CN117210911A - Electroplating equipment and electroplating method for improving uniformity of wafer plating layer - Google Patents
Electroplating equipment and electroplating method for improving uniformity of wafer plating layer Download PDFInfo
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- 238000009713 electroplating Methods 0.000 title claims abstract description 100
- 238000007747 plating Methods 0.000 title claims abstract description 49
- 238000000034 method Methods 0.000 title claims abstract description 19
- 238000009792 diffusion process Methods 0.000 claims abstract description 66
- 239000010949 copper Substances 0.000 claims description 28
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 23
- 229910052802 copper Inorganic materials 0.000 claims description 22
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- 229910000365 copper sulfate Inorganic materials 0.000 claims description 5
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 claims description 5
- 229910021645 metal ion Inorganic materials 0.000 claims description 5
- 239000011159 matrix material Substances 0.000 claims description 4
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- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 description 10
- 229910001431 copper ion Inorganic materials 0.000 description 10
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- 229920000915 polyvinyl chloride Polymers 0.000 description 4
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- -1 Hydrogen ions Chemical class 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910000577 Silicon-germanium Inorganic materials 0.000 description 1
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Abstract
The application provides electroplating equipment and an electroplating method for improving the uniformity of a wafer plating layer, wherein the electroplating equipment comprises a diffusion plate provided with a plurality of through holes, the through holes gradually decrease from the center to the edge along the radial direction, so that the resistance at the center of the diffusion plate is smaller than that at the edge, in the electroplating process, the circuit resistance at the center of a wafer is equal to that at the edge of the wafer, the circuit current at the center of the wafer is equal to that at the edge of the wafer, and the thickness of an finally formed electroplated layer is more uniform. Meanwhile, the shape of the diffusion plate is regulated and controlled, and the diffusion plate is designed to be thin in the center and thick in the edge, so that the uniformity of wafer electroplating can be improved. In addition, the baffle ring is arranged above the diffusion plate, so that the current field intensity and the flow field of the edge area are secondarily limited, the metal ion deposition at the edge of the wafer is further inhibited, the uniformity of the thickness of the electroplated layer is improved, and the subsequent grinding difficulty of the electroplated layer is further reduced.
Description
Technical Field
The application relates to the technical field of semiconductor equipment, in particular to electroplating equipment and an electroplating method for improving the uniformity of a wafer plating layer.
Background
Electroless copper plating includes two processes, chemical and electrical. As shown in fig. 1, the basic principle is as follows: immersing a wafer with a barrier layer and a copper seed layer which are grown as a cathode in a copper sulfate solution with the front face facing downwards, pre-placing copper blocks used for supplementing copper ions in the solution as anodes in a plating solution, dissociating the copper ions in the solution from the anodes to the cathode under the action of an externally applied direct current power supply, and obtaining two electrons on the wafer surface of the cathode to form copper atoms to deposit on the seed layer. Anode (Anode) reaction equation: cu=cu 2+ +2e - Cathode (Cathode) reaction equation: cu (Cu) 2+ +2e - ＝Cu。
However, in ECP electroless plating, the greater the current at a point on the wafer, the faster the plating speed at the same additive concentration and constant voltage. Since the current is applied from the edge of the wafer to the center of the wafer, the center of the wafer is more resistive than the edge of the wafer, i.e., R in the figure, than the copper seed layer wafer . As shown in fig. 2, during the electroplating process, the seed layer of the wafer 101 is immersed in the electroplating solution, the wafer 101 is connected to the negative electrode of the power supply 103, and the copper block 102 is connected to the positive electrode of the power supply. For the edge position of the wafer 101, the resistance in the circuit includes the plating solution resistance R electrolyte For the center position of the wafer, the resistor in the circuit except R electrolyte In addition, the resistance value R of the copper seed layer is also included wafer Because the circuit resistance is different, the circuit current passing through the center position of the wafer is smaller than the circuit current passing through the edge position of the wafer, so that the electroplating speed of the edge of the wafer relative to the center of the wafer can be faster, and the thickness of the finally formed electroplated layer is thicker, as shown in a scatter diagram of the thickness of the electroplated layer changing along with the position of the wafer in fig. 3, the positions edge1 and edge2 can be thicker, and the problem of grinding during the subsequent CMP thinning can be caused because the edge of the wafer is too thick.
