Mask angle calibration mechanism

Abstract

The utility model relates to the technical field of semiconductor, especially point to a mask angle calibration mechanism, including cavity, set up in the mounting cavity of cavity, rotation connection in the support component and at least two visual inspection units of mounting cavity, the support component is used for supporting the mask plate of measurement, first reference line and second reference line are provided in the mounting cavity, one of visual inspection units corresponds with first reference line, and two visual inspection units correspond to the both ends of second reference line respectively, the utility model can compensate the residual translation deviation that mask plate actually exists in X or Y direction, guarantees the collinearity of subsequent capture path.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to a mask angle calibration mechanism. Background Technology

[0002] The calibration chamber, acting as a physical standard carrier, links the equipment's output values ​​to higher-order metrological standards, enabling traceability of measurement values. Through its built-in reference standard, the calibration chamber corrects systematic errors caused by manufacturing tolerances, temperature drift, and other factors in real time, thereby avoiding performance fluctuations due to process variations.

[0003] The existing mask is located at the mechanical interface for picking and placing, corresponding to the gripping component at the end of the robot, which facilitates smooth picking and placing of the mask. The two sides of the mask are designed to be parallel to the picking and placing direction, ensuring that the end of the robot can accurately insert / extract along a straight trajectory, thus realizing the rapid picking and placing of the mask.

[0004] Currently, after the robotic arm places the mask onto the support, the mask is calibrated by rotating the support via a motor. The motor's rotation angle is dynamically corrected through visual feedback. However, due to the lack of an absolute reference to define the initial X and Y directions, during the actual correction process, motor stepping errors, mechanical backlash, or vibrations may cause overshoot or undershoot in angle adjustment, amplifying rather than eliminating deviations in the X and Y directions, such as lateral horizontal offset. Ultimately, the mask actually has residual translational deviations in the X or Y directions, such as lateral center point offset, affecting the collinearity of subsequent grasping paths. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by providing a mask angle calibration mechanism that can compensate for residual translational deviations in the X or Y direction of the mask plate, ensuring collinearity of the subsequent grasping path.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This utility model provides a mask angle calibration mechanism, including a cavity, a mounting cavity disposed in the cavity, a support member rotatably connected in the mounting cavity, and at least two visual detection units. The support member is used to support the mask plate to be tested. A first reference line and a second reference line are disposed in the mounting cavity. One visual detection unit corresponds to the first reference line, and the two visual detection units correspond to the two ends of the second reference line, respectively.

[0008] When the angle of the mask to be tested needs to be adjusted, the vision detection unit detects the two adjacent sides of the mask respectively. The support member rotates to drive the mask to rotate, so that the two adjacent sides of the mask correspond to the first reference line and the second reference line respectively.

[0009] The mounting cavity contains a first reference block, a second reference block, and a third reference block. The first reference block has a first reference portion, the second reference block has a second reference portion and a third reference portion, and the third reference block has a fourth reference portion. The first reference portion and the second reference portion constitute a first reference line, and the third reference portion and the fourth reference portion constitute a second reference line.

[0010] Wherein, the length of the second reference line is greater than the length of the first reference line, the mounting cavity is equipped with a first limiting block and a second limiting block, the inner side of the first limiting block is flush with the second reference line, the third reference block is provided with a fifth reference part parallel to the first reference line, the inner side of the second limiting block is flush with the fifth reference part, and the first limiting block is located between the second reference block and the third reference block.

[0011] The support component includes a support base rotatably connected to the mounting cavity and at least three support frames connected to the support base. The top of each support frame is provided with a support part for supporting the mask plate to be tested. The support frame is connected to the support base with an adjustment component, which is used to adjust the position of the support frame so that the support frame is closer to or farther from the rotation center of the support base.

[0012] The support base is equipped with a temperature sensor, which is used to detect the bottom temperature of the mask to be tested.

[0013] The cavity is equipped with several light sources, which are located on the left side, front side and top of the cavity, respectively.

[0014] A transparent viewing window is installed on one side of the cavity.

[0015] The cavity is rotatably connected to a rotating shaft, the rotating shaft is coaxially connected to a supporting member, and a driving unit is installed in the cavity, the driving unit being drivenly connected to the rotating shaft.

