Wafer stage position correction method and wafer stage

Abstract

The invention discloses a wafer stage position correction method and a wafer stage, and relates to the technical field of wafer carriers. The correction method comprises the following steps of: after a wafer substrate is placed on a carrying table body, judging whether the wafer substrate has position offset relative to the photoelectric sensors based on feedback signals of the plurality of photoelectric sensors; if the position of the wafer substrate deviates, driving the carrying table body to move transversely and / or longitudinally, so that the wafer substrate is located in a positioning area defined by the detection points of the plurality of photoelectric sensors; on the basis of the transverse and / or longitudinal movement distance of the carrying table body, compensating the coordinates of the carrying table body so as to correct the position of the wafer substrate; wherein the plurality of photoelectric sensors are all installed on the carrying table body, and a positioning area defined by detection points of the plurality of photoelectric sensors is matched with the cross section of a wafer substrate, so that the coordinates of the wafer carrying table can be compensated. The wafer stage is used for implementing the wafer stage position correction method.

Description

Technical Field

[0001] This invention relates to the field of wafer carrier technology, and specifically to a wafer stage position correction method and a wafer stage. Background Technology

[0002] During wafer fabrication, wafers need to be transferred to a stage by a robotic arm, such as in the production process of an exposure machine. However, during this transfer, variations in wafer placement (robotic arm operation error) and slight displacement of the wafer substrate caused by vacuuming the stage can lead to positional deviations after the wafer is placed on the stage, causing the alignment lens to miss the mark. Summary of the Invention

[0003] To address the technical problem of wafer positional offset during transfer to a wafer stage, this invention provides a wafer stage position correction method and a wafer stage, which can compensate for the wafer stage coordinates and facilitate wafer position correction.

[0004] This invention is achieved through the following technical solution:

[0005] In a first aspect, the present invention provides a wafer stage position correction method, comprising the following steps:

[0006] After the wafer substrate is placed on the stage body, the positional offset of the wafer substrate relative to the photoelectric sensors is determined based on the feedback signals of multiple photoelectric sensors.

[0007] If the position of the wafer substrate is offset, the stage body is driven to move laterally and / or longitudinally so that the wafer substrate is located within the positioning area enclosed by the multiple photoelectric sensor detection points. Based on the distance of the lateral and / or longitudinal movement of the stage body, the coordinates of the stage body are compensated to correct the position of the wafer substrate.

[0008] In this embodiment, multiple photoelectric sensors are mounted directly opposite the stage body, and at least three photoelectric sensors are provided. The positioning area enclosed by the detection points of the multiple photoelectric sensors is adapted to the shape of the wafer substrate.

[0009] It should be noted that when the wafer is transferred to the stage by the robotic arm, there will be a positional deviation after the wafer is placed on the stage due to the difference in wafer placement each time (robotic arm operation error) and the slight displacement of the wafer substrate caused by the vacuum suction of the stage.

[0010] The wafer stage position correction method provided by the present invention, after the wafer substrate is placed on the stage body, determines whether there is a positional offset of the wafer substrate relative to the photoelectric sensors based on the feedback signals of multiple photoelectric sensors; if there is a positional offset of the wafer substrate, the stage body is driven to move laterally and / or longitudinally, so that the wafer substrate is located within the positioning area enclosed by the detection points of the multiple photoelectric sensors; then, based on the distance of the lateral and / or longitudinal movement of the stage body, the coordinates of the stage body are compensated to correct the position of the wafer substrate.

[0011] Since multiple photoelectric sensors are mounted directly opposite the stage body, and at least three photoelectric sensors are provided, and the positioning area enclosed by the detection points of the multiple photoelectric sensors is adapted to the shape of the wafer substrate, the position of the positioning area enclosed by the detection points of the multiple photoelectric sensors remains unchanged when the stage body moves the wafer substrate. Moving the wafer substrate into the positioning area enclosed by the detection points of the multiple photoelectric sensors ensures that the position of the wafer substrate relative to the photoelectric sensors is basically consistent. At the same time, the feedback data from the multiple photoelectric sensors can determine whether the wafer substrate is placed within the set range. Based on the distance of the lateral and / or longitudinal movement of the stage body, the coordinates of the stage body are compensated, and the position of the wafer substrate can be corrected.

