Positioning device for wafer measurement driving mechanism

Abstract

The utility model relates to a positioning device used for a wafer measurement driving mechanism, the positioning device is installed at a positioning station of the wafer measurement driving mechanism, the positioning device comprises a center positioning module, a rotation phase positioning module and a code identification module, the center positioning module comprises two clamping arms and a clamping arm driving assembly, the clamping claws located on the two clamping arms abut against the edge of the wafer respectively, the wafer abutting portions, abutting against the edge of the wafer, of the clamping claws are always located on the circumference with the fixed circle center position and the same radius, the circle center position is located on a rotating shaft of a rotary table module of the wafer measurement driving mechanism in the positioning station state, and the wafer center positioning precision is improved. Meanwhile, the rotating phase positioning module and the code identification module which are arranged above the central positioning module are driven by the same radial driving equipment to move to proper radius positions, and are used for detecting and identifying directional nicks and codes at the edge of the wafer respectively, so that the number of times that the wafer needs to be transferred between different stations is reduced, and the working efficiency is improved. The measurement process is simplified, and the measurement time is saved.

Description

Technical Field

[0001] This utility model relates to the field of wafer measurement technology, and specifically to a positioning device for a wafer measurement driving mechanism. Background Technology

[0002] One current wafer surface measurement technology involves using laser scanning to scan a high-speed rotating wafer. A light-collecting device gathers reflected light (spectral or diffuse reflection) from the wafer surface, and defect detection or dimensional measurement is performed based on the collected reflected light. Typically, a robotic arm or other transport system transfers the wafer from the wafer cassette to a pre-alignment station. At the pre-alignment station, wafer centering and rotational phase positioning are performed. Rotational phase positioning is achieved by detecting directional markings on the wafer edges, such as notches or flat edges. After wafer centering and rotational phase positioning are completed, the robotic arm transfers the wafer to a wafer measurement drive mechanism located at the measurement station. The wafer measurement drive mechanism then drives the wafer to complete the measurement process.

[0003] However, due to the limitations of the pre-aligner and the robotic arm's own precision, a certain error still exists between the wafer's center and the turntable center of the measurement drive mechanism, affecting the coordinate positioning of wafer defects or critical dimensions. Furthermore, the aforementioned wafer transfer process requires the robotic arm to perform two transfers: from the wafer cassette to the pre-alignment station, and then from the pre-alignment station to the measurement station, making the measurement process cumbersome. Additionally, each wafer is affixed with a code to record wafer information; existing wafer measurement equipment requires a separate barcode scanning station to install barcode scanning equipment, resulting in a redundant structure and increased measurement time.

[0004] Therefore, improving wafer center positioning accuracy while simplifying measurement processes are technical problems that need to be solved in this field. Utility Model Content

[0005] To address the aforementioned technical problems, this utility model proposes a positioning device for a wafer measurement driving mechanism. This positioning device is installed at the positioning station of the wafer measurement driving mechanism and integrates a center positioning module, a rotation phase positioning module, and an encoding and recognition module. Wafer positioning and encoding and recognition operations can be completed at the positioning station of the wafer measurement driving mechanism, thereby improving wafer positioning accuracy and simplifying the measurement process.

[0006] To achieve the above objectives, the positioning device for the wafer metrology driving mechanism of this utility model includes a mounting plate, a center positioning module, a rotation phase positioning module, and an encoding and recognition module; wherein, the center positioning module, the rotation phase positioning module, and the encoding and recognition module are mounted on the mounting plate, and the mounting plate is fixed on the wafer metrology equipment frame.

[0007] The center positioning module includes two gripper arms and a gripper arm drive assembly. The overall structure of the gripper arm drive assembly and the gripper arms adopts a commonly used clamping device in the art, such as an electronic gripper. The gripper arm drive assembly is mounted on a mounting plate, and the two gripper arms are mounted on the gripper arm drive assembly. Driven by the gripper arm drive assembly, the two gripper arms move towards or in opposite directions in a plane parallel to the wafer surface. The grippers on the two gripper arms abut against the edge of the wafer to center the wafer. The wafer abutment portion where the grippers abut against the wafer edge is always located on a circle of the same radius with a fixed center position, allowing the grippers to clamp wafers of different sizes and ensuring that the wafer center is located at a predetermined position. This predetermined position is located on the rotation axis of the turntable module of the wafer measurement drive mechanism in the positioning station state. Wafer center positioning is completed at the positioning station of the wafer measurement drive mechanism. Then, the turntable module of the wafer measurement drive mechanism carries the wafer to complete rotational phase positioning and encoding recognition. Finally, the turntable module carries the wafer to the measurement station of the wafer measurement drive mechanism to complete the wafer measurement work. The wafer measurement drive mechanism described in this article is a commonly used drive component in the wafer measurement field. It typically includes a translation drive module, a vertical displacement drive module, and a turntable module. The translation drive module is mounted on the wafer measurement equipment rack, and the vertical displacement drive module is mounted on the translation drive module. The translation drive module realizes the translation of the wafer during wafer measurement and is also used in this article to switch between the positioning station and the measurement station of the wafer measurement drive mechanism. The turntable module is mounted on the vertical displacement drive module and moves up and down under the drive of the vertical displacement drive module to load and unload wafers from the center positioning module.