[0016] The rotating shaft is provided with a contact part and a limiting part. The cavity is equipped with at least three first detection switches, second detection switches and third detection switches arranged circumferentially along the rotating shaft. The contact part continuously corresponds to the first detection switch. The rotating shaft has a first limit position and a second limit position within its rotation range.

[0017] When the shaft rotates to the first limit position, the limit part corresponds to the second detection switch;

[0018] When the shaft rotates to the second limit position, the limit part corresponds to the third detection switch.

[0019] The first reference part and the second reference part are located at different heights, while the third reference part and the fourth reference part are at the same height.

[0020] The beneficial effects of this utility model are:

[0021] In practical applications, rotating the support component can meet the angular rotation requirements of the support component. The support component provides stable support for the mask plate. The vision inspection unit detects two adjacent sides of the mask plate respectively. The rotation of the support component causes the mask plate to rotate, positioning the first and second reference lines as the references in the X and Y directions respectively. The vision inspection unit can directly measure the absolute position and angle of the side of the mask plate to be measured relative to the first or second reference line. Rotating the mask plate can compensate for any residual translational deviations in the X or Y direction, ensuring the collinearity of the subsequent grasping path. Attached Figure Description

[0022] Figure 1 This is a front view of the structure of the mask angle calibration mechanism.

[0023] Figure 2 This is a top view of the structure of the mask angle calibration mechanism, which lacks a top plate.

[0024] Figure 3 This is a schematic diagram of a structure consisting of a first reference block, a second reference block, and a third reference block.

[0025] Figure 4 This is a three-dimensional structural diagram of the supporting components.

[0026] Figure 5 This is a three-dimensional structural diagram of the mask angle calibration mechanism.

[0027] Figure 6 for Figure 4 Enlarged view of point A in the image.

[0028] Figure 7 This is a three-dimensional view of the installation structure of the first and second reference blocks.

[0029] 1. Cavity; 11. Rotating shaft; 111. Contact part; 112. Limiting part; 12. Drive unit; 13. First detection switch; 14. Second detection switch; 15. Third detection switch;

[0030] 2. Installation cavity;

[0031] 21. First reference block; 211. First reference section; 22. Second reference block; 221. Second reference section; 222. Third reference section; 23. Third reference block; 231. Fourth reference section; 232. Fifth reference section; 24. First limiting block; 25. Second limiting block;

[0032] 3. Supporting components;

[0033] 31. Support base; 32. Support frame; 33. Support section;

[0034] 4. Visual inspection unit;

[0035] 5. Temperature sensor;

[0036] 6. Light source;

[0037] 7. Transparent window. Detailed Implementation

[0038] To facilitate understanding by those skilled in the art, the present invention will be further described below in conjunction with embodiments and accompanying drawings. Specific embodiments of the present invention will be described below. It should be noted that, in order to provide a concise description of these embodiments, this specification cannot provide a detailed description of all features of the actual embodiments.

[0039] refer to Figures 1 to 7 As shown, this utility model provides a mask angle calibration mechanism, including a cavity 1, a mounting cavity 2 disposed in the cavity 1, a support member 3 rotatably connected in the mounting cavity 2, and at least two visual detection units 4. The support member 3 is used to support the mask plate to be tested. A first reference line and a second reference line are disposed in the mounting cavity 2. One of the visual detection units 4 corresponds to the first reference line, and the two visual detection units 4 correspond to the two ends of the second reference line, respectively.

