Wafer edge cleaning device and method
By introducing a spray head, a rotating mechanism, and an angle acquisition device into the wafer edge cleaning device, and using the cosine theorem to calculate the target angle, the problem of poor robot arm flexibility was solved. This enabled control over the edge etching width of wafers of different specifications, avoided contamination in the central area, and improved cleaning accuracy and flexibility.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-18
- Publication Date
- 2026-03-24
AI Technical Summary
In existing technologies, robotic arms have poor flexibility when cleaning wafer edges, and cannot flexibly adjust the etching width, resulting in the inability to meet the edge etching width requirements of wafers of different specifications, and there is a risk of contaminating the central area of the wafer.
By setting spray heads, rotation mechanisms, and angle acquisition devices on a robotic arm, the controller calculates that the contact point of the chemical liquid sprayed by the spray head is located on the etching line. The cosine theorem is used to calculate the target angle, and the rotation angle of the robotic arm is adjusted to achieve flexible control of the equivalent arm length and meet the requirements of different edge etching widths.
It enables flexible control of the edge etching width of wafers of different specifications, avoids contamination in the center area of the wafer, and improves the flexibility and accuracy of the cleaning device.
Smart Images
Figure CN121729005A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to a wafer edge cleaning apparatus and method. Background Technology
[0002] In semiconductor manufacturing, the edges of wafers are cleaned. Bevel clean is an edge cleaning technique that uses etching to remove the edges of the film covering the wafer surface. Specifically, based on pre-treatment, the film layer in an area approximately 1-2 mm wide from the edge is etched away to avoid problems caused by this film layer in subsequent processes.
[0003] Edge cleaning aims to clean the edge areas of a wafer. Existing cleaning equipment typically uses a robotic arm that sweeps across the wafer's center, rotating horizontally at a fixed angle to the wafer's tangent to clean the edges. This poses a risk of contaminating the central wafer area. Furthermore, different wafer sizes often have different edge etching width requirements, and a fixed-angle robotic arm suffers from poor flexibility.
[0004] How to control the edge etching width for wafers of different specifications is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0005] To address the problems existing in the prior art, this application provides a wafer edge cleaning apparatus and method.
[0006] This application provides a wafer edge cleaning apparatus, comprising:
[0007] A robotic arm, including a spray head located at the free end of the robotic arm, for spraying chemical liquid;
[0008] A rotating mechanism is used to drive the robotic arm to rotate at a pivot point;
[0009] An angle acquisition device is used to acquire the angle between the turning point of the robotic arm and the line connecting the center of the wafer on the wafer projection surface and the current robotic arm, as the current angle;
[0010] The controller is configured as follows:
[0011] The angle between the turning point of the robotic arm and the line connecting the wafer center on the projection plane when the contact point of the chemical liquid sprayed by the spray head is located on the etching line is calculated and used as the target angle.
[0012] The difference between the current angle and the target angle controls the rotation mechanism to rotate the robotic arm, so that the contact point of the chemical liquid sprayed by the spray head is located on the etching line of the wafer.
[0013] According to the wafer edge cleaning apparatus provided in this application, the spray head is perpendicular to the wafer, and the step of calculating the target angle includes:
[0014] Obtain the radius and target etching width of the wafer, and use the target etching width to obtain an etching line around the wafer;
[0015] The target angle is calculated using the law of cosines based on the radius of the wafer, the target etching width, the distance from the turning point to the spray head, and the length of the line connecting the turning point and the wafer center on the wafer projection surface.
[0016] According to the wafer edge cleaning apparatus provided in this application, the cosine value of the target angle is calculated using formula (1):
[0017] cosα2=D 2 +L 2 -(R-D1) 2 / 2LD (1)
[0018] Wherein, α2 is the target angle, D is the length of the line connecting the turning point and the wafer center on the wafer projection surface, L is the distance from the turning point to the spray head, D1 is the target etching width, and R is the radius of the wafer.
