Electroplating apparatus

Abstract

An electroplating apparatus, comprising an electroplating cavity (31) for accommodating an electroplating solution; an anode (32) located inside the electroplating cavity (31); a substrate holding device (33) for holding a substrate (10) and immersing a plating surface (101) of the substrate (10) in the electroplating solution during electroplating; and a substrate extension assembly (34), comprising an extended cavity (342), an extended cathode (341) and a diaphragm (343), wherein the extended cathode (341) is located inside the extended cavity (342) and is cathode-biased, and the diaphragm (343) is used for isolating the extended cathode (341) from the electroplating cavity (31). The extended cavity (342) comprises a current guide portion (344) facing the anode (32), and the current guide portion (344) is provided with an opening. During electroplating, the current guide portion (344) is located below the substrate (10), surrounds the radial outer side of the substrate (10) and is parallel to the plating surface (101) during electroplating, and is used for enabling part of a current from the anode (32) to flow through the current guide portion (344) to the extended cathode (341), such that the current guide portion (344) forms an extended plating surface (340) on the radial outer side of the substrate (10). The electroplating apparatus effectively suppresses or even eliminates the negative impact of edge effects on substrates.

Description

Electroplating equipment Technical Field

[0001] This application relates to the field of semiconductor manufacturing equipment, and in particular to an electroplating apparatus. Background Technology

[0002] Electroplating, as one of the key processes in integrated circuit manufacturing, is the cornerstone of achieving electrical interconnection and is widely used in various metal interconnection processes in both front-end and back-end manufacturing. In the electroplating process, the substrate to be plated (e.g., a wafer) serves as the cathode, is held by a fixture and immersed in the electroplating solution. Metal ions in the electroplating solution become charge carriers, flow to the substrate, and are reduced to metal atoms that are deposited on the plating surface of the substrate, thereby forming a metal coating.

[0003] In traditional electroplating processes, a power source supplies current or voltage to the working electrode and the substrate with the seed layer. The substrate, working electrode, power source, and electroplating solution form an electrolytic cell. Due to the "edge effect," the current density distribution on the substrate is uneven, being relatively higher at the edges. This current non-uniformity results in a high electroplating rate at the substrate edges and a low rate at the center, leading to uneven film deposition thickness on the substrate surface. Film thickness uniformity is a key indicator for electroplated products; therefore, suppressing the adverse effects of the edge effect in the electroplating process has become a widely concerned technical issue in the industry to improve product yield. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this application is to provide an electroplating apparatus to solve the problem of uneven coating thickness caused by edge effect in the prior art.

[0005] To achieve the above and other related objectives, one aspect of this application provides an electroplating apparatus, comprising: an electroplating chamber for containing an electroplating solution; an anode located inside the electroplating chamber; a substrate holding device for holding a substrate and immersing the plating surface of the substrate in the electroplating solution during electroplating; and a substrate extension assembly including an extension chamber, an extension cathode, and a diaphragm, wherein the extension cathode is located inside the extension chamber and is biased by the cathode, and the diaphragm is used to isolate the extension cathode from the electroplating chamber; wherein the extension chamber has a drain portion facing the anode, the drain portion having an opening, and during electroplating, the drain portion is located below the substrate, surrounding the radially outer side of the substrate and parallel to the plating surface of the substrate, for allowing current from the anode to partially flow through the drain portion to the extension cathode, so that the drain portion forms an extension plating surface on the radially outer side of the substrate.

[0006] In some embodiments, the extended cathode is located radially outside the drain portion and extends in the vertical direction.

[0007] In some embodiments, the drainage portion has a plurality of portions in the radial direction of the substrate.

[0008] In some embodiments, each of the drainage portions corresponds to an independent extension cavity and an extension cathode.

[0009] In some embodiments, at least a portion of the drainage portion has a continuous opening or multiple openings in the circumferential direction of the substrate.

[0010] In some embodiments, the total area of ​​the openings in each of the drainage portions is different and gradually increases outward along the radial direction of the substrate.

[0011] In some embodiments, the radial dimensions of the plurality of drainage portions gradually increase outward along the radial direction of the substrate.

