Wafer cleaning device and wafer cleaning method
By adjusting the chuck rotation speed, the problem of difficult cleaning of particles in the center of the wafer was solved, improving the cleaning effect and yield of the wafer.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2026-03-24
AI Technical Summary
In existing wafer cleaning equipment, particles in the center of the wafer are difficult to clean, resulting in a decrease in yield.
By adjusting the chuck's rotation speed during the cleaning brush's movement, the chuck's rotation speed is increased when the cleaning brush is at the center of the wafer compared to when it is at the edge of the wafer. This increases the centrifugal force and linear velocity at the center of the wafer, thereby improving the cleaning effect.
It effectively removes particles from the center of the wafer, improves the wafer yield, and prevents particles from accumulating in the center of the wafer.
Smart Images
Figure CN121728996A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of semiconductor manufacturing equipment, and in particular, to a wafer cleaning device and a wafer cleaning method. BACKGROUND
[0002] The production process of semiconductor products often involves multiple process flows. After passing through multiple processes, the wafer will adhere to some residues, particles of chemical agents, and environmental pollution particles, etc. These are possible particle sources, which are a kind of pollution that needs to be cleaned for the wafer. Therefore, the wafer needs to be cleaned.
[0003] In the current wafer cleaning device, a cleaning brush is usually used to clean the particles on the wafer. During the cleaning process, the wafer is fixed on the chuck and rotates with the chuck. The cleaning brush moves from the center of the wafer to the edge and brushes the wafer. During the cleaning process, the rotation speed of the chuck is generally 500 rpm. Under the same rotation speed, the linear speed of the wafer center is the smallest and the centrifugal force is the smallest. Therefore, it is difficult to remove the particles at the center of the wafer, and the particles are likely to gather at the center of the wafer, which ultimately affects the yield of the wafer. However, if the rotation speed of the chuck is increased, the linear speed of the wafer edge will also increase, which will cause the cleaning brush to rub against the wafer edge and form a large number of particles at the wafer edge.
[0004] SUMMARY
[0005] The present application aims to provide a wafer cleaning device and a wafer cleaning method to solve the problem of difficult cleaning of particles at the center of the wafer in the prior art.
[0006] To achieve the above object and other related objects, the present application provides a wafer cleaning method applied to a wafer cleaning device, wherein the wafer cleaning device comprises a cleaning brush for brushing the surface of a wafer and a chuck for carrying and rotating the wafer. The wafer cleaning method comprises:
[0007] rotating the wafer and moving the cleaning brush to brush the surface of the wafer;
[0008] During the movement of the cleaning brush, the rotation speed of the chuck is changed so that the rotation speed of the chuck when the cleaning brush is at the center of the wafer is greater than the rotation speed of the chuck when the cleaning brush is at the edge of the wafer.
[0009] Further, the changing of the rotation speed of the chuck during the movement of the cleaning brush comprises:
[0010] setting a feature position on the movement path of the cleaning brush;
[0011] The chuck rotates at a speed greater than when the cleaning brush moves between the feature position and the wafer center.
[0012] Furthermore, changing the rotational speed of the chuck during the movement of the cleaning brush includes:
[0013] Multiple feature positions are set on the moving path of the cleaning brush, and the multiple feature positions are all on a straight line and at the same height; the multiple feature positions include a second position and a third position, wherein the second position is closer to the center of the wafer than the third position is closer to the center of the wafer;
[0014] When the cleaning brush moves to the second position between the center of the wafer, the rotational speed of the chuck is greater than the rotational speed of the chuck when the cleaning brush moves to the third position between the edge of the wafer.
[0015] Furthermore, the plurality of feature positions also include a first position and a fourth position, wherein the first position, the second position, the third position, and the fourth position are sequentially adjacent; when the cleaning brush moves between the first position and the second position, the rotational speed of the chuck is greater than the rotational speed of the chuck when the cleaning brush moves between the third position and the fourth position.
[0016] Furthermore, the line connecting the first position and the second position passes through the center of the wafer.
[0017] Furthermore, the cleaning brush is moved at a constant speed between adjacent feature positions, and the chuck is rotated at a constant or variable speed.
[0018] Furthermore, the distance between the fourth position and the center of the wafer is equal to the difference between the radius of the wafer and the radius of the cleaning brush.
