Agitating mechanism of electroplating equipment, electroplating equipment and electroplating method

Abstract

The application provides a stirring mechanism of an electroplating device, an electroplating device and an electroplating method, and relates to the technical field of semiconductor manufacturing. The stirring mechanism comprises a shielding area and a stirring area. The shielding area is used for weakening the flow field of the area. The stirring area comprises a plurality of first paddles arranged in parallel. In the process of electroplating a wafer, when a wafer gap is located in the shielding area, the rotation speed of the wafer is a first rotation speed; when the wafer gap is located in the stirring area, the rotation speed of the wafer is a second rotation speed, and the first rotation speed is less than the second rotation speed. The shielding area is used for reducing the total amount of metal ions received by the wafer gap in the shielding area. By arranging the shielding area on the stirring mechanism and controlling the rotation speed of the wafer to reduce the total amount of metal ions received by the wafer gap in the shielding area in a timely manner, the phenomenon that the electroplating height of the peripheral area of the wafer gap is too high in the electroplating process is avoided.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a stirring mechanism for electroplating equipment, electroplating equipment, and electroplating method. Background Technology

[0002] With the widespread adoption of wafer-level packaging (WLP) technology, there is a growing demand for electroplating on wafers containing non-electroplated areas. A typical non-electroplated area is the wafer notch. In some applications, the die chips on the wafer may be arranged asymmetrically, creating irregularly shaped non-electroplated areas. Taking the common wafer notch as an example, in the electroplated area where the chip is located, there are many openings in the photoresist, within which metal is deposited. During electroplating, these metal-deposited openings act as conductive lines. Since no chip is placed within the wafer notch (a non-electroplated area), there are no openings in the photoresist, and no metal is deposited. For both electroplated and non-electroplated areas, under a uniform electric field, the non-electroplated area cannot generate current because there are no conductive lines. This leads to a larger current in the conductive lines of the surrounding area, resulting in a higher metal ion density around the non-electroplated area. Consequently, the electroplating rate is higher, and the final result is a higher plating height compared to other areas. For wafer-level packaging processes, the overall height control is very strict. A high plating height near the wafer notch can easily lead to reduced product yield and production loss. Summary of the Invention

[0003] The purpose of this invention is to provide a stirring mechanism, electroplating equipment, and electroplating method for improving the uniformity of electroplating height.

[0004] In a first aspect, the present invention proposes a stirring mechanism for an electroplating apparatus. The stirring mechanism includes a shielding region and a stirring region. The shielding region is used to weaken the flow field in the region. The stirring region comprises a plurality of parallel first blades. During wafer electroplating, when the wafer notch is located in the shielding region, the wafer rotation speed is a first rotation speed, and when the wafer notch is located in the stirring region, the wafer rotation speed is a second rotation speed, wherein the first rotation speed is less than the second rotation speed. The shielding region is used to reduce the wafer rotation speed, thereby reducing the total amount of metal ions received by the wafer notch when it is located in the shielding region.

[0005] According to a specific implementation of this application, the shielding area includes a region enclosed by a number of sequentially connected straight edges and the edge line of the stirring mechanism.

[0006] According to a specific implementation of this application, the shielding area includes a region enclosed by the curved edge and the edge line of the stirring mechanism.

[0007] According to a specific implementation of this application, the shielding area is a closed block structure, and the height of the upper surface of the shielding area is higher than the height of the upper surface of the first blade.

[0008] According to a specific implementation of this application, a stirring unit is provided in the shielded area, and the stirring force of the stirring unit is weaker than the stirring force of the first blade.

[0009] According to a specific implementation of this application, the stirring unit comprises a plurality of parallel second blades, wherein the stirring force of the second blades located in the shielded area is weaker than the stirring force of the first blades in the stirring area.

[0010] According to a specific implementation of this application, the width of the upper end face of the second blade in the obstruction area is greater than the width of the lower end face of the second blade. According to a specific implementation of this application:

[0011] The height of the upper end face of the second blade in the shielding area is higher than or equal to the height of the upper end face of the first blade in the stirring area.

[0012] According to one specific implementation of this application, the shading area is a hollow frame structure.

[0013] According to a specific implementation of this application, the upper surface of the frame of the shielding area is higher than the upper surface of the stirring area.