[0012] In some embodiments, the effective area of ​​the extended cathode corresponding to the plurality of current-draining portions gradually increases radially outward along the substrate, wherein the effective area is the area of ​​the region on the extended cathode where an electrochemical reaction can occur.

[0013] In some embodiments, the plurality of extended cathodes at least partially overlap in the vertical direction or in the radial direction of the substrate.

[0014] In some embodiments, a diffusion plate is further included, located between the substrate and the anode and facing the plating surface, and the drainage portion is located in the vertical direction between the upper and lower surfaces of the diffusion plate.

[0015] As described above, this application provides an electroplating apparatus that has at least the following beneficial effects:

[0016] (1) During electroplating, the extended plating surface and the plating surface of the substrate are equivalent to a whole plating surface. The extended plating surface is configured as the edge region of the whole plating surface, so that the electric field lines originally concentrated in the edge region of the plating surface are partially dispersed to the extended plating surface, effectively suppressing or even eliminating the negative impact of the edge effect on the substrate.

[0017] (2) There are multiple drainage sections in the radial direction of the substrate, and each drainage section corresponds to an independent extension cavity and an extension cathode, which can better control the ability of the drainage section to attract current in different regions in the radial direction.

[0018] (3) By improving the arrangement of the extended cathode and the structure of the extended cavity, the space utilization rate inside the electroplating cavity is effectively improved, the internal space of the extended cavity is expanded in the limited electroplating cavity, the effective area of ​​the extended cathode is increased, and the effect of the substrate extension assembly in suppressing the substrate edge effect is enhanced.

[0019] Overview of the attached figures

[0020] The features and performance of this application are further described by the following embodiments and accompanying drawings.

[0021] Figure 1 is a schematic diagram of an exemplary substrate electroplating principle;

[0022] Figure 2 is a schematic diagram of the distribution of electric field lines during electroplating in an ideal model of an exemplary electroplating apparatus;

[0023] Figure 3 is a schematic diagram of the electroplating apparatus according to Embodiment 1 of this application;

[0024] Figure 4 is a bottom view of some components of the electroplating apparatus according to Embodiment 1 of this application;

[0025] Figure 5 is a schematic diagram of the electroplating apparatus of Embodiment 2 of this application;

[0026] Figure 6 is a schematic diagram of the electroplating apparatus according to Embodiment 2 of this application;

[0027] Figures 7a to 7c are bottom views of some components of the electroplating apparatus according to different implementations of Embodiment 3 of this application; and

[0028] Figure 8 is a schematic diagram of the electroplating apparatus of Embodiment 4 of this application.

[0029] Preferred embodiments of this application

[0030] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or adjusted based on different viewpoints and applications without departing from the spirit of this application.

[0031] It should be noted that the accompanying drawings are only schematic representations of the basic concept of this application. Although the drawings only show components related to this application and are not drawn according to the actual number, shape and size of the components, the shape, quantity and proportion of each component can be arbitrarily adjusted in actual implementation, and the layout of the components may also be more complex.

[0032] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses consistent with some aspects of this application as detailed in the appended claims.

[0033] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0034] In the description of this application, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0035] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another.

[0036] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., which may be used to indicate the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0037] The electroplating apparatus provided in this application can be widely used in various electroplating processes in integrated circuit manufacturing, including but not limited to metal interconnect processes in the front-end and bump and RDL processes in the back-end advanced packaging processes. By applying the electroplating apparatus provided in this application, the adverse effects of edge effects during substrate electroplating can be effectively suppressed or even eliminated, improving the uniformity of the metal coating on the substrate surface and thus increasing product yield.

[0038] Referring to Figure 1, Figure 1 illustrates an exemplary schematic diagram of substrate electroplating. During substrate electroplating, the plating surface of the substrate 100 to be plated and the anode 200 are horizontally immersed in an electroplating solution (not shown). A power source applies a voltage between the substrate 100 and the anode 200. The substrate 100 is electrically connected to the negative terminal of the power source and is biased by the cathode. Current flows from the positive terminal of the power source, passing sequentially through the anode 200, the substrate 100, and the negative terminal of the power source. Metal ions in the electroplating solution act as charge carriers, flowing towards the substrate 100 and being reduced to metal atoms, which are deposited on the plating surface 1001 of the substrate 100 to form a metal coating. During electroplating, the current at the edges of the substrate 100 is typically greater than the current in the central region. Characterized by electric field lines, as shown in Figure 1, the electric field lines in the edge region of the substrate 100 are more concentrated than those in the central region, resulting in a greater coating thickness at the edges of the substrate 100 than in the center, a phenomenon known as the edge effect. With the continuous development of semiconductor manufacturing processes, the requirements for the uniformity of coating thickness are becoming increasingly stringent. Therefore, solving the problem of uneven coating thickness caused by edge effects has become an urgent task.