[0012] During the wafer substrate position correction process, there is no relative movement between the wafer substrate and the stage body, so the back side of the wafer substrate will not be damaged. This method is suitable for products with circuits on both sides of the wafer substrate.

[0013] In summary, the wafer stage position correction method provided by this invention can compensate for the wafer stage coordinates, which facilitates the correction of the wafer substrate position, ensures that the alignment lens can capture the Mark, and ensures that the final placement position of the wafer substrate (the position subsequently grasped by the robot arm) is basically consistent.

[0014] In one optional embodiment of this application, before the wafer substrate is placed on the stage body, multiple photoelectric sensors are installed above the stage body at predetermined positions to ensure that the feedback signals from the multiple photoelectric sensors can determine whether there is a positional offset of the wafer substrate relative to the photoelectric sensors.

[0015] In one optional embodiment of this application, the positional offset of the wafer substrate relative to the stage body is determined by the reflection value of each of the photoelectric sensors, so as to accurately determine whether the wafer substrate is offset relative to the photoelectric sensors.

[0016] In one optional embodiment of this application, when there is a positional offset of the wafer substrate, the speed at which the stage body moves laterally and / or longitudinally remains constant, so as to facilitate the calculation of the positional offset of the wafer substrate relative to the photoelectric sensor.

[0017] In one optional embodiment of this application, the distance the stage body moves laterally and / or longitudinally is calculated using the moving speed and moving time of the stage body to accurately calculate the positional offset of the wafer substrate relative to the photoelectric sensor.

[0018] In one optional embodiment of this application, the photoelectric sensor is a diffuse reflection infrared photoelectric sensor to ensure that the positional offset of the wafer substrate relative to the photoelectric sensor can be accurately determined through the feedback signals of multiple photoelectric sensors.

[0019] In one optional embodiment of this application, four photoelectric sensors are provided and orthogonally distributed to simplify the wafer substrate position adjustment process and facilitate rapid adjustment of the relative position between the wafer substrate and the photoelectric sensors.

[0020] Secondly, the present invention provides a wafer stage, comprising: a stage body for placing a wafer substrate, and the stage body being capable of longitudinal and lateral movement; and photoelectric sensors, wherein at least three photoelectric sensors are provided, and the plurality of photoelectric sensors are independently disposed above the stage body, wherein the positioning area enclosed by the detection points of the plurality of photoelectric sensors on the stage body is adapted to the shape of the wafer substrate.

[0021] The wafer stage provided by this invention includes a stage body and photoelectric sensors. The stage body is used to place a wafer substrate and is capable of longitudinal and lateral movement to drive the wafer substrate to move longitudinally and laterally. At least three photoelectric sensors are provided, and multiple photoelectric sensors are independently arranged above the stage body. The positioning area enclosed by the detection points of multiple photoelectric sensors on the stage body is adapted to the shape of the wafer substrate. When the stage body drives the wafer substrate to move, the position of the positioning area enclosed by the detection points of multiple photoelectric sensors remains unchanged. Moving the wafer substrate within the positioning area enclosed by the detection points of multiple photoelectric sensors can make the position of the wafer substrate relative to the photoelectric sensors substantially consistent.

[0022] Meanwhile, by using feedback data from multiple photoelectric sensors, it is possible to determine whether the wafer substrate is placed within a set range. Based on the distance the stage body moves laterally and / or longitudinally, the coordinates of the stage body are compensated, and the position of the wafer substrate can be corrected.

[0023] During the wafer substrate position correction process, there is no relative movement between the wafer substrate and the stage body, so the back side of the wafer substrate will not be damaged. This method is suitable for products with circuits on both sides of the wafer substrate.

[0024] In summary, the wafer stage provided by this invention can compensate for the wafer stage coordinates, which facilitates the correction of the wafer position, ensures that the alignment lens can capture the Mark, and guarantees that the final placement position of the wafer substrate (the position subsequently grasped by the robot arm) is basically consistent.

[0025] In one optional embodiment of this application, the photoelectric sensor is a diffuse reflection infrared photoelectric sensor to ensure that the positional offset of the wafer substrate relative to the photoelectric sensor can be accurately determined through the feedback signals of multiple photoelectric sensors.

