Wafer alignment method and apparatus, and semiconductor process device

Abstract

The invention provides a wafer alignment method, a wafer alignment device and semiconductor process equipment. The wafer alignment method comprises the following steps: in a first rotation mode, in response to each rotation of a motor by a first fixed angle, shooting the edge of a wafer by using photographing equipment to obtain a first local image; performing target feature point detection on the first local image to determine a target feature image; determining a first initial coordinate of the target feature point according to the target feature image; in the second rotation mode, the motor is controlled to stop for a fixed time after rotating by a second fixed angle every time, and the edge of the wafer is photographed by the photographing device to obtain a second local image; determining a second initial coordinate of the circle center of the wafer according to the plurality of second local images; determining a to-be-rotated angle and a to-be-adjusted offset according to the first initial coordinate, the second initial coordinate and the target alignment direction; and adjusting the circle center of the wafer according to the to-be-adjusted offset, and / or rotating the target feature point according to the to-be-rotated angle of the target feature point so as to realize wafer alignment.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202511525036.6 (22) Application Date 2025.10.23 (71) Applicant Beijing North Huachuang Microelectronics Equipment Co., Ltd. Address 8 Wenchang Avenue, Beijing Economic and Technological Development Zone, Daxing District, Beijing 100176 (72) Inventors Wu Qidong, Li Pengpeng, Zhu Qiaobian, Guo Dong, Wang Qiang (74) Patent Agency Beijing Tianhao United Intellectual Property Agency Co., Ltd. 11112 Patent Attorney Peng Ruixin, Li Yingya (51) Int.Cl. H10P 72 / 50 (2026.01) G06T 7 / 73 (2017.01) (54) Invention Title Wafer Alignment Method and Apparatus Thereof, Semiconductor Process Equipment (57) Abstract This disclosure provides a wafer alignment method and apparatus, and semiconductor process equipment. The wafer alignment method includes: in a first rotation mode, in response to the motor rotating by a first fixed angle, taking a picture of the wafer edge using an imaging device to obtain a first partial image; detecting target feature points in the first partial image to determine a target feature image; determining the first initial coordinates of the target feature points based on the target feature image; in a second rotation mode, controlling the motor to stop for a fixed time after rotating by a second fixed angle, taking a picture of the wafer edge using an imaging device to obtain a second partial image; determining the second initial coordinates of the wafer center based on multiple second partial images; determining the rotation angle and the offset to be adjusted based on the first initial coordinates, the second initial coordinates, and the target alignment direction; adjusting the wafer center according to the offset to be adjusted, and / or rotating the target feature points according to the rotation angle of the target feature points to achieve wafer alignment. Claims 4 pages, Description 17 pages, Drawings 11 pages, CN 121310948 A 2026.01.09 CN 1 21 31 09 48 A 1. A wafer alignment method, applied to a wafer alignment device, the wafer alignment device including an imaging device, a motor, and a rotating platform connected to the motor, the imaging device having a certain field of view, a portion of the edge of a wafer located on the rotating platform falling into the field of view; the motor including a first rotation mode and a second rotation mode; characterized in that the wafer alignment method includes: In the first rotation mode, in response to the motor rotating by a first fixed angle, using the imaging device to photograph the edge of the wafer to obtain a first partial image of the field of view; performing target feature point detection on the first partial image to determine the first partial image having the target feature point as a target feature image; determining the first initial coordinates of the target feature point based on the target feature image; In the second rotation mode, controlling the motor to stop for a fixed time after rotating by a second fixed angle, using the imaging device to photograph the edge of the wafer to obtain a first partial image of the field of view; performing target feature point detection on the first partial image to determine the first partial image having the target feature point as a target feature image; determining the first initial coordinates of the target feature point based on the target feature image; In the second rotation mode, controlling the motor to stop for a fixed time after rotating by a second fixed angle, using the imaging device to photograph the edge of the wafer to obtain a first partial image of the field of view; performing target feature point detection on the first partial image to determine the first partial image having the target feature point as a target feature image; determining the first initial coordinates of the target feature point based on the target feature image;The device captures images of the wafer edge to obtain a second partial image of the captured field of view; the second partial image does not contain the target feature point; based on multiple second partial images, a second initial coordinate of the wafer center is determined; based on the first initial coordinate, the second initial coordinate, and the target alignment direction, the rotation angle to be determined for the target feature point and / or the adjustment offset between the wafer center and the center of the rotation platform is determined; the wafer center is adjusted according to the adjustment offset to be located at the center of the rotation platform, and / or the target feature point is rotated according to the rotation angle to be determined, so that the line connecting the rotated target feature point and the rotated wafer center is aligned with the target alignment direction. 2. The wafer alignment method according to claim 1, characterized in that, after responding to the motor rotating by a first fixed angle, it further includes: recording a first position when the motor rotates by a first fixed angle; when the first partial image is detected to have the target feature point, determining a second position of the motor when the imaging device captures the target feature image based on the first position and a pre-calibrated delay compensation angle when the imaging device captures the image; controlling the motor to reverse from a third position at the current moment to the second position, so as to rotate the target feature point to the initial position; wherein, the current moment is the moment when the first partial image is detected to have the target feature point. 3. The wafer alignment method according to claim 1, characterized in that, in a first rotation mode, in response to the motor rotating by a first fixed angle, the imaging device captures the edge of the wafer to obtain a first partial image of the imaging field of view area, comprising: in the first rotation mode, controlling the motor to rotate one revolution, and when the motor rotates by a first fixed angle, using the imaging device to capture the edge of the wafer to obtain a first partial image of the imaging field of view area. 4. The wafer alignment method according to claim 3, characterized in that, after obtaining the first partial image of the shooting field of view area, it further includes: performing wafer damage feature detection on the first partial image; if the first partial image has damage features, then ending the alignment of the current wafer and outputting an alarm signal. 5. The wafer alignment method according to claim 3, characterized in that, it further includes: in response to the motor rotating by a first fixed angle, recording the first position when the motor rotates by a first fixed angle, and recording the order of the first partial images captured by the imaging device when the motor rotates by a first fixed angle, and determining the correlation between the first position and the order of the first partial images; In response to having controlled the motor to rotate one revolution, according to the order of the target feature images and the first position and the...The correlation relationship of the order of the first partial images determines the rotation direction in which the target feature point rotates to the shooting field of view area the fastest; based on the order of the target feature images, the correlation relationship between the first position and the order of the first partial images, and the pre-calibrated delay compensation angle when the imaging device takes a picture, the second position of the motor when the imaging device takes the target feature image is determined; the motor is driven to rotate from the third position at the current moment to the second position according to the rotation direction, so as to rotate the target feature point to the initial position; wherein, the current moment is the moment when the motor rotates one revolution. 6. The wafer alignment method according to claim 2 or 5, characterized in that, after rotating the target feature point to the initial position, it further includes: switching the first rotation mode to the second rotation mode. 7. The wafer alignment method according to claim 2 or 5, characterized in that the step of pre-calibrating the delay compensation angle includes: controlling the motor to stand still, using the imaging device to photograph a fixed marker point on the rotating platform, and determining the first coordinate of the fixed marker point; controlling the motor to rotate one revolution, using the imaging device to photograph the fixed marker point on the rotating platform, and determining the second coordinate of the fixed marker point; determining the delay compensation angle based on the first coordinate, the second coordinate, and the pre-calibrated coordinate of the center of the rotating platform. 8. The wafer alignment method according to claim 1, characterized in that, in the second rotation mode, controlling the motor to stop for a fixed time after rotating a second fixed angle, and using the imaging device to photograph the edge of the wafer to obtain a second partial image of the photographed field of view area includes: in the second rotation mode, starting to control the motor to rotate one revolution, and stopping for a fixed time after rotating the second fixed angle, and using the imaging device to photograph a partial image; taking the partial images other than the last partial image from the multiple partial images photographed by the motor rotating one revolution as the second partial image. 9. The wafer alignment method according to claim 1, wherein determining the first initial coordinates of the target feature point based on the target feature image comprises: determining the relative positional relationship between the target feature point and the center point of the shooting field of view based on the pre-calibrated center coordinates of the shooting field of view, the pre-calibrated conversion relationship between the image size and the actual physical size, and the pixel position of the target feature point in the target feature image; determining the first initial coordinates based on the pre-calibrated center coordinates of the shooting field of view, the pre-calibrated coordinates of the center of the rotating platform, and the relative positional relationship between the target feature point and the center point of the shooting field of view. 10. The wafer alignment method according to claim 1, wherein determining the second initial coordinates of the wafer center based on multiple second partial images comprises:Based on the arc features of the wafer in each of the second local images, a preset fitting algorithm is used to fit the rotation trajectory circle of the wafer center rotating around the center of the rotating platform; each wafer center on the rotation trajectory circle uniquely corresponds to a rotation angle of the motor; The coordinates of the wafer center on the rotation trajectory circle corresponding to the motor in the second position are determined as the second initial coordinates of the wafer center. 11. The wafer alignment method according to claim 10, characterized in that the step of determining the rotation angle of the target feature point includes: determining a line segment between the wafer center and the target feature point according to the first initial coordinates and the second initial coordinates; the line segment moves in a circle around the center of the rotating platform; using a preset geometric algorithm, determining the target coordinates of the wafer center on the rotation trajectory circle when the line segment is in the target alignment direction; determining the rotation angle according to the target coordinates of the wafer center, the second initial coordinates of the wafer center, and the pre-calibrated coordinates of the center of the rotating platform. 12. The wafer alignment method according to claim 11, characterized in that the step of determining the offset to be adjusted between the wafer center and the center of the rotating platform includes: determining the offset to be adjusted between the wafer center and the center of the rotating platform according to the target coordinates and the pre-calibrated coordinates of the rotating platform center. 13. The wafer alignment method according to claim 11, characterized in that it further includes: determining the movement amount of the robot arm grasping the wafer according to the pre-calibrated coordinates of the robot arm and the target coordinates; determining the movement angle of the robot arm grasping the wafer according to the pre-calibrated coordinates of the robot arm, the target coordinates, and the pre-calibrated coordinates of the rotating platform center; and controlling the robot arm to move to the rotating platform to grasp the wafer according to the movement amount and the movement angle. 14. The wafer alignment method according to claim 1, wherein adjusting the wafer center according to the offset to be adjusted comprises: controlling a robotic arm to adjust the wafer center according to the offset to be adjusted; and rotating the target feature point according to the rotation angle to be rotated comprises: controlling the rotating platform to rotate the wafer according to the rotation angle to be rotated. 15. The wafer alignment method according to claim 1, wherein the first fixed angle is less than or equal to the difference between the shooting angle of the imaging device and a preset angle, and the preset angle is related to the space occupied by the actual physical feature corresponding to the target feature point; and the first fixed angle is less than the second fixed angle. 16. A wafer alignment device, comprising a controller, an imaging device, a motor, and a device connected to the motor.A rotating platform, wherein the imaging device has a certain field of view, and a portion of the edge of the wafer located on the rotating platform falls into the field of view; the motor includes a first rotation mode and a second rotation mode; the controller is configured to, in the first rotation mode, in response to the motor rotating at a first fixed angle, send a first imaging command to the imaging device to receive a first partial image sent by the imaging device; perform target feature point detection on the first partial image to determine the first partial image containing the target feature point as a target feature image; determine the first initial coordinates of the target feature point based on the target feature image; in the second rotation mode, control the motor to stop for a fixed time after rotating at a second fixed angle and send a second imaging command to the imaging device to receive a second partial image sent by the imaging device; the second partial image does not contain the target feature point; determine the second initial coordinates of the wafer center based on multiple second partial images; and determine the second initial coordinates of the wafer center based on the first initial coordinates. (Claims 3 / 4, page 4, CN 121310948 A) The system uses the first initial coordinates, the second initial coordinates, and the target alignment direction to determine the rotation angle of the target feature point and / or the adjustment offset between the wafer center and the center of the rotation platform; it adjusts the wafer center according to the adjustment offset to position it at the center of the rotation platform, and / or rotates the target feature point according to the rotation angle so that the line connecting the rotated target feature point and the rotated wafer center is aligned with the target alignment direction; the imaging device is configured to, in response to the first imaging command, capture the wafer edge to obtain a first partial image of the imaging field of view area and send it to the controller; in response to the second imaging command, capture the wafer edge to obtain a second partial image of the imaging field of view area and send it to the controller. 17. A semiconductor process apparatus, characterized in that it includes a transfer chamber, a process chamber, a vacuum locking chamber, and a wafer alignment device as described in claim 16, wherein the process chamber, the vacuum locking chamber, and the wafer alignment device are respectively connected to the transfer chamber. 18. A computer device, characterized in that it comprises: a processor, a memory, and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the computer device is running, the processor communicates with the memory via the bus, and the machine-readable instructions, when executed by the processor, perform the steps of the wafer alignment method as described in any one of claims 1 to 15. 19. A computer non-transient readable storage medium, characterized in that the computer non-transient readable storage medium stores a computer program, which, when executed by a processor, performs the steps of the wafer alignment method as described in any one of claims 1 to 15. Claims 4 / 4 pages 5 CN121310948 A Wafer Alignment Method and Apparatus, Semiconductor Process Equipment Technical Field