[0014] Secondly, this application proposes an electroplating apparatus for electroplating on a wafer surface. The electroplating apparatus includes the aforementioned stirring mechanism, and is configured to: during the electroplating process, control the stirring mechanism to move parallel to the wafer to stir the electroplating solution.

[0015] According to a specific implementation of an embodiment of this application: the electroplating equipment further includes a rotatable wafer holding device, the wafer holding device being rotatable, the wafer holding device having a clamp, the clamp being used to fix the wafer to the wafer holding device and rotate with the clamp, the relative position of the wafer notch and the clamp being fixed.

[0016] Thirdly, this application proposes an electroplating method, comprising: setting a stirring mechanism in an electroplating equipment including a shielding region and a stirring region, wherein the shielding region is used to weaken the flow field in the region, and the stirring region includes a plurality of parallel first blades; electroplating is performed on the surface of a wafer using the electroplating equipment with the stirring mechanism, and the stirring mechanism is controlled to move parallel to the wafer to stir the electroplating solution; the shielding region is used to weaken the flow field in the region; the stirring region is composed of a plurality of parallel blades; when the wafer notch is located in the shielding region, the rotational speed of the wafer is a first rotational speed, and when the wafer notch is located in the stirring region, the rotational speed of the wafer is a second rotational speed, wherein the first rotational speed is less than the second rotational speed; the shielding region is used to reduce the total amount of metal ions received by the wafer notch in the shielding region; when the wafer notch is located in the shielding region, the wafer rotational speed is reduced, thereby reducing the total amount of metal ions received by the wafer notch in the shielding region. According to a specific implementation of an embodiment of this application: a rotatable wafer holding device is set in the electroplating equipment, and the rotational speed of the wafer is controlled by adjusting the rotational speed of the wafer holding device.

[0017] The electroplating equipment, electroplating apparatus, and electroplating method of the present invention, by setting a shielding area on the stirring mechanism, reduce the flow rate of the electroplating solution within the shielding area. Simultaneously, by controlling the wafer rotation speed to decrease during the process, the time the wafer notch remains within the shielding area is extended, thereby reducing the total amount of metal ions received by the wafer notch within the shielding area. This prevents excessively high electroplating height around the wafer notch during the electroplating process. Other features and advantages of the present invention will be set forth in the following description and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures pointed out in the description and drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the electroplating equipment structure according to an embodiment of the present invention is shown;

[0020] Figure 2 Another structural schematic diagram of the electroplating equipment according to an embodiment of the present invention is shown;

[0021] Figure 3This diagram illustrates the structure of the region enclosed by a straight edge of the shielding area of ​​the stirring mechanism and the edge line of the stirring mechanism in Embodiment 1 of the present invention.

[0022] Figure 4 This diagram shows a schematic of the area structure formed by the two straight sides of the shielding area of ​​the stirring mechanism and the edge line of the stirring mechanism in Embodiment 1 of the present invention.

[0023] Figure 5 This diagram shows a schematic of the area structure formed by the three straight sides of the shielding area of ​​the stirring mechanism and the edge line of the stirring mechanism in Embodiment 1 of the present invention.

[0024] Figure 6 This diagram shows a schematic of the area structure formed by the curved edge of the shielding area of ​​the stirring mechanism and the edge line of the stirring mechanism in Embodiment 1 of the present invention.

[0025] Figure 7 A three-dimensional schematic diagram of the stirring mechanism in Embodiment 2 of the present invention is shown;

[0026] Figure 8 A three-dimensional schematic diagram of the stirring mechanism in Embodiment 3 of the present invention is shown;

[0027] Figure 9 A schematic diagram of the existing stirring mechanism structure is shown;

[0028] Figure 10 A schematic diagram showing the electron density detection results on different regions of the wafer corresponding to the stirring mechanism of the prior art and the stirring mechanism of the present invention is presented.

[0029] Figure 11a This diagram shows the location of detection area a corresponding to the existing stirring mechanism;

[0030] Figure 11b The diagram shows the variation of electroplating solution flow rate in the X and Z directions of region a during the electroplating process using a prior art stirring mechanism.

[0031] Figure 11c A schematic diagram showing the change of electric field intensity in region a during electroplating using a prior art stirring mechanism is shown.