[0026] In one optional embodiment of this application, four photoelectric sensors are provided and orthogonally distributed to simplify the wafer substrate position adjustment process and facilitate rapid adjustment of the relative position between the wafer substrate and the photoelectric sensors.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] 1. The wafer stage position correction method provided by the present invention, after the wafer substrate is placed on the stage body, determines whether there is a positional offset of the wafer substrate relative to the photoelectric sensors based on the feedback signals of multiple photoelectric sensors; if there is a positional offset of the wafer substrate, the stage body is driven to move laterally and / or longitudinally, so that the wafer substrate is located within the positioning area enclosed by the detection points of the multiple photoelectric sensors; then, based on the distance of the lateral and / or longitudinal movement of the stage body, the coordinates of the stage body are compensated to correct the position of the wafer substrate. Since multiple photoelectric sensors are installed directly opposite the stage body, at least three photoelectric sensors are provided, and the positioning area enclosed by the detection points of the multiple photoelectric sensors is adapted to the shape of the wafer substrate, the position of the wafer substrate relative to the photoelectric sensors can be basically consistent. Furthermore, by compensating the coordinates of the stage body based on the distance of the lateral and / or longitudinal movement of the stage body, the position of the wafer substrate can be corrected.

[0029] 2. The wafer stage position correction method provided by the present invention does not involve relative movement between the wafer substrate and the stage body during the wafer substrate position correction process, and will not damage the back side of the wafer substrate. It is applicable to products with circuits on both sides of the wafer substrate.

[0030] 3. The wafer stage provided by the present invention includes a stage body and photoelectric sensors. The stage body is used to place a wafer substrate. The stage body is capable of longitudinal and lateral movement to drive the wafer substrate to move longitudinally and laterally. At least three photoelectric sensors are provided. Multiple photoelectric sensors are independently arranged above the stage body, and the positioning area enclosed by the detection points of multiple photoelectric sensors on the stage body is adapted to the shape of the wafer substrate. When the stage body drives the wafer substrate to move, the position of the positioning area enclosed by the detection points of multiple photoelectric sensors remains unchanged. Moving the wafer substrate within the positioning area enclosed by the detection points of multiple photoelectric sensors can make the position of the wafer substrate relative to the photoelectric sensors basically consistent. Through the feedback data of multiple photoelectric sensors, it can be determined whether the wafer substrate is placed within the set range. Based on the distance of the lateral and / or longitudinal movement of the stage body, the coordinates of the stage body are compensated, and the position of the wafer substrate can be corrected.

[0031] 4. The wafer stage provided by the present invention does not cause relative movement between the wafer substrate and the stage body during the wafer position correction process, and will not damage the back side of the wafer substrate. It can be applied to products with circuits on both sides of the wafer substrate. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] In the attached diagram:

[0034] Figure 1 This is a schematic diagram of a wafer normally placed on a carrier stage, according to an embodiment of the present invention.

[0035] Figure 2 This is a schematic diagram illustrating the positional shift of a wafer when placed on a carrier stage, as described in an embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram of a correction stage provided by an embodiment of the present invention for wafer position misalignment;

[0037] Figure 4 This is a flowchart illustrating the wafer stage position correction method provided in an embodiment of the present invention.

[0038] Figure 5 This is a schematic diagram of the structure of the wafer stage provided in an embodiment of the present invention when no positional offset occurs during wafer placement;

[0039] Figure 6 This is a schematic diagram of the structure of the wafer stage provided in an embodiment of the present invention when there is a positional offset when placing the wafer.

[0040] The attached diagram shows the markings and corresponding component names:

[0041] 10-Stage body, 11-Photoelectric sensor, 12-Alignment cylinder, 13-Substrate limiting block, 20-Wafer substrate, 21-Positioning notch. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0044] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0045] In the description of this application, it should be noted that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this application is usually placed when in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0046] It should be noted that, where there is no conflict, different features in the embodiments of this application can be combined with each other.

[0047] Please refer to Figure 1 and Figure 2 During the production of wafer substrate 20 (such as during the production of an exposure machine), when the wafer is transferred to the stage by a robot, the wafer substrate will have a positional deviation after being placed on the stage due to the difference in wafer placement each time (robot operation error) and the slight displacement of the wafer substrate caused by the vacuuming of the stage.

[0048] Combination Figure 3 To solve the above-mentioned technical problems, one possible implementation is to set a positioning notch 21 on the wafer substrate 20, and set an alignment cylinder 12 and a substrate limiting block 13 at the corresponding position on the stage. The alignment cylinder 12 extends to align with the positioning notch 21 (substrate notch), and then the substrate limiting block 13 controls the position of the wafer substrate 20. Thus, the substrate limiting block 13 and the alignment cylinder 12 jointly control the position of the wafer substrate on the stage, so that the wafer substrate is placed within the set position range.