[0019] According to a wafer edge cleaning apparatus provided in this application, the spray head has an angle with the direction of gravity, and the step of calculating the target angle includes:
[0020] Obtain the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane and the angle between the spray head and the direction of gravity;
[0021] The target angle is calculated using the law of cosines based on the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane, the radius of the wafer, the target etching width, the distance from the turning point to the spray head, the length of the line connecting the turning point and the center of the wafer on the wafer projection plane, and the angle between the spray head and the direction of gravity.
[0022] According to the wafer edge cleaning apparatus provided in this application, the target angle is calculated using formula (3):
[0023]
[0024] Wherein, D1 is the target etching width, R is the radius of the wafer, H is the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane, θ is the angle between the spray head and the direction of gravity, L is the distance from the turning point to the spray head, D is the length of the line connecting the turning point and the wafer center on the wafer projection plane, and α is the target angle.
[0025] This application also provides a wafer edge cleaning method, implemented based on a wafer edge cleaning device, the wafer edge cleaning device including a robotic arm, a spray head, and a rotating mechanism, the spray head being located at the free end of the robotic arm for spraying chemical liquid, and the rotating mechanism for driving the robotic arm to rotate around a pivot point, including the following steps:
[0026] Obtain the angle between the robotic arm and the line connecting the turning point of the robotic arm and the center of the wafer on the wafer projection surface, and the robotic arm, as the current angle;
[0027] The angle between the turning point of the robotic arm and the line connecting the wafer center on the projection plane when the contact point of the chemical liquid sprayed by the spray head is located on the etching line is calculated and used as the target angle.
[0028] The rotation angle of the robotic arm is determined based on the difference between the current angle and the target angle; and
[0029] The robotic arm is rotated based on the stated rotation angle so that the contact point of the chemical liquid sprayed by the spray head is located on the etching line, thereby performing edge cleaning on the wafer.
[0030] According to a circular edge cleaning method provided in this application, the spray head is perpendicular to the wafer, and the step of calculating the target angle includes:
[0031] Obtain the radius and target etching width of the wafer, and use the target etching width to obtain an etching line around the wafer;
[0032] The target angle is calculated using the law of cosines based on the radius of the wafer, the target etching width, the distance from the turning point to the spray head, and the length of the line connecting the turning point and the wafer center on the wafer projection surface.
[0033] According to the wafer edge cleaning method provided in this application, the cosine value of the target angle is calculated using formula (1):
[0034] cosα=D 2 +L 2 -(R-D1) 2 / 2LD (1)
[0035] Wherein, α is the target angle, D is the length of the line connecting the turning point and the wafer center on the wafer projection surface, L is the distance from the turning point to the spray head, D1 is the target etching width, and R is the radius of the wafer.
[0036] According to a wafer edge cleaning method provided in this application, the spray head has an angle with the direction of gravity, and the step of calculating the target angle includes:
[0037] Obtain the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane and the angle between the spray head and the direction of gravity;
[0038] The target angle is calculated using the law of cosines based on the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane, the radius of the wafer, the target etching width, the distance from the turning point to the spray head, the length of the line connecting the turning point and the center of the wafer on the wafer projection plane, and the angle between the spray head and the direction of gravity.
[0039] According to the wafer edge cleaning method provided in this application, the target angle is calculated using formula (3):
[0040]
[0041] Wherein, D1 is the target etching width, R is the radius of the wafer, H is the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane, θ is the angle between the spray head and the direction of gravity, L is the distance from the turning point to the spray head, D is the length of the line connecting the turning point and the wafer center on the wafer projection plane, and α is the target angle.
[0042] The wafer edge cleaning apparatus provided in this application includes a robotic arm, a spray head located at the free end of the robotic arm for spraying chemical liquid; a rotation mechanism for driving the robotic arm to rotate at a pivot point; and an angle acquisition device for acquiring the angle between the line connecting the pivot point of the robotic arm and the center of the wafer on the wafer projection surface and the current robotic arm, as the current angle.