[0008] The aforementioned rotating phase positioning module and encoding recognition module are positioned above the central positioning module to detect and recognize the directional markings and codes on the wafer edge from above. The rotating phase positioning module and encoding recognition module employ commonly used detection and recognition devices in the art, such as a line laser reflector for the rotating phase positioning module and a visual barcode reader for the encoding recognition module. To accommodate wafers of different sizes, the rotating phase positioning module and encoding recognition module can move radially along the wafer to detect and recognize directional markings and codes at different radii. To simplify the driving structure, the rotating phase positioning module and encoding recognition module use the same radial driving device. Codes are generally located at the wafer edge, as are directional markings. The radial driving device can simultaneously drive the rotating phase positioning module and encoding recognition module to move radially outward or inward along the wafer edge. This design simplifies the driving structure and reduces equipment adjustment time during detection and recognition. Even if the radial driving device cannot simultaneously move the rotating phase positioning module and encoding recognition module into position, only minor adjustments are needed after one process is completed before proceeding to the next process. Compared to existing technologies, this still saves time on wafer transfer and equipment adjustment. The technical effects of this invention are:

[0009] This invention's wafer measurement drive mechanism uses a center positioning module in its positioning device to position the wafer center on the rotation axis of the turntable module in the positioning station state, thus eliminating positioning errors caused by pre-aligners and robotic arms in existing technologies. Simultaneously, the rotating phase positioning module and the encoding recognition module, arranged above the center positioning module, move to a suitable radius position under the drive of the same radial drive device, respectively detecting and recognizing orientation marks and codes located on the wafer edge. This reduces the number of times the wafer needs to be transferred between different stations, simplifies the measurement process, and saves measurement time. Attached Figure Description

[0010] Figure 1 This is a structural diagram of the usage environment of the positioning device.

[0011] Figure 2 This is a structural diagram of the positioning device.

[0012] Figure 3 This is another view of the positioning device structure.

[0013] Figure 4 This is a structural diagram of the central positioning module.

[0014] Figure 5 This is a structural diagram of the housing and translation adjustment assembly.

[0015] Figure 6 This is a cross-sectional view of the fine-tuning mechanism and the clamping arm. Detailed Implementation

[0016] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0017] See Figure 1-6A positioning device for a wafer metrology driving mechanism is installed on the wafer metrology equipment rack 1, located at the positioning station of the wafer metrology driving mechanism 2. It includes a mounting plate 3, a center positioning module 4, a rotational phase positioning module 5, and an encoding and recognition module 6. The center positioning module 4, the rotational phase positioning module 5, and the encoding and recognition module 6 are mounted on the mounting plate 3, which is fixed to the wafer metrology equipment rack 1. The wafer measurement drive mechanism 2 is a commonly used drive component in the wafer measurement field. It includes a translation drive module 2-1, a vertical displacement drive module 2-2, and a turntable module 2-3. The translation drive module 2-1 is mounted on the wafer measurement equipment frame 1, and the vertical displacement drive module 2-2 is mounted on the translation drive module 2-1. The translation drive module 2-1 realizes the translation of the wafer during wafer measurement. The turntable module 2-3 is mounted on the vertical displacement drive module 2-2, and the turntable module 2-3 moves up and down under the drive of the vertical displacement drive module 2-2 to load and unload the wafer from the wafer placement position. In this embodiment, the wafer placement position is the center positioning module 4. The wafer placement position is the positioning station of the wafer measurement drive mechanism 2, and the positioning device is arranged at the positioning station of the wafer measurement drive mechanism 2.

