Wafer cleaning apparatus and wafer cleaning method

Abstract

The present application provides a wafer cleaning apparatus and a wafer cleaning method. The wafer cleaning method is applied to the wafer cleaning apparatus. The wafer cleaning apparatus comprises a cleaning brush for brushing the surface of a wafer and a chuck used for carrying the wafer and driving the wafer to rotate. The wafer cleaning method comprises: rotating the wafer, and moving the cleaning brush to brush the surface of the wafer; and during the movement of the cleaning brush, changing the rotation speed of the chuck, 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. In the method, the centrifugal force and linear velocity at the center of the wafer are increased, so that particles at the center of the wafer can be better cleaned and removed, and a large number of particles are prevented from being gathered at the center of the wafer, thereby improving the wafer yield.

Description

Wafer cleaning device and wafer cleaning method

[0001] This application claims priority to Chinese Patent Application No. 202411321721.2, filed September 20, 2024, the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to the field of semiconductor manufacturing equipment, in particular to a wafer cleaning device and a wafer cleaning method. BACKGROUND

[0003] 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.

[0004] 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 center of the wafer 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 edge of the wafer will also increase, which will cause the cleaning brush to rub against the edge of the wafer, and a large number of particles will also be formed at the edge of the wafer. SUMMARY

[0005] The present application aims to provide a wafer cleaning device and a wafer cleaning method to solve the problem of difficulty in cleaning 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, and 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] a feature position is arranged on the moving path of the cleaning brush;

[0011] the rotation speed of the chuck when the cleaning brush moves between the feature position and the edge of the wafer is greater than the rotation speed of the chuck when the cleaning brush moves between the feature position and the center of the wafer.

[0012] Further, the changing of the rotation speed of the chuck during the movement of the cleaning brush comprises:

[0013] a plurality of feature positions are arranged on the moving path of the cleaning brush, the plurality of feature positions are on a straight line and have the same height; the plurality of feature positions comprises a second position and a third position, the second position is closer to the center of the wafer than the third position;

[0014] the rotation speed of the chuck when the cleaning brush moves between the second position and the center of the wafer is greater than the rotation speed of the chuck when the cleaning brush moves between the third position and the edge of the wafer.

[0015] Further, the plurality of feature positions further comprises a first position and a fourth position, the first position, the second position, the third position and the fourth position are sequentially adjacent; the rotation speed of the chuck when the cleaning brush moves between the first position and the second position is greater than the rotation speed of the chuck when the cleaning brush moves between the third position and the fourth position.

[0016] Further, the line connecting the first position and the second position passes through the center of the wafer.

[0017] Further, the cleaning brush moves at a uniform speed between adjacent feature positions, and the chuck rotates at a uniform speed or a uniform variable speed.

[0018] Further, 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] Further, the cleaning brush rotates the chuck at an acceleration when moving between the second position and the third position, the acceleration is negative when the cleaning brush moves from the center of the wafer to the edge of the wafer; the acceleration is positive when the cleaning brush moves from the edge of the wafer to the center of the wafer.

[0020] Further, the cleaning brush rotates the chuck at a uniform speed when moving between the first position and the second position, and between the third position and the fourth position.

[0021] The application also provides a wafer cleaning device, comprising:

[0022] a cleaning brush for brushing the surface of the wafer;

[0023] a chuck for carrying and rotating a wafer;

[0024] a controller for controlling the movement of the cleaning brush and controlling the rotation of the chuck;

[0025] the controller is configured to change the rotation speed of the chuck during the movement of the cleaning brush, 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.

[0026] The application also provides a control method of a wafer cleaning device, comprising the following steps:

[0027] setting a movement path of the cleaning brush, the movement path comprising a plurality of feature positions;

[0028] constructing a control menu, the control menu comprising rotation parameters of the chuck when the cleaning brush is at each feature position, the rotation parameters comprising 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] controlling the movement of the cleaning brush along the movement path and controlling the rotation of the chuck according to the control menu, and controlling the rotation of the chuck according to the corresponding rotation parameters when the cleaning brush is at each feature position.