[0001] This disclosure belongs to the field of semiconductor manufacturing technology, specifically relating to a wafer alignment method and apparatus, and semiconductor process equipment. Background Art

[0002] A wafer alignment device (Aligner) is a high-precision device used in semiconductor manufacturing processes. It is mainly used for the precise positioning and alignment of wafers before the process, thereby ensuring that the position, angle, and orientation of the wafer meet the process requirements, so as to improve manufacturing accuracy and yield.

[0003] Traditional wafer alignment devices mainly use laser sensors for edge finding to identify features such as notches or flat edges at the edge of the wafer. Then, the notch or flat edge is rotated to a specified direction that meets the process requirements, and the center of the wafer is aligned with the center of the rotating platform to achieve the purpose of wafer alignment.

[0004] Currently, in order to solve the processing difficulties of thinner wafers and meet the back-side process requirements, it is necessary to use transparent mechanical support substrates such as glass or sapphire, and temporarily bond them to the wafer with adhesives to protect the wafer. However, during the bonding process, the adhesive is easily squeezed onto the support substrate area outside the wafer edge, forming a colloid buildup. When performing wafer alignment with such colloid, the laser sensor cannot properly identify the wafer edge position and the angle of target features (such as notches or flat edges) on the wafer edge due to the colloid's blocking effect on the laser and its uneven shape, resulting in alignment failure. Summary of the Invention

[0005] This disclosure aims to at least solve one of the technical problems existing in the prior art by providing a wafer alignment method and apparatus, and semiconductor process equipment.

[0006] In a first aspect, the technical solution adopted to solve the technical problem of this disclosure is a wafer alignment method applied to a wafer alignment device. The wafer alignment device includes an imaging device, a motor, and a rotating platform connected to the motor. The imaging device has a certain field of view, and a portion of the edge of the wafer located on the rotating platform falls into the field of view. The motor includes a first rotation mode and a second rotation mode. The wafer alignment method includes:

[0007] In the first rotation mode, in response to the motor rotating by a first fixed angle, the imaging device is used to photograph the edge of the wafer to obtain a first partial image of the field of view;

[0008] Target feature point detection is performed on the first partial image to determine the first partial image containing the target feature point as a target feature image;

[0009] The first initial coordinates of the target feature point are determined according to the target feature image;

[0010] In the second rotation mode, the motor is controlled to stop for a fixed time after rotating by a second fixed angle, and the imaging device is used to photograph the edge of the wafer to obtain a second partial image of the field of view. The second partial image does not contain the target feature point.

[0011] Based on multiple second partial images, determine the second initial coordinates of the wafer center;

[0012] Based on the first initial coordinates, the second initial coordinates, and the target alignment direction, determine the rotation angle of the target feature point and / or the adjustment offset between the wafer center and the center of the rotation platform; Specification 1 / 17 page 6 CN 121310948 A

[0013] Adjust the wafer center according to the adjustment offset to place it at the center of the rotation platform, and / or rotate the target feature point according to the rotation angle of the target feature point so that the line connecting the rotated target feature point and the rotated wafer center is consistent with the target alignment direction.

[0014] In some embodiments, after responding to the motor rotating by a first fixed angle, the method further includes:

[0015] recording a first position when the motor rotates by a first fixed angle;

[0016] when the first partial image is detected to have the target feature point, determining a second position of the motor when the imaging device captures the target feature image based on the first position and a pre-calibrated delay compensation angle when the imaging device captures the image;

[0017] controlling the motor to reverse from a third position at the current moment to the second position to rotate the target feature point to the initial position; wherein, the current moment is the moment when the first partial image is detected to have the target feature point.

[0018] In some embodiments, in a first rotation mode, in response to the motor rotating by a first fixed angle, the imaging device captures the edge of the wafer to obtain a first partial image of the imaging field of view area, including:

[0019] in the first rotation mode, controlling the motor to rotate one revolution, and capturing the edge of the wafer using the imaging device when the motor rotates by a first fixed angle to obtain a first partial image of the imaging field of view area.

[0020] In some embodiments, after obtaining a first partial image of the shooting field of view, the method further includes:

[0021] performing wafer breakage feature detection on the first partial image; if the first partial image has breakage features, then ending the alignment of the current wafer and outputting an alarm signal.

[0022] In some embodiments, the wafer alignment method further includes:

[0023] in response to the motor rotating by a first fixed angle, recording a first position when the motor rotates by a first fixed angle, and recording the order of the first partial images captured by the imaging device when the motor rotates by a first fixed angle, and determining the correlation between the first position and the order of the first partial images;

[0024] in response to having controlled the motor to rotate one revolution, determining, based on the order of the target feature images and the correlation between the first position and the order of the first partial images, that the target feature point rotates to the shooting field of view the fastest.The rotation direction of the region;

[0025] Based on the order of the target feature images, the correlation between the first position and the order of the first local image, and the pre-calibrated delay compensation angle when the imaging device takes a picture, determine the second position of the motor when the imaging device takes the target feature image;

[0026] Drive the motor to rotate from the third position at the current moment to the second position according to the rotation direction, so as to rotate the target feature point to the initial position; wherein, the current moment is the moment when the motor rotates one revolution.

[0027] In some embodiments, after rotating the target feature point to the initial position, the method further includes:

[0028] Switching the first rotation mode to the second rotation mode.

[0029] In some embodiments, the step of pre-calibrating the delay compensation angle includes:

[0030] controlling the motor to stand still, using the photographing device to photograph a fixed marker point on the rotating platform, and determining the first coordinates of the fixed marker point;

[0031] controlling the motor to rotate one revolution, using the photographing device to photograph the fixed marker point on the rotating platform, and determining the second coordinates of the fixed marker point;

[0032] determining the delay compensation angle based on the first coordinates, the second coordinates, and the pre-calibrated coordinates of the center of the rotating platform. In some embodiments, in the second rotation mode, controlling the motor to stop for a fixed time after rotating a second fixed angle, and using the imaging device to capture the edge of the wafer to obtain a second partial image of the captured field of view area includes:

[0034] In the second rotation mode, starting to control the motor to rotate one revolution, and stopping for a fixed time after rotating the second fixed angle, and using the imaging device to capture a partial image;

[0035] Among the multiple partial images captured by the motor rotating one revolution, the remaining partial images except the last partial image are used as the second partial image.

[0036] In some embodiments, determining the first initial coordinates of the target feature point based on the target feature image includes:

[0037] determining the relative positional relationship between the target feature point and the center point of the shooting field of view based on the pre-calibrated center coordinates of the shooting field of view, the pre-calibrated conversion relationship between the image size and the actual physical size, and the pixel position of the target feature point in the target feature image;

[0038] determining the first initial coordinates based on the pre-calibrated center coordinates of the shooting field of view, the pre-calibrated coordinates of the center of the rotating platform, and the relative positional relationship between the target feature point and the center point of the shooting field of view.

[0039] In some embodiments, determining the second initial coordinates of the wafer center based on multiple second partial images includes:The initial coordinates include:

[0040] Based on the arc features of the wafer in each of the second local images, a preset fitting algorithm is used to fit the rotation trajectory circle of the wafer center rotating around the center of the rotating platform; each wafer center on the rotation trajectory circle uniquely corresponds to a rotation angle of the motor;

[0041] The wafer center coordinates on the rotation trajectory circle corresponding to the motor in the second position are determined as the second initial coordinates of the wafer center.

[0042] In some embodiments, the step of determining the rotation angle of the target feature point includes:

[0043] According to the first initial coordinates and the second initial coordinates, a line segment between the wafer center and the target feature point is determined; the line segment moves in a circle around the center of the rotating platform;

[0044] Using a preset geometric algorithm, the target coordinates of the wafer center on the rotation trajectory circle when the line segment is in the target alignment direction are determined;

[0045] The rotation angle is determined according to the target coordinates of the wafer center, the second initial coordinates of the wafer center, and the pre-calibrated coordinates of the center of the rotating platform.