[0018] The center positioning module 4 includes two gripper arms 4-1 and a gripper arm drive assembly 4-2. The gripper arm drive assembly 4-2 is mounted on the bottom surface of the mounting plate 3. The gripper arm drive assembly 4-2 drives the two gripper arms 4-1 to move towards or in opposite directions in a plane parallel to the wafer surface. The overall structure of the gripper arm drive assembly 4-2 and the gripper arms 4-1 adopts an electronic gripper. Electronic grippers are gripping devices well known to those skilled in the art, and their specific structure will not be described in detail here. Each of the two gripper arms 4-1 is provided with two grippers, each gripper including a wafer support part 4-11 and a wafer abutment part 4-12. The bottom surface of the wafer is supported on the wafer support part 4-11, and the wafer abutment part 4-12 abuts against the edge of the wafer. Four wafer abutment parts 4-12 are located on a circle of the same radius with the center fixed. The four wafer abutment parts 4-12 abut against the edge of the wafer under the drive of the chuck drive assembly 4-2 to position the wafer center. The predetermined position of the wafer center is located on the rotation axis of the turntable module 2-3 of the wafer measurement drive mechanism 2 in the positioning station state.

[0019] For wafers of different sizes, although the clamping arm drive assembly 4-2 can drive the clamping arm 4-1 to move to the appropriate position for clamping, in order to avoid the clamping arm 4-1 moving too far and taking too long, such as when switching between 6-inch, 8-inch and 12-inch wafers, it is preferable to set multiple sets of wafer support parts 4-11 and wafer abutment parts 4-12 on each clamping arm 4-1. The multiple sets of wafer abutment parts 4-12 on each clamping arm 4-1 are located on concentric circles of different radii and are arranged in a stepped manner in the vertical direction to avoid interference.

[0020] The rotating phase positioning module 5 and the encoding recognition module 6 are positioned above the central positioning module 4 to detect and recognize the directional markings and codes on the wafer edge from above. The rotating phase positioning module 5 uses a line laser reflector, and the encoding recognition module 6 uses a visual code reader. The radial drive device 7 simultaneously drives the rotating phase positioning module 5 and the encoding recognition module 6 to move radially outward or inward along the wafer. The radial drive device 7 uses commonly used linear drive devices in the industry, such as linear motors, electric actuators, hydraulic cylinders, and pneumatic cylinders. The electric actuator uses a ball screw, trapezoidal screw, or rack and pinion mechanism. The radial drive device 7 directly drives or drives the rotating phase positioning module 5 and the encoding recognition module 6 to move radially along the wafer, either directly or through a connecting rod. Alternatively, the radial drive device 7 can use commonly used rotary drive devices in the industry, such as rotary motors. A turntable is connected to the output shaft of the rotary motor, and the turntable drives the rotating phase positioning module 5 and the encoding recognition module 6 to move radially along the wafer through a connecting rod.

[0021] In this embodiment, the radial drive device 7 is a linear drive device. The radial drive device 7 is mounted on the top surface of the mounting plate 3 via a bracket 8. The drive portion of the radial drive device 7 is fixed to the bracket 8, and the moving portion of the radial drive device 7 is connected to an encoding identification module 6 and a rotational phase positioning module 5. The encoding identification module 6 is directly fixed to the moving portion of the radial drive device 7, and the moving portion of the radial drive device 7 directly drives the encoding identification module 6 to move radially along the wafer. A second bracket 9 is also provided on the top surface of the mounting plate 3. The rotational phase positioning module 5 is slidably connected to the second bracket 9 via a slide rail 10. The slide rail 10 guides the rotational phase positioning module 5 to move radially along the wafer. The slide rail 10 includes a guide rail fixed to the second bracket 9 and a slider fixed to the rotational phase positioning module 5. A radial traction assembly 11 is provided between the moving part of the radial drive device 7 and the rotary phase positioning module 5. The radial traction assembly 11 includes a guide post 11-1 fixed on the moving part of the radial drive device 7 and a traction rod 11-2 fixed on the rotary phase positioning module 5. The traction rod 11-2 has a guide groove 11-21, and the guide post 11-1 is embedded in the guide groove 11-21 and slides within the guide groove 11-21. The radial drive device 7 drives the guide post 11-1 to move radially along the wafer. The guide post 11-1 slides within the guide groove 11-21 and pushes the traction rod 11-2 to translate along a plane parallel to the wafer surface, thereby driving the rotary phase positioning module 5 to move radially along the wafer.

