Diffusion plate for wafer electroplating and wafer electroplating apparatus
By setting through-holes in different areas on the wafer plating diffusion plate and using a shielding plate to regulate the electrolyte flow, the problem of uneven thickness of the wafer plating layer was solved, and the uniformity and yield of the plating layer were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGBO SEMICON INT CORP
- Filing Date
- 2025-06-20
- Publication Date
- 2026-06-02
AI Technical Summary
In existing technologies, the thickness difference of the bumps in the central and edge areas after wafer electroplating is large, resulting in uneven electroplating layers, which affects product quality and yield.
A diffuser plate is designed to reduce current differences by setting through holes of different diameters and densities in the central and edge regions and using a baffle plate to adjust the electrolyte flow rate and change the ion mobility.
The thickness variation of the electroplated layer within the wafer surface was reduced, improving bump yield and product quality. The bump thickness variation was reduced from 23µm to 5µm, and the yield was increased to 99.9%.
Smart Images
Figure CN224313696U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor technology, and more specifically to a diffusion plate and a wafer electroplating apparatus for wafer electroplating. Background Technology
[0002] With the rapid development of semiconductor technology and the continuous improvement of chip integration, the requirements for wafer surface quality are becoming increasingly stringent. As the basic material for chip manufacturing, the surface quality of the wafer directly affects chip performance. Bumps on the wafer surface serve as connection points between the package and the substrate; the positional accuracy and consistency of these bumps are crucial to the electrical performance and reliability of the package. Simultaneously, equipment defects and increasingly stringent bump specifications from end-users for different products are leading to a decrease in the number of bumps meeting specifications across the entire wafer surface, resulting in low yield. Therefore, optimizing the total thickness variation (TTV) of bumps within the wafer surface to improve bump yield has become an important research topic.
[0003] However, the electroplating equipment in this technology has significant drawbacks. After wafer electroplating, there is a difference of up to 25µm between the bump thickness in the wafer center region and the bump thickness in the wafer edge region. This difference causes the total bump thickness variation in the wafer center and edge regions to exceed the requirements of the final product specifications, thus failing to meet the requirements of subsequent packaging or connection, affecting product quality, and resulting in serious defective products.
[0004] Therefore, improvements are needed to at least partially address the aforementioned problems. Utility Model Content
[0005] The utility model description section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This utility model description section is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.
[0006] To at least partially solve the above problems, this utility model provides a diffusion plate for wafer electroplating, comprising: a main body having a plurality of through holes; a first region and a second region, the first region being located at the center of the main body and the second region being located at the outer periphery of the first region, wherein the flow rate of electrolyte through the through holes in the second region is less than the flow rate of electrolyte through the through holes in the first region.
[0007] For example, the diameter of the through hole in the second region is smaller than the diameter of the through hole in the first region.
[0008] For example, the distribution density of through holes in the second region is less than that in the first region.
[0009] For example, it also includes a shield for blocking part of the through hole in the second region.
[0010] For example, the shield has a hollow annular structure.
[0011] For example, the area of the second region covered by the shielding plate is adjustable.
[0012] For example, the shielding plate includes at least a first sub-shielding plate and a second sub-shielding plate nested within each other, wherein both the first sub-shielding plate and the second sub-shielding plate are hollow annular structures, and the outer circumference of the first sub-shielding plate is tightly fitted with the inner circumference of the second sub-shielding plate.
[0013] For example, the radial dimension of the main body is larger than the radial dimension of the wafer to be electroplated.
[0014] For example, the shape of the main body is the same as the shape of the wafer to be electroplated.
[0015] According to another aspect of the present invention, a wafer electroplating apparatus is provided, comprising: a chamber for storing an electrolyte; and the aforementioned diffusion plate disposed in the chamber.
[0016] According to the diffusion plate for wafer electroplating of this utility model, the flow velocity of electrolyte through the through-hole in the second region is less than that through the through-hole in the first region, which changes the ion mobility of electrolyte in different regions, thereby changing the impedance value in different regions. Ultimately, the current in the second region decreases and the current in the first region increases, thereby reducing the difference in the thickness of the electroplated layer in the wafer surface and improving the quality of the product. Attached Figure Description
[0017] The following drawings, which are incorporated herein by reference as part of this invention, are provided for understanding the invention. The drawings illustrate embodiments of the invention and their descriptions, serving to explain the principles of the invention.
[0018] In the attached image:
[0019] Figure 1 A simplified circuit diagram of electroplating in the prior art is shown;
[0020] Figure 2A schematic diagram of the structure of a diffusion plate for wafer electroplating according to a specific embodiment of the present invention is shown.