[0039] Referring to Figure 2, which shows a schematic diagram of the electric field line distribution during electroplating in an ideal model of an exemplary electroplating apparatus, this application aims to solve the aforementioned problem of uneven film thickness caused by the edge effect by extending an extended plating surface around the plating surface 101 of the substrate 10 to the extended plating surface. Based on this, the inventors of this application have constructed the ideal model shown in Figure 2. In the ideal model constructed by the inventors of this application, an extended cathode 20 is arranged radially outward of the substrate 10, constituting a portion of the substrate 10 extending radially outward. Thus, the plating surface of the extended cathode 20 (i.e., the lower surface of the extended cathode 20) can be directly used as the extended plating surface. In this way, for the overall structure composed of the extended cathode 20 and the substrate 10, the edge effect still exists. The electric field lines from the anode 22 (shown as dashed lines in the figure) are more densely distributed in the edge region of the overall structure, and more uniformly distributed in the inner region of this edge region. The edge region of the overall structure is the extended cathode 20, which does not cover the substrate 10. Therefore, during electroplating, the electric field lines on the substrate 10 are distributed more uniformly, which can form a more uniform metal coating on the plating surface 101 of the substrate 10, effectively suppressing or even eliminating the negative impact of the edge effect on the substrate 10.

[0040] However, in actual electroplating equipment, numerous factors make it difficult to directly place the extended cathode 20 at the radial edge of the substrate 10. For example, in the electroplating process, the substrate 10 needs to be held in a substrate holding assembly (usually a cup-shaped chuck), which needs to perform tilting, rotating, and other actions. Placing the extended cathode 20 on the substrate holding assembly would affect the operation of the substrate holding assembly itself. In addition, the limited space of the substrate holding assembly itself also restricts the shape and size of the extended cathode 20, affecting the realization of its function, etc.

[0041] Example 1

[0042] To address the aforementioned problems, at least one aspect of this application provides an electroplating apparatus. Referring to FIG3, FIG3 shows a schematic structural diagram of the electroplating apparatus according to Embodiment 1 of this application. As shown in FIG3, Embodiment 1 of this application provides an electroplating apparatus including an electroplating chamber 31, an anode 32, a substrate holding device 33, and a substrate extension assembly 34. The anode 32 is disposed at the bottom of the electroplating chamber 31, and an ion exchange membrane 35 is disposed above the anode 32, dividing the electroplating chamber 31 into an anode chamber 31a and a cathode chamber 31b. That is, the anode chamber 31a is below the ion exchange membrane 35, and the cathode chamber 31b is above the ion exchange membrane 35. Referring to FIG3, the substrate holding device 33 is used to hold the substrate 10 and immerse the plating surface 101 of the substrate 10 in the electroplating solution (not shown in the figure) during electroplating. The substrate extension assembly 34 includes an extension cathode 341, an extension chamber 342, and a diaphragm 343. An extended cathode 341 is located inside an extended cavity 342, and a diaphragm 343 is used to isolate the extended cathode 341 from the electroplating cavity 31. The extended cavity 342 has a drain portion 344 facing the anode 32. The drain portion 344 has an opening. During electroplating, the drain portion 344 is located below the substrate 10, surrounding the radially outer side of the substrate 10 and parallel to the plating surface 101 during electroplating, so that the current from the anode 32 flows partially through the drain portion 344 to the extended cathode 341 to form an extended plating surface 340 on the radially outer side of the substrate 10.