[0022] The coding is typically located at the wafer edge, as are the orientation marks. To accommodate wafers of different sizes, the radial drive device 7 moves the coding recognition module 6 and the rotational phase positioning module 5 to the wafer edge. Preferably, the coding recognition module 6 and the rotational phase positioning module 5 arrive at the wafer edge simultaneously to reduce equipment adjustment time during detection and recognition. Therefore, the guide grooves 11-21 form an angle of 45° with the radial movement directions of the coding recognition module 6 and the rotational phase positioning module 5, ensuring that the radial displacements of the coding recognition module 6 and the rotational phase positioning module 5 are identical under the drive of the radial drive device 7.

[0023] The two clamping arms 4-1 need to ensure that the predetermined position of the wafer center is located on the rotation axis of the turntable module 2-3 of the wafer measurement drive mechanism 2 in the positioning position state. To reduce processing and installation accuracy, preferably, a fine-tuning mechanism 4-3 is provided on the clamping arms 4-1. The fine-tuning mechanism 4-3 is located between the drive rod 4-21 of the clamping arm drive assembly 4-2 and the clamping arms 4-1. The fine-tuning mechanism 4-3 includes a housing 4-31, a translation assembly 4-32, and a translation adjustment assembly 4-33. The housing 4-31 is connected to the drive rod 4-21. The housing 4-31 includes a top plate 4-311 and two side plates 4-312, which are located on adjacent sides. The translation component 4-32 adopts an XY-axis linear displacement stage commonly used in the optical industry. In this embodiment, the MiSUMi E-XYSSG series linear guide slide is selected. The specific structure is briefly described here, including two opposing translation plates and a cross plate located between the translation plates. The cross plate consists of two overlapping plates, with grooves formed on the opposing surfaces of the translation plates. The two plates of the cross plate are respectively embedded in the grooves. Linear ball guides and reset tension springs are respectively provided between the two plates of the cross plate and the two translation plates. The top of the translation component 4-32 is fixed to the bottom surface of the top plate 4-311, and the top of the clamping arm 4-1 is fixed to the bottom surface of the translation component 4-32. The translation component 4-32 can assist the clamping arm 4-1 in achieving horizontal displacement along the X and Y axes.

[0024] The translation adjustment assembly 4-33 includes two sets of tightening screw kits 4-331 and a lateral steering component 4-332, used to adjust the X and Y axis displacements of the locking arm 4-1, respectively. Two tightening screw kit mounting holes 4-313 are vertically formed in the top plate 4-311 and the two side plates 4-312. The tightening screw kits 4-331 are respectively installed in the tightening screw kit mounting holes 4-313. Each tightening screw kit 4-331 includes a threaded sleeve and a tightening screw. The threaded sleeve is embedded in the tightening screw kit mounting hole 4-313, and the tightening screw is screwed into the threaded sleeve. A transversely penetrating section is provided in the side plate 4-312 that communicates with the tightening screw kit mounting holes 4-313. A lateral steering component mounting hole 4-314 is provided, and a lateral steering component 4-332 is installed within the lateral steering component mounting hole 4-314. One end of the lateral steering component 4-332 is arc-shaped, and the end of the tightening screw abuts against the arc-shaped end of the lateral steering component 4-332. The other end of the lateral steering component 4-332 abuts against the side of the clamping arm 4-1. When the tightening screw is turned downwards, it pushes the lateral steering component 4-332 laterally, which in turn pushes the clamping arm 4-1 to move horizontally along the X and Y axes, thereby adjusting the predetermined position of the wafer center so that the predetermined position of the wafer center is located on the rotation axis of the turntable module of the wafer measurement drive mechanism 2 in the positioning position state. A transverse groove 3-1 is provided on the mounting plate 3 at the position corresponding to the tightening screw to avoid the tightening screw. The knob end of the tightening screw protrudes from the transverse groove 3-1, allowing the operator to operate from the top side of the mounting plate 3, and the transverse groove 3-1 provides lateral movement space for the tightening screw.

[0025] To ensure the stability of the movement of the housing 4-31, preferably, a guide rail 4-35 is provided between the bottom surface of the mounting plate 3 and the housing 4-31. The guide rail 4-35 guides the movement of the housing 4-31. Preferably, the guide rail 4-35 is a cross roller guide rail.

