Method for improving uniformity of wafer electroplating thickness

Abstract

The present invention provides a method for improving the uniformity of wafer electroplating thickness. The method comprises: electroplating a wafer in an electroplating cavity containing a diffusion plate; measuring the electroplating height of the wafer; inputting the electroplating height into a wafer model, dividing the wafer model into multiple concentric ring areas in a radial direction, and disposing multiple concentric ring areas corresponding to the wafer model on a diffusion plate model, through holes having uniform hole diameters being uniformly distributed on the diffusion plate model; using any electroplating height value as a reference value, calculating the differences between the electroplating height values of other ring areas and the reference value, to determine a rate by which to adjust the electroplating height of each ring area; setting a rate by which to adjust the total area of the through holes of each ring area on the diffusion plate model to be equal to the rate by which to adjust the electroplating height of each ring area, and determining an amount by which to adjust the total area of the through holes in each ring area of the diffusion plate model, so as to obtain an optimized diffusion plate model. The present invention, by means of the optimization of a diffusion plate, improves electroplating quality and enables wafer electroplating thickness to be more uniform.

Description

A method for improving wafer electroplating thickness uniformity Technical Field

[0001] The invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a method for improving the uniformity of wafer electroplating thickness. Background Art

[0002] During the production of semiconductor integrated circuits, the wafer surface is electroplated to form a metal layer. The wafer electroplating process involves placing the wafer in a plating solution, connecting a negative voltage to the wafer as a cathode, and a positive voltage to a soluble or insoluble anode. The electric field causes the metal ions in the plating solution to deposit onto the wafer surface. With the advancement of semiconductor technology, the requirements for wafer surface plating uniformity are becoming increasingly stringent. Even slight variations in plating height can affect wafer quality and yield.

[0003] Summary of the Invention

[0004] In order to achieve high-quality wafer electroplating and improve the thickness uniformity of the electroplated layer, the present invention provides a method for improving the thickness uniformity of wafer electroplating.

[0005] The present invention provides a method for improving the uniformity of wafer electroplating thickness, comprising:

[0006] performing an electroplating process on the wafer in an electroplating chamber provided with a diffusion plate;

[0007] Detect the plating height on the wafer surface after the plating process is completed;

[0008] Inputting the electroplating height into a wafer model, dividing the wafer model into a plurality of concentric ring regions along a radial direction, and setting a plurality of concentric ring regions corresponding to the wafer model on a diffuser plate model corresponding to the diffuser plate, wherein through holes with uniform apertures are evenly distributed on the diffuser plate model;

[0009] Taking the electroplating height value of any ring area of ​​the wafer model as a reference value, calculating the difference between the electroplating height values ​​of other ring areas of the wafer and the reference value, and determining the electroplating height adjustment rate of each ring area of ​​the wafer;

[0010] The total area of ​​the through holes in each ring area on the diffusion plate model is made to be adjusted at a rate equal to the electroplating height adjustment rate of each ring area on the wafer model, and the total area of ​​the through holes in each ring area of ​​the diffusion plate model is determined to obtain an optimized diffusion plate model.

[0011] According to a specific implementation of an embodiment of the present application, the reference value is the maximum value, minimum value or average value of the electroplating height in each ring area of ​​the wafer model.

[0012] According to a specific implementation of an embodiment of the present application, the several concentric ring areas on the wafer model are adjacent to each other and do not overlap with each other, and the common center of the several concentric ring areas on the wafer model is at the center of the wafer model.

[0013] According to a specific implementation method of an embodiment of the present application, it also includes: based on the determined total area value of the through holes in each ring area of ​​the diffusion plate model to be adjusted, when adjusting the total area of ​​the through holes in a certain ring area, the total number of through holes in the ring area is fixed unchanged, and the through holes in the ring area that need to adjust the aperture are defined as second through holes, and the aperture of the second through holes is preset, and the aperture of the second through holes is larger or smaller than the aperture of the first through holes; the number of second through holes in the ring area is calculated so that the adjusted electroplating height of the corresponding ring area of ​​the ring area on the wafer model reaches the reference value.

[0014] According to a specific implementation of the embodiment of the present application, calculating the number of through holes that need to be adjusted in the ring area includes:

[0015] The number n of the second through holes whose apertures need to be adjusted is calculated using the following formula:

[0016] Wherein, n is the number of second through holes whose apertures need to be adjusted;

[0017] s i is the initial total area of ​​the through holes in the ring region;

[0018] h i is the electroplating height of the ring area and the corresponding ring area of ​​the wafer model;

[0019] h0 is the wafer electroplating height reference value;

[0020] r2 is the adjusted radius of the second through hole;

[0021] r1 is the radius of the first through hole in the annular region.