[0046] In some embodiments, the step of determining the offset to be adjusted between the wafer center and the center of the rotating platform includes:

[0047] determining the offset to be adjusted between the wafer center and the center of the rotating platform based on the target coordinates and the pre-calibrated coordinates of the rotating platform center.

[0048] In some embodiments, the wafer alignment method further includes:

[0049] determining the movement amount of the robot arm grasping the wafer based on the pre-calibrated coordinates of the robot arm and the target coordinates;

[0050] determining the movement angle of the robot arm grasping the wafer based on the pre-calibrated coordinates of the robot arm, the target coordinates, and the pre-calibrated coordinates of the rotating platform center;

[0051] controlling the robot arm to move to the rotating platform to grasp the wafer based on the movement amount and the movement angle. Instruction Manual 3 / 17 Page 8 CN 121310948 A

[0052] In some embodiments, adjusting the wafer center according to the offset to be adjusted includes: controlling the robotic arm to adjust the wafer center according to the offset to be adjusted;

[0053] Rotating the target feature point according to the rotation angle to be rotated includes:

[0054] controlling the rotating platform to rotate the wafer according to the rotation angle to be rotated of the target feature point.

[0055] In some embodiments, the first fixed angle is less than or equal to the difference between the shooting angle of the imaging device and a preset angle, wherein the preset angle is related to the space occupied by the actual physical feature corresponding to the target feature point;

[0056] The first fixed angle is less than the second fixed angle.

[0057] Secondly, embodiments of this disclosure also include a wafer alignment device, comprising a controller, an imaging device, a motor, and a rotating platform connected to the motor. The imaging device has a certain field of view, and a portion of the edge of the wafer located on the rotating platform falls into the field of view. The motor includes a first rotation mode and a second rotation mode.

[0058] The controller is configured to, in the first rotation mode, respond to the motor rotating by a first fixed angle... A first image capture command is sent to the imaging device to receive a first partial image sent by the imaging device; target feature point detection is performed on the first partial image to determine the first partial image containing the target feature point as the target feature image; the first initial coordinates of the target feature point are determined according to the target feature image; in the second rotation mode, the motor is controlled to stop for a fixed time after rotating a second fixed angle, and a second image capture command is sent to the imaging device to receive a second partial image sent by the imaging device; the second partial image does not contain the target feature point; the second initial coordinates of the wafer center are determined according to multiple second partial images; the rotation angle to be rotated of the target feature point and / or the adjustment offset between the wafer center and the center of the rotation platform are determined according to the first initial coordinates, the second initial coordinates and the target alignment direction; the wafer center is adjusted according to the adjustment offset to be located at the center of the rotation platform, and / or the target feature point is rotated according to the rotation angle to be rotated so that the line connecting the rotated target feature point and the rotated wafer center is consistent with the target alignment direction;

[0059] The photographing device is configured to, in response to the first photographing command, photograph the edge of the wafer to obtain a first partial image of the photographing field of view area and send it to the controller; and in response to the second photographing command, photograph the edge of the wafer to obtain a second partial image of the photographing field of view area and send it to the controller.

[0060] In a third aspect, embodiments of the present disclosure further include a semiconductor process apparatus, including a transfer chamber, a process chamber, a vacuum locking chamber, and a wafer alignment device as described in the second aspect, wherein the process chamber, the vacuum locking chamber, and the wafer alignment device are respectively connected to the transfer chamber.

[0061] In a fourth aspect, embodiments of the present disclosure further include a computer device, including: a processor, a memory, and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the computer device is running, the processor communicates with the memory via the bus, and when the machine-readable instructions are executed by the processor, the steps of the wafer alignment method as described in any one of the first aspects are performed.

[0062] In a fifth aspect, embodiments of the present disclosure further include a computer non-transient readable storage medium, wherein the computer non-transient readable storage medium is...A computer program is stored on a state-readable storage medium, which, when executed by a processor, performs the steps of the wafer alignment method as described in any one of the first aspects. Brief Description of the Drawings

[0063] FIG1 is a schematic diagram of a wafer alignment apparatus provided in an embodiment of the present disclosure.

[0064] FIG2 is a flowchart of a wafer alignment method provided in an embodiment of the present disclosure. Specification 4 / 17 pages 9 CN 121310948 A

[0065] FIG3 is a schematic diagram of different positions of the motor in a first rotation mode provided in an embodiment of the present disclosure.

[0066] FIG4 is a schematic diagram of calibrating the delay compensation angle provided in an embodiment of the present disclosure.

[0067] FIG5 is a schematic diagram of different positions of the motor in a second rotation mode provided in an embodiment of the present disclosure.

[0068] FIG6 is a schematic diagram of the wafer state when the target feature point is in the initial position provided in an embodiment of the present disclosure.

[0069] FIG7 is a schematic diagram of fitting the rotation trajectory circle provided in an embodiment of the present disclosure.

[0070] FIG8 is a schematic diagram of the wafer before and after rotation provided in an embodiment of the present disclosure.

[0071] Figure 9 is a schematic diagram of the relative positional relationship between the robotic arm and the wafer center provided in an embodiment of this disclosure.

[0072] Figure 10 is a schematic flowchart of a wafer alignment method provided in an embodiment of this disclosure.

[0073] Figure 11 is a front view of a wafer alignment device provided in an embodiment of this disclosure.

[0074] Figure 12 is a schematic structural diagram of a computer device provided in an embodiment of this disclosure. Detailed Description

[0075] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions in the embodiments of this disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The components of the embodiments of this disclosure described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely represents selected embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0076] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising,” “including,” or “including,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their contents.Equivalent, but not excluding other components or objects. Words such as “connection” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. “Up,” “down,” “left,” “right,” etc., are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0077] “Multiple or several” mentioned in this disclosure refers to two or more. “And / or” describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent: A alone, A and B at the same time, and B alone. The character “ / ” generally indicates that the related objects before and after are in an “or” relationship.

[0078] For thin wafers, if there is residual adhesive on their edges, the traditional wafer alignment device using a laser sensor to achieve alignment can easily lead to alignment failure. In related technologies, in order to improve alignment accuracy, image recognition is used, that is, using a camera to capture images of the wafer edges to achieve the purpose of accurate edge finding. However, the image recognition technology in the prior art has the following drawbacks: 1. Image sampling of the entire wafer requires high pixel and precision requirements for the camera used to acquire the image, which results in a high overall cost of the process system. In addition, acquiring an image of the entire wafer requires a sufficiently large field of view. For the current mainstream 8-inch or 12-inch wafers, a large space needs to be reserved on the semiconductor process equipment to support camera sampling, which will also increase the cost of the compact semiconductor process equipment. 2. Image sampling of local areas at the edge of the wafer requires saving each sampled image in order to calculate the offset (Δx, Δy) and deflection angle (Δθ) in subsequent data processing. This requires a large amount of memory space in the control system and a relatively complex algorithm to support the above data processing, which increases the additional cost of the control system. At the same time, the high cost of the manufacturing system is not conducive to widespread application.

[0079] In view of this, the present disclosure provides a wafer alignment method and apparatus, and a semiconductor process equipment. In essence, it achieves high-precision alignment of wafers through a relatively simple algorithm, a relatively simplified control system structure, and a low memory space.

[0080] Specifically, the wafer alignment method provided in this embodiment can be executed by a computer device with certain computing power. For example, the wafer alignment method is applied to a wafer alignment device. Figure 1 is a schematic diagram of the wafer alignment device provided in this embodiment. As shown in Figure 1, the executing entity of the wafer alignment method can be the controller 11 in the wafer alignment device. The wafer alignment device also includes an imaging device 12, a motor 13, and a rotor connected to the motor.Rotating platform 14. During wafer alignment, wafer 15 is placed on rotating platform 14, and motor 13 drives rotating platform 14 to rotate, thereby rotating wafer 15 on it. Imaging device 12 is placed on the side of wafer 15 away from rotating platform 14 and at a certain distance above wafer 15. Imaging device 12 has a certain field of view 120, and part of the edge of wafer 15 on rotating platform 14 falls into the field of view 120. Here, imaging device 12 captures the image located in the field of view 120, so that the image of part of the edge of wafer 15 falling into the field of view can be captured, that is, the partial image (first partial image and second partial image) below.

[0081] In the wafer alignment method provided in the embodiments of this disclosure, the motor has two rotation modes, namely the first rotation mode and the second rotation mode. Figure 2 is a flowchart of the wafer alignment method provided in the embodiments of this disclosure, as shown in Figure 2, including S11 to S17.

[0082] S11. In the first rotation mode, in response to the motor rotating by a first fixed angle, the edge of the wafer is photographed using a photographing device to obtain a first partial image of the photographed field of view.

[0083] S12. Target feature point detection is performed on the first partial image to determine the first partial image with target feature points, which is then used as the target feature image.

[0084] Here, an image recognition model can be used to perform target feature point detection on the first partial image.

[0085] S13. The first initial coordinates of the target feature points are determined based on the target feature image.

[0086] For the first rotation mode, the motor is controlled to rotate at a uniform speed (unlike the non-uniform rotation in the second rotation mode), and when the motor rotates by a first fixed angle, a command is sent to the photographing device to photograph the edge of the wafer to obtain a first partial image of the photographed field of view. This first partial image contains wafer edge features, such as arc features and / or target feature points, which represent notch features or flat edge features. Figure 1 uses notch features as an example; of course, the target feature points in this disclosure can also be other distinctive feature points. Each time the imaging device captures a first partial image, it immediately performs target feature point detection on the first partial image. Regardless of the detection result, the first partial image is discarded. If the detection result indicates that the first partial image has a target feature point, then the first partial image is used as the target feature image. If the detection result indicates that the first partial image does not have a target feature point, then the detection continues on the next first partial image.

