Wafer fixing vision measuring instrument capable of automatically positioning

Abstract

The utility model belongs to the technical field of semiconductor manufacturing and detection, and particularly relates to an automatic positioning wafer fixing vision measuring instrument. Through integration of multi-axis motion control and a negative pressure adsorption technology, the problems of positioning deviation, insufficient data integrity and low efficiency in wafer dynamic measurement are solved. Comprising a workbench; a transverse electric translation table is arranged on the workbench, a stand column is arranged on the transverse electric translation table, and the transverse electric translation table is used for achieving movement of the stand column in the X-axis direction. A longitudinal group distance adjusting electric translation stage is arranged on one side of the upright post; a transverse lens adjusting electric translation stage is arranged on the longitudinal group distance adjusting electric translation stage; a hollow rotating table is arranged on the transverse lens adjusting electric translation table; a wafer measuring device is mounted on the hollow rotating table; the wafer measuring device is used for measuring a wafer to be measured. A four-axis rotary table is arranged on the workbench and below the wafer measuring device, a tray is installed on the four-axis rotary table, and a negative pressure generator is installed at the bottom of the tray.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor manufacturing inspection technology, and particularly relates to an automatic positioning wafer fixing visual measuring instrument; especially to an instrument for high-precision optical measurement of wafer surface morphology and quality parameters. Background Technology

[0002] The increasing precision of wafer fabrication technology places higher demands on the positioning accuracy, stability, and efficiency of measurement systems. Current wafer measurement devices primarily focus on three-dimensional topography inspection, but they lack sufficient optimization for wafer stability during dynamic measurement and for simultaneous acquisition of data from multiple locations.

[0003] For example, the patent with publication number "CN220774302U" proposes a wafer measurement mechanism that detects wafer positional anomalies by blocking the optical path, but it suffers from insufficient stability: the wafer is prone to displacement during rotation or translation, leading to measurement errors and limited efficiency; its single measurement can only acquire local data, requiring repeated position adjustments, which affects overall efficiency; light source interference: traditional light source layouts are prone to producing shadows, reducing imaging clarity and other defects.

[0004] To address the aforementioned issues, this technical solution proposes an integrated dynamic negative pressure adsorption system, an electric rotary table, and a negative pressure generator to achieve stable wafer fixation throughout the entire process; a three-axis precision motion module, employing high-precision linear modules along the X, Y, and Z axes, to achieve multi-dimensional collaborative positioning of the lens and the wafer; and optimized coaxial light source to eliminate imaging shadows and improve the signal-to-noise ratio of measurement data. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing an automatic positioning wafer-fixing vision measurement instrument. Through the integration of multi-axis motion control and negative pressure adsorption technology, it solves problems such as positioning misalignment, insufficient data integrity, and low efficiency in dynamic wafer measurement.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an automatically positioned wafer fixing vision measuring instrument, including a worktable; a transverse electric translation stage is provided on the worktable, and a column is provided on the transverse electric translation stage, the transverse electric translation stage being used to realize the movement of the column along the X-axis direction;

[0007] A longitudinal spacing adjustment electric translation stage is installed on one side of the column, and a transverse lens adjustment electric translation stage is installed on the longitudinal spacing adjustment electric translation stage, which is used to drive the transverse lens adjustment electric translation stage to adjust the displacement in the Z-axis direction.

[0008] A hollow rotary stage is provided on the horizontal lens adjustment electric translation stage, which is used to drive the hollow rotary stage to adjust its displacement in the Y-axis direction; a wafer measuring device is installed on the hollow rotary stage; the wafer measuring device is used to measure the wafer to be measured;

[0009] A four-axis turntable (i.e., an electric rotary table) is set on the worktable below the wafer measurement device. A tray is installed on the four-axis turntable, and a negative pressure generator is installed at the bottom of the tray. The tray is used to place the wafer to be tested. The negative pressure generator fixes the wafer by vacuum adsorption and is used to adsorb the wafer to be tested.

[0010] Furthermore, the horizontal electric translation stage adopts an X-axis linear motion module, the vertical group spacing adjustment electric translation stage adopts a Z-axis linear motion module, and the horizontal lens adjustment electric translation stage adopts a Y-axis linear motion module. Among them, the X-axis linear motion module, Y-axis linear motion module, and Z-axis linear motion module all adopt ball screw driven linear motion modules; and the Z-axis linear motion module is mounted on the slider of the X-axis linear motion module, and the Y-axis linear motion module is mounted on the slider of the Z-axis linear motion module.

[0011] Furthermore, the tray adopts a ring structure with holes that are connected to a negative pressure generator to create an adsorption force on the wafer.

[0012] Furthermore, the hollow rotary table includes a rotary table body, one side of which is connected to the input shaft of motor one. Motor one is mounted on the slider of the Y-axis linear motion module. When motor one rotates, it drives the rotary table body to rotate.

