A cleaning device, a cleaning system and a cleaning method

Abstract

The application discloses a cleaning device, a cleaning system and a cleaning method, and relates to the technical field of chemical mechanical polishing. The application reduces the risk of under cleaning and / or over cleaning of a wafer surface under the condition that the cleaning pressure of a cleaning brush assembly included in the cleaning device is accurately controlled to act on different cleaning areas of the wafer. The cleaning device is applied to the cleaning of a wafer after chemical mechanical polishing. The wafer has at least two cleaning areas, and the impurity distribution characteristics of the at least two cleaning areas are different. The cleaning device comprises a liquid supply unit, a liquid supply pipeline and a cleaning brush assembly. The liquid supply unit supplies cleaning liquid to the cleaning brush assembly through the liquid supply pipeline. The cleaning brush assembly has at least two cleaning areas, and one cleaning area corresponds to one cleaning area. The liquid supply pipeline provides different cleaning forces to the at least two cleaning areas. The application further provides a cleaning system and a cleaning method.

Description

Technical Field

[0001] This invention relates to the field of chemical mechanical polishing technology, and in particular to a cleaning device, cleaning system and cleaning method. Background Technology

[0002] Chemical mechanical polishing (CMP) is a global surface planarization technique. With its widespread application in semiconductor device manufacturing processes, such as CMP after forming interlayer dielectric (ILD), metal plugs, and metal interconnects, post-CMP cleaning has become particularly important.

[0003] The main purpose of cleaning after CMP is to remove impurities introduced during the CMP process, such as abrasive particles, particles from the polished material, and chemical contaminants from the abrasive.

[0004] The cleaning methods offered by related technologies generally include brush cleaning, acid spray cleaning, and megasonite cleaning. Brush cleaning is widely used compared to other cleaning methods because of its strong ability to remove impurities and its high efficiency.

[0005] However, when using the brush cleaning device provided by the relevant technology to clean the surface of the wafer, there are problems of under-cleaning and / or over-cleaning. Summary of the Invention

[0006] The purpose of this invention is to provide a cleaning apparatus, cleaning system, and cleaning method that reduces the risk of under-cleaning and / or over-cleaning of the wafer surface by precisely controlling the cleaning pressure of the cleaning brush assembly included in the cleaning apparatus on different areas to be cleaned on the wafer.

[0007] To achieve the above objectives, the present invention provides a cleaning apparatus for cleaning wafers after polishing. The wafer has at least two areas to be cleaned, and the impurity distribution characteristics of the at least two areas to be cleaned are different. The cleaning apparatus includes a liquid supply unit, a liquid supply pipeline, and a cleaning brush assembly. The liquid supply unit supplies cleaning liquid to the cleaning brush assembly through the liquid supply pipeline. The cleaning brush assembly has at least two cleaning areas, one cleaning area corresponding to one area to be cleaned. The liquid supply pipeline provides different cleaning forces to the at least two cleaning areas, so that the cleaning pressure acting on the area to be cleaned through the cleaning areas is different.

[0008] Compared with existing technologies, the cleaning apparatus provided by this invention, when applied to the cleaning of wafers after chemical mechanical polishing, addresses situations where the wafer surface has at least two areas to be cleaned, and the required cleaning pressures for these two areas differ. By controlling the varying cleaning forces supplied by the liquid supply lines to the cleaning areas (spatially corresponding to the areas to be cleaned) of the cleaning brush assembly, precise cleaning of different areas on the wafer surface can be achieved. Specifically, when the required cleaning pressure for one of the areas to be cleaned on the wafer surface is high, the flow rate of the cleaning fluid supplied to the cleaning brush assembly (corresponding to the areas to be cleaned) can be increased. This increased flow rate enhances the impact force of the cleaning fluid on the areas to be cleaned, thereby increasing the cleaning pressure exerted on the areas to be cleaned through the cleaning lines. Based on this, impurities on the areas to be cleaned can be effectively removed, reducing the risk of under-cleaning of these areas. When the cleaning pressure required for another area to be cleaned on the wafer surface is relatively low, the flow rate of the cleaning fluid supplied to the cleaning brush assembly (corresponding to the area to be cleaned) can be reduced. With a reduced flow rate of the cleaning fluid in the cleaning area, the impact force of the cleaning fluid on the area to be cleaned can be decreased, thereby reducing the cleaning pressure exerted on the area to be cleaned through the cleaning area. Based on this, while effectively removing impurities from the area to be cleaned, the risk of over-cleaning of the area can also be reduced.