[0043] The controller is configured to calculate the angle between the robotic arm's pivot point and the line connecting the wafer center on the projection plane when the contact point of the chemical solution sprayed by the spray head is located on the etching line, using this angle as the target angle. Then, the controller controls the rotation mechanism to rotate the robotic arm based on the difference between the current angle and the target angle, ensuring the contact point of the chemical solution sprayed by the spray head is located on the etching line of the wafer. By rotating the robotic arm, the angle between the robotic arm and the line connecting the pivot point and the wafer center is changed, flexibly altering the equivalent arm length of the robotic arm to meet the requirements of different edge etching widths. Attached Figure Description
[0044] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0045] Figure 1 This is a schematic diagram of the wafer edge cleaning apparatus provided in this application;
[0046] Figure 2 This is one of the top views of the wafer edge cleaning apparatus provided in this application;
[0047] Figure 3 This is a second top view of the wafer edge cleaning apparatus provided in this application;
[0048] Figure 4 This is one of the flowcharts illustrating the wafer edge cleaning method provided in this application;
[0049] Figure 5 This is the second schematic diagram of the wafer edge cleaning method provided in this application;
[0050] Figure 6 This is the third flowchart of the wafer edge cleaning method provided in this application;
[0051] Figure 7a and Figure 7b This is a schematic diagram illustrating the implementation of the wafer edge cleaning method provided in this application. Detailed Implementation
[0052] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0053] The following is combined Figure 1 Figure 7 illustrates the wafer edge cleaning apparatus and method of this application.
[0054] refer to Figure 1The wafer edge cleaning apparatus provided in this application embodiment includes: a rotating shaft 101, a robotic arm 102, a spray head 103, a controller (not shown), a driver (not shown), and an angle acquisition device (not shown). The starting end of the robotic arm 102 is connected to the rotating shaft 101, and the end end of the robotic arm 102 is connected to the spray head 103. The distance L between the fixed points of the rotating shaft 101 and the spray head 103 on the robotic arm 102 is greater than the shortest distance from the rotating shaft 101 to the etching line. In this application embodiment, the rotating shaft 101 and the driver together constitute a rotation mechanism.
[0055] refer to Figure 2 The angle acquisition device is used to acquire the current angle α1 of the robotic arm 102. The current angle α1 is the angle between the robotic arm 102 and the line connecting the center of the rotation axis 101 and the center of the wafer 104 on the wafer projection plane. The controller receives the relevant angle data acquired by the angle acquisition device, calculates it, and determines the target angle to which the robotic arm 102 needs to rotate. It then sends a control signal to the driver, which is configured to drive the rotation axis 101 to rotate.
[0056] refer to Figure 3 In this embodiment of the application, when the contact point of the chemical liquid sprayed by the spray head 103 is on the etching line 105 of the wafer, the angle α2 between the line connecting the center of the rotating axis 101 and the center of the wafer 104 on the projection plane and the robotic arm 102 is the target angle.
[0057] Specifically, the controller and driver in the wafer edge cleaning apparatus provided in this application embodiment can be located near the rotating shaft 101. The rotating shaft 101 is connected to one end of the robotic arm 102. The driver may include a stepper motor, which drives the rotating shaft 101 to rotate, causing the robotic arm 102 to rotate horizontally. The horizontal rotation can be counterclockwise or clockwise, and is not specifically limited here. The other end of the robotic arm 102 is a free end, and a spray head 103 is connected to the free end of the robotic arm 102. Cleaning fluid is sprayed onto the wafer edge through the spray head 103 to clean the wafer edge.
[0058] It should be noted that the spray head 103 and the free end of the robotic arm 102 are movably connected. In a specific implementation, the spray head 103 and the robotic arm 102 can be vertically fixed, and the angle between the spray head 103 and the direction of gravity can also be adjusted. The chemical solution sprayed by the spray head 103 contacts the etching line 105 of the wafer, preventing the cleaning solution from contaminating the central area of the wafer. (Reference) Figure 1 and Figure 2 The dotted circle shown is the etching line 105 of wafer 104. The etching line is a circle of lines formed by all the etching points on the wafer plane that meet the etching width.
[0059] refer to Figure 7a In some embodiments, the angle acquisition device can also acquire the angle between the spray head 103 and the direction of gravity, and the actuator can also be used to adjust the angle between the spray head 103 and the direction of gravity. In the default state, the spray head 103 is perpendicular to the robotic arm 102, that is, the angle between the spray head 103 and the direction of gravity is 0 degrees. The actuator drives the spray head 103 to rotate, so that there is an angle between the spray head 103 and the direction of gravity, such as... Figure 7a The angle θ in the equation.