[0087] Optionally, the first fixed angle is less than or equal to the difference between the shooting angle of the imaging device and the preset angle. The preset angle is related to the space occupied by the actual physical feature corresponding to the target feature point. For example, it is known that the shooting angle of the imaging device occupies a 15° range at the edge of the wafer, and the notch (representing the target feature point) occupies a 3° range at the edge of the wafer. Therefore, the first fixed angle can be set.The angle is set at 12° to ensure that the first partial images overlap partially each time a picture is taken. The motor rotates one revolution and takes 30 first partial images. This ensures that there is at least one image in the first partial images that contains the complete target feature point. Manual 6 / 17 page 11 CN 121310948 A

[0088] The timing of switching from the first rotation mode to the second rotation mode is as follows: In one possible implementation, since the motor rotates in real time and the process of the imaging device taking the first partial image and detecting the target feature point takes a certain amount of time, when the system detects the target feature point, the motor may drive the wafer to rotate the target feature point out of the shooting field of view. Therefore, when the target feature point is detected, it is necessary to determine whether the target feature point is still in the shooting field of view. If not, the target feature point needs to be rotated into the shooting field of view, and then the first rotation mode is switched to the second rotation mode to execute the process in the second rotation mode.

[0089] In another possible implementation, the motor is controlled to rotate one revolution at a constant speed from the original position, that is, return to the original position. If a target feature point is detected during this process, the motor is controlled to continue rotating from its original position to rotate the target feature point into the imaging field of view, and then switched to the second rotation mode to execute the process in the second rotation mode. If no target feature point is detected in the first rotation, the motor is controlled to rotate a second rotation from its original position, and the above process is repeated.

[0090] In some embodiments, before S14, S140 is also included: determining whether to switch to the second rotation mode; if yes, then S14 is executed; otherwise, S11 is returned.

[0091] S14: In the second rotation mode, the motor is controlled to stop for a fixed time after rotating a second fixed angle, and the wafer edge is photographed using the imaging device to obtain a second partial image of the imaging field of view.

[0092] Wherein, the second partial image does not contain the target feature point.

[0093] S15: Based on multiple second partial images, the second initial coordinates of the wafer center are determined.

[0094] For the second rotation mode, the motor is controlled to stop after rotating a second fixed angle, and a command is sent to the imaging device to photograph the wafer edge using the imaging device to obtain a second partial image of the imaging field of view. Since the timing of switching to the second selection mode is when the target feature point is located in the shooting field of view, after controlling the motor to rotate by a second fixed angle, the target feature point is moved out of the shooting field of view. Therefore, the second local image includes the arc feature of the wafer edge but does not include the target feature point, thus avoiding interference from the target feature point on the arc feature and improving the accuracy of subsequently determining the second initial coordinates. This, in turn, can better improve the accuracy of subsequently calculating the adjustment offset (Δx, Δy) of the wafer center.

[0095] In the second rotation mode, the motor can stop after rotating one revolution or after rotating multiple revolutions.Then stop, the specific settings can be made according to the actual application and wafer alignment accuracy. It should be noted that the more times the motor rotates, the more second local images are captured, the higher the accuracy of fitting the wafer center, and the higher the final wafer alignment accuracy. The second fixed angle corresponding to different numbers of motor rotations can be the same or different.

[0096] It should be noted that the second fixed angle is greater than or equal to the shooting angle of the imaging device, that is, the angle corresponding to the shooting field of view area, to ensure that after the motor rotates the second fixed angle, the target feature point moves out of the shooting field of view area. Optionally, the second fixed angle is between 15° and 90°, including the endpoint value. Optionally, the second fixed angle is greater than the first fixed angle.

[0097] Optionally, in the second rotation mode, start controlling the motor to rotate one revolution, and stop for a fixed time after each second fixed angle rotation, and use the imaging device to capture a local image; among the multiple local images captured by the motor rotating one revolution, the remaining local images except the last local image are used as the second local image. For example, the second fixed angle can be 15°, 30°, 45°, 60°, 75°, or 90°. Taking a second fixed angle of 90° as an example, four local images are captured in one rotation of the motor. The first three local images are used as the second local images for calculating the second initial coordinates of the wafer center, while the last local image carrying the target feature point is not used in the calculation. Taking a second fixed angle of 60° as an example, six local images are captured in one rotation of the motor. The first five local images are used as the second local images for calculating the second initial coordinates of the wafer center, while the last local image carrying the target feature point is not used in the calculation. It should be noted that the more second local images involved in the calculation of the second initial coordinates, the more accurate the determined second initial coordinates will be. This disclosure sets the second fixed angle between 15° and 90° on page 7 / 17 of the specification, which can both ensure the accuracy of the second initial coordinates and save the amount of calculation, reducing the memory space required to store the second local images.

[0098] The number of times the first local image is captured is greater than the number of times the second local image is captured. The first local image is captured, inspected, and discarded immediately to save memory. Multiple second local images are stored for use in calculating the second initial coordinates.

[0099] Here, the control motor stops after rotating by a second fixed angle, which can capture the local edge of the wafer in a stable state, thereby obtaining a more stable second local image and ensuring the accuracy of the wafer's local edge features.

[0100] S16. Based on the first initial coordinates, the second initial coordinates, and the target alignment direction, determine the rotation angle of the target feature point and / or the offset to be adjusted between the wafer center and the center of the rotating platform.

[0101] Wherein, the target alignment direction L02 refers to the pre-set specified direction that meets the process requirements, as shown in Figure 8.

[0102] S17. Adjust the wafer center according to the offset to be adjusted so that it is located at the center of the rotating platform, and / or rotate the target feature point according to the rotation angle to be rotated so that the line connecting the rotated target feature point and the rotated wafer center is consistent with the target alignment direction.

[0103] It should be noted that the wafer deviation includes the offset between the wafer center and the center of the rotating platform, and / or the offset of the line connecting the target feature point and the wafer center. If the wafer deviation is only the offset between the wafer center and the center of the rotating platform, then it is only necessary to adjust the wafer center according to the offset to be adjusted so that it is located at the center of the rotating platform. If the wafer deviation is only the offset of the line connecting the target feature point and the wafer center, then it is only necessary to rotate the target feature point according to the rotation angle to be rotated so that the line connecting the rotated target feature point and the rotated wafer center is consistent with the target alignment direction. Alternatively, if the wafer deviation includes the offset between the wafer center and the center of the rotating platform and the offset of the line connecting the target feature point and the wafer center, then wafer alignment includes two parts: the alignment of the wafer center and the alignment of the rotation direction of the target feature point. The alignment of the wafer center refers to moving the wafer center to the center of the rotating platform; the alignment of the rotation direction of the target feature point refers to rotating the wafer so that the line connecting the rotated target feature point and the rotated wafer center is consistent with the target alignment direction. Here, the target alignment direction is also the specified direction that meets the process requirements.

[0104] The wafer alignment method provided in this embodiment sets two rotation modes for the motor. In the first rotation mode, a first partial image is obtained to determine the first initial coordinates of the target feature point; in the second rotation mode, a second partial image is obtained to determine the second initial coordinates of the wafer center. The identification processes of the target feature point and the wafer center are processed separately. Thus, during the identification of the target feature point, the first partial image can be captured, inspected, and discarded immediately, saving memory space required for capturing a large number of first partial images to identify the target feature point. The "more first local images" here can be understood as a larger number compared to the captured second local images. Simultaneously, in the process of independently identifying the wafer center, the second local images do not contain target feature points, eliminating the interference of target feature points on the recognition of arc features, thereby improving the accuracy of the second initial coordinates and thus better improving the precision of the adjusted offset (Δx, Δy). Furthermore, since the second local images are free from the interference of target feature points, only a small number of second local images are needed to determine a relatively accurate second initial coordinate, saving memory space. Additionally, in the second rotation mode, the motor stops after rotating a second fixed angle. In the stopped state, a local edge image of the wafer in a stable state can be captured to obtain a more stable second local image, which can ensure...To ensure the accuracy of local edge features of the wafer, the accuracy of the second initial coordinates is improved. Furthermore, the identification processes of target feature points and the wafer center are handled separately. The first initial coordinates are determined by identifying the target feature points separately, and the second initial coordinates of the wafer center are calculated separately. This simplifies the algorithmic complexity of a single process and simplifies data processing. The above processing can be supported by a system with lower computing power, without sacrificing wafer alignment accuracy. Here, the control system with lower computing power has lower cost, thus the above implementation method of this disclosure is more conducive to the application and use of low-cost devices. In addition, this disclosure utilizes an image recognition model to identify wafer edge features, so that the detection of target feature points is not affected by the colloid on the supporting substrate, reducing the alignment failure caused by the colloid blocking the laser in the application of bonded wafers (page 8 / 17, CN 121310948 A). Furthermore, the imaging field of view of the imaging device of this disclosure is only a local area of ​​the wafer, which can improve the structural compactness of the wafer alignment device compared to related technologies without increasing additional costs.

[0105] In some embodiments, a method for switching from a first rotation mode to a second rotation mode specifically includes S21 to S24.

[0106] S21: In response to the motor rotating by a first fixed angle, record the first position of the motor at each first fixed angle rotation.

[0107] Here, the first position can be a specific rotation angle. Taking a first fixed angle of 12° as an example, a total of 30 first positions are recorded when the motor rotates one revolution. The first first position is 12°, the second first position is 24°, the third first position is 36°, and so on, with the 30th first position being 360°.

[0108] This step S21 is executed synchronously with the above step S11. That is, in response to the motor rotating by a first fixed angle, record the first position of the motor and simultaneously send a command to the imaging device. After receiving the command, the imaging device captures a first partial image. Since the transmission and response of the command, as well as the shooting process, all require a certain amount of time, the first position of the motor is different from the shooting position of the first partial image. Figure 3 is a schematic diagram of the motor in different positions under the first rotation mode provided in the embodiment of this disclosure. As shown in Figure 3, the coordinate system here is the platform coordinate system with the center O of the rotating platform as the origin. O represents the coordinates of the pre-calibrated center of the rotating platform, O1 represents the coordinates of the wafer center, and O2 represents the center coordinates of the pre-calibrated shooting field of view 120. The rotation trajectory of the wafer center O1 around the center O of the rotating platform is a standard circle. Figure (a) shows the situation when the motor is stationary and in the original position (0°), Figure (b) shows the situation when the motor rotates by a first fixed angle and is in the first position (12°), and Figure (c) shows the situation when the motor is in the second position (12°+R0) when the imaging device captures the first partial image.(d) indicates the third position (>12°+R0) of the motor when the first local image is identified as having a target feature point.

[0109] S22. When the first local image is detected to have a target feature point, the second position of the motor when the camera takes a picture of the target feature image is determined according to the first position and the pre-calibrated delay compensation angle when the camera takes a picture.

[0110] Here, the delay compensation angle is a pre-tested angle used to compensate for the transmission and response of the command and the angle through which the motor rotates during the time required for the shooting process, that is, the difference between the second position in Figure (c) and the first position in Figure (b), which is the delay compensation angle R0 as follows.