[0021] Figure 3 A schematic diagram of the structure of a diffusion plate according to a specific embodiment of the present invention is shown;
[0022] Figure 4 A schematic diagram of the structure of a diffusion plate according to another specific embodiment of the present invention is shown;
[0023] Figure 5 A schematic diagram of the structure of a shielding plate according to a specific embodiment of the present invention is shown;
[0024] Figure 6 This invention provides a schematic diagram of the structure of a shielding diffuser plate according to a specific embodiment of the present invention.
[0025] Figure 7 A schematic diagram of the structure of the shielding plate according to another specific embodiment of the present invention is shown;
[0026] Figure 8 A simplified circuit diagram of electroplating according to another specific embodiment of the present invention is shown;
[0027] Figure 9 A schematic diagram of a wafer electroplating apparatus according to a specific embodiment of the present invention is shown. Detailed Implementation
[0028] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.
[0029] It should be understood that this invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this invention to those skilled in the art. In the drawings, for clarity, the dimensions of layers and regions, as well as their relative dimensions, may be exaggerated. The same reference numerals denote the same elements throughout.
[0030] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this utility model, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion.
[0031] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below” or “under” the other element or feature will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.
[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms, unless the context clearly indicates otherwise.
[0033] like Figure 1 As shown, in the electroplating process, there is a significant difference in plating thickness between the wafer's central region and its edge regions. This is mainly due to the difference in current i in the wafer's central region during electroplating. c and wafer edge region current i e The resistance is affected by the wafer resistance *r* and the electrolyte resistance *R*. For the central region of the wafer, the circuit resistance includes both the wafer resistance *r* and the electrolyte resistance *R*. For the edge region of the wafer, the circuit resistance includes only the electrolyte resistance *R*. Because the resistance differs in different regions, the current *i* in the central region of the wafer varies. c smaller than the current i in the wafer edge regione This results in a faster plating rate at the wafer edge than at the wafer center, leading to a thicker plating layer at the edge. This unevenness in the plating layer after wafer plating fails to meet the requirements of subsequent packaging or connection, affecting product quality and causing serious defects.
[0034] Based on the above relationship, reduce the current i in the wafer edge region. e and wafer center region current i c The difference between them has become an important method to reduce the difference in plating thickness between the central and edge regions of the wafer.
[0035] To solve at least one of the above-mentioned technical problems, this application provides a diffusion plate for wafer electroplating, comprising: a main body having a plurality of through holes; a first region and a second region, the first region being disposed at the central region of the main body and the second region being disposed at the outer periphery of the first region, wherein the flow rate of electrolyte through the through holes in the second region is less than the flow rate of electrolyte through the through holes in the first region.
[0036] According to the diffusion plate for wafer electroplating of this application, by reducing the opening area of the through-holes in the second region of the diffusion plate, the flow velocity of the electrolyte through the through-holes in the second region is made less than the flow velocity of the electrolyte through the through-holes in the first region. This changes the ion mobility of the electrolyte in different regions, thereby changing the impedance value in different regions. Ultimately, the current in the second region decreases and the current in the first region increases, thereby reducing the difference in the thickness of the electroplated layer within the wafer surface and improving the quality of the product.
[0037] To fully understand this application, a detailed structure will be presented in the following description to illustrate the technical solutions proposed in this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.
[0038] The following is for reference. Figure 2 A diffusion plate for wafer electroplating according to one embodiment of this application is described, such as... Figure 2 As shown, the diffuser plate 200 includes a main body 201, on which a plurality of through holes 202 are provided; a first region 203 and a second region 204. The first region 203 is located in the central region of the main body 201, and the second region 204 is located on the outer periphery of the first region 203. The flow rate of the electrolyte through the through holes 202 of the second region 204 is less than the flow rate of the electrolyte through the through holes 202 of the first region 203.
[0039] In this embodiment, the main body 201 of the diffuser plate 200 is divided into a first region 203 and a second region 204. The first region 203 is located in the central region of the main body 201 (i.e., the central region of the diffuser plate 200), and the second region 204 is located on the outer periphery of the first region 203 (i.e., the edge region of the diffuser plate 200). By reducing the opening area of the through-holes 202 in the second region 204 of the main body 201, the flow velocity of the electrolyte through the through-holes 202 in the second region 204 is reduced, thereby making the flow velocity of the electrolyte through the through-holes 202 in the second region 204 less than the flow velocity of the electrolyte through the through-holes 202 in the first region 203. During the electroplating process, metal ions move directionally to the surface of the wafer under the action of an electric field. According to the factors affecting electroplating, the faster the flow velocity of the electrolyte during the electroplating process, the faster the ion migration rate, the smaller the corresponding resistance value, and the larger the current value. Since the flow velocity of the electrolyte through the through-hole 202 in the second region 204 is less than that through the through-hole 202 in the first region 203, the ion mobility in the second region 204 is less than that in the first region 203. As a result, the resistance of the second region 204 is greater than that of the first region 203. Ultimately, this reduces the current in the second region 204 of the main body 201 and increases the current in the first region 203 of the main body 201, thereby reducing the difference in the thickness of the electroplated layer within the wafer surface and improving the quality of the product.