[0009] The present invention also provides a cleaning system, which includes a communication unit for acquiring impurity distribution characteristics information on the wafer surface. A processing unit is communicatively connected to the communication unit. The processing unit determines the area to be cleaned on the wafer surface and the required cleaning pressure control signal for the area to be cleaned based on the impurity distribution characteristics information on the wafer surface. The present invention also includes a cleaning apparatus provided in any implementation thereof, wherein the cleaning apparatus is communicatively connected to the communication unit.

[0010] Compared with the prior art, the beneficial effects of the cleaning system provided by the present invention are the same as those of the cleaning device of the above-mentioned technical solution, and will not be repeated here.

[0011] The present invention also provides a cleaning method, the cleaning method comprising:

[0012] Obtain information on the impurity distribution characteristics on the wafer surface.

[0013] Based on the impurity distribution characteristics of the wafer surface, the area to be cleaned on the wafer surface and the required cleaning pressure for the area to be cleaned are determined, and the cleaning pressure control signal is determined based on the cleaning pressure.

[0014] A cleaning pressure control signal is provided to the cleaning device, which, under the control of the cleaning pressure control signal, provides the required cleaning pressure to the area to be cleaned.

[0015] Compared with the prior art, the beneficial effects of the cleaning method provided by the present invention are the same as those of the cleaning system of the above-mentioned technical solutions, and will not be repeated here. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0017] Figure 1 This is a schematic diagram of the cleaning device provided in an embodiment of the present invention;

[0018] Figure 2 This is a graph showing the relationship between the cleaning fluid flow rate and the cleaning pressure on the area to be cleaned on the wafer surface.

[0019] Figure 3 This is a schematic diagram of the cleaning device provided in an embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of a wafer with different areas to be cleaned, provided in an embodiment of the present invention;

[0021] Figure 5 This is an application state diagram of the cleaning device provided in the embodiments of the present invention;

[0022] Figure 6 This is a schematic diagram of the cleaning system provided in an embodiment of the present invention.

[0023] in:

[0024] 1 - Wafer, 10 - Area to be cleaned, 100 - First area to be cleaned

[0025] 101 - Second area to be cleaned, 102 - Third area to be cleaned, 103 - Fourth area to be cleaned;

[0026] 20 - Liquid supply unit, 21 - Liquid supply pipeline, 210 - Main liquid supply line.

[0027] 211-Liquid supply branch, 212-Flow control valve, 22-Cleaning brush assembly,

[0028] 220 - Cleaning area, 2200 - First cleaning area, 2201 - Second cleaning area.

[0029] 2202 - Third cleaning zone, 2203 - Fourth cleaning zone, 221 - Rotating shaft,

[0030] 222-Brush head, 223-Channel, 224-Spray nozzle;

[0031] 3-Communication unit, 4-Processing unit, 5-Information acquisition unit. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0033] Various schematic diagrams illustrating embodiments of the present invention are shown in the accompanying drawings, which are not drawn to scale. Some details have been enlarged and may have been omitted for clarity. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0034] In the following description, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0035] Furthermore, in this invention, directional terms such as "upper" and "lower" are defined relative to the positions of the components shown in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the position of the components in the accompanying drawings.

[0036] In this invention, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0037] Chemical mechanical polishing (CMP) is a surface planarization technique that uses CMP equipment to planarize the surface of a wafer. After planarizing the wafer surface using CMP equipment, impurities usually remain on the wafer surface (including the polished side, the opposite side, and the side surfaces). These impurities include abrasive particles, particles from the polishing material, and chemical contaminants from the abrasive.