[0032] Figure 12a It shows Figure 4 A schematic diagram showing the location of detection area b corresponding to the shielded area of ​​the mixing mechanism;

[0033] Figure 12b It shows Figure 4 The diagram showing the changes in electroplating solution flow velocity in the X and Z directions of region b during the electroplating process using the stirring mechanism; and...

[0034] Figure 12c It shows Figure 4A schematic diagram showing the change in electric field intensity in region b during the electroplating process using the stirring mechanism. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Through actual observation and summarization of the electroplating process and results, the inventors discovered that in order to adapt to the situation where different areas of the wafer in the same electroplating chamber need to correspond to different flow rates of the electroplating solution, this invention proposes to design the structure of the stirring mechanism of the electroplating equipment to accurately control the different requirements of the total amount of metal ions in the electroplating solution that different areas of the wafer need to receive. At the same time, it is combined with the wafer rotation speed for control to achieve better control effect.

[0037] Please refer to Figure 1 and Figure 2 , Figure 1 and Figure 2The diagrams show the structure of the electroplating equipment according to different angles of an embodiment of the present invention. The electroplating equipment of this embodiment includes an electroplating chamber 100 and a stirring mechanism 200, with the stirring mechanism 200 disposed within the electroplating chamber 100. The electroplating chamber 100 is used to contain the electroplating solution. During the process, the wafer 300 is positioned directly above the stirring mechanism 200, and the stirring mechanism 200 moves parallel to the wafer 300 to stir the electroplating solution. In this embodiment, the stirring mechanism 200 is made of an insulator, such as PVC, PC, CPVC, PPS, PEEK, PTFE, or other plastic materials. The stirring mechanism 200 includes a shielding region 201 and a stirring region 202. The shielding region 201 is used to shield the flow field, weakening the stirring force of the electroplating solution within that region, reducing the fluidity of the electroplating solution within that region, and lowering the metal ion density of the electroplating solution within the region corresponding to the shielding region 201. The stirring region 202 consists of multiple parallel first blades 203, with gaps between adjacent first blades 203 allowing liquid and electric field to pass through. During wafer electroplating, when the wafer notch 301 is located in the shielding region 201, the wafer 300 rotates at a first rotational speed. When the wafer notch 301 is located in the stirring region 202, the wafer 300 rotates at a second rotational speed, with the first rotational speed being lower than the second. The shielding region 201 is used to reduce the total amount of metal ions received by the wafer notch 301 within the shielding region 201. The lower first rotational speed ensures that the wafer notch 301 remains in the shielding region 201 for a longer period during a complete electroplating process. This reduces the ion exchange rate around the wafer notch 301, thereby preventing excessively high plating height near the wafer notch 301 and achieving uniform plating.

[0038] Furthermore, when designing the shielding region 201, its area is larger than the area of ​​the wafer notch 301 to ensure that the wafer notch 301 is entirely within the shielding region 201, resulting in a better shielding effect. Specifically, when actually setting up the stirring mechanism 200, its size and shape are matched according to the size and shape of the wafer 300, so that the electroplating solution and electric field in the stirring region 202 can better pass through the gap between adjacent first blades 203; the shielding region 201 is designed according to the position and size of the wafer notch 301, ensuring that its area is larger than the area of ​​the wafer notch 301, thus guaranteeing that the wafer notch 301 is entirely within the shielding region 201. For example, as... Figure 2 As shown, when the wafer notch 301 is located at the edge of the wafer 300, the shielding area 201 is located at the edge of the stirring mechanism 200, and the area of ​​the shielding area 201 is larger than the area of ​​the wafer notch 301.

[0039] refer to Figure 1The electroplating equipment of this embodiment further includes a wafer holding device 400, on which the wafer 300 is fixed. The wafer holding device 400 is rotatable, and the wafer 300, fixed to the wafer holding device 400, rotates with it. The relative position of the wafer notch 301 on the wafer 300 and the wafer holding device 400 is fixed; therefore, the position of the wafer notch 301 can be determined based on the rotational position of the wafer holding device 400. During the electroplating process, the wafer holding device 400 drives the wafer 300 to rotate. The rotation speed can range from 0.1 rpm to 500 rpm, and can be specifically determined according to actual conditions. The position of the wafer notch 301 is tracked according to the rotation speed of the wafer holding device 400. When the wafer notch 301 is in the stirring region 202, the rotation speed of the wafer 300 is controlled to the second rotation speed. When the wafer notch 301 begins to enter the shielding region 201, the rotation speed of the wafer 300 is reduced so that the wafer 300 rotates at the first rotation speed. The reduction in the rotation speed of the wafer 300 reduces the total amount of metal ions received by the wafer notch 301 in the shielding region 201, thus avoiding the generation of a larger metal ion density in the area surrounding the wafer notch 301, which would lead to an excessively high electroplating height in the area surrounding the wafer notch 301.