[0043] During electroplating, the extended plating surface 340 and the plating surface 101 of the substrate 10 are equivalent to a single integrated plating surface. The extended plating surface 340 is configured as the edge region of this integrated plating surface, so that the electric field lines originally concentrated in the edge region of the plating surface 101 are partially dispersed onto the extended plating surface 340, effectively suppressing or even eliminating the negative impact of edge effects on the substrate 10. The extended plating surface 340 is a virtual surface defined by the current-draining portion 344, rather than a solid surface, which will be described in detail below.

[0044] The technical principles and effects of the embodiments of this application are further described below in conjunction with the distribution of electric field lines. The substrate extension assembly 34 of this application constructs an equivalent extension plating surface 340 by providing an extension cavity 342 and a drainage portion 344, and separates the physical extension cathode 341 from the equivalent extension plating surface 340.

[0045] First, during electroplating, both the substrate 10 and the extended cathode 341 are cathode-biased and undergo electrochemical reactions. Therefore, electric field lines from the anode 32 reach the substrate 10 and the extended cathode 341, respectively. The drain portion 344 has an opening that allows ion flow, and the electric field lines reach the drain portion 344 before reaching the extended cathode 341. If the drain portion 344 in FIG. 3 is replaced with a solid cathode, the distribution of electric field lines within the electroplating chamber 31 is essentially the same as the distribution of electric field lines shown in FIG. 3 (shown as dashed lines in FIG. 3). Therefore, although the area where the drain portion 344 is located is not actually plated, the distribution of electric field lines can be equivalent to a plated cathode area. In other words, the area where the drain portion 344 is located defines an equivalent virtual plating surface, namely the extended plating surface 340.

[0046] Furthermore, although the drain portion 344 is located below the substrate 10 and is not flush with the substrate 10 in the vertical direction, it surrounds the radial outer side of the substrate 10 and is parallel to the plating surface 101 during electroplating in the radial direction of the substrate 10. Regarding the distribution of electric field lines, referring to Figures 2 and 3, the electric field line distribution in the region where the drain portion 344 is located in Figure 3 is substantially the same as the electric field line distribution of the extended cathode 20 in Figure 2. In other words, the region where the drain portion 344 is located can be approximately equivalent to the extended cathode 20 in the ideal model (see Figure 2). In some embodiments, the drain portion 344 extends outward from the radial edge of the substrate 10 in the radial direction, that is, the drain portion 344 is in close contact with the edge of the substrate 10 in the radial direction. Furthermore, in the vertical direction, since the extended cathode 341 and the equivalent extended plating surface 340 are separated, the shape and size of the extended cavity 342 and the extended cathode 341, as well as their specific positions in the vertical direction, can be flexibly set according to the actual structure of the electroplating cavity 31.

[0047] Furthermore, due to the reduction reaction of metal ions on the surface of the extended cathode 341, metal deposition occurs. The adhesion of these metal deposits is uneven, preventing them from completely adhering to the surface of the extended cathode 341. This results in some metal deposits remaining as metal particles in the electroplating solution, adversely affecting the electroplating process. Therefore, this application places the extended cathode 341 in a separate extended cavity 342, and provides a diaphragm 343 between the drainage section 344 and the extended cathode 341. The diaphragm 343 can be an ion exchange membrane, isolating the extended cathode 341 from the electroplating cavity 31 without affecting ion exchange on both sides of the diaphragm 343. In this first embodiment, the diaphragm 343 separates the extended cavity 342 into two parts. For ease of description, the part of the extended cavity 342 with the drainage section 344 is referred to as the drainage area 342a, and the part of the extended cavity 342 that houses the extended cathode 341 is referred to as the plating area 342b. It should be noted that "between the drain portion 344 and the extended cathode 341" in this application includes the location of the drain portion 344. Therefore, in other embodiments, the diaphragm 343 may also be disposed at the drain portion 344.

[0048] In this first embodiment, the drainage area 342a can exchange electroplating solution with the electroplating chamber 31 through the drainage part 344, while the plating area 342b, due to the presence of the diaphragm 343, has difficulty exchanging electroplating solution with the electroplating chamber 31. To conduct current between the anode 32 and the extended cathode 341, the plating area 342b should contain electroplating solution. Therefore, in some embodiments, the plating area 342b of the extended chamber 342 further includes an inlet and an outlet, respectively used to allow the electroplating solution to enter and exit the plating area 342b, realizing the circulation and renewal of the electroplating solution within the plating area 342b. This application does not limit the specific location and form of the inlet and outlet; the electroplating solution contained in the plating area 342b can be the same as or different from the electroplating solution in the electroplating chamber 31.