[0111] In one embodiment, FIG4 is a schematic diagram of the calibration delay compensation angle provided in the present disclosure. As shown in FIG4, the step of pre-calibrating the delay compensation angle includes: controlling the motor to stand still, using a photographic device to photograph the fixed mark point of the tool ruler 19 on the rotating platform (as shown in the hexagonal pattern), and determining the first coordinate B1 of the fixed mark point; controlling the motor to rotate one revolution (i.e., rotating 360 degrees from the original position back to the original position), using a photographic device to photograph the fixed mark point on the rotating platform, and determining the second coordinate B2 of the fixed mark point; determining the delay compensation angle based on the first coordinate B1, the second coordinate B2 and the pre-calibrated coordinates of the rotating platform center O. Specifically, a geometric algorithm can be used to calculate the angle R0 between the line connecting point B1 and point O and the line connecting point B2 and point O, which is the delay compensation angle.

[0112] As shown in FIG3, given the delay compensation angle R0 and the first position 12°, the second position is determined to be 12° + R0.

[0113] S23. Control the motor to reverse from the third position at the current moment to the second position, so as to rotate the target feature point to the initial position.

[0114] Wherein, the current moment is the moment when the first local image is detected to have a target feature point. From issuing the shooting command, to taking the picture, and then to detecting the target feature point, the command transmission time, the shooting time, and the feature detection time are experienced. Since the time for command transmission, shooting, and feature detection is relatively fast, the total time of the three is less than the time for the motor to rotate one revolution. Thus, controlling the motor to reverse can ensure that the target feature point returns to the shooting field of view 120 at the fastest speed. Manual 9 / 17 pages 14 CN 121310948 A

[0115] As shown in Figure 3, since it also takes a certain amount of time from taking the first local image to detecting the target feature point, the motor rotates from the second position to the third position. The target feature point corresponding to the third position may have rotated out of the shooting field of view 120. Therefore, in order to ensure that the target feature point is within the shooting field of view 120, this disclosure rotates the target feature point back to the shooting field of view 120 as quickly as possible, that is, controls the motor to reverse from the current third position to the second position. The position of the target feature point under the second position of the motor is taken as the initial position of the target feature point.

[0116] Here, the target feature point is rotated back to the shooting field of view as the initial position of the motor when the second rotation mode is turned on, so as to ensure that the second local image acquired in the second rotation mode will not capture the target feature point, thus removing the interference of the target feature point in the second local image.

[0117] S24, switch the first rotation mode to the second rotation mode.

[0118] Here, after rotating the target feature point back to the shooting field of view, the second rotation mode can be switched.

[0119] Figure 5 is a schematic diagram of different positions of the motor in the second rotation mode provided in the embodiment of this disclosure. As shown in Figure 5, after the mode is switched, the shooting command is triggered every time the motor rotates a second fixed angle (90°). Figure 5(a) shows that the motor rotates a second fixed angle (90°) from the position in Figure 3(c) and the first second local image is captured by the shooting device. Figure 5(b) shows that the motor rotates a second fixed angle (90°) from the position in Figure 5(a) and the second second local image is captured by the shooting device. Figure 5(c) shows the motor rotating from the position in Figure 5(b) by a second fixed angle (90°) and the third second partial image being captured by the imaging device.

[0120] In some embodiments, to avoid wafer breakage, this disclosure adds a breakage detection mechanism to detect whether there is breakage at the edge of the wafer. To avoid missing breakage and reducing yield, it is necessary to ensure that the entire edge of the wafer is detected, so the motor rotates at least one revolution. At the same time, the setting of the first fixed angle needs to be less than or equal to the shooting angle of the imaging device to ensure that each edge of the wafer can be captured by the imaging device when the wafer rotates one revolution.

[0121] Specifically, S31 is included in the above S11: In the first rotation mode, the motor is controlled to rotate one revolution, and when the motor rotates by the first fixed angle, the edge of the wafer is captured by the imaging device to obtain a first partial image of the shooting field of view. Further breakage detection is performed, specifically including S32~S34.

[0122] S32, wafer breakage feature detection is performed on the first partial image.

[0123] It should be noted that before the alignment process, a first feature image with standard notch features of the wafer and a second feature image with standard arc features of the wafer need to be stored in advance. Specific detection methods may include: extracting the notch features (representing target feature points) and arc features of each first local image, comparing them with the standard notch features and standard arc features in the first feature image respectively, calculating the similarity; if the similarity of either is lower than a set value, it indicates that the wafer is damaged. Alternatively, an image recognition model can be used to determine whether the notch features and arc features of the first local image are standard notch features and standard arc features. This recognition technology is not affected by residual adhesive on the supporting substrate and can accurately identify wafer notches and damage.

[0124] S33: Does a damage feature exist? If it does, proceed to S34 and end the detection; otherwise, proceed to S12.

[0125] S34. Output alarm signal. The alarm signal is used to indicate that the currently aligned wafer is damaged and needs to be removed.

[0126] Here, the motor is controlled to rotate one revolution. Taking the first fixed angle as 12° as an example, 30 first local images are sequentially checked for damage. If one image has damage features, the process ends and the wafer is waited to be removed. If the first local image does not have damage features, the target feature point is further detected and then discarded to save memory.

[0127] Unlike the above S31~S34 stages, the stopping time node of the motor rotating according to the first fixed angle in S21~S24 is when the first local image is detected to have target feature points, that is, the time at position 3(d) in Figure 3. The stopping time node of the motor rotating according to the first fixed angle in S31~S34 is when it stops after rotating one revolution. Instruction manual, pages 10 / 17, CN 121310948 A

[0128] In some embodiments, another method of switching from the first rotation mode to the second rotation mode specifically includes S41~S45.

[0129] S41: In response to the motor rotating by a first fixed angle, record the first position when the motor rotates by the first fixed angle, and record the order of the first partial images captured by the camera device when the motor rotates by the first fixed angle, and determine the correlation between the first position and the order of the first partial images.

[0130] Taking the first fixed angle as 12° as an example, a total of 30 first positions are recorded when the motor rotates one revolution. The first first position is 12°, the second first position is 24°, the third first position is 36°, and so on, with the 30th first position being 360°. A total of 30 first partial images are captured, with 12° corresponding to the first first partial image, 24° corresponding to the second first partial image, and so on, with 360° corresponding to the third first partial image. It should be noted that this disclosure does not store 30 first partial images, but only records the order of the first partial images.

[0131] S42. In response to the motor having been controlled to rotate one revolution, the rotation direction in which the target feature point rotates fastest to the shooting field of view is determined according to the order of the target feature images and the correlation between the first position and the order of the first partial images.

[0132] During the rotation of the motor, the target feature point is detected, and the order of the first partial images is recorded, which is the order of the target feature images. According to the correlation between the order and the first position, for example, if the order is 4, then the first position is 48°, and the rotation direction in which the target feature point rotates fastest to the shooting field of view is forward rotation. According to the correlation between the order and the first position, for example, if the order is 20, then the first position is 240°, and the rotation direction in which the target feature point rotates fastest to the shooting field of view is reverse rotation.

[0133] S43. According to the order of the target feature images, the correlation between the first position and the order of the first partial images, and the rotation direction in which the target feature point rotates fastest to the shooting field of view, the rotation direction in which the target feature point rotates fastest to the shooting field of view is reverse rotation.And the pre-calibrated delay compensation angle when the camera takes a picture, determine the second position of the motor when the camera takes a picture of the target feature image.

[0134] According to the order of the target feature images and the correlation between the first position and the order of the first local image, determine the first position of the motor when recording the target feature image. Due to the influence of the shooting delay, the first position of the motor when recording the target feature image is different from the second position of the motor when shooting the target feature image. The specific principle can be seen in Figure 3 above, and the repeated part will not be repeated.

[0135] Taking the first position as 48° as an example, the second position of the motor when the camera takes a picture of the target feature image is determined to be 48° + R0. Taking the first position as 240° as an example, the second position of the motor when the camera takes a picture of the target feature image is determined to be 240° + R0.

[0136] S44, drive the motor to rotate from the third position at the current moment to the second position according to the rotation direction, so as to rotate the target feature point to the initial position.

[0137] Wherein, the current moment is the moment when the motor rotates one revolution.

[0138] Since the motor stops after rotating one revolution in this embodiment, the third position of the motor at the current moment is the original position 0°. For example, controlling the motor to rotate forward by 48° + R0 will rotate the target feature point to the initial position. Or, controlling the motor to rotate backward by 360° - (240° + R0) will rotate the target feature point to the initial position, ensuring that the target feature point rotates to the shooting field of view as quickly as possible, saving time and improving efficiency.

[0139] S45, switch the first rotation mode to the second rotation mode.

[0140] In some embodiments, the step of determining the first initial coordinates A(x1, y1) in S13 specifically includes: determining the relative positional relationship between the target feature point and the center point of the shooting field of view based on the pre-calibrated center coordinates of the shooting field of view, the pre-calibrated conversion relationship between the image size and the actual physical size, and the pixel position of the target feature point in the target feature image; determining the first initial coordinates based on the pre-calibrated center coordinates of the shooting field of view, the pre-calibrated coordinates of the center of the rotating platform, and the relative positional relationship between the target feature point and the center point of the shooting field of view.

[0141] Figure 6 is a schematic diagram of the wafer state when the target feature point is in the initial position according to the embodiment of this disclosure. As shown in Figure 6, the image corresponding to the shooting field of view 120 at this time is the target feature image. The coordinate system here is the platform coordinate system with the center O(x0, y0) of the rotating platform as the origin. O(x0, y0) represents the coordinates of the pre-calibrated center of the rotating platform, and O2(x0', y0') represents the coordinates of the pre-calibrated center of the shooting field of view. For example, the x-coordinate x0' of point O2 can be x0, i.e.Point O is on the same vertical line as point O, i.e., located on the Y-axis of the platform coordinate system. The relative positional relationship C1 between the center O of the rotating platform and the center O2 of the shooting field of view 120 is determined. For example, point O2 is at a distance of y0'-y0 from point O.

[0142] The conversion relationship between the image size and the actual physical size is pre-calibrated. Specifically, the pixel points can be calibrated by having the camera shoot a standard tooling ruler placed on the rotating platform. Knowing the actual physical size of the tooling ruler and the pixel resolution in the shooting field of view, the conversion relationship between the image size and the actual physical size can be determined, thereby determining the size of each pixel point.