[0022] According to a specific implementation of the embodiment of the present application, the number of through holes that need to be adjusted is less than the number of through holes in the ring area.

[0023] According to a specific implementation method of the embodiment of the present application, the through holes whose apertures need to be adjusted are evenly distributed in the ring area where adjustment is required.

[0024] According to a specific implementation of the embodiment of the present application, the through holes requiring aperture adjustment are evenly distributed in at least two quadrants of the diffuser plate, and the second through holes in each quadrant are symmetrically arranged about the center of the diffuser plate.

[0025] According to a specific implementation method of an embodiment of the present application, it also includes: based on the determined total area value of the through holes in each ring area of ​​the diffusion plate model to be adjusted, when adjusting the total area of ​​the through holes in a certain ring area, the aperture of the through holes in the ring area is fixed unchanged, and the number of through holes required in the ring area is calculated so that the adjusted electroplating height of the corresponding ring area of ​​the ring area on the wafer model reaches the reference value.

[0026] According to a specific implementation of the embodiment of the present application, the calculating the number of through holes required in the ring area includes:

[0027] The number of through holes N required in the ring area is calculated using the following formula 2:

[0028] Where N is the number of through holes required in the adjusted ring area;

[0029] s i is the initial total area of ​​the through holes in the ring region;

[0030] h i is the electroplating height of the ring area and the corresponding ring area of ​​the wafer model;

[0031] h0 is the wafer electroplating height reference value;

[0032] r is the radius of the through hole on the diffuser plate model;

[0033] n0 is the initial number of through holes in the adjusted ring area.

[0034] The method of improving the uniformity of wafer electroplating thickness of the present invention, through the optimization of the diffusion plate in the present invention, helps the electroplating equipment to perform the electroplating process on the wafer, and makes the electroplating thickness of the wafer more uniform.

[0035] At the same time, when optimizing the diffusion plate and adjusting the total area of ​​the through holes in certain areas of the diffusion plate, the apertures of all the through holes in the area are not uniformly adjusted in size. Instead, a certain number of through holes in the area are selected for size adjustment to achieve the purpose of adjusting the total area of ​​the through holes. The method of the present invention can concentrate the sizes that need to be adjusted on a preset number of through holes, which has the advantage of being easy to process and can facilitate the control of processing accuracy, thereby effectively ensuring the uniformity of the electroplating thickness.

[0036] In addition, the present application optimizes the diffusion plate in the electroplating equipment by evenly arranging the through holes that need to adjust the aperture size in the adjustment area of ​​the diffusion plate, or distributing the through holes that need to adjust the aperture size in at least two quadrants of the diffusion plate, and the through holes that adjust the aperture size are symmetrically arranged about the center of the diffusion plate, to ensure that each area of ​​the wafer receives a more suitable flow of plating solution as much as possible during the electroplating process, thereby ensuring the uniformity of the electroplating thickness.

[0037] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings.

[0038] Summary of the Figures

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] FIG1 shows a schematic structural diagram of an electroplating device according to an embodiment of the present invention;

[0041] FIG2 is a schematic flow chart showing a method for improving wafer electroplating thickness uniformity according to an embodiment of the present invention;

[0042] FIG3 shows a schematic diagram of a wafer area division structure according to an embodiment of the present invention;

[0043] FIG4 shows a schematic structural diagram of a diffusion plate according to an embodiment of the present invention;

[0044] FIG5 shows a result of detecting the electroplating height of the wafer surface before the diffusion plate is optimized according to an embodiment of the present invention;

[0045] FIG6 shows a schematic diagram of a second through-hole distribution according to an embodiment of the present invention;

[0046] FIG7 shows another schematic diagram of a second through-hole distribution according to an embodiment of the present invention; and

[0047] FIG8 shows the detection results of the electroplating height on the wafer surface after the diffusion plate is optimized according to an embodiment of the present invention.

[0048] Preferred embodiments of the present invention

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0050] Referring to Figure 1, the electroplating equipment involved in the present invention includes an electroplating chamber 100, a wafer holding device 200 and a diffusion plate 300. The electroplating chamber 100 is configured to accommodate an electroplating solution. The wafer holding device 200 is configured to hold a wafer 400 so that the surface to be plated of the wafer 400 is located in the electroplating solution during the electroplating period. The diffusion plate 300 is disposed in the electroplating chamber 100. During the electroplating process, the electroplating solution is evenly distributed and sprayed onto the surface to be plated of the wafer 400 through the rectifying effect of the diffusion plate 300, so that the electroplating thickness on the surface of the wafer 400 is uniform.

[0051] During the actual process, it is found that the electroplating height on the surface of the wafer 400 is not uniform. Therefore, this application proposes a method for improving the uniformity of the wafer electroplating thickness by optimizing the diffusion plate to improve the uniformity of the wafer electroplating thickness.