[0019] Furthermore, the cleaning brush rotates the chuck with acceleration as it moves between the second and third positions. The acceleration is negative when the cleaning brush moves from the center of the wafer to the edge, and positive when the cleaning brush moves from the edge of the wafer to the center.
[0020] Furthermore, as the cleaning brush moves between the first and second positions, and between the third and fourth positions, it rotates the chuck at a constant speed.
[0021] This application also provides a wafer cleaning apparatus, comprising:
[0022] Cleaning brushes are used to scrub the surface of wafers.
[0023] A chuck is used to hold and rotate a wafer.
[0024] The controller is used to control the movement of the cleaning brush and the rotation of the chuck;
[0025] The controller is configured to change the rotational speed of the chuck during the movement of the cleaning brush, such that the rotational speed of the chuck is greater when the cleaning brush is at the center of the wafer than when the cleaning brush is at the edge of the wafer.
[0026] This application also provides a control method for a wafer cleaning apparatus, comprising the following steps:
[0027] The movement path of the cleaning brush is set, and the movement path includes multiple feature positions;
[0028] A control menu is constructed, which includes the rotation parameters of the chuck when the cleaning brush is at each feature position, the rotation parameters including the rotation speed of the chuck; wherein, the rotation speed of the chuck when the cleaning brush is at the center of the wafer is greater than the rotation speed of the chuck when the cleaning brush is at the edge of the wafer;
[0029] The cleaning brush is controlled to move along the moving path and the chuck is controlled to rotate according to the control menu. When the cleaning brush is at each feature position, the chuck is controlled to rotate according to the corresponding rotation parameters.
[0030] Furthermore, the control menu also includes a cyclic movement control item, which includes a number of cycles. The cyclic movement control item is used to control the cleaning brush to move cyclically according to the movement path and the number of cycles.
[0031] As described above, this application provides a wafer cleaning apparatus and a wafer cleaning method, which have the following beneficial effects: In the process of the cleaning brush moving, this application adjusts the rotation speed of the chuck so that the rotation speed of the chuck is faster when the cleaning brush is in the center of the wafer and slower when the cleaning brush is in the edge of the wafer. This increases the centrifugal force and linear velocity in the center of the wafer, so that the particles in the center of the wafer can be better cleaned and removed, avoiding a large number of particles from accumulating in the center of the wafer and improving the wafer yield. Attached Figure Description
[0032] Figure 1 The diagram shown is a schematic diagram of a wafer cleaning apparatus in one embodiment of this application;
[0033] Figure 2 The diagram shown is a schematic representation of a wafer cleaning method in one embodiment of this application;
[0034] Figure 3 The flowchart shown is a control method of a wafer cleaning apparatus according to an embodiment of this application;
[0035] Figure 4 The diagram shown is a schematic representation of the movement path of a cleaning brush in one embodiment of this application.
[0036] Figure 5 The diagram shown is a schematic representation of the movement of a cleaning brush in one embodiment of this application. Detailed Implementation
[0037] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application.
[0038] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this application. Although the illustrations only show components relevant to this application and are not drawn according to the actual number, shape, and size of components in implementation, the shape, quantity, and proportion of each component in actual implementation can be arbitrarily changed, and the layout of the components may also be more complex. In addition, the same reference numerals in multiple figures represent the same or equivalent parts or components.
[0039] This application discloses a wafer cleaning apparatus, with reference to... Figure 1 The wafer cleaning apparatus includes a cleaning brush 1, a chuck 2, and a controller 3. The cleaning brush 1 is used to clean the surface of the wafer w, the chuck 2 is used to support the wafer w and rotate it, and the controller 3 is used to control the movement of the cleaning brush 1 and the rotation of the chuck 2. The controller 3 is configured to change the rotational speed of the chuck 2 during the movement of the cleaning brush 1, such that the rotational speed of the chuck 2 is greater when the cleaning brush 1 is at the center of the wafer w than when the cleaning brush 1 is at the edge of the wafer w. Here, "center of wafer w" refers to the area on the wafer w containing the center of the circle and extending outwards by a certain distance, and "edge of wafer w" refers to the area on the wafer w containing the outer edge and extending inwards by a certain distance. The movement of the cleaning brush 1 includes, but is not limited to, horizontal and vertical movement. The brush surface of the cleaning brush 1 is parallel to the surface of the wafer w and can approach or move away from the surface of the wafer w. Here, "approach" means that the cleaning brush 1 can effectively clean the surface of the wafer w. The specific interval distance or whether the two are in contact can be selected according to the actual situation and conventional standards in the field.