[0013] Furthermore, the other side of the rotary table body is connected to the wafer measurement device.

[0014] Compared with the prior art, this utility model has the following advantages.

[0015] This invention provides an automatic positioning wafer fixing vision measurement instrument, which solves the problems of positioning offset and low efficiency in wafer dynamic measurement by integrating multi-axis motion control and negative pressure adsorption technology. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the following description.

[0017] Figure 1 This is a schematic diagram of a planar detection structure.

[0018] Figure 2 This is a schematic diagram showing the connection between the Y-axis and Z-axis on the column.

[0019] Figure 3 This is a cross-sectional schematic diagram of a hollow rotary table.

[0020] Figure 4 This is a schematic diagram of the horizontal X-axis movement module structure.

[0021] Figure 5 This is a schematic diagram of the installation cross-section of the negative pressure generator.

[0022] Figure 6 This is a schematic diagram of the measuring device.

[0023] Figure 7 This is a schematic diagram of the measuring device structure for multi-faceted measurements.

[0024] In the diagram, 1 is a horizontal electric translation stage, 101 is a motor, 102 is the track of the X-axis motion module, 103 is a slider, and 2 is a column;

[0025] 3. Longitudinal object distance adjustment electric translation stage, 301 motor, 302 Z-axis motion module track, 303 slider;

[0026] 4. Horizontal lens adjustment electric translation stage, 401 motor, 402 track of Y-axis motion module, 403 slider;

[0027] 5. Hollow rotary table; 501. Induction device; 502. Input shaft; 503. Output shaft;

[0028] 6. Measuring device; 601. Aperture; 602. Lens bracket; 603. Lens; 604. Light source mounting plate;

[0029] 7. Tray, 8. Negative pressure generator, 801. Air inlet, 802. Air outlet;

[0030] 9. Four-axis rotary table, 10. Marble worktable, 11. Connecting plate. Detailed Implementation

[0031] To make the objectives, technical solutions, and beneficial effects of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0032] like Figure 1-7 As shown in the specific embodiment: an automatically positioned wafer fixing vision measuring instrument includes a worktable; a transverse electric translation stage 1 is provided on the worktable 10, and a column 2 is provided on the transverse electric translation stage 1. The transverse electric translation stage 1 is used to realize the movement of the column along the X-axis direction.

[0033] A longitudinal spacing adjustment electric translation stage 3 is provided on one side of the column 2. A transverse lens adjustment electric translation stage 4 is provided on the longitudinal spacing adjustment electric translation stage 3, which is used to drive the transverse lens adjustment electric translation stage 4 to adjust the displacement in the Z-axis direction.

[0034] A hollow rotary stage 5 is provided on the horizontal lens adjustment electric translation stage 4, which is used to drive the hollow rotary stage 5 to adjust its displacement in the Y-axis direction; a wafer measuring device 6 is installed on the hollow rotary stage 5; the wafer measuring device 6 is used to measure the wafer to be measured.

[0035] A four-axis turntable 9 (i.e., an electric rotary table) is set on the worktable 10 and below the wafer measuring device 6. A tray 7 is installed on the four-axis turntable 9, and a negative pressure generator 8 is installed at the bottom of the tray 7. The tray 7 is used to place the wafer to be tested, and the negative pressure generator 8 is used to adsorb the wafer to be tested.

[0036] Preferably, the transverse electric translation stage 1 adopts an X-axis linear motion module, the longitudinal group spacing adjustment electric translation stage 3 adopts a Z-axis linear motion module, and the transverse lens adjustment electric translation stage 4 adopts a Y-axis linear motion module. The X-axis, Y-axis, and Z-axis linear motion modules are all ball screw driven linear motion modules; the Z-axis linear motion module is mounted on the slider of the X-axis linear motion module, and the Y-axis linear motion module is mounted on the slider of the Z-axis linear motion module. The ball screw driven linear motion module has a repeatability accuracy ≤ ±2μm. The X-axis, Y-axis, and Z-axis linear motion modules together constitute a three-axis motion platform, or a three-axis positioning system. This is prior art and will not be elaborated upon here. Only an example is given below:

[0037] In a ball screw-driven linear motion module, the connections between components are as follows: The module motor, acting as the power source, is directly connected to one end of the ball screw via a coupling, converting rotational motion into screw rotation. The ball screw is mounted within the main module structure and is fitted with a nut, which is fixedly connected to a slider. When the ball screw rotates, the nut and slider move along the screw's axial direction, achieving linear motion in a predetermined direction. The slider moves on a track, which provides guidance, ensuring smooth and precise movement along the predetermined straight path. Through the coordinated work of these components, the entire module achieves high-precision linear motion control driven by a motor. In a three-axis (X-axis, Y-axis, Z-axis) module system, each axis employs a similar structural design, and the axes are arranged perpendicularly to each other to achieve positioning and motion control in three-dimensional space.