[0038] Related technologies provide a method for cleaning wafer surfaces using a cleaning brush and a cleaning solution. The cleaning solution can be deionized water, ammonium hydroxide, or hydrofluoric acid, etc. The cleaning brush and deionized water are suitable for cleaning after CMP (Continuous Metallurgical Processing) of the interlayer dielectric layer; the cleaning brush and ammonium hydroxide are suitable for cleaning after CMP of tungsten metal; and the cleaning brush, ammonium hydroxide, and hydrofluoric acid are also suitable for cleaning after CMP of tungsten metal.

[0039] When cleaning the wafer surface using the above method, a cleaning brush can be rotated and pressed against the wafer surface (at which time, the wafer can also rotate). Simultaneously, cleaning fluid can be sprayed onto the wafer surface using the cleaning brush, or the cleaning fluid can be sprayed onto the wafer surface solely through a cleaning fluid supply device. The combined action of the cleaning brush and cleaning fluid effectively removes impurities from the wafer surface.

[0040] The inventors discovered that after planarizing a wafer surface using chemical mechanical polishing (CMP), the distribution characteristics of residual impurities differ across different regions of the wafer surface. For example, some regions have a higher density and / or thickness of residual impurities, while others have a lower density and / or thickness. If the cleaning brush applies the same cleaning pressure to all these regions, the cleaning result may be under-cleaning (insufficient cleaning) in areas with higher density and / or thickness, and over-cleaning (excessive cleaning) in areas with lower density and / or thickness. This affects the cleaning effect and even the quality of the wafer. When such wafers are used in semiconductor devices, it will reduce the performance of the semiconductor devices.

[0041] To address the aforementioned technical problems, embodiments of the present invention provide a cleaning device. Figure 1 A schematic diagram of a cleaning apparatus provided in an embodiment of the present invention is shown. Figure 1 As shown, the cleaning apparatus provided in this embodiment of the invention can be applied to the cleaning of wafers after chemical mechanical polishing (CMP), and of course, it can also be applied to the cleaning of wafers polished by other polishing methods. The polished wafer has at least two areas to be cleaned, and the impurity distribution characteristics on these at least two areas are different. These impurity distribution characteristics may include impurity thickness distribution characteristics and / or impurity density distribution characteristics, etc. Because these impurity distribution characteristics are different, the cleaning pressure required to remove impurities from the areas to be cleaned is different. It should be understood that the cleaning pressure can be the pressure applied by the cleaning brush assembly 22 to the wafer surface.

[0042] The aforementioned cleaning apparatus includes a liquid supply unit 20, a liquid supply line 21, and a cleaning brush assembly 22. The liquid supply unit 20 supplies cleaning fluid to the cleaning brush assembly 22 via the liquid supply line 21. The cleaning brush assembly 22 has at least two cleaning zones, each corresponding to a region on the wafer to be cleaned. The liquid supply line 21 provides different cleaning forces to the at least two cleaning zones, and simultaneously, each cleaning zone provides different cleaning pressures to its corresponding region. It should be understood that the greater the cleaning force provided by the cleaning zones, the greater the cleaning pressure applied to the region on the wafer surface, and the more significant the removal effect on impurities on the wafer surface.

[0043] Figure 2 The graph shows the relationship between the cleaning fluid flow rate and the cleaning pressure on the area to be cleaned on the wafer surface. (See figure.) Figure 2 As shown, the cleaning pressure applied to the area to be cleaned on the wafer surface increases with the increase of the cleaning fluid flow rate. When the supply unit 20 supplies cleaning fluid to different cleaning areas of the cleaning brush assembly 22 through the supply pipeline 21, the greater the flow rate of the cleaning fluid supplied to the cleaning area, the greater the impact force of the cleaning fluid passing through the cleaning area on the area to be cleaned on the wafer surface corresponding to the cleaning area. In other words, the greater the cleaning pressure applied to the area to be cleaned through the cleaning area, the smaller the pressure, and vice versa.