Therefore, improvements to existing electroplating equipment are needed to improve the uniformity of the wafer surface coating.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, an object of the present application is to provide an electroplating apparatus and an electroplating method for solving the problem of uneven electroplated layer on the surface of a wafer in the prior art.
To achieve the above and other related objects, the present application provides an electroplating apparatus for improving uniformity of a wafer plating layer, the electroplating apparatus includes a cavity, in which an electroplating solution is contained, and an electroplating anode layer and a diffusion plate are sequentially disposed from bottom to top;
the diffusion plate comprises a plurality of annular areas which are concentrically arranged, through holes are uniformly distributed in the circumferential direction in each annular area, and the through holes in the same annular area have the same size; the sizes of the through holes in the adjacent annular areas are sequentially reduced from the center to the edge of the diffusion plate.
Preferably, the electroplating device further comprises an ion membrane layer and a framework layer, wherein the ion membrane layer is arranged between the electroplating anode layer and the diffusion plate, the framework layer is arranged between the ion membrane layer and the diffusion plate, and the framework layer comprises a plurality of reinforcing plates which are arranged along the radial direction and used for supporting and reinforcing the whole device.
Preferably, the cross-sectional shape of the through hole is hexagonal.
Preferably, the diameter of the through holes ranges from 1.2mm to 0.8mm, the diameters of the through holes of adjacent annular areas differ by 0.01-0.02mm, and the number of the annular areas ranges from 50 to 100 circles.
Preferably, the through holes of adjacent annular regions are spaced apart by 0.4-0.6mm, and the spacing between adjacent through holes in the same annular region is 0.3-0.5mm.
Preferably, the thickness of the diffusion plate increases gradually from the center to the edge.
Preferably, the diffusion plate is concave at the upper surface, or concave at the lower surface, or concave at the same time.
Preferably, the diffusion plate further comprises a blocking ring, wherein the blocking ring is concentrically arranged above the edge area of the diffusion plate, and a plurality of cylindrical through holes are uniformly distributed in the blocking ring along the circumferential direction so as to secondarily limit the current field intensity and the flow field of the edge area.
The application also provides an electroplating method for improving the uniformity of the wafer plating layer, which comprises the following steps:
s1: providing a wafer, wherein the surface of the wafer is covered with a seed layer, the wafer is placed in the cavity of the electroplating equipment according to any one of claims 1-8, the wafer is positioned above the diffusion plate, and the seed layer is immersed in the electroplating liquid;
s2: and connecting the wafer to the negative electrode of an external power supply, connecting the electroplating anode layer to the positive electrode of the external power supply, and depositing metal ions in the electroplating solution to the surface of the wafer seed layer through the diffusion plate to form an electroplating layer with uniform thickness.
Preferably, the seed layer is a copper metal layer, the electroplating anode layer is a copper block, and the electroplating solution is a copper sulfate matrix electroplating solution.
As described above, the present application provides a plating apparatus and a plating method for improving the uniformity of a plating layer on a wafer, the plating apparatus includes a diffusion plate having a plurality of through holes formed therethrough, the through holes being gradually reduced from the center to the edge in a radial direction, such that the resistance at the center of the diffusion plate is smaller than the resistance at the edge. Meanwhile, the shape of the diffusion plate is regulated and controlled, and the diffusion plate is designed to be thin in the center and thick in the edge, so that the purpose of improving the electroplating uniformity of the wafer can be achieved. In addition, the application also arranges the baffle ring above the diffusion plate, and a plurality of column-shaped through holes are uniformly distributed in the baffle ring along the circumferential direction, so as to secondarily limit the current field intensity and the flow field of the edge area, further inhibit the metal ion deposition at the edge of the wafer, and facilitate the improvement of the uniformity of the thickness of the electroplated layer, thereby reducing the subsequent grinding difficulty of the electroplated layer.