[0049] It should be understood that those skilled in the art can reasonably set the position of the current-draining portion 344 in the vertical direction according to the actual situation. In a specific example, the electroplating apparatus also includes a diffusion plate 36, which is disposed in the electroplating chamber 31 (cathode chamber 31b), located between the substrate 10 and the anode 22, and facing the plating surface 101. The current-draining portion 344 is located vertically between the upper and lower surfaces of the diffusion plate 36, and contacts the radial edge of the diffusion plate 36 in the radial direction. It should be noted that the term "between the upper and lower surfaces" includes a position flush with either the upper or lower surface. Exemplarily, as shown in FIG3, the current-draining portion 344 is substantially flush with the lower surface of the diffusion plate 36 in the vertical direction. The diffusion plate 36 is typically made of a high-resistivity material and has multiple through holes facing the plating surface 101, serving to uniformly distribute the current. In other embodiments, the current-draining portion 344 may also be located above or below the diffusion plate 36.

[0050] Referring to Figure 4, which shows a bottom view of some components of the electroplating apparatus according to Embodiment 1 of this application. Further, referring to Figures 3 and 4, in some embodiments, the extension cavity 342 has a drain portion 344 in the radial direction of the substrate 10, and the drain portion 344 has an opening that is continuous in the circumferential direction of the substrate 10. An extension cathode 341 that is continuous in the circumferential direction of the substrate 10 is housed inside the extension cavity 342. The extension cavity 342 extends vertically from the drain portion 344, wherein the extension cathode 341 extends radially along the substrate 10 and is disposed facing the drain portion 344. In these embodiments, the substrate extension assembly 34 has a simple structure and is easy to manufacture.

[0051] Example 2

[0052] Referring to Figure 5, which shows a schematic diagram of the electroplating apparatus of Embodiment 2 of this application, the main difference between Embodiment 2 and Embodiment 1 lies in the different structure of the substrate extension assembly.

[0053] In this second embodiment, the extended cathode 541 is located radially outside the drain portion 544 and extends vertically. It should be noted that the term "extends vertically" is understood to mean extending substantially vertically, with an angular deviation of up to 10 degrees. For example, in some embodiments, the extended cathode 541 may extend at an angle of 89 degrees, 88 degrees, or 85 degrees to the horizontal direction. As shown in Figure 5, in a specific example, the extended cavity 542 is configured with an inverted "L" shaped cross-section, having a long side portion 542a and a short side portion 542b, wherein the extended cathode 541 is located on the long side portion 542a of the extended cavity 542, and the drain portion 544 is located on the short side portion 542b of the extended cavity 542.

[0054] This design allows for better utilization of the limited space within the electroplating chamber 51, increasing the effective area of ​​the extended cathode 541 while providing greater flexibility in the placement of the drain portion 544. This is because, on one hand, the electroplating chamber 51 has more space in the vertical direction than in the horizontal direction. Positioning the extended cathode 541 vertically maximizes this vertical space, increasing its effective area. On the other hand, the presence of the substrate holding assembly 53 limits the vertical extension space of the extended cathode 541 due to the distance between the drain portion 544 and the substrate holding assembly 53. Placing the extended cathode 541 radially outside the drain portion 544 increases its effective area without altering the position of the drain portion 544.

[0055] It should be noted that the effective area of ​​the extended cathode refers to the area of ​​the region on the extended cathode where an electrochemical reaction can occur. For example, in Embodiment 1, the area of ​​the lower surface of the extended cathode 341 is its effective area; in this Embodiment 2, the area of ​​the inner side surface 514a of the extended cathode 541 (the surface of the extended cathode 541 facing the center region of the electroplating chamber 51) is its effective area. Under the same conditions, the larger the effective area of ​​the extended cathode, the stronger its plating capability and the stronger its ability to attract current. Therefore, increasing the effective area of ​​the extended cathode 541 can improve the plating capability of the extended cathode 541 and enhance the effect of the substrate extension assembly 54 in suppressing the edge effect of the substrate 10. Furthermore, after a certain amount of metal is deposited in the effective area of ​​the extended cathode 541, it needs to be replaced and cleaned. According to Embodiment 2, increasing the effective area of ​​the extended cathode 541 can also increase the service life of the extended cathode 541 and reduce the frequency of its replacement and cleaning.