[0040] In some embodiments, the diffuser plate 200 includes a main body 201, on which a plurality of through holes 202 are provided. Exemplarily, the shape of the main body 201 is the same as the shape of the wafer to be electroplated. Typically, the wafer is circular, meaning the main body 201 is also circular. However, when the wafer to be electroplated has other suitable shapes, the shape of the main body 201 can also be other suitable shapes; no specific limitation is made. Specifically, the main body 201 is provided with concentric rings of through holes 202, which allow ions to pass through and allow electrolyte to flow vertically.
[0041] In some embodiments, the main body 201 is made of an insulating material. Exemplarily, the insulating material includes polypropylene, polyvinyl chloride, polyvinylidene fluoride, or polytetrafluoroethylene, etc., and is not specifically limited thereto. Specifically, the insulating diffuser plate 200 can prevent current leakage during the electroplating process. The insulating material also has excellent chemical stability and corrosion resistance, preventing corrosion by the electrolyte during electroplating and maintaining its original physical and chemical properties over a long period, ensuring the stability of the electroplating process. In this embodiment, the main body 201 is made of polyvinyl chloride (PVC).
[0042] In some embodiments, the radial dimension of the main body 201 is larger than the radial dimension of the wafer to be electroplated. Specifically, the radial dimension of the main body 201 is 4cm-6cm larger than the radial dimension of the wafer to be electroplated. For example, the radial dimension of the main body 201 is 4cm, 4.2cm, 4.5cm, 4.8cm, 5cm, 5.2cm, 5.5cm, 5.7cm or 6cm larger than the radial dimension of the wafer to be electroplated, and there is no specific limitation thereto.
[0043] In some embodiments, such as Figure 3 As shown, the main body 201 includes a first region 203 and a second region 204. The first region 203 is located in the central region of the main body 201, and the second region 204 is located on the outer periphery of the first region 203. Specifically, the first region 203 is located in the central region of the main body 201 (i.e., the central region of the diffuser plate 200), and the second region 204 is disposed around the outer periphery of the first region 203 (i.e., the edge region of the diffuser plate 200). For example, the diameter of the through-hole 202 in the second region 204 is smaller than the diameter of the through-hole 202 in the first region 203. Specifically, a series of through-holes 202 are provided on the main body 201, which allow ions to pass through and allow the electrolyte to flow vertically. The through-holes 202 located in the first region 203 (i.e., the central region of the diffuser plate 200) have the same diameter, and the through-holes 202 located in the second region 204 (i.e., the central region of the diffuser plate 200) have the same diameter. However, the diameter of the through-holes 202 located in the second region 204 is smaller than the diameter of the through-holes 202 located in the first region 203. In other words, the larger the void area in the central region of the diffuser plate 200, the smaller the effective area of the central region of the diffuser plate 200. This increases the flow velocity of the electrolyte through the central region, accelerates the ion migration rate, reduces the resistance value corresponding to the central region, and ultimately increases the current value in the central region. This reduces the difference between the current in the central region and the current in the edge region, thereby reducing the thickness difference of the electroplated layer within the wafer surface, improving the uniformity of the electroplated layer within the wafer surface, and thus improving the bump yield.
[0044] In some embodiments, such as Figure 4As shown, the distribution density of through holes 202 in the second region 204 is less than the distribution density of through holes 203 in the first region 203. Besides designing the dimensions of the through holes in the first region 203 and the second region 204, the distribution density of the through holes 202 in the first region 203 and the second region 204 can also be designed to increase the current in the first region 203 and decrease the current in the second region 204. Specifically, the distribution density of through holes 202 in the second region 204 (i.e., the edge region of the diffuser plate 200) of the main body 201 of the diffuser plate is designed to be less than the distribution density of through holes 202 in the first region 203 (i.e., the central region of the diffuser plate 200). In other words, the number of through-holes 202 in the central region of the diffuser plate 200 is greater than the number of through-holes 202 in the edge region of the diffuser plate 200. The void area in the central region of the diffuser plate 200 is larger than that in the edge region. As a result, the flow velocity of the electrolyte through the central region increases, the ion migration rate increases, the resistance value corresponding to the central region decreases, and the current value in the central region increases. Conversely, the flow velocity of the electrolyte through the edge region decreases, the ion migration rate decreases, the resistance value corresponding to the central region increases, and the current value in the edge region decreases. This reduces the difference between the current in the central region and the current in the edge region, ultimately reducing the thickness difference of the electroplated layer within the wafer surface, improving the uniformity of the electroplated layer within the wafer surface, and thus improving the bump yield.