[0044] Figure 3 A schematic diagram of the cleaning device provided in an embodiment of the present invention is shown, as follows: Figure 3 As shown, the flow rate of cleaning fluid supplied to different cleaning areas 220 of the cleaning brush assembly 22 can be controlled by controlling the flow rate of cleaning fluid supplied to these different cleaning areas 220 on the corresponding wafer. This controls the impact force (which can be defined as cleaning force) provided by the different cleaning areas 220 of the cleaning brush assembly 22 to the areas to be cleaned on the wafer. Furthermore, when the different cleaning areas 220 of the cleaning brush assembly 22 apply the impact force to the areas 10 to be cleaned on the wafer, the different areas 10 to be cleaned receive different cleaning pressures. At this time, impurities on the different areas 10 to be cleaned are removed under the action of their respective cleaning pressures.

[0045] See Figure 1 The aforementioned liquid supply unit 20 may include a storage tank (not shown in the figure) for storing cleaning fluid, which may be deionized water, ammonium hydroxide, a mixed solution of ammonium hydroxide and hydrofluoric acid, etc. The liquid supply unit 20 may also include a liquid supply pump (not shown in the figure) for pumping the cleaning fluid from the storage tank into the liquid supply pipeline 21. Of course, the liquid supply unit 20 may also include a connecting pipeline (not shown in the figure) connecting the liquid supply pump and the liquid supply pipeline 21, and a flow control valve (not shown in the figure) installed on the connecting pipeline.

[0046] See Figure 1The aforementioned liquid supply line 21 is a component that provides different cleaning forces to at least two cleaning zones of the cleaning brush assembly 22. Therefore, the flow rate of the cleaning fluid delivered to the at least two cleaning zones of the cleaning brush assembly 22 via the liquid supply line 21 should be adjustable. The cleaning force applied to the cleaning zone can be adjusted or controlled by adjusting or controlling the flow rate of the cleaning fluid in the liquid supply line 21 corresponding to the cleaning zone, and further, the cleaning pressure applied to the area to be cleaned on the wafer via the cleaning zone can be adjusted or controlled.

[0047] See Figure 1 The aforementioned liquid supply line 21 may include a main liquid supply line 210 connected to the liquid supply pump included in the liquid supply unit 20. When there is a connecting line between the liquid supply pump and the main liquid supply line 210, and a flow control valve is installed on the connecting line, the flow rate of the cleaning fluid flowing through the main liquid supply line 210 can be controlled by controlling the opening degree of the flow control valve. The aforementioned liquid supply line 21 may also include a liquid supply branch line 211 connected to the main liquid supply line 210. The number of liquid supply branch lines 211 is related to the number of areas to be cleaned on the wafer. That is, the number of areas to be cleaned on the wafer is related to the number of cleaning areas on the cleaning brush assembly 22, and the number of cleaning areas on the cleaning brush assembly 22 is related to the number of liquid supply branch lines 211. For example, when the number of areas to be cleaned on the wafer is 4, the number of cleaning areas on the cleaning brush assembly 22 and the number of liquid supply branch lines 211 are at least 4. At this time, at least one supply branch 211 provides cleaning fluid to a cleaning area. To precisely control the flow rate of the cleaning fluid flowing through each supply branch 211, at least one flow control valve 212 can be installed on each supply branch 211. By controlling the opening of the flow control valve 212, the flow rate of the cleaning fluid flowing through each supply branch 211 can be controlled. At this time, the cleaning force of the cleaning brush assembly 22 corresponding to the supply branch 211 can be controlled.