[0049] In the aforementioned technical solution, during the alignment process of the wafer substrate, relative displacement occurs between the back side of the wafer substrate 20 and the stage surface, resulting in friction (the wafer substrate 20 is adsorbed onto the stage by negative pressure), which easily causes scratches on the back side of the wafer substrate. For double-sided wafer substrates 20 (e.g., Micro-LED displays), scratches on the back side of the wafer substrate 20 will damage the circuitry. Therefore, the above solution is not suitable for double-sided wafer substrates 20.

[0050] To address the aforementioned problems, the inventors have innovatively designed the following technical solutions, which will be described in detail below with reference to the accompanying drawings. It should be noted that the deficiencies in the existing solutions are the result of the inventors' practical experience and careful research. Therefore, the discovery process of the aforementioned technical problems and the solutions proposed in the embodiments below are contributions made by the inventors to this application during the invention process, and should not be construed as technical content known to those skilled in the art.

[0051] Example 1

[0052] Combination Figure 4 This embodiment provides a wafer stage position correction method, including the following steps:

[0053] After the wafer substrate 20 is placed on the stage body 10, the positional offset of the wafer substrate 20 relative to the photoelectric sensor 11 is determined based on the feedback signals of multiple photoelectric sensors 11.

[0054] If the position of the wafer substrate 20 is offset, the stage body 10 is driven to move laterally and / or longitudinally, so that the wafer substrate 20 is located in the positioning area enclosed by the detection points of the multiple photoelectric sensors 11.

[0055] Based on the distance the stage body 10 moves laterally and / or longitudinally, the coordinates of the stage body 10 are compensated to correct the position of the wafer substrate 20.

[0056] In this embodiment, multiple photoelectric sensors 11 are mounted directly opposite the stage body 10. At least three photoelectric sensors 11 are provided, and the positioning area enclosed by the detection points of multiple photoelectric sensors 11 is adapted to the shape of the wafer substrate 20.

[0057] It should be understood that before the wafer substrate 20 is placed on the stage body 10, multiple photoelectric sensors 11 need to be installed above the stage body 10 in a set position, such as being installed on the support frame of the stage body 10 so that the photoelectric sensors 11 are located above the stage body 10, or the photoelectric sensors 11 are suspended above the stage body 10 by a support rod / frame so that the position of the photoelectric sensors 11 is fixed, while the stage body 10 can move laterally and / or longitudinally relative to the photoelectric sensors 11 to ensure that the feedback signals of the multiple photoelectric sensors 11 can determine whether there is a positional offset of the wafer substrate 20 relative to the photoelectric sensors 11.

[0058] Specifically, the reflection values ​​of each photoelectric sensor 11 are used to determine whether there is a positional shift of the wafer substrate 20 relative to the stage body 10, so as to accurately determine whether there is a positional shift of the wafer substrate 20 relative to the photoelectric sensor 11.

[0059] In this embodiment, when there is a positional offset of the wafer substrate 20, the speed at which the stage body 10 moves laterally and / or longitudinally remains constant, so as to facilitate the calculation of the positional offset of the wafer substrate 20 relative to the photoelectric sensor 11.

[0060] Specifically, the distance the stage body 10 moves laterally and / or longitudinally is calculated using the moving speed and moving time of the stage body 10 to accurately calculate the positional offset of the wafer substrate 20 relative to the photoelectric sensor 11. That is, by multiplying the moving speed and moving time of the stage body 10, the positional offset of the wafer substrate 20 relative to the photoelectric sensor 11 can be obtained.

[0061] Of course, the distance the stage body 10 moves laterally and / or longitudinally can also be detected by setting displacement sensors, distance sensors and other technical means, so as to obtain the position offset of the wafer substrate 20 relative to the photoelectric sensor 11.

[0062] It should be noted that the photoelectric sensor 11 is a diffuse reflection infrared photoelectric sensor to ensure that the feedback signals from multiple photoelectric sensors 11 can accurately determine whether there is a positional offset of the wafer substrate 20 relative to the photoelectric sensor 11.