[0045] In some embodiments, such as Figure 5 and Figure 6 As shown, it also includes a shielding plate 205, which is used to shield part of the through holes 202 in the second region 204. Specifically, the shielding plate 205 is disposed above the main body 201 and is used to shield part of the through holes 202 in the second region 204 (that is, the edge region of the diffuser plate 200). In other words, the void area of the edge region of the diffuser plate 200 is reduced, which is equivalent to increasing the effective area of the edge region of the diffuser plate 200. As a result, the flow velocity of the electrolyte through the edge region decreases, the ion migration rate decreases, the resistance value corresponding to the edge region increases, and the current value of the edge region decreases. This reduces the difference between the current in the central region and the current in the edge region, and ultimately reduces the thickness difference of the electroplated layer within the wafer surface, improving the uniformity of the electroplated layer within the wafer surface. For example, the shielding plate 200 is made of an insulating material, including polypropylene, polyvinyl chloride, polyvinylidene fluoride, or polytetrafluoroethylene, etc., without specific limitation. The insulating shield 200 can prevent current leakage during the electroplating process. The insulating material also has excellent chemical stability and corrosion resistance, which can prevent it from being corroded by the electrolyte during the electroplating process. It can maintain its original physical and chemical properties for a long time and ensure the stability of the electroplating process.
[0046] In some embodiments, such as Figure 6 As shown, the baffle plate 205 has a hollow annular structure. Exemplarily, the annular baffle plate 205 is concentrically arranged with the main body 201 of the diffuser plate 200. The hollow portion in the middle of the baffle plate 200 exposes at least the through-hole 202 of the first region 203 (i.e., the central region of the diffuser plate 200) or a small portion of the through-hole 202 of the second region 204 (i.e., the edge region of the diffuser plate 200). The annular portion of the baffle plate 200 is used to block a portion of the through-hole 202 in the second region 204. In this embodiment, an 8-inch diffuser plate 200 is selected, and the baffle plate 205 blocks half the radius of the diffuser plate 200. Of course, other suitable sizes can also be used. For different sized diffusers, the range of the edge region of the diffuser plate 205 blocked by the baffle plate 205 also changes accordingly, and this is not specifically limited.
[0047] In some embodiments, such as Figure 7 As shown, the area of the second region 204 blocked by the shielding plate 205 is adjustable. Exemplarily, the shielding plate 205 includes at least a first sub-shielding plate 2051 and a second sub-shielding plate 2052 nested within each other. Both the first sub-shielding plate 2051 and the second sub-shielding plate 2052 have hollow annular structures, and the outer circumference of the first sub-shielding plate 2051 is tightly fitted with the inner circumference of the second sub-shielding plate 2052. Specifically, the size of the diffuser plate 200 will change accordingly for wafers of different sizes to be electroplated. Therefore, by designing the shielding plate 205 as multiple nested sub-shielding plates, the second region 204 of the diffuser plate 200 of different sizes can be blocked without replacing the entire device or making complex setting changes. This reduces the thickness difference of the electroplated layer within the wafer surface of different sizes, increasing operational flexibility.
[0048] By reducing the opening area of the second region 204 (i.e., the edge region of the diffuser plate 200), and comparing the bump height full map (BHFM) of a conventional diffuser plate with that of the diffuser plate designed in this application, it can be concluded that the bump height of the diffuser plate designed in this application is uniformly distributed, and the difference in plating thickness between the wafer center region and the edge region is significantly improved, with the total bump thickness variation decreasing from approximately 23µm to 5µm. The yield of BHFM has increased from 80%-85% to approximately 99.9%. Therefore, by reducing the opening area of the second region 204 of the diffuser plate 200, the flow velocity of the electrolyte through the through-holes 202 of the second region 204 is reduced compared to the flow velocity of the electrolyte through the through-holes 202 of the first region 203. This ultimately reduces the current in the second region 204 and increases the current in the first region 203, thereby reducing the difference in plating thickness within the wafer surface and improving the bump yield, thus improving product quality.