[0040] To achieve the above objectives, the present invention has made a series of optimizations to the specific structure of the stirring mechanism 200, which will be described in detail below.

[0041] Example 1

[0042] In this embodiment, the shielding area 201 is a closed block structure. Specifically, the shielding area 201 may include an area enclosed by several straight edges connected in sequence and the edge line of the stirring mechanism. In this embodiment, several means an integer greater than or equal to 1. The shielding area 201 may also be an area enclosed by curved edges and the edge line of the stirring mechanism.

[0043] For example, please refer to Figure 3 The example illustrates that the shielding region 201 is a region enclosed by several sequentially connected straight edges and the edge line of the stirring mechanism, and the shielding region 201 is formed when the number of straight edges is 1. Figure 3 As can be seen, both ends of the straight edge 3011 are directly connected to the edge line 3012 of the stirring mechanism, forming a closed enclosed area, namely the shielding area 201. In this embodiment, the shielding area 201 is a closed block structure; please refer to Figure 4 The example illustrates the occlusion region 201 formed when the number of straight edges is 2. Figure 4It can be seen that the two straight edges 4011a and 4011b are connected sequentially. Then, the free end of straight edge 4011a is connected to the edge line 4012 of the stirring mechanism, and the free end of straight edge 4011b is connected to the edge line 4012 of the stirring mechanism. The enclosed area formed by the two straight edges 4011a and 4011b and the edge line 4012 of the stirring mechanism is the shielding area 201, which is a closed block structure. Here, the free end refers to the end of straight edge 4011a and 4011b located on the outer side. It can be understood that although described as lines or edges, both the stirring mechanism and the shielding area 2011 are structures with a certain thickness. Therefore, the edge line of the stirring mechanism represents the vertical curved surface or plane of the stirring mechanism with the edge line as its cross-section, and the straight edge represents the vertical plane with the straight line as its cross-section in the shielding area.

[0044] Please refer to Figure 5 This example illustrates the occlusion region 201 formed when the number of straight edges is 3; by Figure 5 It can be seen that one end of the straight edge 5011a is connected to the edge line 5012 of the stirring mechanism, the other end of the straight edge 5011a is connected to one end of the straight edge 5011b, the other end of 5011b is connected to one end of the straight edge 5011c, and the other end of 5011c is connected to the edge line 5012 of the stirring mechanism. The straight edges 5011a, 5011b, 5011c and the edge line 5012 of the stirring mechanism together form a closed area, which is the shielding area 201. This area is a closed block structure.

[0045] In other embodiments, the shielding area 201 is a region enclosed by the curved edge and the edge line of the stirring mechanism.

[0046] Please refer to Figure 6 An example illustrates the shielding area 201 formed by the curved edge 6011 and the edge line 6012 of the stirring mechanism; by Figure 6 It can be seen that the two ends of the straight edge 6011 are directly connected to the edge line 6012 of the stirring mechanism, forming a closed enclosed area, namely the shielding area 201. In this embodiment, the shielding area 201 is a closed block structure. It should be understood that the above is only an example illustration. The number of straight edges is not limited in this embodiment of the invention. When the number of straight edges is greater than or equal to 2, the included angle formed by two connected straight edges is not limited in this embodiment of the invention. The specific shape of the curved edge is not specifically limited. The curved edge can be an arc or a wavy curve.

