. When a complete failure is identified, an emergency fault alarm is triggered, and production is locked to prevent production.

Images