[0052] Please refer to Figure 2 for details. The method includes the following steps:

[0053] Step S100: performing an electroplating process on a wafer in an electroplating chamber provided with a diffusion plate.

[0054] Step S200: detecting the electroplating height on the wafer surface after the electroplating process is completed.

[0055] Step S300: input the electroplating height into the wafer model, divide the wafer model into several concentric ring areas along the radial direction of the wafer, and set several concentric ring areas corresponding to the wafer model on the diffusion plate model corresponding to the diffusion plate, and evenly distribute through holes with uniform apertures on the diffusion plate model.

[0056] The wafer model 400' and the diffuser plate model 300' are both digital models. The wafer model 400' and the diffuser plate model 300' are both digital models. The wafer model 400' and the diffuser plate model 300' in the physical system are converted into digital wafer models 400' and diffuser plate models 300' through digital twin technology or 3D modeling technology. They are essentially digital models, and they can be simulated, analyzed and predicted based on the generated digital models.

[0057] When the wafer model 400' is divided into regions, the wafer model 400' is divided into a plurality of concentric ring regions along the radial direction. The plurality of concentric ring regions are adjacent to each other and do not overlap, and the common center of the plurality of concentric ring regions is at the center of the wafer model 400'. Specifically, referring to FIG3 , the divided wafer model 400' includes ring region 401, ring region 402, ring region 403, ring region 404, ring region 405, ring region 406, ring region 407, and ring region 408. Correspondingly, referring to FIG4 , the diffuser plate model 300' includes ring region 301, ring region 302, ring region 303, ring region 304, ring region 305, ring region 306, ring region 307, and ring region 308.

[0058] Step S400: taking the plating height value of any ring area of ​​the wafer model as a reference value, calculating the difference between the plating height values ​​of other ring areas of the wafer and the reference value, and determining the plating height adjustment rate of each ring area of ​​the wafer.

[0059] Specifically, the plating height value of each ring area in the wafer model 400' is obtained, and the resistance height value of any ring area is selected as the reference value. Here, each ring area can only detect one plating height value. As an example, the reference value is the maximum value, minimum value or average value of the plating height of each ring area. When selecting, in order to facilitate the unified adjustment of the diffusion plate, the plating height is preferably selected as the maximum value as the reference value. Exemplarily, the maximum plating height is used as the reference value to determine the area on the wafer model 400' where the reference value is located. In this embodiment, the reference value is in the ring area 401, then the difference between the plating height of the ring area 402, the ring area 403, the ring area 404, the ring area 405, the ring area 406, the ring area 407, and the ring area 408 and the reference value are calculated respectively to determine the plating height adjustment rate of each ring area of ​​the wafer model 400'.

[0060] Among them, the electroplating height adjustment rate

[0061] k i is the adjustment rate of the electroplating height in the selected ring area; h0 is the reference value of the electroplating height; h i It is the electroplating height value of the selected ring area.

[0062] Step S500: Make the total area adjustment rate of the through holes in each ring area on the diffuser plate model equal to the electroplating height adjustment rate of each ring area on the wafer model, and determine the total area adjustment value of the through holes in each ring area of ​​the diffuser plate model to obtain an optimized diffuser plate model.

[0063] The diffuser plate 300 in the physical system is adjusted using the optimized diffuser plate model so that the diffuser plate in the electroplating equipment complies with the scheme involved in the optimized diffuser plate model, thereby ensuring that the electroplating height of each ring area of ​​the wafer reaches the reference value.

[0064] Specifically, the plating height adjustment rate k of each ring area of ​​the wafer model 400' is i The total area of ​​the holes in each ring region on the diffuser plate model 300' is to be adjusted by the rate k m Equal(k i =k m ) principle, the total area of ​​the through holes in each ring area of ​​the diffuser plate model 300' is adjusted. Among them, when calculating the total area of ​​the through holes in each ring area to be adjusted, the total area of ​​the through holes in the selected ring area to be adjusted is calculated. Δs is the total area of ​​the through holes in the ring area to be adjusted; s i The total area of ​​the holes in the ring region is the initial total area. m *s i =k i *s i .

[0065] It should be understood that the total area of ​​the through holes in each ring region may be adjusted by adjusting the aperture size of the through holes in the ring region, or by adjusting the number of the through holes in the ring region.