[0063] Combination Figure 5Four photoelectric sensors 11 are provided, and the four photoelectric sensors 11 are orthogonally distributed. In this embodiment, the four photoelectric sensors 11 are orthogonally distributed vertically and horizontally to simplify the process of adjusting the position of the wafer substrate 20 and facilitate the rapid adjustment of the relative position between the wafer substrate 20 and the photoelectric sensors 11.

[0064] Combination Figure 6 Specifically, when the right photoelectric sensor 11 detects the stage body 10 and the left photoelectric sensor 11 detects the wafer substrate 20, it indicates that the wafer substrate 20 has shifted to the left. At this time, the stage body 10 is driven to move to the right until both the right and left photoelectric sensors 11 detect the stage body 10, thus performing lateral correction on the wafer substrate 20. When the upper photoelectric sensor 11 detects the stage body and the lower photoelectric sensor 11 detects the wafer substrate 20, it indicates that the wafer substrate 20 has shifted to the downward side. At this time, the stage body 10 is driven to move upward until both the upper and lower photoelectric sensors 11 detect the stage body 10, thus performing longitudinal correction on the wafer substrate 20.

[0065] In summary, the wafer stage position correction method provided in this embodiment, after the wafer substrate 20 is placed on the stage body 10, determines whether there is a positional offset of the wafer substrate 20 relative to the photoelectric sensors 11 based on the feedback signals of multiple photoelectric sensors 11; if there is a positional offset of the wafer substrate 20, the stage body 10 is driven to move laterally and / or longitudinally, so that the wafer substrate 20 is located within the positioning area enclosed by the detection points of the multiple photoelectric sensors 11; then, based on the distance of the lateral and / or longitudinal movement of the stage body 10, the coordinates of the stage body 10 are compensated to correct the position of the wafer substrate 20.

[0066] It is understandable that, even without the wafer substrate 20, the reflection values ​​generated by the light from the four photoelectric sensors 11 illuminating the carrier body 10 remain unchanged. Combined with... Figure 5 After placing the wafer substrate 20 on the carrier body 10, if the placement position of the wafer substrate 20 does not shift, within the set area, the wafer substrate 20 will not block the light reflection of the photoelectric sensor 11. At this time, the reflection value generated by the light from the photoelectric sensor 11 shining on the carrier body 10 remains unchanged. If the placement position of the wafer substrate 20 shifts, the wafer substrate 20 will block the light reflection of the photoelectric sensor 11. At this time, the reflection value generated by the light from the photoelectric sensor 11 shining on the carrier body 10 will change. Since the deviation of the wafer substrate 20 is small, it is possible to determine whether the wafer substrate 20 is within the set range by the reflection value of the photoelectric sensor 11.

[0067] In addition, multiple photoelectric sensors 11 are mounted directly opposite the stage body 10, and at least three photoelectric sensors 11 are provided. The positioning area enclosed by the detection points of the multiple photoelectric sensors 11 is adapted to the shape of the wafer substrate 20. Therefore, when the stage body 10 moves the wafer substrate 20, the position of the positioning area enclosed by the detection points of the multiple photoelectric sensors 11 remains unchanged. Moving the wafer substrate 20 into the positioning area enclosed by the detection points of the multiple photoelectric sensors 11 can make the position of the wafer substrate 20 relative to the photoelectric sensors 11 basically consistent. At the same time, through the feedback data of the multiple photoelectric sensors 11, it is possible to determine whether the wafer substrate 20 is placed within the set range. Based on the distance of the lateral and / or longitudinal movement of the stage body 10, the coordinates of the stage body 10 are compensated, and the position of the wafer substrate 20 can be corrected.

[0068] Specifically, the position of the photoelectric sensor 11 is determined based on the external dimensions of the wafer substrate 20, so that when multiple photoelectric sensors 11 are all illuminating the stage body 10, it is determined that the wafer substrate 20 is placed in the correct position (the coordinates for the robotic arm gripping). If the wafer substrate 20 experiences such... Figure 6 When the offset is shown, the coordinates of the wafer substrate 20 are marked as (x, y), and the stage body 10 is moved laterally. The movement stops when the photoelectric sensor 11 on the left side illuminates the stage body 10. The distance the stage body moves laterally at this time is recorded as m. Thus, the coordinates of the wafer substrate 20 after compensation are (x+m, y).