[0030] Further, the control menu further comprises a cycle movement control item, the cycle control item comprising a cycle number, the cycle control item being used for controlling the movement of the cleaning brush according to the movement path in a cycle number.

[0031] As described above, the application provides a wafer cleaning device and a wafer cleaning method, which have the following beneficial effects: the application adjusts the rotation speed of the chuck during the movement of the cleaning brush, so that the rotation speed of the chuck when the cleaning brush is at the center of the wafer is faster, and the rotation speed of the chuck when the cleaning brush is at the edge of the wafer is slower, which increases the centrifugal force and linear speed at the center of the wafer, so that the particles at the center of the wafer can be better cleaned and removed, a large number of particles are avoided from gathering at the center of the wafer, and the yield of the wafer is improved.

[0032] SUMMARY

[0033] The features and properties of the application are further described by the following examples and drawings.

[0034] Fig. 1 shows a schematic diagram of a wafer cleaning device in an embodiment of the application;

[0035] Fig. 2 shows a schematic diagram of a wafer cleaning method in an embodiment of the application;

[0036] Figure 3 shows a flow chart of a control method of a wafer cleaning device according to an embodiment of the present application;

[0037] Figure 4 shows a schematic diagram of a moving path of a cleaning brush according to an embodiment of the present application;

[0038] Figure 5 shows a schematic diagram of a moving process of a cleaning brush according to an embodiment of the present application.

[0039] Preferred embodiments of the present application

[0040] The present application is herein described, by way of example only, with reference to embodiments thereof. It is to be understood that variations and modifications will be apparent to those skilled in the art and that the application herein disclosed can be practiced in different but equivalent manners that are within the scope of the application. It is therefore intended to cover any variations and modifications that only depart from the spirit or essential characteristics of the present application, which is defined in the claims.

[0041] It is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments will be apparent to those of skill in the art upon reading the above description. The scope of the application should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with their full scope of equivalents. Various modifications and changes can be made thereto by those skilled in the art without departing from the spirit and scope of the application, which is defined by the following claims. For example, the order of steps can be modified without departing from the scope of the application.

[0042] The present application provides a wafer cleaning device. Referring to Figure 1, the wafer cleaning device comprises a cleaning brush 1, a chuck 2 and a controller 3. The cleaning brush 1 is used to brush the surface of a wafer w. The chuck 2 is used to support the wafer w and rotate the wafer w. 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 rotation speed of the chuck 2 during the movement of the cleaning brush 1, so that the rotation 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, the "center of the wafer w" refers to a region on the wafer w that includes the center of the wafer w and extends a certain distance outward from the center, and the "edge of the wafer w" refers to a region on the wafer w that includes the outer edge of the wafer w and extends a certain distance inward from the outer edge. The movement of the cleaning brush 1 includes, but is not limited to, horizontal movement 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, and the specific distance or whether the two are in contact can be selected according to actual conditions according to conventional standards in the art.

[0043] As shown in FIG. 1, the wafer cleaning device further comprises a cleaning brush driving mechanism 4 and a chuck driving mechanism 5, and the controller 3 is configured to send control instructions to the cleaning brush driving mechanism 4 and the chuck driving mechanism 5, so as to control the movement of the cleaning brush 1 and the rotation of the chuck 2.

[0044] The present application also provides a wafer cleaning method applied to the wafer cleaning device described above, as shown in FIG. 2, the wafer cleaning method comprises:

[0045] rotating the wafer and moving the cleaning brush to brush the surface of the wafer;

[0046] 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.

[0047] In some embodiments, changing the rotation speed of the chuck during the movement of the cleaning brush comprises:

[0048] a feature position is arranged on the movement path of the cleaning brush;

[0049] When the cleaning brush moves between the feature position and the center of the wafer, the rotation speed of the chuck is greater than the rotation speed of the chuck when the cleaning brush moves between the feature position and the edge of the wafer.