[0040] refer to Figure 1 , 2As shown, in practical applications, when the angle of the mask to be tested needs to be adjusted, an external robotic arm sends the mask to be tested into the mounting cavity 2. The support member 3 is driven by the power unit, which drives the support member 3 to rotate. The power unit can be a magnetohydrodynamic motor or a servo motor to meet the angle rotation requirements of the support member 3. The support member 3 provides stable support for the mask. The vision inspection unit 4 detects two adjacent sides of the mask. The rotation of the support member 3 drives the mask to rotate, positioning the first and second reference lines as the references in the X and Y directions, respectively. The vision inspection unit 4 can directly measure the absolute position and angle of the side of the mask to be tested relative to the first or second reference line. Rotating the mask can compensate for residual translational deviations in the X or Y direction, such as the offset of the side center point, ensuring the collinearity of the subsequent grasping path. After the mask calibration is completed, the robotic arm removes the mask, successfully completing the mask calibration. This avoids relying on the transmission port or other reference lines as indirect references, reducing system errors. It is especially suitable for high-precision applications of mask calibration and facilitates... Improved detection accuracy; by providing timely reference through the first and second baselines, the vision inspection unit 4 can output multiple parameter deviations through a single imaging, reducing iterative techniques for detection and adjustment. For example, after the mask is placed, the vision inspection system directly reads the deviation value in the X or Y direction without the need for the support component 3 to rotate and probe, thus improving production cycle time. The vision inspection unit 4 uses a 3D vision sensor, which facilitates the construction of a 3D vision system. With two vision inspection units 4 corresponding to the two ends of the second baseline, if there is an installation error at the rotating connection of the support component 3 or a slight tilt due to force, the mask it supports will also tilt. The two vision inspection units 4 can accurately measure the height difference or position difference in a certain direction between the two ends of the second baseline, and can calculate the tilt angle of the support component 3 relative to the reference coordinate system in a certain direction, thereby accurately obtaining the actual position and direction angle of the second baseline, rather than a vague point position, significantly improving the long-term stability and measurement accuracy of the system, thereby improving the accuracy, efficiency and reliability of mask calibration, and making it suitable for high-precision mask calibration scenarios.

[0041] refer to Figure 2 , 3As shown, in this embodiment, a first reference block 21, a second reference block 22, and a third reference block 23 are installed in the mounting cavity 2. The first reference block 21 is provided with a first reference portion 211, the second reference block 22 is provided with a second reference portion 221 and a third reference portion 222, and the third reference block 23 is provided with a fourth reference portion 231. The first reference portion 211 and the second reference portion 221 constitute a first reference line, and the third reference portion 222 and the fourth reference portion 231 constitute a second reference line. The first reference line is divided into a first reference portion 211 and a second reference portion 221. The first reference portion 211... The length of the line connecting the first and second reference parts 221 is the reference length corresponding to the first reference line, ensuring that the reference provides a stable reference and avoiding the influence of thermal expansion when using a direct complete reference line. For example, when there are local fluctuations in the temperature control of the cooling pipe, the amount of thermal expansion is reduced, and the thermal drift error is reduced. The length of the line connecting the third reference part 222 and the fourth reference part 231 is the reference length corresponding to the second reference line, ensuring that the reference provides a stable reference. Similarly, the second reference line is split into the third reference part 222 and the fourth reference part 231 to ensure that the reference is not affected by thermal expansion and to ensure the positioning accuracy of the reference.

[0042] refer to Figure 2 , 3 As shown, in this embodiment, the length of the second reference line is greater than the length of the first reference line. The mounting cavity 2 is equipped with a first limiting block 24 and a second limiting block 25. The inner side of the first limiting block 24 is flush with the second reference line. The third reference block 23 is provided with a fifth reference part 232 parallel to the first reference line. The inner side of the second limiting block 25 is flush with the fifth reference part 232. The first limiting block 24 is located between the second reference block 22 and the third reference block 23.

[0043] In practical applications, the length of the second reference line is slightly greater than the length of the corresponding side of the mask, which facilitates the coverage of the edge area. A longer reference line improves accuracy and robustness, enabling efficient closed-loop control. The calibration boundary of the mask is determined by the first limiting block 24 and the second limiting block 25, facilitating accurate positioning of the mask in the X and Y directions and helping to determine a stable calibration area. Positioning the first limiting block 24 between the second reference block 22 and the third reference block 23 maintains the compact layout of the cavity 1 without increasing the volume of the mounting cavity 2. Through the structural arrangement of the first limiting block 24 and the split second reference line, the second reference line does not need to continuously cross the entire detection area, reducing sagging deformation caused by gravity or vibration. Each reference part can be independently fixed in the cavity 1, improving the local accuracy of the reference line. The rigidity and vibration resistance are enhanced. Grooves are provided on the bottom sides of the first limiting block 24 and the second limiting block 25 near the interior of the mounting cavity 2. These grooves hollow out the first and second limiting blocks 24 and 25, facilitating the rational distribution of materials. This allows the structure to achieve an optimal weight ratio while meeting strength and rigidity requirements, thus improving the structure's rigidity and strength. The inner side of the second limiting block 25 is flush with the fifth reference part 232. The first reference part 211, the second reference part 221, the third reference part 222, the fourth reference part 231, and the fifth reference part 232 form a defined rectangular detection boundary. This reduces unnecessary calculation and processing steps, minimizes false detections and missed detections caused by changes in the mask's position and size, improves detection accuracy, and ultimately enhances the overall efficiency of image processing.