[0069] It is understood that during the wafer substrate 20 position correction process, there is no relative movement between the wafer substrate 20 and the stage body 10, and the back side of the wafer substrate 20 will not be damaged. This method is applicable to products with circuitry on both sides of the wafer substrate 20. Furthermore, the wafer stage position correction method provided in this embodiment eliminates the need for a positioning notch 21 on the wafer substrate 20, allowing the wafer substrate 20 to be directly fabricated into a circle or other complete, closed hemisphere. Of course, position correction can also be performed on existing wafer substrates 20 with notches (e.g.,...). Figure 5 and Figure 6 ).

[0070] In summary, the wafer stage position correction method provided in this embodiment can compensate the coordinates of the wafer substrate 20 and the stage body 10, which facilitates the correction of the position of the wafer substrate 20, ensures that the alignment lens can capture the Mark, ensures that the final placement position of the wafer substrate 20 (the position subsequently grasped by the robot arm) is basically consistent, and can avoid damage to the surface of the wafer substrate 20.

[0071] Example 2

[0072] Referring to the figures, this embodiment provides a wafer stage, including: a stage body 10, the stage body 10 being used to place a wafer substrate 20, and the stage body 10 being capable of longitudinal and lateral movement; and photoelectric sensors 11, at least three of which are provided, with multiple photoelectric sensors 11 independently disposed above the stage body 10, wherein the positioning area enclosed by the detection points of the multiple photoelectric sensors 11 on the stage body 10 is adapted to the shape of the wafer substrate 20.

[0073] The longitudinal and lateral movement of the stage body 10 can be achieved by connecting the stage body 10 with correspondingly configured lateral and longitudinal linear drives. If the stage body 10 is connected to the lateral linear drive, and the lateral linear drive is mounted on the moving part of the longitudinal linear drive, the stage body 10 can be moved laterally by the lateral linear drive, and the stage body 10 can be moved longitudinally by the longitudinal linear drive driving the lateral linear drive, thereby achieving the longitudinal and / or lateral movement of the stage body 10.

[0074] It should be understood that the photoelectric sensor 11 is a diffuse reflection infrared photoelectric sensor to ensure that the feedback signals from multiple photoelectric sensors 11 can accurately determine whether there is a positional offset of the wafer substrate 20 relative to the photoelectric sensor 11.

[0075] In this embodiment, four photoelectric sensors 11 are provided, and the four photoelectric sensors 11 are orthogonally distributed. In this embodiment, the four photoelectric sensors 11 are orthogonally distributed vertically and horizontally to simplify the process of adjusting the position of the wafer substrate 20 and facilitate the rapid adjustment of the relative position between the wafer substrate 20 and the photoelectric sensors 11.

[0076] Multiple photoelectric sensors 11 are installed above the platform body 10 at predetermined positions, such as on the support frame of the platform body 10 so that the photoelectric sensors 11 are located above the platform body 10, or the photoelectric sensors 11 are suspended above the platform body 10 by a support rod / frame so that the position of the photoelectric sensors 11 is fixed, while the platform body 10 can move laterally and / or longitudinally relative to the photoelectric sensors 11.

[0077] Combination Figure 6Specifically, when the right photoelectric sensor 11 detects the stage and the left photoelectric sensor 11 detects the wafer substrate 20, it indicates that the wafer substrate 20 has shifted to the left. In this case, the stage body 10 is driven to move to the right until both the right and left photoelectric sensors 11 detect the stage, thus performing lateral correction on the wafer substrate 20. When the upper photoelectric sensor 11 detects the stage and the lower photoelectric sensor 11 detects the wafer substrate 20, it indicates that the wafer substrate 20 has shifted to the downward side. In this case, the stage body 10 is driven to move upward until both the upper and lower photoelectric sensors 11 detect the stage, thus performing longitudinal correction on the wafer substrate 20.

[0078] In summary, the wafer stage provided in this embodiment includes a stage body 10 and photoelectric sensors 11. The stage body 10 is used to place the wafer substrate 20. The stage body 10 is capable of longitudinal and lateral movement to drive the wafer substrate 20 to move longitudinally and laterally. At least three photoelectric sensors 11 are provided. Multiple photoelectric sensors 11 are independently arranged above the stage body 10, and the positioning area enclosed by the detection points of multiple photoelectric sensors 11 on the stage body 10 is adapted to the shape of the wafer substrate 20. When the stage body 10 drives the wafer substrate 20 to move, the position of the positioning area enclosed by the detection points of multiple photoelectric sensors 11 remains unchanged. However, by moving the wafer substrate 20 within the positioning area enclosed by the detection points of multiple photoelectric sensors 11, the position of the wafer substrate 20 relative to the photoelectric sensors 11 can be made substantially consistent.