[0040] like Figure 1 As shown, the wafer cleaning apparatus also includes a cleaning brush drive mechanism 4 and a chuck drive mechanism 5. The controller 3 is used to send control commands to the cleaning brush drive mechanism 4 and the chuck drive mechanism 5, thereby controlling the movement of the cleaning brush 1 and the rotation of the chuck 2.
[0041] This application also proposes a wafer cleaning method, applied to the aforementioned wafer cleaning apparatus, such as...Figure 2 As shown, the wafer cleaning method includes:
[0042] Rotate the wafer and move the cleaning brush to clean the wafer surface;
[0043] During the movement of the cleaning brush, the rotation speed of the chuck is changed so that the rotation speed of the chuck is greater when the cleaning brush is at the center of the wafer than when the cleaning brush is at the edge of the wafer.
[0044] In some embodiments, changing the rotational speed of the chuck during the movement of the cleaning brush includes:
[0045] Set a feature position on the movement path of the cleaning brush;
[0046] The chuck rotates at a speed greater than the speed at which the cleaning brush moves between the feature position and the wafer center.
[0047] In other embodiments, multiple feature positions can be set on the moving path of the cleaning brush. The multiple feature positions are on a straight line and have the same height. Between two adjacent feature positions, the cleaning brush moves at a constant speed, and the chuck rotates at a constant speed or a variable speed.
[0048] like Figure 3 As shown, this application also proposes a control method for a wafer cleaning apparatus, applied to the aforementioned wafer cleaning apparatus. The control method includes the following steps:
[0049] Step S100: Set the moving path of the cleaning brush, the moving path including multiple feature positions distributed along the radial direction of the wafer;
[0050] Step S200: Construct a control menu. The control menu includes the rotation parameters of the chuck when the cleaning brush is at each feature position. The rotation parameters include the rotation speed of the chuck. The rotation speed of the chuck corresponding to the feature position near the center of the wafer is greater than the rotation speed of the chuck corresponding to the feature position near the edge of the wafer.
[0051] In step S300, the cleaning brush is controlled to move along the moving path and the chuck is controlled to rotate according to the control menu. When the cleaning brush is at each feature position, the chuck is controlled to rotate according to the corresponding rotation parameters.
[0052] In order to increase the cleaning time of the cleaning brush at the center of the wafer, so that the particles at the center of the wafer can be better cleaned and removed, in step S100, the total length of the moving path is greater than the radius of the wafer.
[0053] In step S200, the cleaning brush moves at a constant speed between adjacent feature positions, and the chuck rotates at a constant or variable speed. In this embodiment, there are at least two feature positions, one near the wafer center and the other near the wafer edge. When the cleaning brush moves between these two feature positions, the chuck rotates at a variable speed, such that the chuck's rotational speed is greater when the cleaning brush is at the wafer center than when it is at the wafer edge. When there are three or more feature positions, the chuck rotates at a constant or variable speed when the cleaning brush moves between any two adjacent feature positions.
[0054] The steps S100-S300, the wafer cleaning apparatus, and the wafer cleaning method described above are explained below with reference to the accompanying drawings.
[0055] refer to Figure 4 The text indicates a movement path of the cleaning brush, which includes multiple feature positions: first position P1, second position P2, third position P3 and fourth position P4. All feature positions are on a straight line passing through the center of the wafer and have the same height. Figure 4 This is for illustrative purposes only and is not intended to limit the specific movement path of the cleaning brush or the specific location and number of feature positions. Figure 4 In the text, cylinders represent cleaning brushes, and ellipses represent wafers. Figure 4 Each feature location in the image has its preset spatial position in space. Figure 4 The relative positions of each feature location to the wafer surface are shown. The line connecting the first location P1 and the second location P2 passes through the wafer center O. The distance between the second location P2 and the wafer center O is greater than the distance between the first location P1 and the wafer center O. The third location P3 is closer to the second location P2 than the fourth location P4. The distance between the wafer center O and the fourth location P4 is slightly less than the wafer radius. The distance between the fourth location P4 and the outer edge of the wafer is specifically set according to the radius of the cleaning brush. For example, if the sum of the distance between the wafer center O and the fourth location P4 and the radius of the cleaning brush equals the wafer radius, the wafer surface can be thoroughly and comprehensively cleaned.
