Wafer electroplating device
By introducing flow assist components and driving components into the wafer plating device, the flow of the plating solution deep in the plating cavity is improved, and the problems of uneven plating thickness and poor fluid flow are solved, the stability and uniformity of plating are improved, and the ion permeability film is protected.
Patent Information
- Application Number
- CN202510618449.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-14
- Publication Date
- 2025-08-05
AI Technical Summary
In the prior art, there are problems of uneven plating thickness and poor fluid flow during the electroplating process of semiconductor wafers, especially in the deep holes on the surface of the wafer, which makes it difficult to evenly distribute the plating solution, which increases the risk of ion permeation film breakage and metal ion replenishment frequency.
A wafer plating device is designed, including a rotating component, an ion permeation membrane, a rectifier element and a flow assist element. By driving the component to drive the paddle to rotate, improve the flow of the plating solution deep in the plating cavity, enhance flow field control, and protect the ion permeation membrane.
It improves the stability and uniformity of the electroplating production process, reduces the risk of breakage of the ion permeation membrane, reduces the frequency of metal ion concentration replenishment, and improves the uniformity and production efficiency of electroplating.
Smart Images
Figure CN120425438A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of semiconductor manufacturing, and particularly relates to a wafer electroplating device. Background Art
[0002] In the process of integrated circuit (IC) manufacturing, electroplating technology is often used to deposit one or more conductive metal layers on a semiconductor wafer substrate due to advantages such as simple process, low cost, and easy mass production, so as to form single-layer or multi-layer metal interconnects between various semiconductor wafer substrate features. During electroplating, electrical contacts are formed on the seed layer around the perimeter of the wafer, and the wafer is electrically biased to serve as a cathode, bringing the wafer into contact with an electrolyte solution that contains metal ions to be plated.
[0003] In the electroplating process, many factors can cause uneven thickness of the metal electroplated on the semiconductor wafer. To improve the electroplating uniformity, flow fields in multiple directions are introduced. However, while the anisotropic flow field enhances mass transfer inside the deep holes of the patterns on the wafer surface, it can lead to poor fluid mobility in some areas, and even a situation where the fluid flows reversely against the ion permeable membrane. In this case, not only is it difficult for the metal ions generated by the dissolution of the soluble anode to reach the wafer surface as scheduled, and it is necessary to replenish the metal ion concentration in the cathode solution more frequently, increasing the cost. Moreover, the reverse flow of the electroplating solution will generate a relatively large pressure on the ion permeable membrane, increasing the risk of damage to the ion permeable membrane.
[0004] To improve the flow problem of the electroplating solution in the deep part of the electroplating chamber and enhance the stability and electroplating uniformity in the electroplating production process, the present application proposes a wafer electroplating device. Summary of the Invention
[0005] The purpose of the present invention is to provide a wafer electroplating device to solve the problem of uneven thickness of the edge coating of the wafer in the prior art.
[0006] To achieve the above purpose, the technical solution of the present invention is as follows: A wafer electroplating device includes: An electroplating chamber with electroplating solution disposed therein; A rotating assembly for clamping and rotating the wafer to make the lower surface of the wafer contact with the electroplating solution; An ion permeable membrane disposed in the electroplating chamber; A rectifying element disposed in the electroplating chamber and above the ion permeable membrane; A flow assistance element including a transmission assembly and at least one paddle; at least one inclined surface is provided on the paddle, and the paddle is disposed between the rectifying element and the ion permeable membrane, or the paddle is disposed between the rectifying element and the rotating assembly; A driving assembly cooperating with the transmission assembly to drive the paddle to rotate.
[0007] Preferably, a first inlet and a second inlet are provided at the bottom of the electroplating chamber. The first inlet is located near the center of the bottom of the electroplating chamber, and the second inlet is located at the outer edge of the bottom of the electroplating chamber. A first outlet is also provided at the bottom of the electroplating chamber.
[0008] Preferably, the transmission component includes a transmission gear and a rotating gear. The paddle is arranged inside the rotating gear. The driving component includes a motor and a rotating connecting rod. One end of the rotating connecting rod is connected to the motor, and the other end is connected to the transmission gear. The transmission gear meshes with the rotating gear.
[0009] Preferably, the paddle has a bottom surface, a first surface, and a second surface that are pairwise connected. The bottom surface is parallel to the horizontal plane. The first surface is inclined with respect to the bottom surface, and the angle between the second surface and the first surface is less than 90°.
[0010] Preferably, the overall shape of the paddle is set in a fan blade shape, and the width of the paddle gradually increases from the end far from the rotating gear to the end close to the rotating gear.
[0011] Preferably, there are 3 - 7 paddles, and the paddles are evenly distributed along the inner wall of the rotating gear.