Drawings
Fig. 1 is a schematic diagram showing the chemical reaction principle of a prior art electroplating process.
Fig. 2 is a simplified circuit schematic of prior art electroplating.
FIG. 3 shows a scatter plot of the thickness of a prior art electroplated layer as a function of wafer position.
Fig. 4 shows a simplified circuit schematic for a prior art arrangement of a high-resistance virtual anode.
FIG. 5 is a schematic view showing the structure of the electroplating apparatus according to the present application.
FIG. 6 is a schematic top view of a diffuser plate according to the present application.
FIG. 7 is a schematic side view of the diffuser plate of the present application with a thick middle thin edge.
FIG. 8 is a schematic view showing the position of the baffle ring in the electroplating apparatus according to the present application.
Fig. 9 is a schematic view showing a structure of a baffle ring in the present application.
FIG. 10 is a simplified circuit schematic of the diffuser plate and blocker ring of the present application.
Description of element reference numerals
11. Electroplating anode layer
12. Ion membrane layer
13. Framework layer
14. Diffusion plate
15. Barrier ring
141. Annular region
142. Through-hole
151. Cylindrical through hole
101. Wafer with a plurality of wafers
102. Copper block
103. Power supply
104. High-resistance virtual anode
Detailed Description
Other advantages and effects of the present application will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present application with reference to specific examples. The application may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present application.
As described in detail in the embodiments of the present application, the cross-sectional view of the device structure is not partially enlarged to a general scale for convenience of explanation, and the schematic drawings are only examples, which should not limit the scope of the present application. In addition, the three-dimensional dimensions of length, width and depth should be included in actual fabrication.
For ease of description, spatially relative terms such as "under", "below", "beneath", "above", "upper" and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. Furthermore, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers or one or more intervening layers may also be present. As used herein, "between … …" is meant to include both endpoints.
In the context of the present application, a structure described as a first feature being "on" a second feature may include embodiments where the first and second features are formed in direct contact, as well as embodiments where additional features are formed between the first and second features, such that the first and second features may not be in direct contact.
It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present application by way of illustration, and only the components related to the present application are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of each component in actual implementation may be changed at will, and the layout of the components may be more complex.
In order to improve the uniformity of electroplated layers, a current-flux-suppressing channel is added to the electroplating solution, and as shown in FIG. 4, a high-resistance virtual anode (HRVA: high Resistance Virtual Anode) is arranged below the wafer, so that the circuit resistance passing through the edge of the wafer is R electrolyte +R h ，R electrolyte R is the resistance of the electroplating solution h The resistance value of the high-resistance virtual anode is R, and the circuit resistance passing through the center of the wafer is R electrolyte +R h +R wafer ，R wafer Is the resistance of the seed layer on the wafer, and R h Far greater than R electrolyte R is R wafer So that R is h The resistance of the wafer is dominant, so that the relative difference between the resistance of the edge of the wafer and the resistance of the center of the wafer is reduced, and the uniformity of the plating layer is improved. The high-resistance virtual anode is a material layer with a through hole, and the through hole enables copper ions to pass upwards and enables electroplating liquid to pass up and down. The arrangement of the high-resistance virtual anode improves the uniformity of the electroplated layer to a certain extent, but still cannot reach an ideal state. Based on the above, the application provides electroplating equipment, which further improves the high-resistance virtual anode and improves the uniformity of an electroplated layer.