[0047] Furthermore, the height of the upper surface of the shielding region 201 is higher than the height of the upper surface of the first blade 203 of the stirring region 202. This means that during the process, the upper surface of the shielding region 201 is closer to the wafer 300 than the upper surface of the first blade 203. Since the distance between the shielding region 201 and the wafer 300 is less than the distance between the first blade 203 and the wafer 300, the space between the shielding region 201 and the wafer 300 is smaller during the stirring process, resulting in less electroplating solution that can be accommodated. Simultaneously, because the fluidity of the electroplating solution in the area corresponding to the shielding region 201 is less than that in the area corresponding to the stirring region 202, the metal ion exchange rate in the electroplating solution will be lower than that in the stirring region 202. When the wafer notch 301 rotates into this area, the wafer 300 is controlled to decelerate, causing the wafer notch 301 to be positioned within this area. The extended duration of the shielding region 201 reduces the total amount of metal ions received by the area surrounding the wafer notch 301, thereby reducing the plating height around the wafer notch 301 and ensuring uniform plating height across the entire wafer 300. Simultaneously, the shielding region 201 is a closed block structure made of insulating material, preventing the electric field below it from reaching the wafer 300. Therefore, the current density within the shielding region 201 is also lower, resulting in less plating on the area corresponding to the shielding region 201 on the wafer 300 during plating. When the wafer notch 301 remains within the shielding region 201 for an extended period, the effect of suppressing the plating height around the notch 301 is more pronounced than in the non-notch area, thus ensuring uniform plating height across the entire wafer 300. It should be understood that in other embodiments, the relative height between the upper surface of the shielding region 201 and the upper surface of the first blade 203 in the stirring region 202 can be set according to actual needs.

[0048] During the electroplating process, when the wafer notch 301 is located within the shielding region 201, the shielding region 201 acts as a shield for the electric field, resulting in a relatively low current density within the shielding region 201. At this time, reducing the rotational speed of the wafer 300 increases the time the wafer notch 301 spends within the shielding region 201. Consequently, the amount of plating layer deposited on the area of ​​the wafer 300 shielded by the shielding region 201 decreases, thus controlling the plating height around the wafer notch 301. Because the block structure has a closed characteristic, the electric field within the electroplating chamber 100 is blocked when it passes through the shielding region 201 of the closed block structure. Especially when the stirring mechanism in this embodiment uses an insulating material, the electric field cannot pass through the shielding region 201, reducing the total charge received by the area around the wafer notch 301 within the shielding region 201, thereby suppressing the plating height around the wafer notch 301. Meanwhile, when the shielding area 201 is a closed block structure, its effect of stirring the electroplating solution is weak. As a result, the fluidity of the electroplating solution in the shielding area 201 is weaker than that in the stirring area 202, which reduces the total amount of metal ions received by the wafer notch 301 in the shielding area 201 and further suppresses the electroplating height in the area surrounding the wafer notch 301.

[0049] Example 2

[0050] The structure of the stirring mechanism in Example 2 differs slightly from that in Example 1. A stirring unit is disposed within the shielded area, and the stirring force of the stirring unit is weaker than the stirring force of the blades within the stirring area. For example, the stirring unit can have multiple parallel blades, and the blades within the shielded area can be perpendicular to or parallel to the blades within the stirring area. Figure 7As shown. This embodiment uses a stirring unit consisting of multiple parallel blades, with the second blade 204 in the shielding region 201 parallel to the first blade 203 in the stirring region 202 as an example. To make the stirring force of the second blade 204 weaker than that of the first blade 203, various design factors can be considered, including but not limited to: the cross-sectional shape of the second blade 204, the gap between adjacent second blades 204, etc. Furthermore, the width of the upper end face of the second blade 204 is greater than the width of the lower end face of the second blade 204, in order to weaken the flow field while shielding the electric field. For example, the cross-sectional shape of the second blade 204 includes, but is not limited to, an inverted trapezoid, an inverted "T" shape, or an inverted triangle. The distance between adjacent second blades 204 can be less than the distance between adjacent first blades 203, or it can be greater than or equal to the distance between adjacent first blades 203. In this embodiment, no specific limitations are made on the various factors affecting the stirring force of the stirring unit. As long as the stirring force of the second blade 204 located in the shielded area 201 is weaker than the stirring force of the first blade 203 in the stirring area 202, the solution falls within the protection scope of this invention. In the actual manufacturing process, the first blade 203 and the second blade 204 can be manufactured by segmenting the same blade and forming it integrally, or they can be manufactured in segments and then installed and fixed.

[0051] Furthermore, the height of the upper surface of the second blade 204 is higher than or equal to the height of the upper surface of the first blade 203.