[0143] The pixel position of the target feature point in the target feature image is detected when the target feature image is subjected to target feature point detection. It should be noted that before the alignment process, a first feature image with the standard notch feature of the wafer needs to be pre-stored. The specific detection method may include: comparing the edge features of the first local image with the standard notch feature of the first feature image, calculating the similarity between the two, and if the similarity between the two exceeds a set value, it is considered that the first local image contains a target feature point. Thus, based on the pixel position of the target feature point in the target feature image, combined with the size of the pixel and the number of horizontal and vertical pixels from the pixel position of the target feature point to point O2, the horizontal and vertical distances of the target feature point from point O2 are determined, which is the relative positional relationship C2 between the target feature point and the center point of the shooting field of view. Given the relative positional relationship C1 between the center of the rotating platform and the center point of the shooting field of view, and the relative positional relationship C2 between the target feature point and the center of the shooting field of view, the relative positional relationship C3 between the target feature point and the center of the rotating platform can be determined, thereby determining the first initial coordinate A (x1, y1).

[0144] In some embodiments, the step of determining the second initial coordinate B (x2, y2) for the above S15 specifically includes: based on the arc features of the wafer in each second local image, using a preset fitting algorithm, fitting the rotation trajectory circle of the wafer center rotating around the center of the rotating platform; determining the wafer center coordinates on the rotation trajectory circle corresponding to the second position of the motor, as the second initial coordinates of the wafer center.

[0145] Figure 7 is a schematic diagram of the fitted rotation trajectory circle provided in the embodiment of this disclosure. As shown in Figure 7, the motor rotates, the wafer makes an eccentric motion, but the wafer center O1 rotates around the center O of the rotating platform, and the trajectory of the wafer center O1 is a standard circle. Taking a second fixed angle of 90° as an example, there are a total of 3 second local images. Here, the arc features of the wafer in the second local image can be extracted using an image recognition model. As shown in Figure 5, the arc features in the second local image when the motor rotates to 90° are extracted, the arc features in the second local image when the motor rotates to 180° are extracted, and the arc features in the second local image when the motor rotates to 270° are extracted.The arc features of the wafer are used to fit the rotation trajectory circle of the wafer center around the center of the rotating platform using the arc features of the three second local images. Here, the fitting method can be RANSAC, least squares method, etc., and can be implemented by a single method or a combination of multiple methods. No specific restrictions are imposed here. As shown in Figure 7, each wafer center O1 on the fitted rotation trajectory circle uniquely corresponds to the rotation angle of a motor. The coordinates of the wafer center on the rotation trajectory circle corresponding to the second position of the motor (that is, when the target feature point is in the initial position) are output, which are the second initial coordinates B(x2, y2) of the wafer center.

[0146] Optionally, based on the second initial coordinates B(x2, y2) of the wafer center and the coordinates O(x0, y0) of the center of the rotating platform, it is determined whether the wafer center to the center of the rotating platform exceeds the preset position deviation allowable value. If it exceeds the allowable value, the calculation is stopped, the process ends, and the wafer is waited to be moved out. If it does not exceed the allowable value, the process can continue. Instruction manual, pages 12 / 17, CN 121310948 A

[0147] Further, the step of determining the rotation angle Δθ of the target feature point includes: determining the line segment between the wafer center and the target feature point according to the first initial coordinate and the second initial coordinate; the line segment moves in a circle around the center of the rotating platform; using a preset geometric algorithm, determining the target coordinates of the wafer center on the rotation trajectory circle when the line segment is in the target alignment direction; determining the rotation angle according to the target coordinates of the wafer center, the second initial coordinates of the wafer center and the coordinates of the pre-calibrated center of the rotating platform.

[0148] Here, the preset geometric algorithm can be a calculation method such as vector geometric constraint solution or nonlinear equation numerical solution. In the field of semiconductor equipment, this type of calculation is often called "wafer feature point rotation positioning algorithm" or "angle constraint-based notch search method". This disclosure does not limit this.

[0149] Figure 8 is a schematic diagram of the wafer before and after rotation provided in the embodiment of this disclosure. As shown in Figure 8, the solid line represents the state before the wafer rotation and the dashed line represents the state after the wafer rotation. The rotation trajectory of the wafer center is a standard circle. L0 represents the line segment between the wafer center and the target feature point, and line segment L0 moves in a circle around the center O of the rotation platform. Based on the first initial coordinates A (x1, y1) and the second initial coordinates B (x2, y2), the initial extension direction L01 of line segment L0 can be determined; the target alignment direction L02 of line segment L0 is also known. Based on the initial extension direction L01, the target alignment direction L02, the first initial coordinates A (x1, y1), the second initial coordinates B (x2, y2), and the coordinates O (x0, y0) of the rotation platform center, the target coordinates C (x3, y3) of the wafer center on the rotation trajectory circle when line segment L0 is in the target alignment direction L02 can be determined using a vector geometry constraint solution algorithm.The target coordinates C(x3, y3) of the wafer center, the second initial coordinates B(x2, y2) of the wafer center, and the coordinates O(x0, y0) of the pre-calibrated rotation platform center are used to solve the angle between the line connecting points O and B and the line connecting points O and C using geometry. This angle is the rotation angle Δθ.

[0150] Further, the step of determining the adjustment offset (Δx, Δy) between the wafer center and the rotation platform center includes: determining the adjustment offset (Δx, Δy) between the wafer center and the rotation platform center based on the target coordinates C(x3, y3) and the pre-calibrated coordinates O(x0, y0). Specifically, Δx = x3 - x0, Δy = y3 - y0.

[0151] In some embodiments, the wafer alignment system includes a host computer, a wafer alignment device, and a robot arm. The robot arm is mainly used to adjust the wafer offset. The wafer alignment method also includes determining the motion parameters of the robot arm, including the amount of movement (Δx1, Δy1) and the movement angle Δθ1 of the wafer gripper. Specifically, the amount of movement of the robot arm gripping the wafer can be determined based on the pre-calibrated coordinates of the robot arm and the target coordinates; the movement angle of the robot arm gripping the wafer can be determined based on the pre-calibrated coordinates of the robot arm, the target coordinates, and the pre-calibrated coordinates of the center of the rotating platform; and the robot arm is controlled to move to the rotating platform to grip the wafer based on the amount of movement and the movement angle. Here, the controller of the wafer alignment device can control the movement of the robot arm, or the controller can send the amount of movement and the movement angle to the host computer, and the host computer can control the movement of the robot arm.

[0152] Figure 9 is a schematic diagram of the relative positional relationship between the robot arm and the center of the wafer provided in the embodiment of this disclosure. As shown in Figure 9, the coordinates of the robot arm can be the coordinates of the gripping center M (x4, y4) of the robot arm. The amount of movement of the robot arm gripping the wafer includes Δx1 = x4 - x3, Δy1 = y4 - y3. The ordinate y4 of point M can be y0, that is, it is on the same horizontal line as point O, that is, located on the X-axis of the platform coordinate system. According to the pre-calibrated coordinates M (x4, y4) of the robot arm, the target coordinates C (x3, y3) and the pre-calibrated coordinates O (x0, y0) of the center of the rotating platform, the angle between the line connecting points M and O and the line connecting points M and C is calculated using geometry, which is the moving angle Δθ1 of the robot arm to grasp the wafer. The robot arm can be controlled to deflect the moving angle Δθ1, move Δx1 along the X direction and Δy1 along the Y direction, so as to align with points M and C to grasp the wafer.

[0153] Further, the robot arm can be controlled to adjust the center of the wafer according to the offset to be adjusted so that it is located at the center of the rotating platform, that is, move Δx along the X direction and Δy along the Y direction, so that the center of the wafer coincides with the center of the rotating platform. And / or, the rotating platform can be controlled to rotate the wafer according to the rotation angle Δθ of the target feature point, so that the direction of the line connecting the rotated target feature point and the center of the rotated wafer is consistent with the target alignment direction L02. It should be noted that this disclosure does not limit the adjustment to the specification.Page 13 / 17 18 CN 121310948 A The order of adjusting the offset (△x, △y) and the rotation angle △θ can also be that △θ is adjusted first, and then (△x, △y) is adjusted.

[0154] In order to facilitate the understanding of the above wafer alignment method in this disclosure, a complete process example is given below. Figure 10 is a schematic diagram of a specific process of a wafer alignment method provided by an embodiment of this disclosure. As shown in Figure 10, it includes S51~S512.

[0155] S51: Start the motor according to the first rotation mode and control the motor to rotate to the original position.

[0156] Here, the original position means that the motor rotates to the 0° position.

[0157] S52: Start controlling the motor to rotate one revolution, and take a first partial image using a camera device every time it rotates the first fixed angle.

[0158] S53: Determine whether there is a wafer on the rotating platform. If so, execute S54 in sequence; otherwise, execute S513.

[0159] Here, feature comparison can be used to determine whether a wafer exists on the rotating platform. For example, before the alignment process, a first feature image with the standard notch feature of the wafer and a second feature image with the standard arc feature of the wafer are pre-stored. The first partial image actually captured is checked to see if it has features that conform to the above standard features. If it does, it means that a wafer exists; otherwise, it means that a wafer does not exist.

[0160] S54. Determine whether the wafer is damaged. If not, execute S55 sequentially; otherwise, execute S513.

[0161] S55. Detect target feature points on the first partial image to determine the target feature image, and execute S56 and S57 simultaneously.

[0162] S56. Determine the first initial coordinates of the target feature point based on the target feature image.

[0163] S57. Control the motor to rotate the target feature point to the initial position.

[0164] S58. Switch to the second rotation mode.

[0165] S59. Start controlling the motor to rotate one revolution, and stop for a fixed time after rotating a second fixed angle, and take a second partial image using a camera.

[0166] S510. Based on multiple second partial images, fit the rotation trajectory circle of the wafer center rotating around the center of the rotating platform, and determine the second initial coordinates of the wafer center.

[0167] S511. Based on the first initial coordinates, the second initial coordinates, and the target alignment direction, determine the rotation angle of the target feature point and / or the offset to be adjusted between the wafer center and the center of the rotating platform.

[0168] S512. Adjust the wafer center according to the offset to be adjusted, and / or rotate the target feature point according to the rotation angle of the target feature point.

[0169] S513. End the process and output an alarm signal.