[0048] See Figure 1 When the cleaning brush assembly 22 includes a rotating shaft 221 and a brush head 222 sleeved on the rotating shaft, and the rotating shaft 221 has a channel 223 opened along the axial direction of the rotating shaft 221 and a spray port 224 opened along the radial direction of the rotating shaft 221, the positional relationship between the liquid supply line 21 and the cleaning brush assembly 22 can be:

[0049] See Figure 1The portion connecting the main liquid supply line 210 and the branch liquid supply lines 211, as well as the branch liquid supply lines 211, can be located within the channel 223. For example, when the cleaning brush assembly 22 has four cleaning zones, four branch liquid supply lines 211 can branch off from the main liquid supply line 210. Each branch liquid supply line 211 has an outlet located within one cleaning zone. Spatially, the branch liquid supply lines 211 can be sequentially spaced along the axial direction of the rotation axis 221 within the channel 223.

[0050] See Figure 1 It should be understood that there are multiple spray nozzles 224 opened radially along the rotation axis 221. For example, the spray nozzles 224 can be evenly distributed in an array along the circumference of the rotation axis 221. In this case, each cleaning area corresponds to multiple spray nozzles 224.

[0051] See Figure 1 To ensure that the cleaning force of the cleaning fluid sprayed from the multiple nozzles 224 evenly distributed along the circumference of the rotation axis 221 is consistent in each cleaning area, multiple liquid supply branches 211 can be set in each cleaning area, and the outlets of the multiple liquid supply branches 211 are evenly distributed in the circumference of the channel 223.

[0052] To better understand the wafer cleaning process of the cleaning apparatus provided in this embodiment of the invention, a detailed description is given below, taking a wafer 1 with four areas to be cleaned and a cleaning brush assembly with four cleaning areas as an example. It should be understood that the following description is for illustrative purposes only and is not intended to limit the scope of the invention.

[0053] See Figure 4 and Figure 5 For ease of explanation, from the center of wafer 1 to its edge, the four areas to be cleaned 10 are sequentially defined as the first area to be cleaned 100, the second area to be cleaned 101, the third area to be cleaned 102, and the fourth area to be cleaned 103. The cleaning areas of the cleaning brush assembly corresponding to the first area to be cleaned 100, the second area to be cleaned 101, the third area to be cleaned 102, and the fourth area to be cleaned 103 are defined as the first cleaning area 2200, the second cleaning area 2201, the third cleaning area 2202, and the fourth cleaning area 2203, respectively.

[0054] The impurity distribution characteristics in the third cleaning area 102 differ from those in the other three cleaning areas. In other words, the density and / or thickness of impurities in the third cleaning area 102 are greater than those in the other three cleaning areas. Therefore, the cleaning pressure required for the third cleaning area 102 is greater than that required for the other three cleaning areas.

[0055] See Figure 5When cleaning a wafer 1 with the above-mentioned characteristics using the cleaning apparatus provided in this embodiment of the invention, if equal cleaning pressure is required on both the polished surface and the opposite surface of wafer 1, cleaning brush assemblies 22 provided in this embodiment of the invention can be provided on both the polished surface and the opposite surface of wafer 1. In this case, one cleaning brush assembly 22 presses against the polished surface of wafer 1, and the other cleaning brush assembly 22 presses against the other surface (opposite to the polished surface) of wafer 1. The two cleaning brush assemblies 22 can share a single liquid supply unit 20, and each cleaning brush assembly 22 is provided with a corresponding set of liquid supply lines 21. That is, the two sets of liquid supply lines 21 share a single liquid supply unit 20. It should be further explained that the wafer 1 to be cleaned can be supported by a wafer carrier (not shown in the figure), and the wafer carrier can drive the wafer 1 to rotate.

[0056] See Figure 5 During cleaning, the cleaning brush assembly 22 and the wafer 1 rotate simultaneously. At the same time, the cleaning fluid flows from the liquid supply unit 20 through the liquid supply pipeline 21 and is delivered to the cleaning area 10 through the liquid supply branch 211 included in the liquid supply pipeline 21, and is sprayed out from the spray nozzle 224 in the cleaning area 10.