[0060] The wafer edge cleaning apparatus provided in this application has a robotic arm connected at one end to a rotating axis and at the other end to a spray head. The angle between the spray head and the robotic arm is adjusted by a driver, changing the angle between the chemical solution sprayed by the spray head and the wafer. An angle acquisition device acquires the current angle between the robotic arm and the line connecting the rotating axis and the wafer center on the wafer projection surface. Based on the controller, the target angle to which the robotic arm needs to rotate is calculated. Then, based on the current angle acquired by the angle acquisition device, the required rotation angle of the rotating axis is further calculated, and a corresponding control signal is sent to the driver. The driver, based on the control signal, drives the rotating axis to rotate horizontally, causing the robotic arm to rotate, so that the contact point of the chemical solution sprayed by the spray head is located on the etching line. By rotating the robotic arm through the rotating axis, the angle between the robotic arm and the line connecting the rotating axis and the wafer center on the projection surface is changed, effectively changing the arm length of the robotic arm. For different edge etching width requirements, the robotic arm can be rotated to the target angle by the driver, flexibly changing the equivalent arm length of the robotic arm to meet the needs of different edge etching widths.
[0061] This application also provides a wafer edge cleaning method, implemented based on the wafer edge cleaning apparatus of the above embodiments.
[0062] Figure 4 This is one of the flowcharts illustrating the wafer edge cleaning method provided in this application, such as... Figure 4 As shown, the wafer edge cleaning method of this application embodiment includes the following steps:
[0063] S401. Obtain the angle between the line connecting the turning point of the robotic arm and the center of the wafer on the wafer projection surface and the current robotic arm, and use it as the current angle;
[0064] Specifically, in this step, the angle between the line connecting the turning point of the robotic arm 102 and the center of the wafer on the wafer projection surface and the current robotic arm 102 is obtained by the angle acquisition device in the wafer edge cleaning device described above.
[0065] S402. When the contact point of the chemical liquid sprayed by the spray head is located on the etching line, calculate the angle between the line connecting the turning point of the robotic arm and the center of the wafer on the projection plane and the robotic arm, and use it as the target angle.
[0066] Specifically, in this step, it is necessary to first determine the location of the etching line, which is determined based on the target etching width.
[0067] refer to Figure 3 When the contact point of the chemical liquid sprayed by the spray head 103 is located on the etching line 105, the projection point of the spray head 103 on the wafer projection surface will intersect with the etching line 105. In this embodiment, the spray head 103 is perpendicular to the plane of the wafer in the vertical direction, that is, the spray head 103 and the robotic arm 102 are perpendicular to each other. In this case, the spray head 103 is located directly above the etching line. The angle between the line connecting the rotation point of the robotic arm 102 and the center of the wafer on the projection surface and the robotic arm 102 is the target angle α2 to be calculated.
[0068] S403. Determine the rotation angle based on the difference between the current angle and the target angle;
[0069] Specifically, after obtaining the current angle and target angle of the robotic arm 102, the difference between the target angle and the current angle is calculated to obtain the rotation angle, which is the angle required for the robotic arm 102 to rotate the spray head 103 to be directly above the etching line so that the contact point of the chemical liquid sprayed by the spray head 103 is located on the etching line.
[0070] S204. Based on the rotation angle, rotate the robotic arm so that the contact point of the chemical liquid sprayed by the spray head is located on the etching line, and perform edge cleaning on the wafer.
[0071] Specifically, in this step, after the controller calculates the required rotation angle of the robotic arm 102 based on the current angle and the target angle, it sends a corresponding control signal to the driver. The driver drives the rotating shaft 101 to rotate by the rotation angle based on the control signal, moving the spray head 103 directly above the etching line 105. That is, the contact point of the chemical liquid sprayed by the spray head 103 is located on the etching line 105. In conjunction with the rotating wafer, the edge of the wafer is cleaned by the chemical liquid sprayed by the spray head 103.
