Patent Application
20240044037
The present invention relates to semiconductor fabrication, more specifically, to a uniform flow control agitation device for electroplating.
Electroplating is a process of depositing a thin layer of other metals or alloys onto certain metal surfaces using electrolysis. This technique has been widely used in various fields, ranging from its initial use for aesthetic decoration purposes, such as forming a shiny film on the surface of containers, to its application in high-tech industries where it has become an indispensable technology.
In the semiconductor industry, electroplating is used to form metal coatings on wafers, including gold, copper, lead-tin alloy, and others. To achieve high-quality results, it is crucial that the surface of the wafer is free of bubbles when immersed in the electroplating solution. However, the input of the solution into the electroplating tank can cause fluctuations that create bubbles on the wafer surface, thereby compromising the electroplating quality.
Therefore, a device that can eliminate these fluctuations is urgently needed to ensure the high-quality electroplating of wafers.
The object of the present invention is to provide a uniform flow control agitation device for electroplating, which solves technical problems encountered in prior devices. The uniform flow control agitation device effectively eliminates fluctuations in the electroplating solution during the electroplating process, thereby preventing the formation of bubbles on the wafer's surface and ensuring a high-quality electroplated coating,
To achieve the above object, the present invention provides a uniform flow control agitation device for electroplating, which comprises: an electroplating tank, a horizontally arranged flow-uniformization plate in the electroplating tank, and a driving unit that can rotate the flow-uniformization plate in the electroplating tank. The rotation of the flow-uniformization plate can effectively eliminate the fluctuation of the electroplating solution during electroplating, thus preventing bubbles from forming on the wafer's surface. Additionally, the rotation of the flow-uniformization plate can also promote ion movement in the electroplating solution and increase the uniformity of the electrodeposit coating on the wafer's surface.
Further, in different embodiments, the uniform flow control agitation device for electroplating further comprises a driven assembly, which includes: a drive gear connected to the driving unit to receive the output motions; and a driven gear that is in meshing engagement with the drive gear and is coupled to the flow-uniformization plate.
Further, in different embodiments, the driving unit is a stepper motor with a driving output gear installed on its output shaft, and the driven assembly further includes a driving input gear and a transmission shaft, with the driving input gear and drive gear mounted on the transmission shaft; the driving output gear meshes with the driving input gear. In these embodiments, the output shaft of the stepper motor drives the transmission shaft through the driving output gear and the driving input gear, such a structural design allows the stepper motor and the transmission shaft to be arranged left and right, thus making the uniform flow control agitation device has a simpler structure and a smaller volume.
Further, in different embodiments, the flow-uniformization plate is provided with multiple flow-guiding regions, and each flow-guiding region has one or more flow-guiding openings in its length direction; and a first and second flow-guiding wall are formed on either side of each flow-guiding region, extending upward to guide the flow of the electroplating solution and further reduce fluctuation and bubble formation.
Further, in different embodiments, the height of the first flow-guiding wall and the second flow-guiding wall is between 6 mm and 8 mm, this height range allows the walls to provide the best guidance, with an optimal value of 7 mm.
Further, in different embodiments, the first flow-guiding wall and the second flow-guiding wall are inclined to effectively reduce the bubbles generated by back pressure when the flow-uniformization plate rotates and to reduce the dead zone in the central flow field of the wafer.
Further, in different embodiments, the angle between the first flow-guiding wall and the second flow-guiding wall is between 38° and 42°, with an optimal value of 40°.
To achieve the above object, the present invention also provides a uniform flow control agitation device for electroplating, which comprises: an electroplating tank; a first and a second flow-uniformization plates horizontally arranged in the electroplating tank, with the first plate positioned directly above the second plate; a driving unit that can rotate the first and second flow-uniformization plates in the electroplating tank at different speeds, thereby eliminating electroplating solution fluctuations and preventing bubbles from forming on the wafer's surface. The rotation of the plates also promotes ion movement in the electroplating solution, resulting in a more uniform electrodeposit coating on the wafer.
Further, in different embodiments, the driving unit can rotate the plates in opposite directions. It is worth noting that when the first and second flow-uniformization plates rotate in opposite directions, they are considered to have a rotation speed difference regardless of the absolute values of their rotation speeds.
Further, in different embodiments, the driving unit can rotate the first and second. flow-uniformization plates in the same direction but at different rotation speeds.
Further, in different embodiments, the driving unit can rotate the plates at a fixed speed difference throughout the electroplating process to maintain a stable electroplating solution and reduce bubble formation.
Further, in different embodiments, the uniform flow control agitation device for electroplating further comprises a control unit that adjusts the rotation speed difference between the plates according to the electroplating thickness of the wafer. This design can better meet the plating requirements and improve the plating quality.
Further, in different embodiments, the driving unit includes a driving source, such as a stepper motor, that simultaneously rotates the first and second flow-uniformization plates.
Further, in different embodiments, the uniform flow control agitation device for electroplating further comprises a driven assembly, which includes: a transmission shaft connected to the driving unit to receive the output motions; a first drive gear and a second drive gear set on the transmission shaft, with the first drive gear meshing with a tumbler gear; a first driven gear in meshing engagement with the tumbler gear and coupled to the first flow-uniformization plate; and a second driven gear in meshing engagement with the second drive gear and coupled to the second flow-uniformization plate.
