Method for monitoring the position error of a rotating mechanism and control system

Abstract

A position error monitoring method and control system of a rotating mechanism, in the position error monitoring method of the rotating mechanism, angular position data of an encoder of a first motor and an encoder of a second motor are acquired as first position data during a process; then, during a non-process, the relative speed between the first motor and the second motor is adjusted while the rotating mechanism remains in a rotating state, so that the relative position of the first rotating part and the second rotating part is dynamically adjusted to a preset calibration phase, and second position data are acquired during operation at the calibration phase; the transition from the process phase to the calibration phase can be completed without stopping the rotating mechanism, time loss and mechanical impact caused by frequent start and stop are avoided, and the operation efficiency and productivity of the rotating mechanism are improved; in addition, whether there is a transmission error is determined by calculating the deviation value between the second position data and the first position data, which helps to find faults in time and improve the consistency and yield of the process.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing, and more particularly to a method and control system for monitoring the position error of a rotating mechanism. Background Technology

[0002] In the semiconductor and microelectronics manufacturing field, physical vapor deposition (PVD) is a key technology for preparing functional thin films. The core of this process lies in using gas discharge to excite plasma to bombard a target material in a vacuum environment, causing target atoms to sputter and deposit onto the substrate surface to form a thin film. To ensure the uniformity of the deposited film thickness and the consistency of its physical properties, precise control of the plasma field distribution within the reaction chamber is essential. Using a specifically arranged magnetic field to constrain and guide the electron trajectory, thereby adjusting the plasma density distribution and etching morphology on the target surface, is a fundamental prerequisite for optimizing sputtering effects and improving process yield.

[0003] To achieve dynamic and precise modulation of the aforementioned magnetic field, PVD equipment typically employs a multi-station linkage (UMM) rotary mechanism mounted on the vacuum chamber cover. This mechanism mechanically comprises a main rotating component and a secondary rotating component eccentrically positioned on a large disk, where the smaller disk carries a permanent magnet assembly for generating the specific magnetic field. During the process, the rotation of the large disk drives the entire smaller disk assembly to revolve, ensuring the magnetic field effectively covers specific areas such as the edge of the target material. Simultaneously, the independent rotation of the smaller disk is used to adjust the attitude angle of the permanent magnet in real time. Both the large and small disks are powered by independent servo motors and driven by flexible transmission components such as belts, aiming to achieve precise control of the plasma field through this composite motion trajectory.

[0004] However, the rotary mechanism still has room for improvement in practical applications, especially in the accuracy of position feedback and the stability of mechanical transmission, which cannot meet the requirements of high-precision processes for magnet position. Summary of the Invention

[0005] The problem solved by the embodiments of the present invention is to provide a method and control system for monitoring the position error of a rotating mechanism, which can perform real-time dynamic monitoring of the transmission of the rotating mechanism, help to detect faults in a timely manner, and improve the consistency and yield of the process.

[0006] To address the aforementioned problems, this invention provides a method for monitoring the position error of a rotating mechanism. The rotating mechanism includes: a first rotating component driven by a first motor; and a second rotating component eccentrically mounted on the first rotating component, driven by a second motor. Both the first and second rotating components are provided with marker features detectable by corresponding position sensors. The position error monitoring method includes: during process handling, the first and second rotating components operate according to a preset process setting; and when the position sensor detects that the corresponding marker feature has reached a predetermined detection position and is triggered, the angular position values ​​of the encoders of the first and second motors are obtained. The first position data is used as the first position data; during non-processing, the relative speed between the first motor and the second motor is adjusted in the rotating state of the rotating mechanism to adjust the relative position of the first rotating component and the second rotating component to a preset calibration phase; during operation at the calibration phase, the first rotating component and the second rotating component operate with the same preset process settings, and when the position sensor detects that the corresponding marker feature has reached the predetermined detection position and is triggered, the angular position data of the encoder of the first motor and the encoder of the second motor are used as the second position data; the deviation value between the second position data and the first position data is calculated, and the presence of transmission error in the rotating mechanism is determined based on the deviation value.

[0007] Optionally, the first motor drives the first rotating component through a first flexible transmission component, and the second motor drives the second rotating component through a second flexible transmission component; both the first and second flexible transmission components include belts; the first rotating component includes a first turntable, and the second rotating component includes a second turntable, on which a permanent magnet is disposed, the permanent magnet being used to modulate plasma distribution.

[0008] Optionally, the step of determining whether the rotating mechanism has a transmission error based on the deviation value includes: comparing the deviation value with a preset alarm deviation limit; when the deviation value is greater than the alarm deviation limit, executing an alarm and controlling the rotating mechanism to stop or issuing a maintenance command; when the deviation value does not exceed the alarm deviation limit, adjusting the angular position data of the encoder of the first motor and the encoder of the second motor so that the relative position of the first rotating component and the second rotating component is adjusted to the phase required by the process.

[0009] Optionally, the position sensor may include a diffuse reflective photoelectric sensor.

[0010] Optionally, the marking features include a first reflector disposed on the first rotating component and a second reflector disposed on the second rotating component, and a permanent magnet is disposed on the second rotating component at a position corresponding to the second reflector. The second reflector and the permanent magnet are respectively disposed on the front and back sides of the second rotating component. During the operation of the rotating mechanism, the position sensor is stationary. The position sensor includes a first position sensor and a second position sensor, wherein the first position sensor is used to detect the first reflector and the second position sensor is used to detect the second reflector.

[0011] Optionally, the preset calibration phase is when the angle between the first reflector and the second reflector is 0 degrees; when the position sensor detects that the corresponding marker feature has reached the predetermined detection position and is triggered, the angle between the first reflector and the second reflector is 0 degrees.

[0012] Optionally, when the position sensor detects that the corresponding marker feature has reached the predetermined detection position and is triggered, the first rotating component and the second rotating component rotate, and the first reflector passes through the detection area of ​​the first position sensor, and the second reflector passes through the detection area of ​​the second position sensor.

[0013] Optionally, the position error monitoring method of the rotating mechanism further includes: before acquiring the first position data, performing a homing operation on the first rotating component and the second rotating component to establish a mechanical zero point; the homing operation includes: first controlling the first rotating component to move to a preset zero point position of the first rotating component, and after it stops, controlling the second rotating component to move to a preset zero point position of the second rotating component.