[0050] In other embodiments, a plurality of feature positions can also be arranged on the movement path of the cleaning brush, the plurality of feature positions are on a straight line and have the same height, the cleaning brush is moved at a uniform speed between any two adjacent feature positions, and the chuck is rotated at a uniform speed or a uniform variable speed.

[0051] As shown in FIG. 3, the present application also provides a control method of a wafer cleaning device, applied to the wafer cleaning device described above, the control method comprises the following steps:

[0052] Step S100, a movement path of the cleaning brush is arranged, the movement path comprises a plurality of feature positions distributed along the radial direction of the wafer;

[0053] Step S200, a control menu is constructed, the control menu comprises rotation parameters of the chuck when the cleaning brush is at each feature position, the rotation parameters comprise the rotation speed of the chuck; wherein the rotation speed of the chuck corresponding to the feature position close to the center of the wafer is greater than the rotation speed of the chuck corresponding to the feature position close to the edge of the wafer;

[0054] Step S300, the cleaning brush is controlled to move along the movement path, and the chuck is controlled to rotate according to the control menu, and when the cleaning brush is at each feature position, the chuck is controlled to rotate according to the corresponding rotation parameters.

[0055] In order to increase the cleaning time of the cleaning brush in the center of the wafer, so that the particles in 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.

[0056] In step S200, the cleaning brush moves at a uniform speed between adjacent feature positions, and the chuck rotates at a uniform speed or a uniform variable speed. In this embodiment, the number of feature positions is at least two, one of which is close to the center of the wafer, and the other is close to the edge of the wafer. When the cleaning brush moves between these two feature positions, the chuck rotates at a uniform variable speed, so that the rotational speed of the chuck when the cleaning brush is in the center of the wafer is greater than the rotational speed of the chuck when the cleaning brush is at the edge of the wafer. When the number of feature positions is more than three, the cleaning brush moves between each two adjacent feature positions, and the chuck rotates at a uniform speed or a uniform variable speed.

[0057] The above steps S100-S300, wafer cleaning device and wafer cleaning method are described below in conjunction with the accompanying drawings.

[0058] Referring to FIG. 4, a moving path of the cleaning brush is shown, which includes a plurality of feature positions: first position P1, second position P2, third position P3 and fourth position P4, and the plurality of feature positions are on a straight line passing through the center of the wafer and have the same height. FIG. 4 is only an example and is not used to limit the specific moving path of the cleaning brush and the specific position, number, etc. of the feature positions. In FIG. 4, the cleaning brush is represented by a cylinder and the wafer is represented by an oval. Each feature position in FIG. 4 has a preset spatial position in space, and FIG. 4 shows the relative position relationship between each feature position and the surface of the wafer. The line connecting the first position P1 and the second position P2 passes through the center O of the wafer, and the distance between the second position P2 and the center O of the wafer is greater than the distance between the first position P1 and the center O of the wafer. The third position P3 is closer to the second position P2 than to the fourth position P4. The distance between the center O of the wafer and the fourth position P4 is slightly less than the radius of the wafer. The distance between the fourth position P4 and the outer edge of the wafer is set according to the radius of the cleaning brush. For example, the sum of the distance between the center O of the wafer and the fourth position P4 and the radius of the cleaning brush is equal to the radius of the wafer, so that the wafer surface can be fully and comprehensively cleaned.

[0059] 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. When the cleaning brush moves between the first position P1 and the second position P2, the chuck rotates at a higher speed; in comparison, when the cleaning brush moves between the third position P3 and the fourth position P4, the chuck rotates at a lower speed. In this embodiment, the speed of the chuck is adjusted so that the chuck rotates at a higher speed when the cleaning brush is at the center of the wafer, and the first position P1 and the second position P2 are arranged on both sides of the wafer center O, which increases 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 addition, the chuck rotates at a lower speed when the cleaning brush is at the edge of the wafer, which reduces the linear speed of the wafer edge, and in turn reduces the friction between the cleaning brush and the wafer edge, thereby avoiding the formation of a large number of particles at the wafer edge due to friction.