[0012] Preferably, openings are provided on the paddle.
[0013] Preferably, the rotating component includes a round cup, a conical part, a support rod, a top plate, a main shaft, and a motor. The motor is connected to the top plate. The conical part is located between the top plate and the round cup. The support rod is sequentially connected to the top plate, the conical part, and the round cup.
[0014] Compared with the prior art, a wafer electroplating device of the present application has the following beneficial effects: In the present invention, the driving component drives the flow assistance element to rotate, thereby improving the flow problem of the electroplating solution in the deep part of the electroplating chamber, enhancing the stability and uniformity of the electroplating production process, and strengthening the control of the flow field direction. At the same time, it also protects the necessary element in the electroplating chamber - the ion permeable membrane. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 is a schematic structural diagram of a wafer electroplating device provided by an embodiment of the present invention; Figure 2 is a schematic structural diagram of an electroplating cavity provided by an embodiment of the present invention; Figure 3 is a schematic structural diagram of a flow assistance element provided by an embodiment of the present invention; Figure 4 is a schematic cross - sectional view of a wafer electroplating device provided by an embodiment of the present invention; Figure 5Top view of the rotating gear and the paddle provided by the embodiment of the present invention; Figure 6 Another structural schematic diagram of the flow assistance element provided by the embodiment of the present invention; Figure 7 A structural schematic diagram of the paddle provided by the embodiment of the present invention; Figure 8 Another schematic diagram of the paddle provided by the embodiment of the present invention; Figure 9 Another schematic diagram of the paddle provided by the embodiment of the present invention. Detailed implementation manners
[0016] The following is further detailed through specific implementation manners: The reference numerals in the accompanying drawings of the specification include: electroplating chamber 1, rotating assembly 2, wafer 3, ion permeable membrane 4, rectifying element 5, paddle 6, first inlet 7, second inlet 8, first outlet 9, first flow direction 10, second flow direction 11, transmission gear 12, rotating gear 13, motor 14, rotating connecting rod 15, first surface 16, second surface 17, opening 18, through hole 19, round cup 101, conical part 102, support rod 103, top plate 104, main shaft 105, motor 106.
[0017] As shown in the attached Figures 1-4 As shown, this embodiment shows a wafer 3 electroplating device, including an electroplating chamber 1, a rotating assembly 2, an ion permeable membrane 4, a rectifying element 5, a flow assistance element and a driving assembly. Among them, an electroplating solution is provided inside the electroplating chamber 1; the rotating assembly 2 is used to clamp and rotate the wafer 3 so that the lower surface of the wafer 3 contacts the electroplating solution in the electroplating chamber 1.
[0018] Both the ion permeable membrane 4 and the rectifying element 5 are provided in the electroplating chamber 1. Among them, the rectifying element 5 is located above the ion permeable membrane 4, and a through hole 19 is provided on the rectifying element 5. The flow assistance element includes a transmission assembly and at least one paddle 6. At least one inclined surface is provided on the paddle 6. The paddle 6 is provided between the rectifying element 5 and the ion permeable membrane 4, or the paddle 6 is provided between the rectifying element 5 and the rotating assembly 2. The driving assembly cooperates with the transmission assembly to drive the paddle 6 to rotate.
[0019] The paddle 6 is integrally set as a fan-shaped structure. At least one inclined surface is provided on the paddle 6, which can uniformly stir the electroplating solution during rotation, and the inclined surface will apply an obliquely upward force to the electroplating solution when rotating. When the paddle 6 is placed in the middle area between the rectifying element 5 and the ion permeable membrane 4, the rotation of the paddle 6 will push the electroplating solution to surge above the rectifying element 5 instead of surging in the direction of the ion permeable membrane 4.
[0020] Specifically, as shown in Figure 3As shown, the paddle 6 has a bottom surface, a first surface 16, and a second surface 17 that are pairwise connected. The bottom surface is parallel to the horizontal plane. The first surface 16 is inclined with respect to the bottom surface, and the angle between the second surface 17 and the first surface 16 is less than 90°.
[0021] When the paddle 6 is placed in the intermediate region between the rectifying element 5 and the wafer 3, that is, when the paddle 6 is disposed between the rectifying element 5 and the rotating assembly 2, the rotation of the paddle 6 will increase the flow rate of the fluid above the rectifying element 5, reduce the pressure in the region above the through-hole 19 of the rectifying element 5, and promote the upward influx of the electroplating solution below the through-hole 19 of the rectifying element 5. The upward-inflowing electroplating solution can be quickly mixed evenly with the electroplating solution flowing in from other directions under the agitation of the paddle 6 and is pushed obliquely upward to attack the inside of the deep holes of the surface pattern of the wafer 3 at an inclined angle, so that the electroplating reaction solution in the deep holes of the wafer 3 is quickly replaced.