[0056] Furthermore, the substrate extension assembly 54 in this embodiment makes good use of the vertical space inside the electroplating cavity 51, which also increases the internal space of the extension cavity 542. This increases the fluidity of the electroplating solution in the extension cavity 542 and prevents the formation of electroplating solution crystals in the extension cavity 542, thus avoiding the normal progress of the electrochemical reaction in the extension cavity 542.

[0057] For example, in this second embodiment, the diaphragm 543 is disposed between the long side portion 542a and the short side portion 542b. In a specific example, as shown in FIG5, the diaphragm 543 is disposed vertically.

[0058] Example 3

[0059] Referring to Figures 6 and 7a to 7c, Figure 6 shows a schematic structural diagram of the electroplating apparatus according to Embodiment 3 of this application, and Figures 7a to 7c show bottom views of some components of different implementations of the electroplating apparatus according to Embodiment 3 of this application. The main difference between Embodiment 3 and Embodiment 2 is that the current-draining portion 644 has multiple portions radially on the substrate 10. Optionally, in some specific examples, each current-draining portion 644 corresponds to an independent extension cavity 642 and an extension cathode 641. This allows for better control of the current-attracting ability of the current-draining portion 644 in different radial regions. The extension cavity 642 contains a diaphragm 643.

[0060] Referring to Figures 6 and 7a, in a specific example, there are three drainage portions 644 in the radial direction of the substrate 10, and each drainage portion 644 has a continuous opening in the circumferential direction of the substrate 10. For ease of description, the three drainage portions 644 in the radial direction of the substrate 10 from the inside to the outside are respectively labeled as drainage portion 644a, drainage portion 644b, and drainage portion 644c.

[0061] It should be understood that for the overall plating surface composed of the extended plating surface 640 and the plating surface 101 of the substrate 10, the plating capability of the extended cathode 641 surface should be stronger closer to the radial edge. Therefore, for embodiments with multiple drain portions 644, it is preferable that the total area of ​​the openings of each drain portion 644 is different and gradually increases radially outward along the substrate 10. In some specific examples, the radial dimensions of the multiple drain portions 644 gradually increase radially outward along the substrate 10. As shown in FIG7a, the radial dimensions of drain portions 644a, 644b, and 644c are D1, D2, and D3, respectively. Wherein, D1, D2, and D3 gradually increase, thereby realizing that the total area of ​​the openings of drain portions 644a, 644b, and 644c is different and gradually increases radially outward along the substrate 10.

[0062] Furthermore, optionally, in some embodiments, the effective area of ​​the extended cathode 641 corresponding to the plurality of drain portions 644 gradually increases radially outward along the substrate 10. For example, as shown in FIG6, the effective area of ​​the extended cathode corresponding to the drain portions 644a, 644b, and 644c gradually increases.

[0063] Referring to FIG. 7b, in another specific implementation of Embodiment 3, exemplarily, three drainage portions 644 are provided radially on the substrate 10, and each drainage portion 644 has multiple openings circumferentially on the substrate 10. For example, as shown in FIG. 7b, drainage portions 644a, 644b, and 644c each have 10 openings. Referring to FIG. 7c, in another specific implementation of Embodiment 3, drainage portions 644a, 644b, and 644c each have 3 openings, and the 9 openings are configured to be spirally distributed circumferentially on the substrate 10. It should be understood that the substrate 10 is rotated during electroplating; therefore, even if the multiple openings of each drainage portion 644 are spaced apart circumferentially on the substrate 10, edge effects in all circumferential edge regions of the substrate 10 can be suppressed.