Example 1
The present embodiment provides an electroplating apparatus for improving uniformity of a wafer plating layer, as shown in fig. 5 and 6, the electroplating apparatus includes:
the cavity is used for accommodating electroplating liquid, and an electroplating anode layer 11 and a diffusion plate 14 are sequentially arranged in the cavity from bottom to top;
the diffusion plate 14 includes a plurality of annular regions 141 concentrically arranged, through holes 142 are uniformly distributed in the circumferential direction in each annular region 141, and the through holes 142 located in the same annular region 141 have the same size; the through holes 142 of adjacent annular regions 141 decrease in size in sequence from the center to the edge of the diffusion plate 14.
Specifically, the diffusion plate 14 is a high-resistance virtual anode, which is made of PVC polyvinyl chloride material, and the through holes 142 provided therein enable copper ions to pass through upwards and enable electroplating solution to pass through vertically. The diffusion plate is provided with a circle of penetrating through holesThe holes and the through holes are sequentially reduced, that is, the hole area is larger as the hole is closer to the center, which is equivalent to reducing the effective area at the center, so that the resistance at the center of the diffusion plate is smaller than the resistance at the edge, and referring to fig. 4, during electroplating, the circuit resistance at the center of the wafer is R electrolyte +R h +R wafer The circuit resistance across the wafer edge is R electrolyte +R h Due to the arrangement of the through holes in the application, R at the center of the diffusion plate h Less than R at the edge h Finally, the circuit resistance passing through the center of the wafer is equal to the circuit resistance passing through the edge of the wafer, so that the circuit current passing through the center of the wafer is equal to the circuit current passing through the edge of the wafer, the electroplating speed of the edge of the wafer and the center of the wafer is consistent, and the thickness of the finally formed electroplated layer is more uniform. It will be appreciated from another aspect that the larger the central region through hole is, the larger the hole area is, the more ions pass upward, which naturally covers the thicker plating in the central region of the wafer.
Further, the electroplating device further comprises an ion membrane layer 12 and a framework layer 13, the ion membrane layer 12 is arranged between the electroplating anode layer 11 and the diffusion plate 14, the framework layer 13 is arranged between the ion membrane layer 12 and the diffusion plate 14, and the framework layer 13 comprises a plurality of reinforcing plates arranged along the radial direction and used for supporting and reinforcing the whole device. In the electroplating process, the wafer is positioned above the diffusion plate, the seed layer of the wafer is immersed in the electroplating liquid, the seed layer of the wafer is connected with the negative electrode of the external power supply, and the electroplating anode layer is connected with the negative electrode of the external power supply. As an example, the plating solution is a copper sulfate matrix plating solution, and the seed layer is a copper seed layer. The plating solution may also include chloride ions (Cl) - ) Hydrogen ions (H) + ) And other ions. The anode layer is electroplated with copper blocks for supplementing copper ions, and copper ions (Cu) are formed in electroplating solution 2+ ) Copper ion (Cu) 2+ ) A copper plating layer is deposited on the copper seed layer. In other implementations, the plating anode can also be anode made of other materials, and the plating solution can also be electricity of other metal ionsThe plating solution can be used for plating the seed layer, and the seed layer can be made of other materials as long as an electroplated layer can be precipitated on the seed layer. That is, the plating apparatus of the present application is not limited to the plating of copper alone, but may be applied to the plating of other metal layers such as silver without being excessively limited thereto.
Further, the cross-sectional shape of the through-hole 142 is hexagonal, the diameter of the through-hole 142 ranges from 1.2mm to 0.8mm, the diameters of the through-holes of adjacent annular regions differ by 0.01-0.02mm, and the number of annular regions is 50-100 circles. For example, the diameter of the through-hole located at the innermost ring is 1mm, the diameters of the through-holes in adjacent annular regions differ by 0.02mm, and the diameter of the through-hole located at the outermost ring is 0.8mm when the annular region is set to 100 rings. Still further, the through-holes of adjacent annular regions are spaced apart by 0.4 to 0.6mm, that is, the spacing between radially adjacent through-holes is 0.4 to 0.6mm, preferably 0.5mm. The spacing between adjacent through holes in the same annular region is 0.3-0.5mm, preferably 0.4mm. By limiting the above size range, it is advantageous to control the current flow rate (plating rate) and reduce the liquid surface resistance. The thickness of the diffusion plate is 10-20mm. In practical application, the application can also be round, octagonal and other shapes, and the technical purpose of uniform electroplating can be realized as long as the gradual reduction of the radial through hole size is ensured.