[0038] Preferably, the tray 7 adopts a ring structure, and the ring structure has holes that are connected to a negative pressure generator to form an adsorption force on the wafer.

[0039] Preferably, the hollow rotary table 5 includes a rotary table body, one side of which is connected to the input shaft 502 of a motor. The motor is mounted on the slider of the Y-axis linear motion module. Rotation of the motor drives the rotary table body to rotate. The motor is equipped with a sensing device 501, such as an encoder. The rotary table body is connected to the wafer measuring device 6 via an output shaft 503; one end of the output shaft 503 is connected to the rotary table body, and the other end is connected to the wafer measuring device 6.

[0040] Preferably, the other side of the rotary table body is connected to the wafer measurement device 6. The wafer measurement device includes a high-resolution optical lens and a coaxial light source module. The coaxial light source module is mounted above the motorized rotary table via an adjustable bracket, and its optical path is coaxially aligned with the optical lens to eliminate shadow interference during the measurement process. Its camera is a 400,000-pixel gigabit Ethernet industrial area array camera with a CMOS sensor and a resolution of 720 pixels × 540 pixels. Combined with a WWH40-65CT megapixel telecentric lens and a high-angle ring light source, a chip image acquisition platform is established, ensuring that the acquired data has sufficient resolution and quality.

[0041] Example 1: The optical acquisition system of the wafer measurement device has the following configuration: The industrial camera module uses a 400,000-pixel CMOS camera with a gigabit Ethernet interface, a sensor resolution of 720×540 pixels, a frame rate ≥30fps, supports real-time high-definition image transmission, and has a built-in 12-bit ADC analog-to-digital converter with a dynamic range ≥70dB, ensuring low-noise and high signal-to-noise ratio image output. The optical imaging component is equipped with a WWH40-65CT megapixel telecentric lens with a working distance of 65mm, a distortion rate ≤0.05%, and matches the target surface size of the CMOS sensor to eliminate perspective errors. It also uses a high-angle ring light source, supports multi-level brightness adjustment, and has a uniformity deviation ≤5%, suitable for highly reflective and matte wafer surfaces. The dynamic light intensity control system achieves dynamic adjustment of the light source brightness through a PID closed-loop control algorithm. The control system has a built-in material database and automatically matches the optimal light intensity parameters according to different wafer surface properties (such as silicon, GaN, sapphire) to ensure image clarity and contrast. With the above configuration, the optical acquisition platform can acquire wafer surface topography data at submicron resolution and adapt to imaging requirements under multiple material and process scenarios, providing high-quality input for subsequent visual measurement algorithms.

[0042] Example 2: The worktable is made of marble as the measurement reference surface. It has the advantages of precise structure, uniform texture, good stability and high hardness, and is particularly suitable for high-precision measuring instruments.

[0043] Example 3: The horizontal electric translation stage 1 is used to precisely control the left and right movement of the camera in the horizontal direction. Its core purpose is to ensure that the camera can accurately position itself at the preset measurement position, thereby ensuring the accuracy of the measurement position. The vertical object distance adjustment electric translation stage 3 is installed on the right side of the column 2. This device is responsible for driving the camera to move up and down in the vertical direction. Through this movement, the object distance can be flexibly adjusted, allowing the camera to accurately complete the focusing operation. The horizontal lens adjustment electric translation stage 4 is installed on the slider 303 of the vertical object distance adjustment electric translation stage 3 and is used to control the movement of the lens. The wafer measurement device 6 is the data acquisition terminal of the entire measurement system and is installed on the right side of the horizontal lens adjustment electric translation stage 4.

[0044] Example 4: The wafer measurement device 6 integrates multiple high-precision sensors and data acquisition modules, enabling it to capture and record image information and other relevant measurement parameters acquired by the camera in real time. This data is processed and converted into digital signals by the internal signal processing and conversion circuitry of the measurement device and transmitted to the back-end data processing system for further analysis and processing.

[0045] Example 5: The four-axis rotary table 9 achieves precise wafer positioning. It can precisely rotate the wafer to a preset angle and position, meeting the wafer positioning requirements of different measurement tasks. A negative pressure generator 8 is used to fix the wafer and is connected to the tray through a through-hole. Its working principle is based on air pressure difference. When the negative pressure generator is activated, a negative pressure environment is formed on the tray surface, allowing the wafer to adhere tightly to the tray. Several fine holes are evenly distributed on the tray, and these holes are connected to the negative pressure generator, together forming a stable negative pressure adsorption system. In this way, the wafer can remain fixed during measurement, effectively avoiding measurement errors caused by vibration, displacement, and other factors. To ensure that the negative pressure can be achieved stably and effectively, the surface of the tray needs to meet a series of strict standards, including surface flatness, roughness, and material permeability. Strict adherence to these standards is a prerequisite for ensuring the normal operation of the negative pressure generator and is of great significance for improving the accuracy and reliability of wafer measurement.