[0057] See Figure 5 Because the cleaning pressure required for the third area 102 to be cleaned on wafer 1 is greater than that required for the other three areas to be cleaned, the opening of the flow control valve 212 on the liquid supply branch 211 corresponding to the third area 102 can be controlled to increase the impact force of the cleaning fluid on the brush head 222 portion of the cleaning brush assembly 22 (third cleaning area 2202) opposite to the third area 102. With the brush head 222 pressed against the surface of wafer 1, it expands under the greater impact force provided by the cleaning fluid, thus increasing the cleaning pressure exerted by the brush head on the third area 102 to be cleaned on wafer 1. When this cleaning pressure acts on the third area 102, impurities on the third area 102 can be effectively removed, reducing the risk of under-cleaning of the third area 102.

[0058] See Figure 5Correspondingly, since the cleaning pressure required for the other three areas to be cleaned on wafer 1 is less than that required for the third area to be cleaned 102, the opening degree of the flow control valve 212 on the liquid supply branch 211 corresponding to the other three areas to be cleaned can be controlled, so that the impact force of the cleaning fluid on the brush head 222 in the cleaning area 10 of the cleaning brush assembly 22 corresponding to the other three areas to be cleaned is reduced. With the brush head 22 pressed against the surface of wafer 1, the brush head 22 will not expand or will expand only slightly under the smaller impact force provided by the cleaning fluid. At this time, the cleaning pressure exerted by the brush head 222 on the other three areas to be cleaned on wafer 1 is reduced. When the aforementioned cleaning pressure acts on the other three areas to be cleaned, impurities on the three areas to be cleaned are effectively removed, while the risk of over-cleaning the three areas to be cleaned is also reduced.

[0059] Furthermore, the combined action of the cleaning fluid and the cleaning brush assembly not only cleans the wafer surface but also achieves chemical-mechanical polishing of the wafer surface through the corrosion of the cleaning fluid and the cleaning force exerted by the cleaning brush assembly. Therefore, while cleaning the wafer surface, planarization can also be achieved.

[0060] This invention also provides a cleaning system. Figure 6 A schematic diagram of the cleaning system provided in an embodiment of the present invention is shown. Figure 6 As shown, the cleaning system includes a communication unit 3, a processing unit 4 communicatively connected to the communication unit 3, and a cleaning device communicatively connected to the communication unit 3. The communication unit 3 is used to acquire information on the impurity distribution characteristics of the wafer 1 surface. The processing unit 4 determines multiple areas 10 to be cleaned on the wafer 1 surface and the required cleaning pressure for the multiple areas 10 based on the impurity distribution characteristics information. Once the required cleaning pressure for the multiple areas 10 is determined, the cleaning device provides the cleaning pressure to the multiple areas 10 to be cleaned.

[0061] See Figure 6 The impurity distribution characteristics information on the surface of wafer 1 mentioned above include, but are not limited to, impurity density distribution information and impurity thickness distribution information. It should be understood that the greater the impurity density and / or the greater the impurity thickness distributed on the surface of wafer 1, the greater the cleaning pressure required to be applied to the surface of wafer 1 by the cleaning device.

[0062] See Figure 6In practical applications, the communication unit 3 acquires the impurity distribution characteristics information of the surface of wafer 1 after chemical mechanical polishing and sends the impurity distribution characteristics information of the surface of wafer 1 to the processing unit 4. After receiving the impurity distribution characteristics information of the surface of wafer 1, the processing unit 4 divides the surface of wafer 1 into multiple areas 10 to be cleaned according to the impurity distribution characteristics information of the surface of wafer 1.

[0063] See Figure 6 For example, the actual thickness information of wafer 1 can be obtained using communication unit 3, and the preset thickness information of wafer 1 after chemical mechanical polishing is pre-stored in processing unit 4. The difference between the actual thickness information and the preset thickness information can be defined as the impurity distribution thickness information on the surface of wafer 1, and this can be used as the impurity distribution characteristic information on the surface of wafer 1. Processing unit 4 can divide the surface of wafer 1 into multiple areas 10 to be cleaned according to the impurity distribution thickness information. After the areas 10 to be cleaned on the wafer surface are determined, the processing unit can also generate a cleaning pressure control signal according to the impurity distribution thickness information in each area 10 to be cleaned.