Further, in addition to designing the through-holes in the diffusion plate, the diffusion plate 14 itself may be designed to have a thin center and thick edge, so that the resistance in the center area is relatively smaller than that in the edge area, as shown in fig. 7. Since the circuit resistance through the center of the wafer is R electrolyte +R h +R wafer The circuit resistance across the wafer edge is R electrolyte +R h The diffusion plate is arranged with different thickness, so that R at the center of the diffusion plate h Less than R at the edge h Finally, the circuit resistance passing through the center of the wafer is equal to the circuit resistance passing through the edge of the wafer, and the circuit resistance is gradually reduced from the through holeThe same effect is small, and the uniformity of the electroplated layer is ensured. It will be appreciated from another aspect that the center region is thinner than the edge regions, so that ions passing upward are more likely to pass through more, and naturally cover the center region of the wafer with a thicker electroplated layer. The specific shape of the diffusion plate with thin center and thick edge may be a shape with concave upper surface, a shape with concave lower surface, or a shape with concave upper and lower surfaces simultaneously, which is similar to the shape of concave lens, without limitation.
It should be understood that, for the diffusion plate, the design scheme that the size of the through hole is gradually reduced along the radial direction can be adopted independently to realize the uniformity of the wafer electroplating, the design that the center is thin and the edge is thick can also be adopted independently to realize the uniformity of the wafer electroplating, or the two are combined and used simultaneously to promote the uniformity of the wafer electroplating, and the diffusion plate can be selected flexibly according to factors such as operation efficiency, cost, use convenience and the like.
According to the embodiment, through improving the structure of the existing high-resistance virtual anode, the plurality of through holes are formed in the diffusion plate, the through holes gradually decrease from the center to the edge along the radial direction, the resistance at the center of the diffusion plate is smaller than that at the edge, in the electroplating process, the circuit resistance at the center of the wafer is equal to that at the edge of the wafer, the circuit current at the center of the wafer is equal to that at the edge of the wafer, the electroplating speed of the edge of the wafer is consistent with that of the center of the wafer, and the thickness of the finally formed electroplated layer is more uniform. Meanwhile, the shape of the diffusion plate is regulated and controlled, and the diffusion plate is designed to be thin in the center and thick in the edge, so that the purpose of improving the electroplating uniformity of the wafer can be achieved.
Example two
In this embodiment, on the basis of the electroplating apparatus of the first embodiment, a component for suppressing the thickness of the edge plating is further added to improve the uniformity of the plating layer.
Specifically, as shown in fig. 8 and 9, the electroplating apparatus of the present embodiment further includes:
the blocking ring 15 is concentrically arranged above the edge area of the diffusion plate, and a plurality of cylindrical through holes 151 are uniformly distributed in the blocking ring 15 along the circumferential direction and are used for secondarily limiting the current field intensity and the flow field of the edge area,
as shown in FIG. 10, after the baffle ring is added, the circuit resistance through the center of the wafer is R electrolyte +R h +R wafer The circuit resistance across the wafer edge is R electrolyte +R h +Rs, the arrangement of the blocking ring in this embodiment is such that the resistance Rs, rs and R of the blocking ring are introduced into the circuit at the wafer edge wafer After the equivalent, the circuit resistance passing through the center of the wafer is equal to the circuit resistance passing through the edge of the wafer, so that the uniformity of the electroplated layer is ensured. It will be appreciated from another aspect that the addition of the blocking ring further blocks the upward passage of ions, reduces metal ions deposited on the wafer edge, and naturally covers the wafer edge with a thinner electroplated layer, which tends to be uniform throughout the thickness of the electroplated layer.