[0072] In one embodiment, reference Figure 1 If the spray head is perpendicular to the plane of the wafer in the vertical direction, then the specific execution steps of S402 are as follows: Figure 5 As shown, Figure 5 This is the second schematic flowchart of the wafer edge cleaning method provided in this application, as shown below. Figure 5 As shown, the specific method for calculating the target angle is as follows:
[0073] S501. Obtain the radius R and target etching width D1 of the wafer, and obtain an etching line on the wafer with the target etching width.
[0074] In practice, it is necessary to first obtain the radius R of the wafer to be processed and the target etching width D1. The target etching width D1 corresponding to the target wafer is determined according to the specifications of the target wafer. Alternatively, the target etching width D1 of the wafer can be determined according to the specific process requirements. The specific determination method is not limited here.
[0075] S502. Based on the wafer radius R, target etching width D1, distance L from the rotation axis 101 to the spray head, and length D of the line connecting the rotation axis 101 and the wafer center on the wafer projection surface, the target angle is calculated using the cosine theorem.
[0076] Specifically, in this step, based on the radius R, the target etching width D1, the distance L from the rotation axis 101 to the spray head, and the length D of the line connecting the rotation axis 101 and the center of the wafer 104 on the wafer projection surface, the cosine theorem is used to calculate the size of the target angle α2 when the spray head 103 is directly above the etching line.
[0077] refer to Figure 3 When the spray head 103 is directly above the etching line 105, the line connecting the rotation axis 101 and the center of the wafer 104 on the wafer projection plane, the projection point of the spray head 103 on the wafer projection plane and the line connecting the center of the wafer 104 on the wafer projection plane, and the line connecting the rotation axis 101 and the spray head 103 form a triangle. In this case, the value of the target angle can be accurately calculated using the cosine theorem based on the known values of the sides of the triangle. Figure 3 α2 in.
[0078] Optionally, the target angle can be calculated using formula (1), as follows:
[0079] Specifically, for the triangle formed by the three sides mentioned above, the adjacent side of the angle where the target angle is located is the line connecting the rotation axis 101 and the center of the wafer 104 on the wafer projection surface and the line connecting the rotation axis 101 and the spray head 103. The opposite side is the projection point of the spray head 103 on the wafer projection surface and the line connecting the center of the wafer 104 on the wafer projection surface.
[0080] The Law of Cosines is a mathematical theorem describing the relationship between the lengths of the three sides of a triangle and the cosine value of an angle. It is a generalization of the Pythagorean theorem to the case of general triangles. The Law of Cosines is an important theorem revealing the relationship between the sides and angles of a triangle, and it can solve problems such as finding the third side given two sides and the included angle, or finding the three angles given three sides. In the embodiments of this application, the problem is the case of finding the angles given three sides.
[0081] Based on the three sides of the triangle that have already been determined, the cosine value of the target angle is determined, and then the target angle is obtained by reverse calculation using the inverse cosine function.
[0082] The cosine value of the target angle is determined using formula (1):
[0083] cosα2=D 2 +L 2 -(R-D1) 2 / 2LD (1)
[0084] Where α2 is the target angle, D is the distance between the line connecting the center of the rotation axis 101 and the center of the wafer 104 on the wafer projection surface, L is the distance between the rotation axis 101 and the fixed point of the spray head on the robotic arm 102, D1 is the edge etching width, and R is the radius of the wafer.
[0085] After determining the cosine value of the target angle, the target angle is determined by inverse cosine function, as shown in the following formula (2):
[0086] α2=arccos(cosα2) (2)
[0087] The wafer edge cleaning method provided in this application determines the etching line based on the set edge etching width, then accurately calculates the target angle through the controller, and then calculates the rotation angle that the robotic arm 102 needs to rotate based on the current angle and the target angle. The corresponding control signal is sent to the driver, and the driver drives the rotating shaft 101 to rotate by the rotation angle based on the control signal, rotating the robotic arm to the target angle, which is equivalent to changing the arm length of the robotic arm, improving the flexibility of the wafer edge cleaning method and expanding the application scenarios.