[0022] As shown in Figure 1 As shown, the rotating assembly includes a round cup 101, a conical part 102, a support rod 103, a top plate 104, a main shaft 105, and a motor 106. The motor 106 is connected to the top plate 104. The conical part 102 is located between the top plate 104 and the round cup 101. The support rod 103 is sequentially connected to the top plate 104, the conical part 102, and the round cup 101. The round cup 101 is used to fixedly hold the wafer, and the conical part 102 tightly clamps the wafer in the round cup 101. The rotating assembly is supported by the support rod 103, and the support rod 103 is connected to the top plate 104. The round cup 101, the conical part 102, the support rod 103, and the top plate 104 are driven by the motor 106 via the main shaft 105 connected to the top plate 104. During electroplating, the main shaft 105 transfers torque from the motor 106 to the conical part 102, thereby rotating the wafer held therein. After the wafer is inserted between the round cup 101 and the conical part 102, the conical part 102 meshes with the round cup 101 to fix the wafer in the device, so that one working surface of the wafer is exposed for contact with the electroplating solution.
[0023] As shown in Figures 2-3 As shown, the transmission assembly includes a transmission gear 12 and a rotating gear 13. The paddle 6 is disposed inside the rotating gear 13; the driving assembly includes a motor 14 and a rotating connecting rod 15. One end of the rotating connecting rod 15 is connected to the motor 14, and the other end is connected to the transmission gear 12; the transmission gear 12 meshes with the rotating gear 13. The motor 14 drives the transmission gear 12 to rotate through the rotating connecting rod 15. The transmission gear 12 meshes with the rotating gear 13, thereby driving the paddle 6 inside the rotating gear 13 to rotate. The one meshing with the rotating gear 13 can be disposed below or above the rectifying element 5 with the through-hole 19.
[0024] As shown in Figure 4As shown in the figure, a first inlet 7 and a second inlet 8 are provided at the bottom of the electroplating chamber 1. The first inlet 7 is located near the center of the bottom of the electroplating chamber 1, and the second inlet 8 is located at the outer edge of the bottom of the electroplating chamber 1. A first outlet 9 is also provided at the bottom of the electroplating chamber 1.
[0025] The electroplating solution entering the electroplating chamber 1 through the first inlet 7 has a first flow direction 10, and its flow path sequentially passes through the ion permeable membrane 4, the paddle 6, and the rectifying element 5 and then reaches the surface of the wafer 3 in the vertical direction. The electroplating solution entering the electroplating chamber 1 through the second inlet 8 has a second flow direction 11, and its flow reaches the surface of the wafer 3 directly in the horizontal direction. Since the ion permeable membrane 4 usually has a relatively thin thickness to ensure its functionality, its mechanical strength is difficult to support the passage of high-flow-rate fluids. Therefore, the electroplating solution with the second flow direction 11 usually has a greater flow intensity than the electroplating solution with the first flow direction 10, resulting in the electroplating solution with the first flow direction 10 being difficult to cross-mix with the electroplating solution with the second flow direction 11 and jointly reach the surface of the wafer 3, but preferentially flowing out through the first outlet 9. Similarly, during the electroplating process, when the flow intensity of the electroplating solution with the second flow direction 11 far exceeds that of the electroplating solution with the first flow direction 10, the electroplating solution with the second flow direction 11 will also tend to surge downward while flowing horizontally and reach the first outlet 9 along the path opposite to the first flow direction 10.
[0026] The addition of the paddle 6 can solve this problem. When the paddle 6 rotates, the liquid below the rectifying element 5 is driven, giving the electroplating solution with the first flow direction 10 a spiral upward driving force without applying greater pressure to the ion permeable membrane 4. The additional driving force makes the electroplating solution with the first flow direction 10 have a greater flow intensity, which is conducive to its upward surge and cross-mixing with the electroplating solution with the second flow direction 11 on the surface of the wafer 3, making the mixed electroplating solution have a faster mass transfer speed and attacking the deep hole pattern on the surface of the wafer 3 at a certain angle.
[0027] During the electroplating process, the rotation of the paddle 6 will inevitably block some electric field lines. To solve this problem, as Figure 5 shown, the overall shape of the paddle 6 is set in a fan blade shape, and the width of the paddle 6 gradually increases from the end far from the rotating gear 13 to the end close to the rotating gear 13. The increase in the width of the paddle 6 close to the rotating gear 13 means stronger shielding and better agitation mass transfer, which can solve the problem of thicker coatings in the edge area of the wafer 3 caused by the difference in internal resistance of the wafer 3, and the problem that the deep holes in the edge area of the wafer 3 have a higher aspect ratio due to uneven photoresist coating, resulting in bottom voids being easily generated in the edge area of the wafer 3 during the electroplating process.