[0170] Those skilled in the art will understand that in the above method of the specific embodiment, the writing order of each step andThis does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0171] This embodiment of the present disclosure also provides a wafer alignment device corresponding to the wafer alignment method. Since the principle of the device in this embodiment of the present disclosure for solving the problem is similar to the wafer alignment method described above in this embodiment of the present disclosure, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0172] As shown in FIG1, the wafer alignment device includes a controller 11, an imaging device 12, a motor 13 and a rotating platform 14 connected to the motor 13. The imaging device 12 has a certain shooting field of view area 120, and part of the edge of the wafer 15 located on the rotating platform 14 falls into the shooting field of view area; the motor includes a first rotation mode and a second rotation mode. The controller is configured to, in a first rotation mode, send a first image capture command to an imaging device every time the motor rotates a first fixed angle, to receive a first partial image sent by the imaging device (see page 14 / 17 of the imaging manual, CN 121310948 A); perform target feature point detection on the first partial image to determine a first partial image containing the target feature point, which is taken as the target feature image; determine the first initial coordinates of the target feature point based on the target feature image; in a second rotation mode, control the motor to stop for a fixed time after rotating a second fixed angle and send a second image capture command to the imaging device, to receive a second partial image sent by the imaging device; the second partial image does not contain the target feature point; determine the second initial coordinates of the wafer center based on multiple second partial images; determine the rotation angle to be rotated for the target feature point and / or the adjustment offset between the wafer center and the center of the rotation platform based on the first initial coordinates, the second initial coordinates, and the target alignment direction; adjust the wafer center according to the adjustment offset to position it at the center of the rotation platform, and / or rotate the target feature point according to the rotation angle to be rotated, so that the line connecting the rotated target feature point and the rotated wafer center is consistent with the target alignment direction. The imaging device is configured to, in response to a first imaging command, capture a wafer edge to obtain a first partial image of the imaging field of view and send it to the controller; and in response to a second imaging command, capture a wafer edge to obtain a second partial image of the imaging field of view and send it to the controller.

[0173] It should be noted that the controller in this embodiment is configured to execute steps S11 to S17 in the wafer alignment method described above, and repeated parts will not be described again.

[0174] The wafer alignment device provided in this embodiment sets two rotation modes for the motor. In the first rotation mode, a first partial image is obtained to determine the first initial coordinates of the target feature point; in the second rotation mode, a second partial image is obtained to determine the second initial coordinates of the wafer center; the identification process of the target feature point and the wafer center is separated.This processing method allows for the immediate capture, inspection, and discarding of the first local image during target feature point identification, saving memory space compared to the large number of first local images required for target feature point identification. Here, "larger number of first local images" can be understood as a greater number compared to the number of second local images captured. Simultaneously, in the process of independently identifying the wafer center, the second local image does not contain target feature points, eliminating interference from target feature points on arc feature identification, thereby improving the accuracy of the second initial coordinates and further enhancing the precision of the adjusted offset (Δx, Δy). Furthermore, since the second local image is free from target feature point interference, only a small number of second local images are needed to determine a relatively accurate second initial coordinate, saving memory space. Additionally, in the second rotation mode, the motor stops after rotating a second fixed angle. While stopped, a local edge image of the wafer in a stable state can be captured to obtain a more stable second local image, ensuring the accuracy of the wafer's local edge features and improving the precision of the second initial coordinates. In addition, the identification processes of target feature points and wafer center are handled separately. The target feature points are identified separately to determine the first initial coordinates, and the second initial coordinates of the wafer center are calculated separately. This simplifies the algorithm complexity of a single process and simplifies data processing. The above processing can be supported by a system with lower computing power, without sacrificing wafer alignment accuracy. Here, the control system with lower computing power has lower cost, so the above implementation method of this disclosure is more conducive to the application and use of low-cost devices. In addition, this disclosure uses an image recognition model to identify wafer edge features, so that the detection of target feature points is not affected by the colloid on the supporting substrate, reducing the alignment failure caused by the colloid blocking the laser in the application of bonding wafers. In addition, the shooting field of view of the imaging device of this disclosure is only a local area of ​​the wafer, which can improve the structural compactness of the wafer alignment device compared with related technologies without increasing additional costs.

[0175] As shown in FIG1, the imaging device 12 includes a camera 121 and a camera controller 122. The camera 121 is used to acquire local images and transmit them to the camera controller 122. The camera controller 122 sends the local images to the controller 11 for image processing. Alternatively, the camera controller 122 performs the target feature point detection and damage detection process and sends the detection results to the controller 11.

[0176] Figure 11 is a front view of the wafer alignment device provided in the embodiment of this disclosure. As shown in Figure 11, the wafer alignment device also includes a backlight source 16. The backlight source 16 is fixedly installed on the side of the wafer 15 away from the imaging device 12 and is set directly opposite to the shooting field of view 120. The wafer alignment device station uses glass (upper glass window 171, lower glass window 172) above and below to block out the atmosphere.Environmental isolation, i.e., wafer 15 is located inside vacuum chamber 18. The imaging device 12 and backlight source 16 are installed in the atmospheric environment. The emitted light from backlight source 16 shines vertically upward through the glass window onto the bottom of the wafer, which can increase the contrast of the wafer.

[0177] In addition, this disclosure also provides a wafer alignment system including a host computer, a wafer alignment device and a robot. The specific structure and function of the wafer alignment device are as described in the above embodiments. The wafer alignment device determines the offset to be adjusted (Δx, Δy) between the center of the wafer and the center of the rotating platform, the moving angle Δθ1 of the robot gripping the wafer and the moving amount (Δx1, Δy1) of the robot gripping the wafer. The host computer controls the robot to move to the position indicated by the target coordinate C (x3, y3) of the wafer center according to the moving angle Δθ1 and the moving amount (Δx1, Δy1), and grips the wafer and moves it to the center O (x0, y0) of the rotating platform. And / or, the wafer alignment device determines the rotation angle Δθ of the target feature point. The controller of the wafer alignment device controls the motor to rotate by an angle Δθ, so that the line connecting the rotated target feature point and the rotated wafer center is aligned with the target alignment direction.

[0178] In addition, this disclosure also provides a semiconductor process apparatus, including a transfer chamber, a process chamber, a vacuum locking chamber, and a wafer alignment device as described in any of the above embodiments and combinations thereof, wherein the process chamber, the vacuum locking chamber, and the wafer alignment device are respectively connected to the transfer chamber.

[0179] Optionally, the alignment chamber in the wafer alignment device is a vacuum chamber, and the wafer alignment device is a vacuum wafer alignment device.

[0180] A transfer mechanism, such as a vacuum manipulator, is provided in the transfer chamber. The process chamber, the vacuum locking chamber, and the wafer alignment device are respectively connected to the transfer chamber, so that the wafer can be transferred to any station using the transfer mechanism (such as a vacuum manipulator) in the transfer chamber. For example, the wafer located in the vacuum locking chamber is transferred to the vacuum wafer alignment device using the vacuum manipulator, and the wafer is aligned using the vacuum wafer alignment device.

[0181] Further, a transfer mechanism (such as a vacuum manipulator) within the transfer chamber can be used to transfer the wafer to the process chamber corresponding to the next station to perform the fabrication process of the next process stage. This embodiment of the present disclosure does not specify any particular process limitations.

[0182] Figure 12 is a schematic diagram of the structure of a computer device provided in an embodiment of the present disclosure. As shown in Figure 12, this embodiment of the present disclosure provides a computer device including: one or more processors 601, a memory 602, and one or more I / O interfaces 603. The memory 602 stores one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement any of the wafer alignment methods described in the above embodiments; one or more I / O interfaces...I / O interface 603 is connected between the processor and the memory, configured to enable information interaction between the processor and the memory.

[0183] Wherein, the processor 601 is a device with data processing capabilities, including but not limited to a central processing unit (CPU); the memory 602 is a device with data storage capabilities, including but not limited to random access memory (RAM, more specifically SDRAM, DDR, etc.), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory (FLASH); I / O interface (read / write interface) 603 is connected between the processor 601 and the memory 602, enabling information interaction between the processor 601 and the memory 602, including but not limited to a data bus (Bus).

[0184] In some embodiments, the processor 601, the memory 602 and the I / O interface 603 are interconnected through a bus 604, and then connected to other components of the computing device.

[0185] According to embodiments of the present disclosure, a non-transient readable storage medium for computers is also provided. The computer non-transient readable storage medium stores a computer program, which, when executed by a processor, implements the steps in any of the wafer alignment methods described in the above embodiments.

[0186] In particular, according to embodiments of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, embodiments of the present disclosure include a computer program product comprising a computer program carried on a machine-readable medium, the computer program containing program code for performing the methods shown in the flowchart. In such embodiments, the computer program can be downloaded and installed from a network via a communication portion, and / or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), it performs the functions defined in the system of the present disclosure.

[0187] It should be noted that the computer non-transient readable medium shown in the present disclosure can be a computer-readable signal medium or a computer-readable storage medium or any combination thereof. Computer-readable storage media can be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), and erasable programmable read-only memory (EPROM).Computer-readable storage media can be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In this disclosure, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can also be any non-transient readable storage medium other than a computer-readable storage medium, which can transmit, propagate, or transfer a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the non-transient readable storage medium can be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0188] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two adjacent blocks may actually represent substantially parallel execution, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0189] It is understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present disclosure, and the present disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and such modifications and improvements are also considered to be within the scope of protection of this disclosure. Specification 17 / 17 pages 22 CN 121310948 A Figure 1 Specification Figure 1 / 11 pages 23 CN 121310948 A Figure 2 Specification Figure 2 / 11 pages 24 CN 121310948 A Figure 3Figure 4 (Page 3 / 11, CN 121310948 A) Figure 5 (Page 5 / 11, CN 121310948 A) Figure 6 (Page 6 / 11, CN 121310948 A) Figure 7 (Page 7 / 11, CN 121310948 A) Figure 8 (Page 8 / 11, CN 121310948 A) Figure 9 (Page 9 / 11, CN 121310948 A) Figure 10 (Page 10 / 11, CN 121310948 A) Figure 11 (Page 11 / 11, CN 121310948 A) Abstract The present disclosure provides a wafer alignment method and apparatus, and a semiconductor process device. The wafer alignment method includes: in a first rotation mode, in response to each rotation of a motor by a first fixed angle, shooting an edge of a wafer by a photographing device to obtain a first local image; performing target feature point detection on the first local image to determine a target feature image; determining a first initial coordinate of a target feature point based on the target feature image; in a second rotation mode, controlling the motor to stop for a fixed period of time after rotating by a second fixedangle every time, and shooting the edge of the wafer by the photographing device to obtain a second local image; determining a second initial coordinate of a center of the wafer based on a plurality of second local images; determining a to-be-rotated angle and a to-be-adjusted offset based on the first initial coordinate, the second initial coordinate, and a target alignment direction; adjusting the center of the wafer based on the to-be-adjusted offset, and / or rotating the target feature point based on the to-be-rotated angle of the target feature point, thereby realizing wafer alignment.