[0014] This invention also provides a rotary mechanism control system for implementing the method, comprising: a first motor and a second motor, respectively used to drive a first rotating component and a second rotating component; a first position sensor and a second position sensor, respectively used to detect marking features fixed on the first rotating component and the second rotating component, wherein the first position sensor and the second position sensor directly monitor the physical positions of the first rotating component and the second rotating component, thereby forming a closed-loop monitoring of the mechanical transmission chain from the first motor to the first rotating component and from the second motor to the second rotating component; and a controller, communicatively connected to the first motor, the second motor, the first position sensor, and the second position sensor; the controller is configured to issue control commands to the first motor and the second motor. The control system includes: a control signal for maintaining process speed or adjusting phase; and logical operations including: real-time acquisition of encoder position data fed back by the first and second motors; synchronously locking and recording the encoder position data of the first and second motors at the moment when trigger signals are received from the first and second position sensors, respectively, as the first position data and the second position data; comparing the calculated deviation between the first position data and the second position data with an alarm deviation limit to determine whether there is a transmission error; the rotary mechanism control system also includes: a host computer, which is bidirectionally connected to the controller, and the host computer is used to send the alarm deviation limit to the controller and receive real-time position data or alarm status uploaded by the controller.

[0015] Optionally, the controller includes a programmable logic controller with a scan period of less than 1 millisecond.

[0016] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:

[0017] In the position error monitoring method for a rotating mechanism provided in this embodiment of the invention, marker features detectable by corresponding position sensors are set on both the first and second rotating components. Then, during process processing, the angular position data of the encoders of the first and second motors are acquired as first position data. Next, during non-process processing, the relative speed between the first and second motors is adjusted while the rotating mechanism remains rotating, dynamically adjusting the relative position of the first and second rotating components to a preset calibration phase. Second position data is acquired during operation at the calibration phase. The verification process of the position error monitoring method for a rotating mechanism provided in this embodiment of the invention can be performed during process flow intervals, completing the transition from the process phase to the calibration phase without stopping the rotating mechanism. This avoids time loss and mechanical shock caused by frequent start-stop cycles, improving the operating efficiency and productivity of the rotating mechanism. Furthermore, by calculating the deviation between the second and first position data to determine whether a transmission error exists, real-time dynamic monitoring of the rotating mechanism's transmission is possible, helping to detect faults promptly and improving process consistency and yield.

[0018] The rotating mechanism control system provided in this embodiment of the invention includes a first motor and a second motor, as well as a first position sensor and a second position sensor for detecting marking features on the first and second rotating components, respectively. The controller is configured to perform logical operations: upon receiving trigger signals from the first and second position sensors, it synchronously locks and records the encoder position data of the first motor and the second motor at that moment. Therefore, the first and second position sensors directly monitor the physical positions of the first and second rotating components. Combined with the synchronous locking logic of the controller, a fully closed-loop monitoring of the mechanical transmission chain in the rotating mechanism is formed between the motor drive end and the load output end. This allows for the capture and quantification of whether there are gaps or errors in the mechanical transmission chain, overcoming the deficiency of traditional semi-closed-loop control in being unable to perceive the true state of the load end. Furthermore, the controller compares the deviation value with an alarm deviation limit issued by the host computer, enabling the system to automatically determine whether the transmission error exceeds the standard based on the set threshold. This achieves automated and intelligent fault diagnosis, thereby improving the reliability and safety of the entire rotating mechanism control system. Attached Figure Description

[0019] Figure 1 This is a flowchart of the position error monitoring method of the rotating mechanism in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the first rotating component, the second rotating component, the first reflector, the second reflector, the first position sensor, and the second position sensor in the triggered state in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of the first rotating component, the second rotating component, the first reflector, the second reflector, the first position sensor, and the second position sensor in the non-triggered state of an embodiment of the present invention;

[0022] Figure 4 In this embodiment of the invention, when the deviation value is greater than the alarm deviation limit, an alarm is triggered and the rotating mechanism is stopped or a maintenance command is issued.

[0023] Figure 5 In this embodiment of the invention, when the deviation value does not exceed the alarm deviation limit, the angular position data of the encoder of the first motor and the encoder of the second motor are adjusted so that the relative position of the first rotating component and the second rotating component is adjusted to the phase required by the process.

[0024] Figure 6 This is an architecture diagram of the rotary mechanism control system in an embodiment of the present invention. Detailed Implementation

[0025] As the background technology reveals, the semi-closed-loop control system used in existing multi-station linkage rotary mechanisms has significant technical defects. This system primarily relies on encoder values ​​from the servo motor to indirectly calculate the load position. Since the motor and the small disk carrying the magnet are connected by a belt, this flexible transmission method inevitably experiences belt slippage, tension loosening, or increased mechanical transmission clearance during long-term operation under stress and frequent start-stop cycles. These mechanical errors prevent the encoder feedback data from accurately and absolutely reflecting the actual physical position of the magnet, leading to positional deviations in the control system. In PVD processes, which are extremely sensitive to magnet angles, any deviation of the magnet's actual orientation from the preset trajectory directly alters the plasma field distribution characteristics, resulting in decreased coating uniformity and even batch wafer scrapping. Currently, there is a lack of a technical solution that can quickly verify the actual magnet position without reducing production efficiency, making it impossible to promptly detect and correct positional offsets caused by transmission errors.

[0026] To address the technical problem, the position error monitoring method for a rotating mechanism provided in this embodiment of the invention includes setting marker features detectable by corresponding position sensors on both the first and second rotating components. During process processing, the angular position data of the encoders of the first and second motors are acquired as first position data. Then, during non-process processing, the relative speed between the first and second motors is adjusted while the rotating mechanism remains rotating, dynamically adjusting the relative position of the first and second rotating components to a preset calibration phase. Second position data is acquired during operation at the calibration phase. The verification process of the position error monitoring method for a rotating mechanism provided in this embodiment of the invention can be performed during process flow intervals, completing the transition from the process phase to the calibration phase without stopping the rotating mechanism. This avoids time loss and mechanical shock caused by frequent start-stop cycles, improving the operating efficiency and productivity of the rotating mechanism. Furthermore, by calculating the deviation between the second and first position data to determine the existence of transmission errors, real-time dynamic monitoring of the rotating mechanism's transmission is possible, helping to detect faults promptly and improving process consistency and yield.