[0079] Meanwhile, by using feedback data from multiple photoelectric sensors 11, it is possible to determine whether the wafer substrate 20 is placed within a set range. Based on the distance the stage body 10 moves laterally and / or longitudinally, the coordinates of the stage body 10 are compensated, thereby correcting the position of the wafer substrate 20.

[0080] During the position correction process of the wafer substrate 20, there is no relative movement between the wafer substrate 20 and the stage body 10, so the back side of the wafer substrate 20 will not be damaged. This method is applicable to products with circuits on both sides of the wafer substrate 20.

[0081] In summary, the wafer stage provided in this embodiment can compensate for the coordinates of the wafer stage, which facilitates the correction of the position of the wafer substrate 20, ensures that the alignment lens can capture the Mark, ensures that the final placement position of the wafer substrate 20 (the position subsequently grasped by the robot) is basically consistent, and can avoid damage to the surface of the wafer substrate 20 during the correction process.

[0082] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for calibrating the position of a wafer stage, characterized in that, Includes the following steps: After the wafer substrate (20) is placed on the stage body (10), the positional offset of the wafer substrate (20) relative to the stage body (10) is determined based on the feedback signals of multiple photoelectric sensors (11). If the position of the wafer substrate (20) is offset, the stage body (10) is driven to move laterally and / or longitudinally, so that the wafer substrate (20) is located in the positioning area surrounded by the detection points of the multiple photoelectric sensors (11), and the coordinates of the stage body (10) are compensated based on the distance of the lateral and / or longitudinal movement of the stage body (10) to correct the position of the wafer substrate (20). In this process, multiple photoelectric sensors (11) are installed directly opposite the stage body (10), and at least three photoelectric sensors (11) are provided. The positioning area enclosed by the detection points of multiple photoelectric sensors (11) is adapted to the shape of the wafer substrate (20).

2. The wafer stage position correction method according to claim 1, characterized in that, Before the wafer substrate (20) is placed on the stage body (10), a plurality of photoelectric sensors (11) are installed above the stage body (10) in a set position.

3. The wafer stage position correction method according to claim 1, characterized in that, The positional offset of the wafer substrate (20) relative to the photoelectric sensor (11) is determined by the reflection value of each photoelectric sensor (11).

4. The wafer stage position correction method according to claim 1, characterized in that, When there is a positional offset in the wafer substrate (20), the stage body (10) moves at a constant speed in the lateral and / or longitudinal directions.

5. The wafer stage position correction method according to claim 4, characterized in that, The distance that the platform body (10) moves laterally and / or longitudinally is calculated by the moving speed and moving time of the platform body (10).

6. The wafer stage position correction method according to any one of claims 1 to 5, characterized in that, The photoelectric sensor (11) is a diffuse reflection infrared photoelectric sensor.

7. The wafer stage position correction method according to any one of claims 1 to 5, characterized in that, Four photoelectric sensors (11) are provided, and the four photoelectric sensors (11) are orthogonally distributed.

8. The wafer stage position correction method according to any one of claims 1 to 5, characterized in that, When the photoelectric sensor (11) located on the upper right side of the stage body (10) detects the stage body (10) and the photoelectric sensor (11) located on the upper left side of the stage body (10) detects the wafer substrate 20, the stage body (10) is driven to move to the right until both the photoelectric sensor (11) located on the upper right side of the stage body (10) and the photoelectric sensor (11) located on the upper left side of the stage body (10) detect the stage body (10) to perform lateral correction on the wafer substrate (20).

9. A wafer carrier, characterized in that, include: A stage body (10) is used to place a wafer substrate (20), and the stage body (10) is capable of moving longitudinally and laterally. Photoelectric sensor (11), at least three of the photoelectric sensor (11) are provided, and multiple photoelectric sensors (11) are independently arranged above the stage body (10); The positioning area formed by the detection points of the multiple photoelectric sensors (11) on the stage body (10) is adapted to the shape of the wafer substrate (20).

10. The wafer stage according to claim 9, characterized in that, Four photoelectric sensors (11) are provided, and the four photoelectric sensors (11) are orthogonally distributed.

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