[0044] refer to Figure 2 , 4 As shown, in this embodiment, the support member 3 includes a support base 31 rotatably connected to the mounting cavity 2 and at least three support frames 32 connected to the support base 31. The top end of the support frame 32 is provided with a support part 33 for supporting the mask to be tested. The support frame 32 is connected to the support base 31 with an adjustment component. The adjustment component is used to adjust the position of the support frame 32 so that the support frame 32 is closer to or farther from the rotation center of the support base 31. In actual application, the adjustment component is a bolt. Both the support frame 32 and the support base 31 are provided with corresponding mounting holes. When the support frame 32 moves to the required position, the adjustment component passes through the corresponding mounting hole and locks the support frame 32, thereby adjusting the position of the support frame 32 to facilitate the support of masks of different sizes.

[0045] refer to Figure 2 , 4As shown, in this embodiment, the support base 31 is equipped with a temperature sensor 5, which is used to detect the bottom temperature of the mask to be tested. In actual application, the temperature sensor 5 is a resistance temperature detector (RTD) sensor with a detection accuracy of 0.03 degrees Celsius, which facilitates real-time and accurate measurement of the temperature of the mounting cavity 2, ensuring that the mask is in the optimal and stable thermal state required by the process, so as to ensure the accuracy of the photolithography pattern, the accuracy of overlay and the consistency of the process, and prevent thermal damage to the mask.

[0046] refer to Figure 2 , 5 As shown, in this embodiment, the cavity 1 is equipped with several light sources 6, which are located on the left, front and top sides of the cavity 1 respectively. The combination of multi-angle light sources 6 can significantly improve the contrast between the mask and the mounting cavity 2, which is beneficial to highlight the surface details of the mask, making it easier for the vision system to identify small defects or key information, ensuring the uniformity of image illumination, and reducing the difficulty of algorithm processing.

[0047] refer to Figure 1 , 5 As shown in this embodiment, a transparent window 7 is installed on one side of the cavity 1 to facilitate a direct view of the internal working conditions of the cavity 1.

[0048] refer to Figure 2 , 4 As shown in Figure 6, in this embodiment, the cavity 1 is rotatably connected to a rotating shaft 11, the rotating shaft 11 is coaxially connected to the support member 3, the cavity 1 is equipped with a driving unit 12, and the driving unit 12 is drivenly connected to the rotating shaft 11; the rotating shaft 11 is provided with a contact part 111 and a limiting part 112, and the cavity 1 is equipped with at least three first detection switches 13, second detection switches 14 and third detection switches 15 arranged circumferentially along the rotating shaft 11, the contact part 111 continuously corresponds to the first detection switch 13, and the rotating shaft 11 has a first limit position and a second limit position within its rotation range.

[0049] In practical applications, the drive unit 12 uses a magnetohydrodynamic motor, and the first detection switch 13, the second detection switch 14, and the third detection switch 15 are slotted photoelectric switches. During the process of the drive unit 12 driving the rotating shaft 11 to rotate, when the rotating shaft 11 rotates to the first limit position, the limiting part 112 corresponds to the second detection switch 14 to ensure that one end of the rotating shaft 11 and the support member 3 rotates to the limit position. When the rotating shaft 11 rotates to the second limit position, the limiting part 112 corresponds to the third detection switch 15 to ensure that the other end of the rotating shaft 11 and the support member 3 rotates to the limit position, which makes it easy to determine the rotation range of the rotating shaft 11 and the support member 3. The first detection switch 13 provides a continuous signal output, which makes it easy to monitor in real time whether the rotating shaft 11 is rotating or in the default position, prevents detection interruption, and avoids system failure due to signal loss.