Claims

1. A wafer alignment method, applied to a wafer alignment apparatus, the wafer alignment apparatus comprising an imaging device, a motor and a rotating platform connected to the motor, the imaging device having a certain field of view, wherein a portion of the edge of a wafer located on the rotating platform falls into the field of view; The motor includes a first rotation mode and a second rotation mode; characterized in that the wafer alignment method includes: In the first rotation mode, in response to the motor rotating by a first fixed angle, the imaging device is used to capture the edge of the wafer to obtain a first partial image of the field of view. Target feature point detection is performed on the first local image to determine the first local image containing the target feature points, which is then used as the target feature image. Based on the target feature image, determine the first initial coordinates of the target feature points; In the second rotation mode, the motor is controlled to stop for a fixed time after rotating a second fixed angle, and the imaging device is used to capture the edge of the wafer to obtain a second partial image of the captured field of view; the second partial image does not contain the target feature point. Based on multiple second local images, determine the second initial coordinates of the wafer center; Based on the first initial coordinates, the second initial coordinates, and the target alignment direction, determine the rotation angle of the target feature point and / or the adjustment offset between the wafer center and the center of the rotation platform; Adjust the wafer center according to the offset to be adjusted so that it is located at the center of the rotating platform, and / or rotate the target feature point according to the rotation angle of the target feature point so that the line connecting the rotated target feature point and the rotated wafer center is consistent with the target alignment direction.

2. The wafer alignment method according to claim 1, characterized in that, After responding to each rotation of the motor by a first fixed angle, the method further includes: Record the first position of the motor when it rotates by the first fixed angle; If the first local image is found to have the target feature point, the second position of the motor when the camera takes the picture is determined based on the first position and the pre-calibrated delay compensation angle when the camera takes the picture. The motor is controlled to reverse from the third position at the current moment to the second position, so as to rotate the target feature point to the initial position; wherein, the current moment is the moment when the first local image is detected to have the target feature point.

3. The wafer alignment method according to claim 1, characterized in that, In the first rotation mode, in response to each first fixed angle rotation of the motor, the imaging device captures an image of the wafer edge to obtain a first partial image of the captured field of view, including: In the first rotation mode, the motor is controlled to rotate one revolution, and when the motor rotates by a first fixed angle, the edge of the wafer is photographed using the imaging device to obtain a first partial image of the imaging field of view area.

4. The wafer alignment method according to claim 3, characterized in that, After obtaining the first partial image of the captured field of view, the process further includes: The first local image is subjected to wafer damage feature detection. If the first local image has damage features, the alignment of the current wafer is terminated and an alarm signal is output.

5. The wafer alignment method according to claim 3, characterized in that, Also includes: In response to each rotation of the motor by a first fixed angle, the first position of the motor at each rotation of the first fixed angle is recorded, and the order of the first partial images captured by the imaging device at each rotation of the motor by the first fixed angle is recorded, and the correlation between the first position and the order of the first partial images is determined. In response to the fact that the motor has been controlled to rotate one revolution, the rotation direction in which the target feature point rotates to the shooting field of view is determined according to the relationship between the order of the target feature images and the order of the first position and the first local image. Based on the order of the target feature images, the correlation between the first position and the order of the first local images, and the pre-calibrated delay compensation angle when the camera takes a picture, the second position of the motor when the camera takes the target feature image is determined; Drive the motor to rotate from the third position at the current moment to the second position in the direction of rotation, so as to rotate the target feature point to the initial position; wherein, the current moment is the moment when the motor completes one revolution.

6. The wafer alignment method according to claim 2 or 5, characterized in that, After rotating the target feature point to its initial position, the process further includes: Switch the first rotation mode to the second rotation mode.

7. The wafer alignment method according to claim 2 or 5, characterized in that, The step of pre-calibrating the delay compensation angle includes: The motor is kept stationary, and the photographic device is used to photograph a fixed marker point on the rotating platform to determine the first coordinate of the fixed marker point. Control the motor to rotate one revolution, use the imaging device to photograph the fixed mark point on the rotating platform, and determine the second coordinate of the fixed mark point; The delay compensation angle is determined based on the first coordinate, the second coordinate, and the pre-calibrated coordinates of the center of the rotating platform.

8. The wafer alignment method according to claim 1, characterized in that, In the second rotation mode, the motor is controlled to stop for a fixed time after rotating a second fixed angle, and the imaging device is used to capture the edge of the wafer to obtain a second partial image of the captured field of view, including: In the second rotation mode, the motor is controlled to rotate one revolution, and after each rotation of the second fixed angle, it stops for a fixed time and a partial image is captured using a camera. Of the multiple partial images captured when the motor rotates one revolution, the remaining partial images, except for the last one, are used as the second partial image.

9. The wafer alignment method according to claim 1, characterized in that, Determining the first initial coordinates of the target feature points based on the target feature image includes: Based on the pre-calibrated center coordinates of the shooting field of view, the pre-calibrated conversion relationship between the image size and the actual physical size, and the pixel position of the target feature point in the target feature image, the relative positional relationship between the target feature point and the center point of the shooting field of view is determined; The first initial coordinates are determined based on the pre-calibrated center coordinates of the shooting field of view, the pre-calibrated coordinates of the center of the rotating platform, and the relative positional relationship between the target feature point and the center point of the shooting field of view.

10. The wafer alignment method according to claim 1, characterized in that, The step of determining the second initial coordinates of the wafer center based on multiple second local images includes: Based on the arc features of the wafer in each of the second local images, a preset fitting algorithm is used to fit the rotation trajectory circle of the wafer center rotating around the center of the rotating platform; each wafer center on the rotation trajectory circle uniquely corresponds to a rotation angle of the motor. The coordinates of the wafer center on the rotation trajectory circle corresponding to the motor in the second position are determined as the second initial coordinates of the wafer center.

11. The wafer alignment method according to claim 10, characterized in that, The steps for determining the rotation angle of the target feature point include: Based on the first initial coordinates and the second initial coordinates, a line segment is determined between the center of the wafer and the target feature point; the line segment moves in a circle around the center of the rotating platform. Using a preset geometric algorithm, the target coordinates of the wafer center on the rotation trajectory circle are determined when the line segment is in the target alignment direction; The angle to be rotated is determined based on the target coordinates of the wafer center, the second initial coordinates of the wafer center, and the pre-calibrated coordinates of the rotation platform center.

12. The wafer alignment method according to claim 11, characterized in that, The steps for determining the offset to be adjusted between the wafer center and the center of the rotating platform include: Based on the target coordinates and the pre-calibrated coordinates of the rotating platform center, determine the offset to be adjusted between the wafer center and the rotating platform center.

13. The wafer alignment method according to claim 11, characterized in that, Also includes: Based on the pre-calibrated coordinates of the robotic arm and the target coordinates, the amount of movement by which the robotic arm grasps the wafer is determined; The movement angle of the robot arm to grasp the wafer is determined based on the pre-calibrated coordinates of the robot arm, the target coordinates, and the pre-calibrated coordinates of the center of the rotating platform; Based on the amount of movement and the angle of movement, the robotic arm is controlled to move to the rotating platform to grasp the wafer.

14. The wafer alignment method according to claim 1, characterized in that, The step of adjusting the wafer center according to the offset to be adjusted includes: controlling a robotic arm to adjust the wafer center according to the offset to be adjusted; The step of rotating the target feature point according to the rotation angle of the target feature point includes: The rotating platform is controlled to rotate the wafer according to the rotation angle of the target feature point.

15. The wafer alignment method according to claim 1, characterized in that, The first fixed angle is less than or equal to the difference between the shooting angle of the camera and the preset angle, and the preset angle is related to the space occupied by the actual physical feature corresponding to the target feature point; The first fixed angle is smaller than the second fixed angle.

16. A wafer alignment apparatus, characterized in that, The device includes a controller, a camera, a motor, and a rotating platform connected to the motor. The camera has a certain field of view, and a portion of the edge of the wafer located on the rotating platform falls into the field of view. The motor includes a first rotation mode and a second rotation mode. The controller is configured to, in a first rotation mode, send a first image capture command to the imaging device in response to the motor rotating by a first fixed angle, and to receive a first partial image sent by the imaging device. Target feature point detection is performed on the first partial image to determine the first partial image containing the target feature point, which is then used as the target feature image. Based on the target feature image, the first initial coordinates of the target feature point are determined. In the second rotation mode, the motor is controlled to stop for a fixed time after rotating a second fixed angle, and a second image capture command is sent to the imaging device to receive the second partial image sent by the imaging device. The second partial image does not contain the target feature point. Based on multiple second partial images, the second initial coordinates of the wafer center are determined. Based on the first initial coordinates, the second initial coordinates, and the target alignment direction, the rotation angle to be determined for the target feature point and / or the adjustment offset between the wafer center and the center of the rotation platform are determined. The wafer center is adjusted according to the adjustment offset to be located at the center of the rotation platform, and / or the target feature point is rotated according to the rotation angle to be determined, so that the line connecting the rotated target feature point and the rotated wafer center is aligned with the target alignment direction. The imaging device is configured to, in response to the first imaging command, capture an image of the wafer edge to obtain a first partial image of the imaging field of view and send it to the controller; and in response to the second imaging command, capture an image of the wafer edge to obtain a second partial image of the imaging field of view and send it to the controller.

17. A semiconductor process apparatus, characterized in that, It includes a transfer chamber, a process chamber, a vacuum locking chamber, and a wafer alignment device as described in claim 16, wherein the process chamber, the vacuum locking chamber, and the wafer alignment device are respectively connected to the transfer chamber.

18. A computer device, characterized in that, include: The computer device includes a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the computer device is running, the processor communicates with the memory via the bus. When the machine-readable instructions are executed by the processor, they perform the steps of the wafer alignment method as described in any one of claims 1 to 15.

19. A computer non-transient readable storage medium, characterized in that, The computer non-transient readable storage medium stores a computer program that, when executed by a processor, performs the steps of the wafer alignment method as described in any one of claims 1 to 15.

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