[0027] To make the above-mentioned objects, features and advantages of the embodiments of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0028] This invention provides a method for monitoring the position error of a rotating mechanism. (See reference...) Figure 2 , Figure 3 and Figure 6 The rotating mechanism includes: a first rotating component 100 (e.g., Figure 2 As shown), the first rotating component 100 is powered by a first motor 103 (as shown). Figure 6 (as shown) drive; second rotating component 200 (as shown) Figure 3 As shown), the second rotating component 200 is eccentrically mounted on the first rotating component 100, and the second rotating component 200 is powered by the second motor 203 (as shown). Figure 6 As shown, the first rotating component 100 and the second rotating component 200 are both equipped with marking features that can be detected by the corresponding position sensors.

[0029] The first rotating component 100 is driven by the first motor 103 and serves as the main load-bearing structure. The second rotating component 200 is eccentrically mounted on the first rotating component 100 and is driven by the second motor 203. The first motor 103 and the second motor 203 together constitute a multi-axis linkage in the physical vapor deposition equipment, enabling complex composite motion trajectories. Because both the first rotating component 100 and the second rotating component 200 are equipped with marking features, the positions of these marking features are detected by position sensors, preparing for subsequent position error monitoring.

[0030] It should be noted that when the first rotating component 100 rotates, the second rotating component 200 revolves around the first rotating component 100; at the same time, the second rotating component 200 can also rotate independently, achieving its own rotation. Through the combined motion of revolution and rotation, the permanent magnet set on the second rotating component can cover the edge area of ​​the target material, thereby optimizing the sputtering effect.

[0031] In some embodiments, the first motor 103 and the second motor 203 are both independently controlled by the controller 300. The first motor 103 can adjust the rotational speed of the first rotating component 100, and the second motor 203 can adjust the rotational speed of the second rotating component 200.

[0032] It should be noted that a marking feature is fixedly provided on the surface of the first rotating component 100 and the second rotating component 200, respectively. When the marking features on the first rotating component 100 and the second rotating component 200 rotate to a specific angle along with their respective components, they will be detected by the position sensor, preparing for subsequent position error monitoring.

[0033] Specifically, the first motor 103 drives the first rotating component 100 through the first flexible transmission component; the second motor 203 drives the second rotating component 200 through the second flexible transmission component; both the first and second flexible transmission components include belts. The first rotating component 100 includes a first turntable, and the second rotating component 200 includes a second turntable. A permanent magnet is disposed on the second turntable, and the permanent magnet is used to modulate the plasma distribution.

[0034] The first motor 103 and the second motor 203 transmit torque to the load end through the first flexible transmission component and the second flexible transmission component, respectively. They drive the first rotating component 100 and the second rotating component 200 to rotate through the flexible connection of the belt, thereby changing the attitude angle of the permanent magnet on the second rotating component 200. This allows the permanent magnet fixed on the second rotating component 200 to modulate the plasma distribution in the cavity according to the rotation trajectory, thus optimizing the sputtering uniformity of the target material.

[0035] It should be noted that during the transmission process, belt slippage, stretching, aging, or changes in tension may cause transmission gaps or accumulated errors. This will lead to a deviation between the theoretical rotation angle fed back by the encoders of the first motor 103 and the second motor 203 and the actual rotation angle of the first rotating component 100 and the second rotating component 200. This will directly translate into an error in the permanent magnet angle. The attitude angle of the permanent magnet directly affects the distribution of plasma in the vacuum chamber, which in turn determines the uniformity of target sputtering and the quality of the thin film finally deposited on the wafer substrate, thus affecting the stability and yield of the process.

[0036] In some embodiments, the position sensor includes a diffuse reflection photoelectric sensor. The diffuse reflection photoelectric sensor emits a light beam toward the rotating first rotating component 100 and the second rotating component 200 and receives reflected signals. It can perform non-contact detection of marking features on the first rotating component 100 and the second rotating component 200 using the photoelectric conversion principle without interfering with the mechanical movement of the first rotating component 100 and the second rotating component 200. It quickly responds to marking features passing through the detection area, thereby generating a high-precision trigger signal the instant the marking feature reaches a specific physical position. This provides the control system with the moment to capture encoder data from the first motor 103 and the second motor 203, enabling the real-time acquisition of angular position data from the encoders of the first motor 103 and the second motor 203.

[0037] As an example, the emitting unit of the position sensor emits a beam of infrared light. When the first reflector 102 on the first rotating component 100 and the second reflector 202 on the second rotating component 200 enter the detection area, part of the light is diffusely reflected back to the receiving unit of the sensor, and the internal circuit of the position sensor outputs a trigger signal.

[0038] The marking features include a first reflector 102 disposed on the first rotating component 100 and a second reflector 202 disposed on the second rotating component 200, and a permanent magnet disposed on the second rotating component 200 at a position corresponding to the second reflector 202. The second reflector 202 and the permanent magnet are respectively disposed on the front and back sides of the second rotating component 200. During the operation of the rotating mechanism, the position sensor is stationary. The position sensor includes a first position sensor 101 and a second position sensor 201. The first position sensor 101 is used to detect the first reflector 102, and the second position sensor 201 is used to detect the second reflector 202.

[0039] The first reflector 102 and the second reflector 202, as the targets to be detected, are fixed on the first rotating component 100 and the second rotating component 200, respectively. The second reflector 202 and the permanent magnet are fixedly disposed on opposite sides of the second rotating component 200, so that detecting the second reflector 202 is equivalent to confirming the actual position of the permanent magnet. When the rotating component drives the first reflector 102 and the second reflector 202 past the sensor detection area, the position sensor obtains the physical position of the first reflector 102 and the second reflector 202, thus monitoring the actual rotation state of the first rotating component 100 and the second rotating component 200 of the rotating mechanism.

[0040] It should be noted that the second reflector 202 and the permanent magnet are mounted on opposite sides of the second rotating component 200. That is, the second reflector 202 and the permanent magnet are at the same angular position. Therefore, when the second position sensor 201 detects the second reflector 202, the controller 300 can determine the angular position of the permanent magnet at that moment.