[0052] In some embodiments, when the upper end face of the second blade 204 and the upper end face of the first blade 203 are on the same horizontal plane, the stirring force achieved by the cross-sectional shape of the second blade 204, the gap between adjacent second blades 204, or a combination thereof, can be adjusted and designed to achieve a stirring force that is weaker than that of the first blade 203.

[0053] In other embodiments, the upper surface of the second blade 204 is higher than the upper surface of the first blade 203. That is, during the process, the upper surface of the second blade 204 is closer to the wafer 300 than the upper surface of the first blade 203. The distance between the second blade 204 and the wafer 300 is less than the distance between the first blade 203 and the wafer 300. This results in the electroplating solution having lower flow rate in the shielding region 201 than in the stirring region 202 during stirring. Consequently, the metal ion exchange rate in the electroplating solution in the shielding region 201 is lower than that in the stirring region 202. When the wafer notch 301 rotates into the shielding region 201, the wafer 300 is controlled to decelerate to a first rotational speed, increasing the time the wafer notch 301 remains in the shielding region 201. This reduces the metal ion mass transfer rate, thereby reducing the electroplating height around the wafer notch 301 and maintaining a uniform overall electroplating height for the wafer 300. It should be understood that when the upper surface of the second blade 204 is higher than the upper surface of the first blade 203, factors such as the cross-sectional shape of the second blade 204 and the first blade 203, the gap between adjacent blades, or a combination of both can be considered to adjust the stirring force of the shielding area 201 and the stirring area 202, so as to better achieve the purpose of the stirring force of the second blade 204 being weaker than that of the first blade 203.

[0054] The height of the upper surface of the second blade 204 can be set according to actual needs.

[0055] Example 3

[0056] The structure of the stirring mechanism in Example 3 differs slightly from that in Example 1. In Example 1, the blocking area 201 is a solid structure. The blocking area 201 is a hollow frame structure. No structure is set inside the hollow frame design of the blocking area 201. In this example, the blocking area 201 is formed only by the edge line of the stirring mechanism and curved edges or several straight edges connected in sequence. The shape of the blocked area 201 formed is similar to that in Example 1. Figures 3-6 As shown, details will not be elaborated here. Since no paddle-like structure is provided within the shielding area 201, the stirring force within the shielding area 201 is weaker than that within the stirring area 202. Consequently, the flow rate of the electroplating solution within the shielding area 201 is also weaker than that within the stirring area 202. This results in a lower mass transfer rate of metal ions in the electroplating solution compared to the stirring area 202. Combined with the control method that slows down the wafer 300 when the wafer notch 301 rotates into the shielding area 201, the time the wafer notch 301 remains within the shielding area 201 is prolonged, further reducing the mass transfer rate of metal ions. This, in turn, reduces the electroplating height around the wafer notch 301, ensuring a uniform overall electroplating height for the wafer 300.

[0057] Furthermore, please refer to Figure 8 The upper surface of the edge frame of the shielding area 201 is higher than the upper surface of the impeller in the stirring area 202 to prevent rapid exchange between the electroplating solution in the stirring area 202 and the electroplating solution in the shielding area 201. It should be understood that the height of the upper surface of the edge frame of the shielding area 201 can also be chosen to be equal to the height of the upper surface of the impeller in the stirring area 202.

[0058] For specific settings, please refer to Example 1 for the position and shape of the occlusion area 201, which will not be elaborated here.

[0059] This application also provides an electroplating method using electroplating equipment, comprising:

[0060] Step S1: A stirring mechanism including a shielding area and a stirring area is set in the electroplating equipment, wherein the shielding area is used to weaken the flow field in the area, and the stirring area includes a plurality of parallel first blades;

[0061] Step S2: Electroplating is performed on the wafer surface using electroplating equipment. The stirring mechanism is controlled to move parallel to the wafer to stir the electroplating solution. When the wafer notch is located in the shielding area, the wafer rotation speed is the first rotation speed. When the wafer notch is located in the stirring area, the wafer rotation speed is the second rotation speed. The first rotation speed is less than the second rotation speed. The shielding area is used to reduce the total amount of metal ions received by the wafer notch in the shielding area.

[0062] The wafer rotation speed setting in the above steps can be controlled by the controller in the electroplating equipment.