[0026] The basic principles, main features, and advantages of this utility model in the explored field have been described in detail above, and some usage examples have been detailed. Finally, it should be noted that the examples given above are only for illustrative purposes and are not intended to limit this utility model. Although we have described this utility model in detail with reference to the examples, those skilled in the art can still modify the described examples and solutions, or replace related technical parts. Therefore, any modifications or equivalent substitutions made within the spirit and principles of this utility model are within the protection scope of the claims of this utility model patent.

Claims

1. A positioning device for a wafer measurement driving mechanism, characterized in that: The system includes a mounting plate, a center positioning module, a rotating phase positioning module, an encoding and recognition module, and a radial drive device. The center positioning module, rotating phase positioning module, encoding and recognition module, and radial drive device are mounted on the mounting plate, which is fixed to the wafer metrology equipment frame. The rotating phase positioning module and the encoding and recognition module are positioned above the center positioning module. The center positioning module includes two clamping arms and a clamping arm drive assembly. The clamping arm drive assembly is mounted on the mounting plate, and the two clamping arms are mounted on the clamping arm drive assembly. Each clamping arm has a clamping jaw. The wafer contact portion of the clamping jaw abuts against the wafer edge, and the jaw is always located on a circle of the same radius with a fixed center position. The center position is located on the rotation axis of the turntable module of the wafer metrology drive mechanism in the positioning position state. The radial drive device simultaneously drives the rotating phase positioning module and the encoding and recognition module to move radially outward or inward along the wafer.

2. The positioning device for a wafer measurement driving mechanism as described in claim 1, characterized in that: The radial drive device is a linear drive device, which is mounted on the top surface of the mounting plate via a bracket. The clamping arm drive assembly of the center positioning module is mounted on the bottom surface of the mounting plate. One of the encoding recognition module or the rotation phase positioning module is fixed on the moving part of the radial drive device, and the other module is slidably connected to the bracket on the top surface of the mounting plate. The moving part of the radial drive device is connected to the other module via a radial traction assembly.

3. The positioning device for a wafer measurement driving mechanism as described in claim 2, characterized in that: The radial traction assembly includes a guide post and a traction rod. The guide post is fixed on the moving part of the radial drive device, and the traction rod is fixed on the rotary phase positioning module. A guide groove is provided on the traction rod, and the guide post is embedded in the guide groove and slides within the guide groove.

4. The positioning device for a wafer measurement driving mechanism as described in claim 3, characterized in that: The angle between the guide groove and the radial movement direction of the encoding and identification module and the rotating phase positioning module is 45°.

5. The positioning device for a wafer measurement driving mechanism as described in claim 1, characterized in that: Multiple sets of wafer support parts and wafer abutment parts are provided on the card arm. The multiple sets of wafer abutment parts are located on concentric circles of different radii and are arranged in a stepped manner in the vertical direction.

6. The positioning device for a wafer measurement driving mechanism as described in claim 1, characterized in that: A fine-tuning mechanism is provided on the clamping arm, and the fine-tuning mechanism is located between the drive rod of the clamping arm drive assembly and the clamping arm.

7. The positioning device for a wafer measurement driving mechanism as described in claim 6, characterized in that: The fine-tuning mechanism includes a housing, a translation component, and a translation adjustment component. The housing is connected to a drive rod. The housing includes a top plate and two side plates, which are located on adjacent sides. The translation component uses an XY-axis linear displacement stage. The top of the translation component is fixed to the bottom surface of the top plate, and the top of the clamping arm is fixed to the bottom surface of the translation component. The translation adjustment component is mounted on the housing.

8. The positioning device for a wafer measurement driving mechanism as described in claim 7, characterized in that: The translation adjustment assembly includes two sets of tightening screw kits and a lateral steering component. Two tightening screw kit mounting holes are vertically formed in the top plate and two side plates. Each tightening screw kit includes a threaded sleeve and a tightening screw. The threaded sleeve is fitted into the tightening screw kit mounting hole, and the tightening screw is screwed into the threaded sleeve. A lateral steering component mounting hole is provided in the side plate, communicating laterally with the tightening screw kit mounting holes. The lateral steering component is installed in the lateral steering component mounting hole. One end of the lateral steering component is arc-shaped, and the end of the tightening screw abuts against the arc-shaped end of the lateral steering component. The other end of the lateral steering component abuts against the side of the locking arm. A transverse groove is provided on the mounting plate corresponding to the position of the tightening screw.

9. The positioning device for a wafer measurement driving mechanism as described in claim 7, characterized in that: A second guide rail is provided between the bottom surface of the mounting plate and the housing.

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