[0041] It should be noted that the semiconductor device includes a housing and an inner process chamber and an outer process chamber located within the housing; the inner process chamber is used for process processing; the outer process chamber is located outside the inner process chamber, and a transparent window is provided on the outer process chamber, where the wafer and target are disposed; a first rotating component 100 and a second rotating component 200 are disposed within the outer process chamber, and a transparent window is provided on the outer process chamber; the position sensor is disposed on the housing outside the outer process chamber and faces the outer process chamber, and the position sensor obtains the reflected light signals given by the first reflector 102 on the first rotating component 100 and the second reflector 202 on the second rotating component 200 in the outer process chamber through the transparent window of the outer process chamber.

[0042] In some embodiments, the housing is provided with two position sensors, namely a first position sensor 101 and a second position sensor 201. The first position sensor 101 is aligned with the rotation trajectory of the first reflector 102, and the second position sensor 201 is aligned with the rotation trajectory of the second reflector 202. Correspondingly, the outer process chamber has two spaced-apart first transparent windows and second transparent windows. The first position sensor 101 is used to obtain the reflected light signal given by the first reflector 102 through the first transparent window, and the second position sensor 201 is used to obtain the reflected light signal given by the second reflector 202 through the second transparent window.

[0043] As an example, the first and second transparent windows are two annular windows.

[0044] The first reflector 102 disposed on the first rotating component 100 and the second reflector 202 disposed on the second rotating component 200 serve as position markers, providing a high signal-to-noise ratio detection target for the non-contact position sensor.

[0045] As an example, the first position sensor 101 is model number MRM1-LS1, and the second position sensor 201 is model number MRM1-LS2.

[0046] It should be noted that the first rotating component 100 and the second rotating component 200 are disposed in the same process chamber.

[0047] refer to Figure 1 Step S1, the position error monitoring method of the rotating mechanism further includes: before acquiring the first position data, performing a homing operation on the first rotating component 100 and the second rotating component 200 to establish a mechanical zero point; the homing operation includes: first controlling the first rotating component 100 to move to a preset zero point position of the first rotating component 100; then controlling the second rotating component 200 to move to a preset zero point position of the second rotating component 200.

[0048] The homing operation is used to initialize the position error monitoring before it begins. By executing specific timing logic, the first rotating component 100 is first controlled to return to the zero point and stop, and then the second rotating component 200 is controlled to return to the zero point. This prevents mechanical interference or collisions that may be caused by the simultaneous movement of the first rotating component 100 and the second rotating component 200. It can establish a unified mechanical zero point, providing reference coordinates for the subsequently acquired first position data, thereby making the subsequent error comparison calculation more accurate.

[0049] Specifically, the homing operation requires the coordinated operation of multiple components, such as the controller 300, the first motor 103, the second motor 203, the first rotating component 100, and the second rotating component 200 degrees. During the homing operation, the controller 300 sends commands to the drivers of the first motor 103 and the second motor 203 via a high-speed industrial bus (such as EtherCAT). The drivers control the first motor 103 to drive the first rotating component 100 to rotate, and control the second motor 203 to drive the second rotating component 200 to rotate.

[0050] As an example, firstly, the controller 300 sends a command to the first motor 103, which drives the first rotating component 100 to rotate to its preset zero position. This zero position can be determined by a fixed zero-point sensor or a limit switch. After the controller 300 sends a command to the first motor 103, it continuously monitors the status of the first motor 103. When the first rotating component 100 has completely stopped at the zero position, the controller 300 sends a command to the second motor 203, driving the second rotating component 200, which is eccentrically mounted on the first rotating component 100, to move until the second rotating component 200 reaches its preset zero position.

[0051] After both the first rotating component 100 and the second rotating component 200 are at their respective physical zero positions, the encoders of the first motor 103 and the second motor 203 are set to zero. Therefore, the angular position data read from the encoders of the first motor 103 and the second motor 203 during subsequent process processing, non-process processing, and operation in calibrated phase are all based on this zero point.

[0052] It should be noted that at the zero position, the angle between the first reflector 102 on the first rotating component 100 and the second reflector 202 on the second rotating component 200 is 0 degrees (e.g., Figure 2 (As shown).

[0053] refer to Figure 4 In step S2, during the process, the first rotating component 100 and the second rotating component 200 operate according to the preset process settings. When the position sensor detects that the corresponding marker feature has reached the predetermined detection position and is triggered, the angular position data of the encoder of the first motor 103 and the encoder of the second motor 203 are used as the first position data.

[0054] During the process, the first rotating component 100 and the second rotating component 200 operate according to the preset process settings. Through the logic operation function of the controller 300, at the moment when the position sensor is triggered by the corresponding marker feature, the angular position data of the encoder of the first motor 103 and the encoder of the second motor 203 are synchronously locked and recorded as the first position data, forming the comparison benchmark required for subsequent verification.

[0055] The process of acquiring the first position data for the reference occurs during the physical vapor deposition process, when the first rotating component 100 and the second rotating component 200 are coupled and moving according to the speed and relative phase relationship required by the process. As the rotating components rotate at the process speed, the marking features on the first rotating component 100 and the second rotating component 200 periodically pass through the detection areas of the corresponding position sensors. At the instant the marking feature enters the detection area and is recognized by its respective sensor, the sensor generates a high-level or low-level trigger signal and sends it to the controller 300. Within the same scan cycle of capturing the signal, the controller 300 immediately and synchronously reads the angular position data fed back by the encoders communicatively connected to the first motor 103 and the second motor 203. This set of synchronously acquired angular position data from the first motor 103 and the second motor 203 is defined as the first position data and stored by the controller 300 as a reference value for subsequent deviation calculations.

[0056] It should be noted that when the first rotating component 100 and the second rotating component 200 are running with preset process settings, a process is being performed in the process chamber, such as physical vapor deposition on the wafer using a target material.

[0057] It should also be noted that during the process, multiple speed ranges may occur depending on the process requirements. In each speed range, the position sensors corresponding to the first rotating component 100 and the second rotating component 200 will be triggered. For each speed range, the corresponding first position data is recorded, thereby enabling separate monitoring of transmission errors at different operating speeds.