[0046] The work process is as follows: 1. Planar inspection operation.

[0047] During the experimental operation, the wafer to be tested is first placed stably on tray 7. Then, the negative pressure generator 8 is activated, utilizing its negative pressure effect to securely position and fix the wafer on tray 7. After the wafer is fixed, the electric rotary table is turned on, putting it into working mode. For precise positioning of the test location, advanced control algorithms and an encoder feedback system are used. Through the coordinated work of these two systems, the transverse electric translation stage 1 and the four-axis rotary table 9 are precisely controlled, enabling rapid and accurate location of the test position. After positioning the test location, the longitudinal spacing adjustment electric translation stage 3 needs to be finely adjusted. By adjusting the position of the longitudinal spacing adjustment electric translation stage 3, the object distance can be effectively adjusted, ensuring accurate and reliable data is obtained under suitable object distance conditions.

[0048] II. Multi-faceted inspection operation.

[0049] During the experimental operation, the negative pressure generator 8 is first turned on to enable its adsorption capacity, and then the wafer to be tested is placed stably on the tray 7. Utilizing the negative pressure effect generated, the wafer is stably positioned and fixed on the tray. After the wafer is fixed, the electric rotary stage is turned on to enter working mode. For precise positioning of the test location, advanced control algorithms and an encoder feedback system are used. Through the coordinated work of these two systems, the transverse electric translation stage 1 and the four-axis rotary stage 9 are precisely controlled, thereby achieving rapid and accurate location of the test location and fixation of the measurement surface. After completing the positioning of the test location, the longitudinal electric translation stage needs to be finely adjusted. By adjusting the position of the longitudinal electric translation stage, the object distance can be effectively adjusted to ensure accurate and reliable data acquisition under appropriate object distance conditions.

[0050] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "preferred embodiment," "detailed description," or "preferred embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0051] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Therefore, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of this utility model.

Claims

1. An automatic positioning wafer fixing vision measuring instrument, comprising a worktable; characterized in that: The workbench (10) is provided with a transverse electric translation stage (1), and a column (2) is provided on the transverse electric translation stage (1). The transverse electric translation stage (1) is used to realize the movement of the column along the X-axis. A longitudinal group spacing adjustment electric translation stage (3) is provided on one side of the column (2), and a transverse lens adjustment electric translation stage (4) is provided on the longitudinal group spacing adjustment electric translation stage (3) to drive the transverse lens adjustment electric translation stage (4) to adjust the displacement in the Z-axis direction. A hollow rotary stage (5) is provided on the horizontal lens adjustment electric translation stage (4) for driving the hollow rotary stage (5) to adjust its displacement in the Y-axis direction; a wafer measuring device (6) is installed on the hollow rotary stage (5); the wafer measuring device (6) is used to measure the wafer to be measured; A four-axis turntable (9) is set on the worktable (10) and below the wafer measuring device (6). A tray (7) is installed on the four-axis turntable (9). A negative pressure generator (8) is installed at the bottom of the tray (7). The tray (7) is used to place the wafer to be tested, and the negative pressure generator (8) is used to adsorb the wafer to be tested.

2. The automatic positioning wafer fixing vision measuring instrument according to claim 1, characterized in that: The horizontal electric translation stage (1) adopts an X-axis linear motion module, the vertical group spacing adjustment electric translation stage (3) adopts a Z-axis linear motion module, and the horizontal lens adjustment electric translation stage (4) adopts a Y-axis linear motion module. The X-axis linear motion module, Y-axis linear motion module and Z-axis linear motion module all adopt ball screw driven linear motion modules. The Z-axis linear motion module is installed on the slider of the X-axis linear motion module, and the Y-axis linear motion module is installed on the slider of the Z-axis linear motion module.

3. The wafer fixing vision measuring instrument with automatic positioning according to claim 1, characterized in that: The tray (7) adopts a ring structure, and the ring structure has holes, which are connected to the negative pressure generator to form an adsorption force on the wafer.

4. The automatic positioning wafer fixing vision measuring instrument according to claim 1, characterized in that: The hollow rotary table (5) includes a rotary table body. One side of the rotary table body is connected to the input shaft (502) of motor one. Motor one is installed on the slider of the Y-axis linear motion module. When motor one rotates, it drives the rotary table body to rotate.

5. The automatic positioning wafer fixing vision measuring instrument according to claim 4, characterized in that: The other side of the rotary table body is connected to the wafer measurement device (6).

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