[0056] For example, when the cleaning brush is at the center of the wafer, the chuck rotates at 2000 rpm; when the cleaning brush is at the edge of the wafer, the chuck rotates at 500 rpm. The chuck rotates faster when the cleaning brush moves between the first position P1 and the second position P2; conversely, the chuck rotates slower when the cleaning brush moves between the third position P3 and the fourth position P4. In this embodiment, adjusting the chuck's rotation speed results in a faster rotation when the cleaning brush is at the center of the wafer. Furthermore, the first position P1 and the second position P2 are positioned on either side of the wafer's center O, increasing the cleaning time at the wafer center, allowing for better cleaning and removal of particles at the wafer center. Additionally, the slower rotation of the chuck at the wafer edge reduces the linear velocity at the wafer edge, thereby reducing friction between the cleaning brush and the wafer edge and preventing the formation of numerous particles due to friction at the wafer edge.
[0057] The chuck's rotation parameters also include the acceleration of the chuck's rotation when the cleaning brush moves between the second position P2 and the third position P3. The acceleration is negative when the cleaning brush moves from the wafer center to the edge, and positive when it moves from the wafer edge to the center. Specifically, when the cleaning brush moves from P2 to P3, the acceleration is negative, and the chuck rotates with uniform deceleration; conversely, when the cleaning brush moves from P3 to P2, the acceleration is positive, and the chuck rotates with uniform acceleration. The chuck rotates at a constant speed when the cleaning brush moves between the first position P1 and the second position P2, and between the third position P3 and the fourth position P4.
[0058] In some embodiments, the direction of the cleaning brush's movement path is from the wafer center to the wafer edge. (Combined) Figure 5 The following is a specific example of the movement process of a cleaning brush.
[0059] After the cleaning process begins, the cleaning brush moves from P1 to P2. During this time, the chuck rotates at a first rotational speed R1. The cleaning brush passes the wafer center O during its movement from P1 to P2. After passing P2, the chuck begins to decelerate. When the cleaning brush reaches P3, the chuck rotates at a second rotational speed R2. The first and second rotational speeds R1 and R2 are set according to the actual process conditions. The deceleration A of the chuck rotation during the cleaning brush's movement from P2 to P3 can be calculated based on the first rotational speed R1, the second rotational speed R2, the distance between P2 and P3, and the cleaning brush's moving speed V. During the cleaning brush's movement from P3 to P4, the chuck rotation speed remains at the second rotational speed R2. One cleaning cycle is completed when the cleaning brush reaches P4.
[0060] Table 1 shows an example of a control menu, whose parameters are the same as those described above. Figure 5 The examples shown correspond to those described.
[0061] Table 1:
[0062]
[0063] refer to Figure 5 The origin can be set to the wafer center O, with the right side as the positive direction and the left side as the negative direction. In some embodiments, for a wafer with a reference diameter of 300mm, the characteristic position of the cleaning brush ranges from -150mm to 150mm.
[0064] Preferably, the control menu further includes a cyclic movement control item, which includes a number of cycles. This cyclic movement control item is used to control the cleaning brush to move cyclically according to the movement path and the number of cycles. The number of cycles is determined based on the actual process conditions; for example, in this embodiment, it can be set to twice.
[0065] In some embodiments, the movement path of the cleaning brush further includes characteristic positions P0 and P5, such as... Figure 5 As shown, P0 is positioned directly above P1, and P5 is positioned directly above P4, with P5 at the same height as P0. Before the cleaning process begins, the cleaning brush is located at P0, and the chuck rotates at the first rotational speed R1. After the cleaning process begins, the cleaning brush descends from P0 to P1, approaches the wafer surface, and cleans the wafer surface. When the cleaning brush moves to P4, it continues to rise to P5, then returns to P0, preparing for the next cycle. During this process, the chuck's rotational speed increases from the second rotational speed R2 to the first rotational speed R1.
[0066] In other embodiments, the direction of the cleaning brush's movement path can also be from the wafer edge to the wafer center. Accordingly, the chuck rotates at a constant speed or with uniform acceleration. It is only necessary to set the chuck's rotational speed when the cleaning brush is at the wafer edge to be lower than the chuck's rotational speed when the cleaning brush is at the wafer center.