[0058] It should be noted that the preset process settings may include one or more speed ranges. The method of this invention can acquire the angular position data of the first motor 103 and the second motor 203 respectively when the position sensor is triggered in each speed range, thereby enabling the monitoring of transmission errors at different operating speeds.

[0059] As an example, the controller 300 utilizes its high-speed scan cycle to accurately capture the rising or falling edge of the trigger signal. For instance, through high-speed input capture, it achieves precise response to microsecond-level signal changes, ensuring the synchronization and accuracy of data latching. For example, the scan cycle of the controller 300 is less than 1 millisecond.

[0060] When the position sensor detects that the corresponding marker feature has reached the predetermined detection position and is triggered, the angle between the first reflector 102 and the second reflector 202 is 0 degrees.

[0061] The angle between the first reflector 102 and the second reflector 202 is 0°, which is used to define the reference for error verification of the system, ensuring that the first rotating component 100 and the second rotating component 200 are in a specific spatial alignment at the moment the position sensor is triggered. By forcibly requiring the relative positions of the two to be zero at the moment of detection, the measurement uncertainty caused by the dynamic phase change during the process can be eliminated, thereby providing a unified reference for subsequent acquisition of second position data and improving the accuracy of position error monitoring.

[0062] It should be noted that the first reflector 102 is arranged radially along the first rotating component 100, and the extension direction of the first reflector 102 passes through the rotation center of the first rotating component 100; the second reflector 202 is arranged radially along the second rotating component 200, and the extension direction of the second reflector 202 passes through the rotation center of the second rotating component 200.

[0063] When the angle between the first reflector 102 and the second reflector 202 is 0 degrees, the first reflector 102 and the second reflector 202 are in a parallel or aligned state in space, and the relative mechanical angle between the first rotating component 100 and the second rotating component 200 is zero.

[0064] When the angle between the first reflector 102 and the second reflector 202 is 0 degrees, the first reflector 102 and the second reflector 202 can simultaneously enter the detection spot of their respective position sensors and be detected simultaneously.

[0065] It should be noted that both the first position data and the second position data obtained by calibrating the phase are acquired when the angle between the first reflector 102 and the second reflector 202 is 0. The angle between the first reflector 102 and the second reflector 202 is 0 as the trigger condition for the acquisition of the first position data and the second position data. This means that when comparing the first position data and the second position data, the encoder readings of the two motors under the same load physical event are compared, thus eliminating the interference caused by the phase difference.

[0066] It should also be noted that when the controller 300 drives the first rotating component 100 and the second rotating component 200 to rotate synchronously at a zero-degree angle (calibration phase), the first position sensor 101 and the second position sensor 201 will simultaneously output trigger signals.

[0067] refer to Figure 1 In step S3, during non-processing, the relative speed between the first motor 103 and the second motor 203 is adjusted while the rotating mechanism is in rotation, so that the relative position of the first rotating component 100 and the second rotating component 200 is adjusted to a preset calibration phase.

[0068] The step of adjusting the relative speed to achieve the preset calibration phase while maintaining rotation during non-processing is used to realize the dynamic switching from process operation mode to online detection mode. By changing the relative phase of the first rotating component 100 and the second rotating component 200 through the speed difference of the first motor 103 and the second motor 203, the phase reconstruction can be completed using the gap time such as wafer transfer without stopping the rotating mechanism. This avoids the production interruption, time loss and impact on mechanical transmission components caused by frequent equipment start-stop in traditional detection methods, thereby significantly improving the operating efficiency and capacity of the equipment.

[0069] It should be noted that the non-processing period refers to the workpiece transfer time from the completion of processing one wafer to the transfer of the next wafer to the processing position.

[0070] The controller 300 sends varying control signals to the servo drivers of the first motor 103 and the second motor 203 to control the relative speed between the first motor 103 and the second motor 203.

[0071] As an example, at the end of the process, the angle between the first reflector 102 on the first rotating component 100 and the second reflector 202 on the second rotating component 200 is 90 degrees, while the preset calibration phase is a state where the angle between the first reflector and the second reflector is 0 degrees. The controller 300 changes the rotational speed relationship between the first motor 103 and the second motor 203. For example, it keeps the speed of the first motor 103 constant and increases the speed of the second motor 203 until the controller 300 calculates that the encoder of the second motor rotates 90 degrees relative to the encoder of the first motor, so that the angle between the first reflector 102 and the second reflector 202 is 0. It should be noted that throughout the entire adjustment process, the first rotating component 100 and the second rotating component 200 continue to rotate without stopping.

[0072] refer to Figure 1 In step S4, during operation with the calibrated phase, the first rotating component 100 and the second rotating component 200 operate with the same preset process settings. When the position sensor detects that the corresponding marker feature has reached the predetermined detection position and is triggered, the angular position data of the encoder of the first motor 103 and the encoder of the second motor 203 are used as the second position data.

[0073] In the step of acquiring the second position data during operation with the calibrated phase, the angular position data of the encoder of the first motor 103 and the encoder of the second motor 203 are synchronously locked and read at the moment the position sensor is triggered by the high-speed scanning of the controller 300.

[0074] It should be noted that after the calibration phase is reached, the controller 300 instructs the first motor 103 and the second motor 203 to operate with the same preset process settings as during the process, and the operating parameters are completely consistent with those when the first position data is initially acquired. For example, the first rotating component 100 operates at the same revolution speed as "during the process", and the second rotating component 200 operates at the same rotation speed as "during the process".

[0075] During the process of performing the same preset process settings as during the process processing, when the angle between the first reflector 102 and the second reflector 202 is 0 degrees, the first reflector 102 passes through its corresponding detection area, and the second reflector 202 passes through its corresponding detection area. Both reflect light to their respective sensors to generate trigger signals and send them to the controller 300. The controller 300 triggers the first position sensor 101 and the second position sensor 201 to collect the instantaneous angular position data of the encoder of the first motor 103 and the encoder of the second motor 203 as the second position data based on the trigger signal.

[0076] When the position sensor detects that the corresponding marker feature passes through its detection area, the first rotating component 100 and the second rotating component 200 rotate, and the first reflector 102 passes through the detection area of ​​the first position sensor 101, and the second reflector 202 passes through the detection area of ​​the second position sensor 201.