[0028] The paddle 6 can be provided with 3 - 7. Specifically, in some embodiments, as Figure 6As shown, three paddles 6 can be provided, and the three paddles 6 are evenly distributed along the inner wall of the rotating gear 13. When the paddle 6 is placed in the middle area between the rectifying element 5 and the wafer 3, the design of the rapid rotation of the paddle 6 will increase the flow rate of the fluid above the rectifying element 5, reduce the pressure in the area above the through hole 19 of the rectifying element 5, and promote the electroplating solution below the through hole 19 of the rectifying element 5 to surge upward. The electroplating solution surging upward can be quickly mixed evenly with the electroplating solution surging in other directions under the agitation of the paddle 6, and is pushed obliquely upward to attack the inside of the deep holes of the surface pattern of the wafer 3 at an inclined angle, so that the electroplating reaction solution in the deep holes of the wafer 3 is quickly replaced. The design of multiple paddles 6 can reduce the shielding range of the current while having a stronger agitation effect and speed up the electroplating speed.
[0029] In some other embodiments, such as Figures 7-9 As shown, the paddle 6 has bottom surfaces with different shapes and sizes. The larger bottom surface can strengthen the force of pushing the electroplating solution, but has a larger current shielding area. When the shielding area of the bottom surface is large, vertical openings 18 with different shapes can be designed on the paddle 6. Since the paddle 6 has a first surface 16 that is inclined downward with a curvature, the vertical openings 18 have little influence on the rotation of the paddle 6.
[0030] The shape of the opening 18 can be set to be circular or rectangular, and this embodiment does not limit it here.
[0031] The above are only embodiments of the present invention, and common knowledge such as specific structures and characteristics known in the solution is not described too much here. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, and these should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicability of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners and the like recorded in the specification can be used to explain the content of the claims.
Claims
1. A wafer electroplating device, characterized in that: include: an electroplating chamber (1) containing an electroplating solution; A rotating assembly (2) for clamping and rotating a wafer (3) so that the lower surface of the wafer (3) contacts the electroplating solution; an ion permeable membrane (4) disposed in the electroplating chamber (1); A rectifying element (5) is disposed in the electroplating chamber (1) and located above the ion permeable membrane (4); A flow assisting element comprises a transmission assembly and at least one paddle (6); the paddle (6) is provided with at least one inclined surface, and the paddle (6) is provided between a rectifying element (5) and an ion permeable membrane (4), or the paddle (6) is provided between the rectifying element (5) and a rotating assembly (2); A driving assembly cooperates with the transmission assembly to drive the paddle (6) to rotate.
2. A wafer electroplating device according to claim 1, characterized in that: A first inlet (7) and a second inlet (8) are provided at the bottom of the electroplating chamber (1); the first inlet (7) is located near the center of the bottom of the electroplating chamber (1); the second inlet (8) is located at the outer edge of the bottom of the electroplating chamber (1); and a first outlet (9) is also provided at the bottom of the electroplating chamber (1).
3. The wafer electroplating device according to claim 1, wherein: The transmission assembly includes a transmission gear (12) and a rotating gear (13), and the paddle (6) is arranged on the inner side of the rotating gear (13); the driving assembly includes a motor (14) and a rotating connecting rod (15), one end of the rotating connecting rod (15) is connected to the motor (14), and the other end is connected to the transmission gear (12); the transmission gear (12) is meshed with the rotating gear (13).
4. A wafer electroplating device according to claim 3, characterized in that: The paddle (6) comprises a bottom surface, a first surface (16) and a second surface (17) connected to each other in pairs, the bottom surface is parallel to the horizontal plane, the first surface (16) is arranged with an inclined bottom surface, and the angle between the second surface (17) and the first surface (16) is less than 90°.
5. A wafer electroplating device according to claim 4, characterized in that: The paddle (6) is shaped like a fan blade as a whole, and the width of the paddle (6) gradually increases from the end of the paddle (6) away from the rotating gear (13) to the end of the paddle (6) close to the rotating gear (13).
6. A wafer electroplating device according to claim 4 or 5, characterized in that: The number of the paddles (6) is 3-7, and the paddles (6) are evenly distributed along the inner wall of the rotating gear (13).
7. A wafer electroplating device according to claim 6, characterized in that: The paddle (6) is provided with an opening (18).
8. A wafer electroplating device according to claim 1, characterized in that: The rotating assembly comprises a round cup (101), a conical portion (102), a support rod (103), a top plate (104), a main shaft (105) and a motor (106), wherein the motor (106) is connected to the top plate (104), the conical portion (102) is located between the top plate (104) and the round cup (101), and the support rod (103) sequentially connects the top plate (104), the conical portion (102) and the round cup (101).