[0088] refer to Figure 7a In another embodiment, due to the requirements of the edge washing process, there is an angle between the spray head and the direction of gravity. This application also provides another method for calculating the target angle; when there is an angle between the spray head and the direction of gravity, the specific execution steps of S402 described above are... Figure 6 As shown, Figure 6 This is the third flowchart of the wafer edge cleaning method provided in this application, as shown below. Figure 6 As shown, the specific method for calculating the target angle is as follows:
[0089] S601. Obtain the vertical distance H between the fixed point of the spray head on the robotic arm and the wafer plane, and the angle θ between the spray head and the direction of gravity.
[0090] Specifically, in this embodiment, the angle between the spray head 103 and the direction of gravity can be adjusted to meet the needs of different edge washing processes. Since the spray head 103 has a certain length, it will have a projection on the wafer projection surface. The angle θ between the adjusted spray head 103 and the direction of gravity is obtained through an angle acquisition device.
[0091] It should be further noted that the angle θ between the spray head 103 and the direction of gravity is adjusted according to process requirements, and the general adjustment range is between 20 and 30 degrees. The specific value is not limited here. When adjusting the angle θ between the spray head 103 and the direction of gravity, it is necessary to ensure that the contact point of the chemical liquid sprayed by the spray head 103 is located on the etching line 105.
[0092] S602. Based on the vertical distance H between the fixed point of the spray head on the robotic arm and the wafer plane, the wafer radius R, the target etching width D1, the distance L from the rotation axis to the spray head, the distance D between the line connecting the rotation axis 101 and the wafer center on the wafer projection plane, and the angle between the spray head and the direction of gravity, the target angle α2 is calculated using the cosine theorem.
[0093] like Figure 7a As shown, there is an angle θ between the spray head 103 and the direction of gravity, and the spray head 103 will have a corresponding projection on the wafer projection surface.
[0094] Given that there is an angle θ between the spray head 103 and the direction of gravity, and considering the vertical distance H between the fixed point of the spray head 103 on the robotic arm 102 and the wafer plane, the length of the projection of the spray head 103 on the wafer projection plane can be calculated based on the tangent function.
[0095] like Figure 7b As shown, the distance L between the fixed point of the spray head 103 on the robotic arm 102 and the line connecting the center of the wafer 104 on the wafer projection surface, the target etching width D1, and the projection length of the spray head 103 on the wafer projection surface are equal to the radius R of the wafer. The size of the target angle is determined by the above relationship.
[0096] In this embodiment, the relationship between the angle θ between the spray head 103 and the direction of gravity and the target angle α2 satisfies formula (3):
[0097]
[0098] Where D is the length of the line connecting the rotation axis and the wafer center on the wafer projection plane.
[0099] The value of the target angle can be derived from formula (3).
[0100] The wafer edge cleaning method provided in this application is applicable to situations where the angle between the spray head and the robotic arm can be adjusted, i.e., there is an angle between the spray head and the direction of gravity. In this case, the adjustable range of the spray head is increased, which can meet different process requirements and optimize the defects that are prone to occur in processes such as sputtering.
[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A wafer edge cleaning apparatus, characterized in that, include: A robotic arm, including a spray head located at the free end of the robotic arm, for spraying chemical liquid; A rotating mechanism is used to drive the robotic arm to rotate at a pivot point; An angle acquisition device is used to acquire the angle between the turning point of the robotic arm and the line connecting the center of the wafer on the wafer projection surface and the current robotic arm, as the current angle; The controller is configured as follows: The angle between the turning point of the robotic arm and the line connecting the wafer center on the projection plane when the contact point of the chemical liquid sprayed by the spray head is located on the etching line is calculated and used as the target angle. The difference between the current angle and the target angle controls the rotation mechanism to rotate the robotic arm, so that the contact point of the chemical liquid sprayed by the spray head is located on the etching line of the wafer.
2. The wafer edge cleaning apparatus as described in claim 1, characterized in that, The spray head is perpendicular to the wafer, and the step of calculating the target angle includes: Obtain the radius and target etching width of the wafer, and use the target etching width to obtain an etching line around the wafer; The target angle is calculated using the law of cosines based on the radius of the wafer, the target etching width, the distance from the turning point to the spray head, and the length of the line connecting the turning point and the wafer center on the wafer projection surface.