[0077] The process of the first rotating component 100 and the second rotating component 200 rotating and causing their respective reflectors to pass through the detection areas of the corresponding position sensors, such that the first reflector 102 and the second reflector 202 pass through their respective detection areas at the same time and the included angle between the first reflector 102 and the second reflector 202 is 0 degrees, will trigger the controller 300 to acquire the angular position data of the encoder of the first motor 103 and the encoder of the second motor 203, so that the acquired position data can truly reflect the mechanical transmission characteristics of the rotating mechanism under dynamic operation.

[0078] When the first rotating component 100 and the second rotating component 200 rotate, the first reflector 102 and the second reflector 202 follow suit, performing circular motion. When the reflective surface of either reflector enters the beam detection range of its corresponding position sensor, the intensity of the reflected light received by the position sensor changes, causing the output state of its internal circuit to flip, thereby generating a trigger signal. When the first reflector 102 and the second reflector 202 simultaneously pass through the detection area of ​​their respective sensors during rotation, and the included angle is 0 degrees, two nearly synchronous trigger signals are generated, facilitating the controller 300 to collect the instantaneous angular position data of the encoders of the first motor 103 and the second motor as the second position data.

[0079] refer to Figure 1Step S5: Calculate the deviation between the second position data and the first position data, and determine whether there is a transmission error in the rotating mechanism based on the deviation value.

[0080] By performing a difference calculation between the second position data acquired during calibration phase operation and the first position data acquired during process processing, it is found that the motion state of the rotating mechanism is the same when the first position data and the second position data are acquired successively. This can determine the cumulative position drift of the rotating mechanism caused by factors such as belt slippage, loosening, or wear during operation. By comparing the deviation value between the second position data and the first position data, the abstract mechanical state is transformed into a measurable numerical index, thereby realizing real-time diagnosis of the flexible transmission between the first motor 103, the second motor 203 and the first rotating component 100 and the second rotating component 200, which is beneficial for timely detection and location of problems in the transmission chain.

[0081] The first position data is the angular position data of the first motor 103 encoder and the second motor 203 encoder, collected and stored under preset process settings before system initialization or process start. The second position data is the angular position data of the first motor 103 encoder and the second motor 203 encoder, collected under the same preset process settings after phase calibration during non-processing periods.

[0082] In calculating the deviation between the second position data and the first position data, the controller 300 calculates the first and second position data of the first motor, and the first and second position data of the second motor. For example, the deviation of the first motor 103 is calculated to be equal to the phase angle φ of the first motor 103 in the second position data. 12 Subtract the first motor 103φ from the first position data 11 Phase angle; the deviation of the second motor 203 is calculated to be equal to the phase angle φ of the second motor 203 in the second position data. 22 Subtract the phase angle φ of the second motor from the first position data (203). 21 .

[0083] refer to Figure 1 and Figure 4 The steps for determining whether there is a transmission error in the rotating mechanism based on the deviation value include: comparing the deviation value with the preset alarm deviation limit value issued by the host computer 400; step S51, when the deviation value is greater than the alarm deviation limit value, executing an alarm and controlling the rotating mechanism to stop or issuing a maintenance command.

[0084] The deviation value is compared with the alarm deviation limit, and an alarm or shutdown is triggered when the limit is exceeded. The current transmission error is determined to be within the safe range allowed by the semiconductor process based on the threshold set by the host computer (400). When the deviation value exceeds the alarm deviation limit, the production process is immediately stopped and maintenance is prompted, thereby preventing abnormal plasma distribution due to magnet position deviation, avoiding the production of defective wafers, and ensuring the consistency of the physical vapor deposition process.

[0085] As an example, the host computer 400 sets one or more "alarm deviation limits," such as warning limits and alarm limits, based on process accuracy requirements and equipment health status. During operation, the host computer 400 sends the set alarm deviation limits to the controller 300 (PLC) via an industrial bus (such as EtherCAT).

[0086] After the controller 300 calculates the deviation value, it immediately performs a comparison operation, comparing the deviation value with the stored alarm deviation limit. When the deviation value exceeds the alarm deviation limit, the controller 300 determines that an unacceptable transmission error has occurred and executes a preset fault handling procedure. For example, it may trigger an alarm by illuminating the alarm light and triggering the buzzer via the I / O module, and displaying an alarm message on the host computer 400 interface. Alternatively, it may send an emergency stop or safety stop command to the servo drivers of the first motor 103 and the second motor 203 to stop the rotating mechanism; or it may record detailed maintenance information such as time and deviation value in the system log of the host computer 400 and mark the equipment status as "requires maintenance," prompting the operator to check the tension of the flexible transmission components or mechanical connections.

[0087] In addition, the controller 300 uploads alarm status and real-time data to the host computer 400 for monitoring and subsequent fault analysis.

[0088] refer to Figure 1 and Figure 5 In step S52, when the deviation value does not exceed the alarm deviation limit, the angular position data of the encoder of the first motor 103 and the encoder of the second motor 203 are adjusted so that the relative position of the first rotating component 100 and the second rotating component 200 is adjusted to the phase required by the process.

[0089] When the deviation value does not exceed the limit, the relative position is restored to the phase required by the process, so that the detection process can be seamlessly connected with the subsequent process. After online monitoring, the next wafer can be processed immediately, reducing the impact of auxiliary time on production and helping to maintain the efficient and continuous operation of the production line.

[0090] Once the deviation value has not exceeded the alarm deviation limit, the controller 300 automatically executes the phase recovery procedure before receiving the instruction that the next process cycle is about to begin. The phase recovery is dynamically completed while the first rotating component 100 and the second rotating component 200 are continuously rotating, avoiding the mechanical shock and time loss caused by start-stop.

[0091] The controller 300 fine-tunes the speeds of the first motor 103 and the second motor 203 again based on the stored phase values ​​required for the next process.

[0092] As an example, if the calibration phase recovers from 0 degrees to the process phase of 45 degrees, the controller 300 can increase the speed of one motor or decrease the speed of another motor, while monitoring the position difference between the encoders of the first motor 103 and the second motor 203 in real time. When the position difference reaches 45 degrees, the first rotating component 100 and the second rotating component 200 operate stably with the relative phase relationship and speed required by the process, ready to receive the instruction to start processing the next wafer, thus achieving a seamless connection after "flying inspection".