[0067] In other embodiments, the movement path of the cleaning brush can also be set to a diameter of the wafer or slightly shorter than the diameter, that is, the direction of the movement path can also be from the edge of the wafer, through the center of the wafer, and back to the edge of the wafer. Accordingly, the chuck rotates at a slower speed when the cleaning brush is at the edge of the wafer, the speed of the chuck increases when the cleaning brush moves to the center of the wafer, and the speed of the chuck decreases again when the cleaning brush moves to the edge of the wafer.
[0068] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.
Claims
1. A wafer cleaning method, applied to a wafer cleaning apparatus, the wafer cleaning apparatus comprising a cleaning brush for scrubbing the wafer surface and a chuck for supporting and rotating the wafer, characterized in that, The method includes: The wafer is rotated, and the cleaning brush is moved to clean the wafer surface; During the movement of the cleaning brush, the rotational speed of the chuck is changed so that the rotational speed of the chuck is greater when the cleaning brush is at the center of the wafer than when the cleaning brush is at the edge of the wafer.
2. The wafer cleaning method according to claim 1, characterized in that, Changing the rotational speed of the chuck during the movement of the cleaning brush includes: A feature position is set on the moving path of the cleaning brush; The chuck rotates at a speed greater than when the cleaning brush moves between the feature position and the wafer center.
3. The wafer cleaning method according to claim 1, characterized in that, Changing the rotational speed of the chuck during the movement of the cleaning brush includes: Multiple feature positions are set on the moving path of the cleaning brush, and the multiple feature positions are all on a straight line and at the same height; the multiple feature positions include a second position and a third position, wherein the second position is closer to the center of the wafer than the third position is closer to the center of the wafer; When the cleaning brush moves to the second position between the center of the wafer, the rotational speed of the chuck is greater than the rotational speed of the chuck when the cleaning brush moves to the third position between the edge of the wafer.
4. The wafer cleaning method according to claim 3, characterized in that, The plurality of feature positions also include a first position and a fourth position, wherein the first position, the second position, the third position and the fourth position are sequentially adjacent; when the cleaning brush moves between the first position and the second position, the rotational speed of the chuck is greater than the rotational speed of the chuck when the cleaning brush moves between the third position and the fourth position.
5. The wafer cleaning method according to claim 4, characterized in that, The line connecting the first and second positions passes through the center of the wafer.
6. The wafer cleaning method according to claim 4, characterized in that, The cleaning brush is moved at a constant speed between adjacent feature positions, and the chuck is rotated at a constant or variable speed.
7. The wafer cleaning method according to claim 4, characterized in that, The distance between the fourth position and the center of the wafer is equal to the difference between the radius of the wafer and the radius of the cleaning brush.
8. The wafer cleaning method according to claim 4, characterized in that, The cleaning brush rotates the chuck with acceleration as it moves between the second and third positions. The acceleration is negative when the cleaning brush moves from the center of the wafer to the edge, and positive when the cleaning brush moves from the edge of the wafer to the center.
9. The wafer cleaning method according to claim 8, characterized in that, As the cleaning brush moves between the first and second positions, and between the third and fourth positions, it rotates the chuck at a constant speed.
10. A wafer cleaning apparatus, characterized in that, include: Cleaning brushes are used to scrub the surface of wafers. A chuck is used to hold and rotate a wafer. The controller is used to control the movement of the cleaning brush and the rotation of the chuck; The controller is configured to change the rotational speed of the chuck during the movement of the cleaning brush, such that the rotational speed of the chuck is greater when the cleaning brush is at the center of the wafer than when the cleaning brush is at the edge of the wafer.
11. A control method for a wafer cleaning apparatus, characterized in that, Includes the following steps: The movement path of the cleaning brush is set, and the movement path includes multiple feature positions; A control menu is constructed, which includes the rotation parameters of the chuck when the cleaning brush is at each feature position, the rotation parameters including the rotation speed of the chuck; wherein, the rotation speed of the chuck when the cleaning brush is at the center of the wafer is greater than the rotation speed of the chuck when the cleaning brush is at the edge of the wafer; The cleaning brush is controlled to move along the moving path and the chuck is controlled to rotate according to the control menu. When the cleaning brush is at each feature position, the chuck is controlled to rotate according to the corresponding rotation parameters.
12. The control method according to claim 11, characterized in that, The control menu also includes a cycle movement control item, which includes the number of cycles. The cycle movement control item is used to control the cleaning brush to move cyclically according to the movement path and the number of cycles.