Similar to the diffusion plate, the blocking ring is also made of PVC polyvinyl chloride material, the number and the size of the cylindrical through holes formed in the blocking ring can be adjusted according to actual needs, in the embodiment, six cylindrical through holes are taken as an example, and the six cylindrical through holes are uniformly distributed; the thickness of the blocking ring is 0.2-5mm, preferably 1mm; the width of the blocking ring is 2-8mm, preferably 4mm, and the diameter of the cylindrical through hole is 0.5-3mm, preferably 1mm. Similar to the diffusion plate, the shape of the cylindrical through holes may be circular, hexagonal, octagonal, etc., without being excessively limited thereto.
Further, besides the blocking ring, a circle of metal coil can be added above the edge area of the diffusion plate, and an electric field in the current generation direction is externally connected, so that the flux of metal cations in the edge area to the surface of the wafer is inhibited under the action of the electric field, the field intensity can be changed by adjusting the magnitude of the externally connected current in the process, and the inhibition capability to the metal cations is regulated and controlled.
Example III
Based on the electroplating apparatus in the first embodiment and the second embodiment, the present embodiment provides a corresponding electroplating method, and in combination with fig. 10, the electroplating method includes the following steps:
s1: providing a wafer 101, wherein the surface of the wafer 101 is covered with a seed layer, the wafer is placed in a cavity of the electroplating equipment, the wafer 101 is positioned above the diffusion plate 14, and the seed layer is immersed in the electroplating liquid:
s2: the wafer 101 is connected to the negative electrode of the external power supply 103, the electroplating anode layer 11 is connected to the positive electrode of the external power supply 103, and metal ions in the electroplating solution pass through the diffusion plate to deposit on the surface of the wafer seed layer to form an electroplating layer with uniform thickness.
Specifically, the wafer includes, but is not limited to, a Si substrate, a Ge substrate, a SiGe substrate, etc., preferably a Si silicon substrate. The main salt of the electroplating solution is salt containing metal ions and is used for providing ions of electrodeposited metal; in addition, the electroplating solution can also comprise conductive salt for increasing the conductivity of the solution, anode active agent for promoting anode dissolution, buffer for regulating and controlling the pH value of the solution, and additive for improving the performance of the plating layer and the electroplating quality. The seed layer and the anode layer are also made of corresponding metal materials according to the metal species to be plated, for example, when copper plating is performed, the seed layer formed on the wafer is a copper metal layer, the anode layer is copper block, the plating solution is copper sulfate matrix plating solution, the anode layer is copper block for supplementing copper ions, and copper ions (Cu 2 + ) Copper ion (Cu 2) + ) A copper plating layer is deposited on the copper seed layer. By utilizing the electroplating equipment, an electroplating layer with more uniform thickness can be obtained, and the subsequent grinding thinning of the electroplating layer is facilitated.
In summary, the present application provides a plating apparatus and a plating method for improving uniformity of a wafer plating layer, where the plating apparatus includes a diffusion plate having a plurality of through holes formed therethrough, the through holes gradually decrease from a center to an edge in a radial direction, so that a resistance at a center of the diffusion plate is smaller than a resistance at the edge. Meanwhile, the shape of the diffusion plate is regulated and controlled, and the diffusion plate is designed to be thin in the center and thick in the edge, so that the purpose of improving the electroplating uniformity of the wafer can be achieved. In addition, the application also arranges the baffle ring above the diffusion plate, and a plurality of column-shaped through holes are uniformly distributed in the baffle ring along the circumferential direction, so as to secondarily limit the current field intensity and the flow field of the edge area, further inhibit the metal ion deposition at the edge of the wafer, and facilitate the improvement of the uniformity of the thickness of the electroplated layer, thereby reducing the subsequent grinding difficulty of the electroplated layer.