[0060] The rotation parameters of the chuck also include the acceleration of the chuck when the cleaning brush moves between the second position P2 and the third position P3. When the cleaning brush moves from the center of the wafer to the edge, the acceleration is negative; when the cleaning brush moves from the edge of the wafer to the center, the acceleration is positive. Specifically, when the cleaning brush moves from P2 to P3, the acceleration is negative, and the chuck rotates at a uniform deceleration; conversely, when the cleaning brush moves from P3 to P2, the acceleration is positive, and the chuck rotates at a uniform acceleration. 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, the chuck rotates at a uniform speed.

[0061] In some embodiments, the direction of the movement path of the cleaning brush is from the center of the wafer to the edge of the wafer. In combination with FIG. 5, a specific example of a cleaning brush movement process is given below.

[0062] After starting the cleaning process, the cleaning brush moves from P1 to P2, during which the chuck rotates at a first speed R1; wherein the cleaning brush moves from P1 to P2, passing through the wafer center O. After the cleaning brush passes through P2, the chuck starts to decelerate, and when the cleaning brush reaches P3, the speed of the chuck is R2. The first speed R1 and the second speed R2 are set according to the actual process, and the deceleration A of the chuck during the movement of the cleaning brush from P2 to P3 can be calculated according to the first speed R1, the second speed R2, the distance between P2 and P3, and the movement speed V of the cleaning brush. During the movement of the cleaning brush from P3 to P4, the speed of the chuck remains R2. After the cleaning brush reaches P4, it completes a cleaning process.

[0063] Table 1 shows an example of a control menu, the parameters in this example correspond to the embodiment shown in FIG. 5 above.

[0064] Table 1:

[0065] Referring to FIG. 5, the wafer center O can be set as the origin, and the right side is the positive direction and the left side is the negative direction. In some embodiments, referring to a wafer with a diameter of 300 mm, the range of the characteristic positions of the cleaning brush is -150 mm to 150 mm.

[0066] Preferably, the control menu further comprises a circular movement control item, which comprises a number of cycles, and the circular movement control item is used to control the cleaning brush to move according to the movement path for a number of cycles. The number of cycles is determined according to the actual process, for example, it can be set to two in the present embodiment.

[0067] In some embodiments, the movement path of the cleaning brush further comprises characteristic positions P0 and P5, as shown in FIG. 5, P0 is set directly above P1, P5 is set directly above P4, and P5 is at the same height as P0. Before the cleaning process starts, the cleaning brush is located at P0, and the rotation speed of the chuck is the first rotation speed R1. After the cleaning process starts, 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 and returns to P0, preparing for the next cycle of movement. During this process, the rotation speed of the chuck is increased from the second rotation speed R2 to the first rotation speed R1.

[0068] In other embodiments, the direction of the movement path of the cleaning brush can also be from the wafer edge to the wafer center. Correspondingly, the chuck rotates at a uniform speed or uniform acceleration, and it is only necessary to set the rotation speed of the chuck when the cleaning brush is at the wafer edge to be lower than the rotation speed of the chuck when the cleaning brush is at the wafer center.

[0069] In other embodiments, the movement path of the cleaning brush can also be set as a diameter of the wafer or slightly shorter than the diameter, i.e. the direction of the movement path can also be from the wafer edge, through the wafer center, and then to the wafer edge. Correspondingly, the chuck rotates at a slower speed when the cleaning brush is at the wafer edge, the rotation speed of the chuck increases when the cleaning brush moves to the wafer center, and the rotation speed of the chuck slows down again when the cleaning brush moves to the wafer edge.