[0063] Furthermore, a rotatable wafer holding device is installed in the electroplating equipment, and the wafer rotation speed is controlled by adjusting the rotation speed of the wafer holding device. Specifically, the rotation speed of the wafer holding device can be adjusted by the controller of the electroplating equipment.

[0064] To illustrate the effects achieved by this invention, the example given is a closed block structure in the shielding area 201 of the stirring mechanism 200. Please refer to [link / reference]. Figure 9 and Figure 4 , Figure 9 A schematic diagram of a prior art stirring mechanism is shown.

[0065] Under the same electroplating process conditions, place them separately in the electroplating chamber Figure 9 and Figure 4 The stirring mechanism was used to detect the charge density in the plating solution below the wafer. For specific results, please refer to [reference needed]. Figure 10 , Figure 10 The diagram shows the charge density detection results on different regions of the wafer corresponding to the stirring mechanism of the prior art and the stirring mechanism of the present invention. Figure 10In the figure, the horizontal axis represents the coordinates of wafer 300 extending from one edge along the diameter direction to the other side, which shows that the size of wafer 300 in this embodiment is 300mm. Figure 10 The vertical axis represents the charge density value of the lower surface of wafer 300; line a represents the measurement results of the charge density at different positions on the wafer during the electroplating process using a stirring mechanism of the prior art; line b represents the measurement results of the charge density at different positions on the wafer during the electroplating process using the stirring mechanism of the present invention. Figure 10 As shown, when the wafer 300 extends from one edge along the diameter to the other, line a and line b intersect. The area between the first intersection point A and the second intersection point B is the shielding area 201 corresponding to the wafer notch 301. The charge density of line b in the shielding area 201 is significantly less than that of line a. This indicates that the stirring mechanism 200 with the shielding area 201 can significantly reduce the charge density in the shielding area 201. During the electroplating process, when the wafer notch 301 enters the shielding area 201, the total charge received will decrease, thereby reducing the electroplating height of the area surrounding the wafer notch 301.

[0066] Further testing was conducted on the electroplating solution flow rate within the same area of ​​the stirring mechanism 200 with a shielded area and the stirring mechanism 600 without a shielded area. Specifically, when the wafer 300 was placed within the wafer holding device 400, a detection area was defined with the central axis of the wafer notch 301 as the center, and the area was the same as that of the shielded area 201. For the detection area corresponding to the existing stirring mechanism, please refer to [reference needed]. Figure 11a Region a is the detection region; please refer to the detection region corresponding to the stirring mechanism of this invention. Figure 12a Region b is the detection area. The flow velocity in the X and Z directions is detected within regions a and b. For the flow velocity results in region a in the X direction, please refer to [reference needed]. Figure 11b , Figure 11b The horizontal axis represents the position coordinates of the endpoint of X on the edge of wafer 300 extending along the X direction to the other endpoint, and the vertical axis represents the flow velocity of the plating solution on the surface of wafer 300. As shown in the figure, the average flow velocity in the X direction within region a is 0.0035 m / s. For the flow velocity results in the Z direction within region a, please refer to [reference needed]. Figure 11c , Figure 11c The horizontal axis represents the position coordinates of the lower endpoint of the Z-axis on the edge of wafer 300, extending along the Z-direction to the other endpoint. The vertical axis represents the flow velocity of the plating solution on the surface of wafer 300. As shown in the figure, the average flow velocity in the Z-direction within region a is 0.0031 m / s. For the flow velocity results in the X-direction within region b, please refer to [reference needed]. Figure 12b , Figure 12bThe horizontal axis represents the position coordinates of the endpoint of X on the edge of wafer 300 extending along the X direction to the other endpoint, and the vertical axis represents the flow velocity of the electroplating solution on the surface of wafer 300. As shown in the figure, the average flow velocity in the X direction within region b is 0.0014 m / s. For the flow velocity results in the Z direction within region b, please refer to [reference needed]. Figure 12c , Figure 12c The horizontal axis is the position coordinate of the lower endpoint of Z on the edge of wafer 300, extending along the Z direction to the other endpoint of Z. The vertical axis is the flow velocity of the electroplating solution on the surface of wafer 300. As can be seen from the figure, the average flow velocity in the Z direction in region b is 0.0021 m / s.