3. The wafer edge cleaning apparatus according to claim 2, characterized in that, The cosine value of the target angle is calculated using formula (1): cosα2=D 2 +L 2 -(R-D1) 2 / 2LD (1) Wherein, α2 is the target angle, D is the length of the line connecting the turning point and the wafer center on the wafer projection surface, L is the distance from the turning point to the spray head, D1 is the target etching width, and R is the radius of the wafer.
4. The wafer edge cleaning apparatus according to claim 1, characterized in that, The spray head forms an angle with the direction of gravity. The steps for calculating the target angle include: Obtain the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane and the angle between the spray head and the direction of gravity; The target angle is calculated using the law of cosines based on the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane, the radius of the wafer, the target etching width, the distance from the turning point to the spray head, the length of the line connecting the turning point and the center of the wafer on the wafer projection plane, and the angle between the spray head and the direction of gravity.
5. The wafer edge cleaning apparatus according to claim 4, characterized in that, The target angle is calculated using formula (3): Wherein, D1 is the target etching width, R is the radius of the wafer, H is the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane, θ is the angle between the spray head and the direction of gravity, L is the distance from the turning point to the spray head, D is the length of the line connecting the turning point and the wafer center on the wafer projection plane, and α is the target angle.
6. A wafer edge cleaning method, implemented based on a wafer edge cleaning device, the wafer edge cleaning device comprising a robotic arm, a spray head, and a rotating mechanism, wherein the spray head is located at the free end of the robotic arm and is used to spray a chemical solution, and the rotating mechanism is used to drive the robotic arm to rotate around a pivot point, characterized in that... Includes the following steps: Obtain the angle between the robotic arm and the line connecting the turning point of the robotic arm and the center of the wafer on the wafer projection surface, and the robotic arm, as the current angle; The angle between the turning point of the robotic arm and the line connecting the wafer center on the projection plane when the contact point of the chemical liquid sprayed by the spray head is located on the etching line is calculated and used as the target angle. The rotation angle of the robotic arm is determined based on the difference between the current angle and the target angle; as well as The robotic arm is rotated based on the stated rotation angle so that the contact point of the chemical liquid sprayed by the spray head is located on the etching line, thereby performing edge cleaning on the wafer.
7. The wafer edge cleaning method according to claim 6, characterized in that, The spray head is perpendicular to the wafer, and the step of calculating the target angle includes: Obtain the radius and target etching width of the wafer, and use the target etching width to obtain an etching line around the wafer; The target angle is calculated using the law of cosines based on the radius of the wafer, the target etching width, the distance from the turning point to the spray head, and the length of the line connecting the turning point and the wafer center on the wafer projection surface.
8. The wafer edge cleaning method according to claim 7, characterized in that, The cosine value of the target angle is calculated using formula (1): cosα=D 2 +L 2 -(R-D1) 2 / 2LD (1) Wherein, α is the target angle, D is the length of the line connecting the turning point and the wafer center on the wafer projection surface, L is the distance from the turning point to the spray head, D1 is the target etching width, and R is the radius of the wafer.
9. The wafer edge cleaning method according to claim 8, characterized in that, The spray head forms an angle with the direction of gravity. The steps for calculating the target angle include: Obtain the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane and the angle between the spray head and the direction of gravity; The target angle is calculated using the law of cosines based on the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane, the radius of the wafer, the target etching width, the distance from the turning point to the spray head, the length of the line connecting the turning point and the center of the wafer on the wafer projection plane, and the angle between the spray head and the direction of gravity.
10. The wafer edge cleaning method according to claim 9, characterized in that, The target angle is calculated using formula (3): Wherein, D1 is the target etching width, R is the radius of the wafer, H is the vertical distance from the fixed point of the spray head on the robotic arm to the wafer plane, θ is the angle between the spray head and the direction of gravity, L is the distance from the turning point to the spray head, D is the length of the line connecting the turning point and the wafer center on the wafer projection plane, and α is the target angle.