[0070] The above embodiments are only illustrative of the principles and effects of the present application, and are not intended to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought of the present application should be covered by the claims of the present application.

Claims

1. A wafer cleaning method applied to a wafer cleaning apparatus including a cleaning brush for brushing a wafer surface and a chuck for carrying the wafer and rotating the wafer, characterized by, The method comprises: rotating the wafer, and moving the cleaning brush to brush the wafer surface; during the movement of the cleaning brush, changing the rotation speed of the chuck so that the rotation speed of the chuck when the cleaning brush is at the wafer center is greater than the rotation speed of the chuck when the cleaning brush is at the wafer edge.

2. The wafer cleaning method according to claim 1, wherein The changing of the rotation speed of the chuck during the movement of the cleaning brush comprises: setting a feature position on the movement path of the cleaning brush; when the cleaning brush moves between the feature position and the wafer center, the rotation speed of the chuck is greater than when the cleaning brush moves between the feature position and the wafer edge.

3. The wafer cleaning method of claim 1, wherein The changing of the rotation speed of the chuck during the movement of the cleaning brush comprises: setting a plurality of feature positions on the movement path of the cleaning brush, the plurality of feature positions are on a straight line and have the same height; the plurality of feature positions include a second position and a third position, the second position is closer to the wafer center than the third position; when the cleaning brush moves between the second position and the wafer center, the rotation speed of the chuck is greater than when the cleaning brush moves between the third position and the wafer edge.

4. The wafer cleaning method according to claim 3, wherein The plurality of feature positions further include a first position and a fourth position, 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 rotation speed of the chuck is greater than when the cleaning brush moves between the third position and the fourth position.

5. The wafer cleaning method according to claim 4, wherein The line connecting the first position and the second position passes through the wafer center.

6. The wafer cleaning method of claim 4, wherein Between adjacent feature positions, the cleaning brush moves at a uniform speed, and the chuck rotates at a uniform speed or a uniform variable speed.

7. The wafer cleaning method of claim 4, wherein The fourth position is at a distance from the wafer center equal to the difference between the radius of the wafer and the radius of the cleaning brush.

8. The wafer cleaning method of claim 4, wherein When the cleaning brush moves between the second position and the third position, the chuck rotates with an acceleration; when the cleaning brush moves from the wafer center to the edge, the acceleration is negative; when the cleaning brush moves from the wafer edge to the center, the acceleration is positive.

9. The wafer cleaning method according to claim 8, wherein, When the cleaning brush moves between the first position and the second position, and between the third position and the fourth position, the chuck rotates at a uniform speed.

10. A wafer cleaning apparatus, characterized by comprising: It comprises: a cleaning brush for brushing the wafer surface; a chuck for carrying the wafer and rotating the wafer; a controller for controlling the movement of the cleaning brush and controlling the rotation of the chuck; The controller is configured to change the rotation speed of the chuck during the movement of the cleaning brush, so that the rotation speed of the chuck when the cleaning brush is at the wafer center is greater than the rotation speed of the chuck when the cleaning brush is at the wafer edge.

11. A control method of a wafer cleaning apparatus, characterized by, It comprises the following steps: setting a movement path of the cleaning brush, the movement path comprising a plurality of feature positions; constructing a control menu, the control menu comprising the rotation parameters of the chuck when the cleaning brush is at each feature position, the rotation parameters comprising the rotation speed of the chuck; wherein the rotation speed of the chuck when the cleaning brush is at the wafer center is greater than the rotation speed of the chuck when the cleaning brush is at the wafer edge; controlling the cleaning brush to move along the movement path and controlling the chuck to rotate according to the control menu, and when the cleaning brush is located at each feature position, controlling the chuck to rotate according to a corresponding rotation parameter.

12. The control method according to claim 11, characterized by, The control menu further comprises a cycle movement control item, the cycle control item comprising a cycle number, the cycle control item being used to control the cleaning brush to move cyclically according to the movement path for the cycle number.

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