[0064] See Figure 6 The communication unit 3 can also receive and send cleaning pressure control signals to the cleaning device. Based on these signals, the cleaning device controls the liquid supply lines to provide cleaning force to different cleaning areas 220 of the cleaning brush assembly 22, where each cleaning area 220 is opposite to the area 10 to be cleaned on the wafer surface. Therefore, multiple areas 10 to be cleaned on the wafer 1 surface can receive different cleaning pressures.

[0065] See Figure 6 The cleaning system described above may further include an information acquisition unit 5, which is communicatively connected to the communication unit 3. The information acquisition unit 5 can acquire information on the impurity distribution characteristics of the wafer 1 surface and transmit this information to the communication unit 3.

[0066] When the impurity distribution characteristics information on the wafer surface is the impurity distribution thickness information on the wafer surface, contact sensors such as inductive displacement sensors, capacitive displacement sensors, potentiometer displacement sensors, and Hall effect displacement sensors, or non-contact sensors such as eddy current thickness sensors, magnetic thickness sensors, capacitive thickness sensors, ultrasonic thickness sensors, nuclear radiation thickness sensors, X-ray thickness sensors, and microwave thickness sensors can be used to detect the thickness of the wafer after chemical mechanical polishing.

[0067] This invention also provides a cleaning method, which includes:

[0068] See Figure 6The information acquisition unit 5 acquires information on the impurity distribution characteristics of the wafer 1 surface. When the impurity distribution characteristics of the wafer 1 surface are the impurity distribution thickness information of the wafer surface, the information acquisition unit 5 can first acquire the thickness of the wafer 1 after chemical mechanical polishing (defined as the actual thickness of the wafer). The communication unit 3 receives the actual thickness of the wafer 1 from the information acquisition unit 5.

[0069] See Figure 6 Based on the impurity distribution characteristics of the wafer 1 surface, multiple cleaning areas 10 on the wafer 1 surface are determined, along with the required cleaning pressure for each cleaning area 10. A cleaning pressure control signal is then determined based on the cleaning pressure. When the communication unit 3 receives the actual thickness of the wafer 1 from the information acquisition unit 5, the communication unit 3 sends the actual thickness of the wafer 1 to the processing unit 4. The processing unit 4 can pre-store preset thickness information for the wafer 1. The difference between the actual thickness information and the preset thickness of the wafer 1 is the impurity distribution thickness information on the wafer 1 surface. The processing unit 3 can determine the cleaning areas 10 on the wafer 1 surface based on the impurity distribution thickness information. It should be understood that the impurity distribution thickness information of the same cleaning area 10 on the wafer 1 surface is basically consistent, while the impurity distribution thickness information of different cleaning areas 10 on the wafer 1 surface differs. After determining the cleaning areas 10 on the wafer surface, the processing unit 3 can also determine the required cleaning pressure for each cleaning area 10 based on the impurity distribution thickness information of the cleaning area 10. Furthermore, the processing unit 3 can also generate a cleaning pressure control signal corresponding to each cleaning area 10 based on the cleaning pressure of the area to be cleaned 10.

[0070] A cleaning pressure control signal is provided to the cleaning device, which, under the control of the cleaning pressure control signal, provides the required cleaning pressure to the area 10 to be cleaned. When the processing unit 4 generates the cleaning pressure control signal corresponding to the area to be cleaned, the communication unit 3 can also receive the cleaning pressure control signal and send it to the cleaning device. Under the control of the cleaning pressure control signal, the cleaning device provides the required cleaning pressure to the area 10 to be cleaned.