The above embodiments are merely illustrative of the principles of the present application and its effectiveness, and are not intended to limit the application. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the application. Accordingly, it is intended that all equivalent modifications and variations of the application be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.
Claims (10)
1. The electroplating equipment for improving the uniformity of the wafer plating layer is characterized by comprising a cavity, wherein the cavity is used for accommodating electroplating liquid, and an electroplating anode layer and a diffusion plate are sequentially arranged in the cavity from bottom to top;
the diffusion plate comprises a plurality of annular areas which are concentrically arranged, through holes are uniformly distributed in the circumferential direction in each annular area, and the through holes in the same annular area have the same size; the sizes of the through holes in the adjacent annular areas are sequentially reduced from the center to the edge of the diffusion plate.
2. The electroplating apparatus for improving uniformity of a wafer plating layer according to claim 1, wherein: the electroplating device further comprises an ion membrane layer and a framework layer, wherein the ion membrane layer is arranged between the electroplating anode layer and the diffusion plate, the framework layer is arranged between the ion membrane layer and the diffusion plate, and the framework layer comprises a plurality of reinforcing plates which are arranged along the radial direction and used for supporting and reinforcing the whole device.
3. The electroplating apparatus for improving uniformity of a wafer plating layer according to claim 1, wherein: the cross section of the through hole is hexagonal.
4. The electroplating apparatus for improving uniformity of a wafer plating layer according to claim 1, wherein: the diameter range of the through holes is 1.2mm-0.8mm, the diameters of the through holes of adjacent annular areas differ by 0.01-0.02mm, and the number of the annular areas is 50-100 circles.
5. The electroplating apparatus for improving uniformity of a wafer plating layer according to claim 1, wherein: the distance between the through holes of adjacent annular areas is 0.4-0.6mm, and the distance between the adjacent through holes in the same annular area is 0.3-0.5mm.
6. The electroplating apparatus for improving uniformity of a wafer plating layer according to claim 1, wherein: the thickness of the diffusion plate gradually increases from the center to the edge.
7. The electroplating apparatus for improving uniformity of a wafer plating layer according to claim 1, wherein: the diffusion plate is concave downwards on the upper surface or concave upwards on the lower surface or concave inwards on both the upper surface and the lower surface.
8. The electroplating apparatus for improving uniformity of a wafer plating layer according to claim 1, wherein: the diffusion plate is characterized by further comprising a blocking ring which is concentrically arranged above the edge area of the diffusion plate, and a plurality of cylindrical through holes are uniformly distributed in the blocking ring along the circumferential direction so as to secondarily limit the current field intensity and the flow field of the edge area.
9. An electroplating method for improving the uniformity of a wafer coating is characterized by comprising the following steps:
s1: providing a wafer, wherein the surface of the wafer is covered with a seed layer, the wafer is placed in the cavity of the electroplating equipment according to any one of claims 1-8, the wafer is positioned above the diffusion plate, and the seed layer is immersed in the electroplating liquid;
s2: and connecting the wafer to the negative electrode of an external power supply, connecting the electroplating anode layer to the positive electrode of the external power supply, and depositing metal ions in the electroplating solution to the surface of the wafer seed layer through the diffusion plate to form an electroplating layer with uniform thickness.
10. The plating method according to claim 9, characterized in that: the seed layer is a copper metal layer, the electroplating anode layer is a copper block, and the electroplating solution is a copper sulfate matrix electroplating solution.
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| CN113388875A (en) * | 2020-07-22 | 2021-09-14 | 台湾积体电路制造股份有限公司 | Electroplating apparatus and method of electroplating a wafer |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113388875A (en) * | 2020-07-22 | 2021-09-14 | 台湾积体电路制造股份有限公司 | Electroplating apparatus and method of electroplating a wafer |
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