[0064] Optionally, in some embodiments, when the area of ​​each opening is substantially the same, the plating capability of different extended cathodes 641 can be adjusted by changing the number of openings on different drain portions 644. For example, each drain portion 644 has multiple openings in the circumferential direction of the substrate 10, and the number of openings of the multiple drain portions 644 gradually increases radially outward along the substrate 10. For example, in a specific example, drain portion 644a has 12 openings, drain portion 644b has 16 openings, and drain portion 644c has 18 openings.

[0065] It should be understood that in some embodiments, the different openings shown in FIG7a to FIG7c can be combined with each other. For example, at least one drainage portion 644 has a continuous opening as shown in FIG7a, at least one drainage portion 644 has multiple openings as shown in FIG7b or FIG7c, etc.

[0066] Example 4

[0067] Referring to Figure 8, Figure 8 shows a schematic diagram of the electroplating apparatus according to Embodiment 4 of this application. The main difference between Embodiment 4 and Embodiment 1 is that the fourth embodiment has multiple drainage portions 844 in the radial direction of the substrate 10, and each drainage portion 844 corresponds to an independent extension cavity 842 and an extension cathode 841, wherein the multiple extension cathodes 841 at least partially overlap in the vertical direction or in the radial direction of the substrate 10. For example, as shown in Figure 8, the extension cathode 841 is located above the drainage portion 844 and extends radially along the substrate 10. There are three drainage portions 844 in the radial direction of the substrate 10, and each drainage portion 844 corresponds to an independent extension cavity 842 and an extension cathode 841. The extension cavity 842 contains a diaphragm 843.

[0068] Multiple extended cathodes 841 partially overlap radially on the substrate 10, which can improve the utilization of the radial space of the electroplating cavity 81 and increase the overall effective area of ​​the extended cathodes 841 in a limited radial space. It should be understood that in some embodiments, multiple extended cathodes 841 extend vertically and at least partially overlap in the vertical direction, which can improve the utilization of the vertical space of the electroplating cavity 81.

[0069] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. An electroplating apparatus, characterized in that, include: Electroplating chamber, used to hold electroplating solution; The anode is located inside the electroplating chamber; A substrate holding device for holding a substrate and immersing the plated surface of the substrate in the electroplating solution during electroplating; A substrate extension assembly includes an extension cavity, an extension cathode, and a diaphragm, wherein the extension cathode is located inside the extension cavity and is biased by the cathode, and the diaphragm is used to isolate the extension cathode from the electroplating cavity; The extended cavity has a drain portion facing the anode, the drain portion having an opening. During electroplating, the drain portion is located below the substrate, surrounding the radially outer side of the substrate and parallel to the plating surface of the substrate, for allowing current from the anode to partially flow through the drain portion to the extended cathode, so that the drain portion forms an extended plating surface on the radially outer side of the substrate.

2. The electroplating apparatus according to claim 1, characterized in that, The extended cathode is located radially outside the drain section and extends vertically.

3. The electroplating apparatus according to claim 1, characterized in that, The drainage portion has multiple portions in the radial direction of the substrate.

4. The electroplating apparatus according to claim 3, characterized in that, Each of the drainage portions corresponds to an independent extension cavity and an extension cathode.

5. The electroplating apparatus according to claim 3 or 4, characterized in that, At least a portion of the drainage portion has a continuous opening or multiple openings in the circumferential direction of the substrate.

6. The electroplating apparatus according to claim 5, characterized in that, The total area of ​​the openings in each of the drainage portions is different and gradually increases outward along the radial direction of the substrate.

7. The electroplating apparatus according to claim 6, characterized in that, The radial dimensions of the plurality of drainage portions gradually increase outward along the radial direction of the substrate.

8. The electroplating apparatus according to claim 5, characterized in that, The effective area of ​​the extended cathode corresponding to each of the plurality of current-draining portions gradually increases outward along the radial direction of the substrate, wherein the effective area is the area of ​​the region on the extended cathode where an electrochemical reaction can occur.

9. The electroplating apparatus according to claim 5, characterized in that, The plurality of the extended cathodes at least partially overlap in the vertical direction or in the radial direction of the substrate.

10. The electroplating apparatus according to claim 1, characterized in that, It also includes a diffuser plate located between the substrate and the anode and facing the plating surface, and the drainage portion is located vertically between the upper and lower surfaces of the diffuser plate.

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