[0067] Experimental data shows that when using the existing stirring mechanism 600 to stir the electroplating solution, the flow rate and electric field intensity of the electroplating solution in the area corresponding to the wafer notch are relatively high, easily leading to excessively high electroplating height around the wafer notch. However, the stirring mechanism 200 of this invention can significantly reduce the flow rate and electric field intensity of the electroplating solution in the area corresponding to the wafer notch, thereby suppressing the electroplating height around the wafer notch and making the electroplating height on the wafer surface more uniform. Taking a certain RDL (redistribution layer) product as an example, the actual required electroplating height is 4µm. When using the existing stirring mechanism, the final electroplating result is that the electroplating height around the wafer notch can reach as high as 8µm. However, after using the stirring mechanism designed in this invention, when the wafer notch rotates to the shielded area, the wafer rotation speed is controlled to be reduced to 5% of the original speed, and the final electroplating result is that the electroplating height around the wafer notch can be reduced by 50%, meeting the requirement (electroplating height of 4µm).

[0068] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A stirring mechanism for an electroplating device, characterized in that, Application in electroplating equipment: The stirring mechanism includes a shielding area and a stirring area; the shielding area is used to weaken the flow field in that area; the stirring area includes multiple parallel-arranged first blades; wherein... The electroplating equipment is configured such that, during the wafer electroplating process, when the wafer notch is located in the shielding area, the wafer rotation speed is a first rotation speed, and when the wafer notch is located in the stirring area, the wafer rotation speed is a second rotation speed, wherein the first rotation speed is less than the second rotation speed. The shielding area is used to reduce the total amount of metal ions received by the wafer notch within the shielding area; The shielding area is a closed block structure, and the height of the upper surface of the shielding area is higher than the height of the upper surface of the first blade, or The shielding area has a hollow frame structure, and the upper surface of the frame of the shielding area is higher than the upper surface of the stirring area.

2. The stirring mechanism according to claim 1, characterized in that: The shielding area includes a region enclosed by a number of sequentially connected straight edges and the edge line of the stirring mechanism.

3. The stirring mechanism according to claim 1, characterized in that: The shielding area includes the region enclosed by the curved edge and the edge line of the stirring mechanism.

4. The stirring mechanism according to claim 1, characterized in that: A stirring unit is provided within the shielded area, and the stirring force of the stirring unit is weaker than that of the first blade.

5. The stirring mechanism according to claim 4, characterized in that: The stirring unit includes a plurality of parallel second blades, the stirring force of which is weaker than that of the first blade.

6. The stirring mechanism according to claim 5, characterized in that: The width of the upper end face of the second blade is greater than the width of the lower end face of the second blade.

7. The stirring mechanism according to claim 6, characterized in that: The height of the upper end face of the second blade is higher than or equal to the height of the upper end face of the first blade.

8. An electroplating apparatus for electroplating on the surface of a wafer, characterized in that: The electroplating equipment includes a stirring mechanism as described in any one of claims 1-7, and the electroplating equipment is configured to: control the stirring mechanism to move parallel to the wafer during the electroplating process to stir the electroplating solution.

9. The electroplating equipment according to claim 8, characterized in that: The electroplating equipment also includes a rotatable wafer holding device, which has a clamp for fixing the wafer, and the wafer notch is fixed in relative position to the clamp.

10. An electroplating method, characterized in that, include: An agitation mechanism comprising a shielding area and an agitation area is provided in an electroplating equipment, wherein the shielding area is used to weaken the flow field in the area, and the agitation area includes a plurality of parallel first blades; Electroplating is performed on the surface of a wafer using the aforementioned electroplating equipment, and the stirring mechanism is controlled to move parallel to the wafer to stir the electroplating solution; When the wafer notch is located in the shielding region, the wafer rotates at a first rotational speed; when the wafer notch is located in the stirring region, the wafer rotates at a second rotational speed, where the first rotational speed is less than the second rotational speed. The shielding region is used to reduce the total amount of metal ions received by the wafer notch within the shielding region. Wherein, the shielding area is a closed block structure, and the height of the upper surface of the shielding area is higher than the height of the upper surface of the first blade, or The shielding area has a hollow frame structure, and the upper surface of the frame of the shielding area is higher than the upper surface of the stirring area.

11. The electroplating method according to claim 10, characterized in that: A rotatable wafer holding device is installed in the electroplating equipment, and the rotational speed of the wafer is controlled by adjusting the rotational speed of the wafer holding device.

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