[0093] refer to Figure 6This invention also provides a rotating mechanism control system for implementing a position error monitoring method for a rotating mechanism, comprising: a first motor 103 and a second motor 203, respectively used to drive a first rotating component 100 and a second rotating component 200; a first position sensor 101 and a second position sensor 201, respectively used to detect marking features fixed on the first rotating component 100 and the second rotating component 200, wherein the first position sensor 101 and the second position sensor 201 directly monitor the physical positions of the first rotating component 100 and the second rotating component 200, thereby forming a closed-loop monitoring of the mechanical transmission chain from the first motor 103 to the first rotating component and from the second motor 203 to the second rotating component; and a controller 300, communicatively connected to the first motor 103, the second motor 203, the first position sensor 101, and the second position sensor 201. 0 is configured to: send control signals to the first motor 103 and the second motor 203 to maintain process speed or adjust phase; perform logical operations, including: acquiring encoder position data fed back by the first motor 103 and the second motor 203 in real time; when receiving trigger signals from the first position sensor 101 and the second position sensor 201, synchronously locking and recording the encoder position data of the first motor 103 and the second motor 203 at this moment, respectively as the first position data and the second position data; comparing the calculated deviation value between the first position data and the second position data with the alarm deviation limit to determine whether there is a transmission error; and also includes: a host computer 400, which is bidirectionally connected to the controller 300, and the host computer 400 is used to send alarm deviation limits to the controller 300 and receive real-time position data or alarm status uploaded by the controller 300.

[0094] The rotating mechanism control system provided in this embodiment of the invention includes a first motor 103 and a second motor 203, as well as a first position sensor 101 and a second position sensor 201 for detecting marking features on the first rotating component 100 and the second rotating component 200, respectively. The controller 300 is configured to perform a logical operation: upon receiving a trigger signal from the first position sensor 101 and the second position sensor 201, synchronously lock and record the encoder position data of the first motor 103 and the encoder position data of the second motor 203 at that moment. Therefore, the first position sensor 101 and the second position sensor 201 directly monitor the physical positions of the first rotating component 100 and the second rotating component 200. Combined with the synchronization locking logic of the controller 300, a closed-loop monitoring system for the mechanical transmission chain in the rotating mechanism is formed between the motor drive end and the load output end. This system can capture and quantify whether there are gaps or errors in the mechanical transmission chain, overcoming the defect of traditional semi-closed-loop control that cannot perceive the true state of the load end. In addition, the controller 300 is used to compare the deviation value with the alarm deviation limit value issued by the host computer 400, so that the system can automatically determine whether the transmission error exceeds the standard according to the set threshold, realizing the automation and intelligence of fault diagnosis, thereby improving the reliability and safety of the entire rotating mechanism control system.

[0095] As the core hub of the entire control system, the controller 300 sends control signals to the first motor 103 and the second motor 203 to maintain or adjust the process speed and relative phase of the rotating components. Simultaneously, the controller 300 is also configured to perform core logic operations. These operations acquire motor encoder position data in real time and, upon receiving physical position trigger signals from the first position sensor 101 and the second position sensor 201, synchronously lock and record the current motor encoder position data. This establishes a closed-loop monitoring link between the motor drive end and the load output end, directly reflecting potential position deviations introduced by flexible transmission components such as belts. Furthermore, by comparing position data collected at different times to calculate the deviation value and comparing it with preset alarm deviation limits, the controller can automatically determine whether the transmission system has errors exceeding the allowable range. This facilitates real-time dynamic monitoring and automated fault diagnosis of the rotating mechanism's health status, ensuring consistency and yield in process handling.

[0096] Specifically, the controller 300 includes a Beckhoff PLC. The scanning cycle of the controller 300 is less than 1 millisecond. The controller 300 is connected to the servo drivers of the first motor 103 and the second motor 203, as well as the first position sensor 101 and the second position sensor 201, via a high-speed industrial bus (e.g., EtherCAT). This allows the controller 300 to accurately capture the instant of the sensor trigger signal and obtain the position readings of the encoders of the first motor 103 and the second motor 203 in high-speed rotation.

[0097] When performing logical operations, the controller 300 works in conjunction with the first motor 103, the second motor 203, the first position sensor 101, and the second position sensor 201. The specific steps are as follows:

[0098] During the process, the controller 300 maintains the first motor 103 and the second motor 203 running at a preset process speed. When the first position sensor 101 detects a marking feature (such as the first reflector 102) on the first rotating component 100 and the second position sensor 201 detects a marking feature (such as the second reflector 202) on the second rotating component 200, the sensors generate trigger signals respectively. Upon receiving these trigger signals, the controller 300 synchronously locks and records the encoder angular position data fed back by the first motor 103 and the second motor 203 at that moment, storing it in memory as first position data.

[0099] During non-processing periods (such as wafer transfer time in PVD processes), the controller 300 actively adjusts the relative speeds of the first motor 103 and the second motor 203, dynamically adjusting the relative positions of the first rotating component 100 and the second rotating component 200 from the process phase to a preset calibration phase. For example, the angle between the first reflector 102 and the second reflector 202 is set to zero degrees.

[0100] During stable operation with calibrated phase, the controller 300 obtains the trigger signals of the first position sensor 101 and the second position sensor 201, and records the position data of the encoder of the first motor 103 and the encoder of the second motor 203 at the moment of triggering as the second position data.

[0101] The controller 300 compares the second position data with the stored first position data to determine the deviation between the two positions. Then, it compares the deviation value with an alarm deviation limit received from the host computer 400. If the deviation value exceeds the limit, a transmission error is detected, and the controller 300 issues an alarm and stops the rotating mechanism or issues a maintenance command. If the deviation value is within the limit, the controller 300 restores the relative positions of the two rotating components to the required phase before the start of the next process cycle.

[0102] The host computer 400 and the controller 300 establish a bidirectional communication connection to control the rotating mechanism. Specifically, the host computer 400 sends process parameters, such as alarm deviation limits, to the controller 300, providing a benchmark for the controller 300 to perform transmission error judgment. The host computer 400 also receives real-time data uploaded by the controller 300, such as real-time position data or alarm status information of the first motor 103 and the second motor 203, thereby enabling it to display the system's operating status and potential fault warnings to the operator.