[0071] For example, the communication unit 3 can send the cleaning pressure control signal to the flow control valve 212 on the liquid supply branch 211 included in the cleaning device to control the opening of the flow control valve 212, thereby controlling the flow rate of the cleaning liquid on each liquid supply branch 211, so that the cleaning area 220 corresponding to each liquid supply branch 211 has different cleaning force. When the cleaning force acts on the surface of the wafer 1 and the area to be cleaned 10 corresponding to the cleaning area 220, the area to be cleaned 10 has different cleaning pressure.

[0072] It should be further explained that the aforementioned information on the impurity distribution characteristics of the wafer surface may also include information on the impurity distribution density and the type of impurities on the wafer surface.

[0073] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the device embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0074] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cleaning device, characterized in that, The cleaning device is used for cleaning after wafer polishing, wherein the wafer has at least two areas to be cleaned, and the impurity distribution characteristics of the at least two areas to be cleaned are different; the cleaning device includes a liquid supply unit, a liquid supply pipeline, and a cleaning brush assembly. The liquid supply unit supplies cleaning liquid to the cleaning brush assembly through the liquid supply pipeline. The cleaning brush assembly has at least two cleaning areas, and one cleaning area corresponds to one area to be cleaned. The liquid supply line provides different cleaning forces to at least two of the cleaning zones, so that the cleaning pressure acting on the area to be cleaned through the cleaning zones is different. The liquid supply pipeline includes a main liquid supply line connected to the liquid supply unit, and at least two liquid supply branches connected to the main liquid supply line; at least one of the liquid supply branches corresponds to one of the cleaning areas and provides the cleaning liquid. The cleaning brush assembly includes a rotating shaft and a brush head sleeved on the rotating shaft; The rotating shaft has a channel extending along the axial direction of the rotating shaft and a jet nozzle extending radially along the rotating shaft; the jet nozzle communicates with the channel. At least the liquid supply branch included in the liquid supply pipeline is located within the channel.

2. The cleaning device according to claim 1, characterized in that, Each of the aforementioned liquid supply branches has at least one flow control valve.

3. A cleaning system, characterized in that, include: A communication unit is used to acquire information on the impurity distribution characteristics on the wafer surface; A processing unit, which is communicatively connected to the communication unit; The processing unit determines the area to be cleaned on the wafer surface and the cleaning pressure control signal required for the area to be cleaned based on the impurity distribution characteristics information on the wafer surface. And the cleaning device according to claim 1 or 2, wherein the cleaning device is communicatively connected to the communication unit.

4. The cleaning system according to claim 3, characterized in that, The cleaning system also includes: An information acquisition unit is communicatively connected to the communication unit; the information acquisition unit is used to acquire impurity distribution characteristic information on the wafer surface and send the impurity distribution characteristic information on the wafer surface to the communication unit.

5. The cleaning system according to claim 3, characterized in that, When the required cleaning pressure for the area to be cleaned is determined, the communication unit is also used to send a cleaning pressure control signal to the cleaning device, and the cleaning device provides the cleaning pressure to the cleaning area under the control of the cleaning pressure control signal.

6. A cleaning method, characterized in that, include: Obtain information on the impurity distribution characteristics on the wafer surface; Based on the impurity distribution characteristics of the wafer surface, the area to be cleaned on the wafer surface is determined, as well as the required cleaning pressure for the area to be cleaned, and a cleaning pressure control signal is determined based on the cleaning pressure. The cleaning pressure control signal is provided to the cleaning device, and the cleaning device provides the required cleaning pressure to the area to be cleaned under the control of the cleaning pressure control signal; the cleaning device is the cleaning device according to claim 1 or 2.

7. The cleaning method according to claim 6, characterized in that, The impurity distribution characteristics information on the wafer surface include impurity distribution thickness information, impurity distribution density information, and impurity type information.

8. The cleaning method according to claim 6, characterized in that, Providing the cleaning pressure control signal to the cleaning device, wherein the cleaning device, under the control of the cleaning pressure control signal, provides the required cleaning pressure to the area to be cleaned, including: The flow rate of cleaning fluid supplied by the supply line to the cleaning area of ​​the cleaning brush assembly is controlled, the cleaning area being opposite to the area to be cleaned.

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