Further, in different embodiments, the driving unit is a stepper motor with a driving output gear installed on its output shaft; and the driven assembly further includes a driving input gear set on the transmission shaft, with the driving output gear meshing with the driving input gear. Such a design allows the stepper motor and the transmission shaft to be arranged left and right, which simplifies the structure and reduces the volume of the uniform flow control agitation device.
Further, in different embodiments, the driving unit comprises a first driving source and a second driving source, which respectively rotate the first and second flow-uniformization plates. The driving sources can be stepper motors, servo motors, cylinders, or other types of motors, and they can drive the plates directly or indirectly. If the plates are indirectly driven, this can be accomplished through gear-driven assemblies, cam ejector driven assemblies, crankshaft driven assemblies, and other mechanisms.
Further, in different embodiments, the first flow-uniformization plate is provided with multiple flow-guiding regions, each flow-guiding region has one or more flow-guiding openings in its length direction; both sides of each flow-guiding region extend upward to form a first flow-guiding wall and a second flow-guiding wall. The flow-guiding walls can guide the flow of the electroplating solution, so as to further reduce the fluctuation of the electroplating solution, and avoid bubbles on the surface of the wafer.
Further, in different embodiments, the height of the first flow-guiding wall and the second flow-guiding wall is between 6 mm and 8 mm, which allows the flow-guiding walls to play the best guiding role, with 7 mm being the optimal value.
Further, in different embodiments, the first flow-guiding wall and the second flow-guiding wall are inclined, such design can effectively reduce the bubbles generated by the back pressure when the flow-uniformization plate rotates, and reduce the dead zone of the central flow field of the wafer.
Further, in different embodiments, the angle between the first flow-guiding wall and the second flow-guiding wall is between 38° and 42°, with an optimal value of 40°.
Further, in different embodiments, the second flow-uniformization plate is provided with multiple radially distributed flow-guiding openings.
Further, in different embodiments, the first and second flow-uniformization plates have a circular shape, with their rotation centers located on a vertical axis. This circular design reduces resistance when the plates rotate in the electroplating solution, effectively eliminating solution fluctuation and preventing bubbles from forming on the wafer's surface, as compared to other plate shapes.
Compared to the prior art, the present invention has the following beneficial effects:
The present invention provides a uniform flow control agitation device for electroplating, which involves the rotation of one or two flow-uniformization plates within an electroplating tank. This design effectively eliminates fluctuations in the electroplating solution during the electroplating process, thereby preventing bubbles from forming on the surface of the wafer. Simultaneously, the rotation of the flow-uniformization plates promotes the movement of ions in the electroplating solution, resulting in greater uniformity in the electrodeposit coating on the wafer's surface.
Various exemplary embodiments are described herein by way of example in conjunction with the following Figures, wherein:
The present invention will be described more fully for those skilled in the art hereinafter with reference to the accompanying drawings by introducing some of the preferable embodiments of the present invention, for the purpose of clarity and better understanding of the techniques. This invention may be embodied in various different forms and the invention should not be construed as being limited to the embodiments set forth herein.
In the description, elements with identical structures are marked with the same reference numerals, and like elements with similar structure or function are marked to throughout with like reference numerals, respectively. The dimension and thickness of each of the elements in the accompanying drawings are arbitrarily shown, and the invention does not define the dimension and thickness of each element. Certain elements may be shown somewhat exaggerated in thickness in the interest of clarity.
Directional relative terms mentioned in the present invention, such as “upper”, “lower”, “front”, “back”, “left”, “right”, “inside”, “outside”, “side”, and the like, are only directions by referring to the accompanying drawings, and are merely used to explain and describe the present invention, but the present invention is not limited thereto.
It will be understood that when an element is referred to as being “on/above” another element, it can be directly placed on the other element, or there may be an intermediate element on which it is placed, and the intermediate element is placed on the other element. When an element is referred to as being “mounted to” or “connected to” another element, either one can be understood as being directly “mounted” or “connected”, or via an intermediate element to be indirectly “mounted to” or “connected to” the other element.
As shown in
The rotation speed of the flow-uniformization plate 20 in the electroplating tank 4 can be designed in a fixed mode, that is, the flow-uniformization plate 20 always rotates at the same speed under the drive of the driving unit 1, so that the electroplating solution can maintain a stable state throughout the plating process, further reducing the possibility of bubbles generation. Of course, users can also design the rotation speed of the flow-uniformization plate 20 in the electroplating tank 4 as an adjustable mode according to actual needs. Specifically, a control unit can be set up, which can adjust the rotation speed of the flow-uniformization plate 20 based on the plating thickness of the wafer, thereby better meeting the actual plating requirements and improve the plating quality.
In the present embodiment, the driving unit 1 rotates the flow-uniformization plate 20 in the electroplating tank 4 through the driven assembly 18. Specifically, as shown in
When the output shaft of the stepper motor rotates, it drives the driving output gear to rotate, which in turn drives the driving input gear. The driving input gear then drives the transmission shaft 5 to rotate, which further rotates the drive gear 31. The driven gear 32 meshes with the drive gear 31 and receives its motions, thus driving the rotation of the flow-uniformization plate 20.