[0103] As an example, the host computer 400 includes an industrial personal computer or workstation with dedicated monitoring software installed, and the host computer 400 includes a graphical user interface (GUI) for interacting with operators.

[0104] In terms of communication with the controller 300, the host computer 400 is used to transmit alarm deviation limits to the controller 300. These limits are sent via the communication link and stored in the controller 300, serving as the basis for the controller 300 to determine whether the transmission error exceeds the limit. The host computer 400 is also used to send process parameters to the controller 300, such as the rotational speed and relative phase angle that the first rotating component 100 and the second rotating component 200 need to maintain during the process.

[0105] In terms of upward communication, the host computer 400 is used to receive position data from the encoders of the first motor 103 and the second motor 203. The host computer 400 is also used to generate an alarm status signal and upload it to the host computer 400 when the deviation value calculated by the controller 300 exceeds the alarm deviation limit issued by the host computer 400. Upon receiving the signal, the host computer 400 will immediately trigger an alarm response, such as popping up a prominent alarm window on the screen, issuing an audible alarm, or recording an alarm log.

[0106] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method of position error monitoring of a rotary mechanism, the rotary mechanism comprising: a first rotating component driven by a first motor; a second rotating component eccentrically arranged on the first rotating component, the second rotating component being driven by a second motor, and the first rotating component and the second rotating component each being provided with a mark feature capable of being detected by a corresponding position sensor; the position error monitoring method comprises the following steps: the mark feature comprises a first reflective plate arranged on the first rotating component and a second reflective plate arranged on the second rotating component, and a permanent magnet is arranged on the second rotating component at a position corresponding to the second reflective plate, the second reflective plate and the permanent magnet being arranged on opposite surfaces of the second rotating component respectively; during operation of the rotating mechanism, the position sensor is stationary, and the position sensor comprises a first position sensor and a second position sensor, the first position sensor being used to detect the first reflective plate, and the second position sensor being used to detect the second reflective plate; during process treatment, the first rotating component and the second rotating component are operated at a preset process setting, and when the position sensor is triggered by the corresponding mark feature reaching a predetermined detection position, the angular position data of the encoder of the first motor and the encoder of the second motor are taken as first position data; during non-process treatment, the relative speed between the first motor and the second motor is adjusted under the rotating state of the rotating mechanism, so that the relative position of the first rotating component and the second rotating component is adjusted to a preset calibration phase; the preset calibration phase is a state in which the included angle between the first reflective plate and the second reflective plate is 0 degrees; when the position sensor is triggered by the corresponding mark feature reaching a predetermined detection position, the included angle between the first reflective plate and the second reflective plate is 0 degrees; during operation at the calibration phase, the first rotating component and the second rotating component are operated at the same preset process setting, and when the position sensor is triggered by the corresponding mark feature reaching a predetermined detection position, the angular position data of the encoder of the first motor and the encoder of the second motor are taken as second position data; the deviation value between the second position data and the first position data is calculated, and whether the rotating mechanism has a transmission error is judged according to the deviation value.

2. The method of claim 1, wherein the first motor drives the first rotating component through a first flexible transmission component, and the second motor drives the second rotating component through a second flexible transmission component; the first flexible transmission component and the second flexible transmission component each comprise a belt; the first rotating component comprises a first rotating disc, and the second rotating component comprises a second rotating disc, and a permanent magnet is arranged on the second rotating disc, the permanent magnet being used to modulate plasma distribution.

3. The method of claim 1, wherein the step of judging whether the rotating mechanism has a transmission error according to the deviation value comprises: comparing the deviation value with a preset alarm deviation limit value; when the deviation value is greater than the alarm deviation limit value, an alarm is executed and the rotating mechanism is controlled to stop or a maintenance instruction is issued; When the deviation value does not exceed the alarm deviation limit value, the angular position data of the encoders of the first motor and the second motor are adjusted, so that the relative positions of the first rotating part and the second rotating part are adjusted to the required phase of the process.

4. The method of claim 1, wherein The position sensor comprises a diffuse reflective photoelectric sensor.

5. The method of claim 1, wherein When the position sensors are triggered by detecting that the corresponding mark features reach the predetermined detection positions, the first rotating part and the second rotating part rotate, and the first reflective plate passes through the detection area of the first position sensor, and the second reflective plate passes through the detection area of the second position sensor.

6. The method of claim 1, wherein The position error monitoring method of the rotating mechanism further comprises: before acquiring the first position data, performing a home operation on the first rotating part and the second rotating part to establish a mechanical zero point. The home operation comprises: first controlling the first rotating part to move to a preset zero point position of the first rotating part, and then controlling the second rotating part to move to a preset zero point position of the second rotating part after the first rotating part stops.

7. A rotary mechanism control system for implementing the method of any one of claims 1 to 6, characterized by The rotating mechanism comprises: a first motor and a second motor for driving the first rotating part and the second rotating part, respectively; a first position sensor and a second position sensor for detecting mark features fixed on the first rotating part and the second rotating part, respectively, the first position sensor and the second position sensor directly monitoring the physical positions of the first rotating part and the second rotating part, thereby constituting a closed-loop monitoring of the mechanical transmission chain from the first motor to the first rotating part and from the second motor to the second rotating part; a controller in communication connection with the first motor, the second motor, the first position sensor and the second position sensor; the controller is configured to issue control signals to the first motor and the second motor for maintaining a process speed or adjusting a phase; performing a logical operation, which comprises: acquiring encoder position data fed back by the first motor and the second motor in real time, when a trigger signal of the first position sensor and the second position sensor is received, synchronously locking and recording the first motor encoder position data and the second motor encoder position data at this moment as the first position data and the second position data, respectively; comparing a deviation value between the calculated first position data and second position data with an alarm deviation limit value to determine whether there is a transmission error; The rotating mechanism control system further comprises: an upper computer in bidirectional communication connection with the controller, the upper computer being configured to issue the alarm deviation limit value to the controller and receive real-time position data or alarm states uploaded by the controller.

8. The rotary mechanism control system of claim 7, wherein, The controller comprises a programmable logic controller with a scanning period less than 1 millisecond.

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