[0049] It should be noted that, as Figure 8 As shown, an auxiliary resistor r1 can also be introduced into the edge region of the electrolytic liquid crystal wafer, making the resistance of the auxiliary resistor r1 equal to the resistance of the wafer resistor r. In this case, for the center region of the wafer, the circuit resistance includes the wafer resistor r and the electrolyte resistor R; for the edge region of the wafer, the circuit resistance includes the electrolyte resistor R and the auxiliary resistor r1. Since the auxiliary resistor r1 is equal to the wafer resistor r, the current i in the edge region of the wafer will be... e Equal to the current i in the center region of the wafer c This method can also reduce the difference in the thickness of the electroplated layer within the wafer surface, thereby improving product quality.
[0050] In summary, the diffusion plate for wafer electroplating according to the embodiments of this application reduces the opening area of the second region of the diffusion plate, making the flow velocity of the electrolyte through the through-holes in the second region less than the flow velocity of the electrolyte through the through-holes in the first region. This changes the ion mobility of the electrolyte in different regions, thereby changing the impedance value of different regions. Ultimately, this reduces the current in the second region and increases the current in the first region, thereby reducing the difference in the thickness of the electroplated layer within the wafer surface and improving the quality of the product.
[0051] This application also provides a wafer electroplating apparatus, such as Figure 9 As shown, it includes: a chamber 301 for storing electrolyte; and the aforementioned diffuser plate 200 disposed in the chamber 301.
[0052] In some embodiments, such as Figure 9 As shown, the wafer electroplating apparatus also includes an anode 302 and a cathode 303. The anode 302 is disposed at the bottom of the chamber 301, the cathode 303 is disposed at the top of the chamber 301 and electrically connected to the wafer 304 to be electroplated, and the diffuser plate 200 is disposed in the chamber 301 and located between the anode 302 and the cathode 303.
[0053] According to the wafer electroplating apparatus of the present application embodiment, the flow velocity of the electrolyte through the through-hole in the second region is less than the flow velocity of the electrolyte through the through-hole in the first region, thereby changing the ion mobility of the electrolyte in different regions, thus changing the impedance value in different regions, ultimately reducing the current in the second region and increasing the current in the first region, thereby reducing the difference in the thickness of the electroplated layer within the wafer surface and improving the quality of the product.
[0054] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.
[0055] Similarly, it should be understood that, in order to simplify this application and aid in understanding one or more aspects of the application, various features of this application may sometimes be grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of this application. However, this approach should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, the point of application is that the corresponding technical problem can be solved with fewer features than all of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.
[0056] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features but not others included in other embodiments, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.
[0057] It should be noted that the above embodiments are illustrative of this application and not limiting of it, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.
Claims
1. A diffusion plate for wafer electroplating, characterized in that, include: The main body is provided with a plurality of through holes; A first region and a second region, wherein the first region is located at the center of the main body and the second region is located on the outer periphery of the first region, wherein the flow rate of the electrolyte through the through-hole in the second region is less than the flow rate of the electrolyte through the through-hole in the first region.
2. The diffuser plate as described in claim 1, characterized in that, The diameter of the through hole in the second region is smaller than the diameter of the through hole in the first region.
3. The diffusion plate as described in claim 1, characterized in that, The distribution density of through holes in the second region is less than that in the first region.
4. The diffuser plate as described in claim 1, characterized in that, It also includes a shielding plate, which is used to shield part of the through hole in the second region.
5. The diffuser plate as described in claim 4, characterized in that, The shield has a hollow ring structure.
6. The diffuser plate as described in claim 5, characterized in that, The area of the second region covered by the shielding plate is adjustable.
7. The diffuser plate as described in claim 6, characterized in that, The shielding plate includes at least a first sub-shielding plate and a second sub-shielding plate nested within each other, wherein both the first sub-shielding plate and the second sub-shielding plate are hollow annular structures, and the outer circumference of the first sub-shielding plate is tightly fitted with the inner circumference of the second sub-shielding plate.
8. The diffusion plate as described in claim 1, characterized in that, The radial dimension of the main body is larger than the radial dimension of the wafer to be electroplated.
9. The diffuser plate as described in claim 8, characterized in that, The shape of the main body is the same as the shape of the wafer to be electroplated.
10. A wafer electroplating apparatus, characterized in that, include: A chamber for storing electrolyte; The diffuser plate as described in any one of claims 1-9, wherein the diffuser plate is disposed in the chamber.