As shown in
As shown in
Furthermore, as shown in
As shown in
Specifically, as shown in
The first and second flow-uniformization plates 2,3 are horizontally arranged in the electroplating tank 4, with the first plate 2 positioned directly above the second plate 3, and the driving unit 1 can rotate the plates 2,3 in the electroplating tank 4 at different speeds. This design can effectively reduce fluctuations in the electroplating solution during electroplating and prevent bubbles from forming on the surface of the wafer. Moreover, the rotation of the plates 2,3 can also promote ion movement in the electroplating solution and enhance the uniformity of the electrodeposit coating on the wafer's surface.
The first flow-uniformization plate 2 and the second flow-uniformization plate 3 can have a rotation speed difference by either of the following two ways: first, the two plates 2,3 rotate in the same direction, but their rotation speeds are different, thus creating a relative rotation speed difference; second, the two plates 2,3 rotate in opposite directions, and in this case, they also have a relative rotation speed difference due to the direction of the rotation speed, regardless of whether the absolute values of their rotation speeds are the same or not.
Furthermore, the rotation speed difference between the first flow-uniformization plate 2 and the second flow-uniformization plate 3 in the electroplating tank 4 can be designed to be in a fixed mode, where the first and the second flow-uniformization plates 2,3 always rotate at the same speed difference under the drive of the driving unit 1, thus maintaining a stable state of the electroplating solution throughout the electroplating process and further reducing the possibility of bubble generation.
Of course, users can also design the rotation speed difference between the first flow-uniformization plate 2 and the second flow-uniformization plate 3 in the electroplating tank 4 to be adjustable. Specifically, a control unit can be set up to adjust the rotation speed difference of the first and the second flow-uniformization plates 2,3 based on the electroplating thickness of the wafer, which can better meet the actual electroplating needs and improve the plating quality.
The driving unit 1 can include a driving source that simultaneously drives the first flow-uniformization plate 2 and the second flow-uniformization plate 3 to rotate through transmission components such as gears. Using the same driving source to drive the rotation of the first and second flow-uniformization plates 2,3 can simplify the structure of the device. Of course, to facilitate the adjustment of the rotation speed and direction of the first and second flow-uniformization plates 2,3, users can also set up two driving sources to drive them separately.
As a preferred embodiment, the driving unit 1 includes only one driving source, which drives the first flow-uniformization plate 2 and the second flow-uniformization plate 3 to rotate at a fixed speed difference in opposite directions through the driven assembly 18. Specifically, the driving unit 1 is a stepper motor, and a driving output gear is provided on the output shaft of the stepper motor.
As shown in
The first drive gear 7 engages with the tumbler gear 6, the tumbler gear 6 engages with the first driven gear 9, and the first driven gear 9 is coupled to the first flow-uniformization plate 2. The second drive gear 8 engages with the second driven gear 10, and the second driven gear 10 is coupled to the second flow-uniformization plate 3.
With the above design, when the first drive gear 7 and the second drive gear 8 rotate under the driving of the transmission shaft 5, the second drive gear 8 drives the second driven gear 10 engaged with it to rotate, and the second driven gear 10 further drives the second flow-uniformization plate 3 to rotate. At the same time, the first drive gear 7 drives the tumbler gear 6 engaged with it to rotate, and the tumbler gear 6 changes the rotation direction of the output of the transmission shaft 5, causing the first driven gear 9 engaged with it to rotate in the direction opposite to the rotation direction of the second driven gear 10. The first driven gear 9 then further drives the first flow-uniformization plate 2 to rotate. Therefore, the first flow-uniformization plate 2 and the second flow-uniformization plate 3 rotate in opposite directions at a fixed speed difference.
The rotation speed difference between the first flow-uniformization plate 2 and the second flow-uniformization plate 3 can be adjusted by changing the number of teeth or the diameter of the tumbler gear 6.
Further, regarding the structural design of the first flow-uniformization plate 2 and the second flow-uniformization plate 3, as shown in
Furthermore, a plurality of flow-uniformization openings 16 are uniformly arranged on both the first and second flow-uniformization plates 2,3. The term “uniformly arranged” refers to the flow-uniformization openings 16 arranged in an array, concentric circles, or radical distribution. The uniform arrangement of flow-uniformization openings 16 helps to increase the uniformity of the plating solution.
As a more preferred embodiment, the first flow-uniformization plate 2 of this embodiment adopts the same structural design as that of the flow-uniformization plate 20 described in the first embodiment, as shown in
In addition, as shown in
Regarding the design of the second flow-uniformization plate 3, as shown in
The above are only the preferable embodiments of the present invention. Without departing from the principles of the present invention, persons skilled in the art can further make improvements and polishments to the above technical solutions. Such improvements and polishments shall be within the protection scope of the present invention. It is worth noting that the uniform flow control agitation device of the present invention can comprise one or two or more flow-uniformization plates.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022109251673 | Aug 2022 | CN | national |