[0050] refer to Figure 2 , 7 As shown, in this embodiment, the first reference part 211 and the second reference part 221 are located at different heights, while the third reference part 222 and the fourth reference part 231 are at the same height. In practical applications, when the mask plate has a small pitch angle or yaw angle in the direction corresponding to the first reference line, by placing the first reference part 211 and the second reference part 221 at different heights, but with the first reference part 211 and the second reference part 221 parallel, the vision inspection system can use these two reference points at different heights to directly measure or compensate for the pitch angle change of the mask plate around the Y-axis during movement. This provides a direct means of detecting and correcting angular displacement at the physical level. By using the height difference to transform the reference line into an angle sensor, real-time dynamic compensation of linear displacement error is achieved, significantly improving positioning accuracy.

[0051] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present utility model without departing from the scope of the present utility model shall fall within the scope of the present utility model.

Claims

1. A mask angle calibration mechanism, characterized in that, It includes a cavity (1), an installation cavity (2) disposed in the cavity (1), a support member (3) rotatably connected in the installation cavity (2), and at least two vision detection units (4). The support member (3) is used to support the mask plate to be tested. A first reference line and a second reference line are disposed in the installation cavity (2). One vision detection unit (4) corresponds to the first reference line, and the two vision detection units (4) correspond to the two ends of the second reference line respectively. When the angle of the mask to be tested needs to be adjusted, the vision detection unit (4) detects the two adjacent sides of the mask respectively, and the support member (3) rotates to drive the mask to rotate so that the two adjacent sides of the mask correspond to the first reference line and the second reference line respectively.

2. The mask angle calibration mechanism according to claim 1, characterized in that, The mounting cavity (2) is equipped with a first reference block (21), a second reference block (22) and a third reference block (23). The first reference block (21) is provided with a first reference part (211), the second reference block (22) is provided with a second reference part (221) and a third reference part (222), and the third reference block (23) is provided with a fourth reference part (231). The first reference part (211) and the second reference part (221) constitute a first reference line, and the third reference part (222) and the fourth reference part (231) constitute a second reference line.

3. The mask angle calibration mechanism according to claim 2, characterized in that, The length of the second reference line is greater than the length of the first reference line. The mounting cavity (2) is equipped with a first limiting block (24) and a second limiting block (25). The inner side of the first limiting block (24) is flush with the second reference line. The third reference block (23) is provided with a fifth reference part (232) parallel to the first reference line. The inner side of the second limiting block (25) is flush with the fifth reference part (232). The first limiting block (24) is located between the second reference block (22) and the third reference block (23).

4. The mask angle calibration mechanism according to claim 1, characterized in that, The support member (3) includes a support base (31) rotatably connected to the mounting cavity (2) and at least three support frames (32) connected to the support base (31). The top end of the support frame (32) is provided with a support part (33) for supporting the mask plate to be tested. The support frame (32) is connected to the support base (31) with an adjustment component. The adjustment component is used to adjust the position of the support frame (32) so that the support frame (32) is close to or far away from the rotation center of the support base (31).

5. The mask angle calibration mechanism according to claim 4, characterized in that, The support base (31) is equipped with a temperature sensor (5), which is used to detect the bottom temperature of the mask to be tested.

6. The mask angle calibration mechanism according to claim 1, characterized in that, The cavity (1) is equipped with several light sources (6), which are located on the left side, front side and top of the cavity (1).

7. The mask angle calibration mechanism according to claim 1, characterized in that, A transparent viewing window (7) is installed on one side of the cavity (1).

8. The mask angle calibration mechanism according to claim 1, characterized in that, The cavity (1) is rotatably connected to a rotating shaft (11), the rotating shaft (11) is coaxially connected to the support member (3), and the cavity (1) is equipped with a drive unit (12), the drive unit (12) is drivenly connected to the rotating shaft (11); The rotating shaft (11) is provided with a contact part (111) and a limiting part (112). The cavity (1) is equipped with at least three first detection switches (13), second detection switches (14) and third detection switches (15) arranged circumferentially along the rotating shaft (11). The contact part (111) continuously corresponds to the first detection switch (13). The rotating shaft (11) has a first limit position and a second limit position within its rotation range. When the rotating shaft (11) rotates to the first limit position, the limiting part (112) corresponds to the second detection switch (14); When the rotating shaft (11) rotates to the second limit position, the limit part (112) corresponds to the third detection switch (15).

9. The mask angle calibration mechanism according to claim 2, characterized in that, The first reference part (211) and the second reference part (221) are located at different heights, while the third reference part (222) and the fourth reference part (231) are at the same height.

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