[0066] For example, in one embodiment, when adjusting the total area of ​​through-holes in a ring region of the diffuser plate model 300', the total number of through-holes in the ring region is fixed, and the through-holes in the ring region that require aperture adjustment are defined as second through-holes. The aperture of the second through-holes is preset, and the aperture of the second through-holes is larger or smaller than the aperture of the first through-holes. The number of second through-holes in the ring region is then calculated so that the adjusted electroplating height of the corresponding ring region of the ring region on the wafer model 400' reaches the reference value. The number n of second through-holes that require aperture adjustment is calculated using the following formula 1:

[0067] Wherein, n is the number of second through holes whose apertures need to be adjusted;

[0068] s i is the initial total area of ​​the through holes in the ring region;

[0069] h i is the electroplating height of the ring area and the corresponding ring area of ​​the wafer model;

[0070] h0 is the wafer electroplating height reference value;

[0071] r2 is the adjusted radius of the second through hole;

[0072] r1 is the radius of the first through hole in the annular region.

[0073] It should be understood that when the plating height of a certain ring area on the wafer model 400' is to be adjusted by the rate k i When it is 0, the plating height of the ring area does not need to be adjusted. Correspondingly, the total area of ​​the through holes in the ring area of ​​the diffusion plate model 300' is to be adjusted. mIf it is also 0, then the number n of through-holes that need to be adjusted in the ring area is 0, indicating that the total through-hole area of ​​the ring area does not need to be adjusted. Referring to Figure 5, in the embodiment of the present invention, the ring area 301 of the diffusion plate model 300' is the ring area corresponding to the ring area where the reference value of the wafer model 400' is located. The total through-hole area of ​​the ring area 301 does not need to be adjusted. The electroplating heights of the ring areas 402, 403, 404, 405, 406, and 407 of the wafer 400 are equal to the electroplating height of the ring area 401, that is, the electroplating height adjustment rate k of the ring areas 402, 403, 404, 405, 406, and 407 is i = 0, the plating height within these ring regions does not need to be adjusted. Therefore, the total through-hole area within ring regions 302, 303, 304, 305, 306, and 307 of diffuser plate model 300' does not need to be adjusted. However, the plating height within ring region 408 of wafer model 400' differs from the reference value and needs to be adjusted to the reference value. Therefore, the total through-hole area of ​​ring region 308 of diffuser plate model 300' is adjusted. The specific adjustment method is based on the above-mentioned steps S400 and S500 and is not detailed here. After calculating the number of second through holes that need to be adjusted, adjustments are made within the annular region 308 of the diffuser plate model 300'. During the adjustments, the through holes whose apertures need to be adjusted are evenly distributed within the annular region of the adjusted annular region to ensure that the diffuser plate prepared according to the optimized diffuser plate model can provide a corresponding flow rate of plating solution to the plating surface of the wafer 400 during the electroplating process, so that the plating height of the plating surface of the wafer 400 is more uniform. For example, after determining that the number of second through holes whose apertures need to be adjusted within the annular region 308 is n=8, the specified number of second through holes 3081 are evenly distributed within the annular region 308, as shown in Figure 6. It should be understood that after obtaining the optimized diffuser plate model, the diffuser plate 300 can be actually processed in accordance with the optimized diffuser plate model in the physical system, or a new diffuser plate 300 that meets the optimization scheme can be re-prepared.

[0074] In another embodiment, in order to facilitate processing and manufacturing and further ensure the uniformity of electroplating, the second through holes 3081 whose apertures need to be adjusted are evenly distributed in at least two quadrants of the annular region (the annular region 308 in this embodiment) of the diffuser plate 300 where the total through hole area needs to be adjusted, and the second through holes 3081 in the annular region for adjusting the total through hole area are symmetrically arranged about the center of the diffuser plate 300. Therefore, when the diffuser plate model 300' is used for simulation analysis, the second through holes 3081 whose apertures need to be adjusted are evenly distributed in at least two quadrants of the annular region (the annular region 308 in this embodiment) of the diffuser plate model 300' where the total through hole area needs to be adjusted, and the second through holes 3081 in the annular region for adjusting the total through hole area are symmetrically arranged about the center of the diffuser plate model 300'. Please refer to Figure 7 for details.

[0075] Furthermore, in order to facilitate processing and manufacturing, it is required that the number of through holes that need to be adjusted in size in each ring area is less than the total number of through holes in the ring area.

[0076] Please refer to Figure 8. After the above-mentioned adjustment of the total area of ​​the through holes in the ring area 408 of the diffuser plate model 300' and the uniform distribution of the second through holes that need to adjust the aperture in the pattern of Figure 7, the diffuser plate 300 prepared according to the optimized diffuser plate model 300' is placed in the electroplating equipment and the wafer is re-electroplated. The electroplating height of the surface of the wafer 400 is detected. The detection result of the electroplating height of the surface of the wafer 400 is shown in Figure 8. It can be seen that the electroplating height of the electroplated surface of the wafer 400 by the optimized electroplating equipment is more uniform, the uniformity of the electroplating thickness is effectively improved, and the electroplating quality is further improved.

[0077] In this embodiment, when optimizing the diffuser plate model and adjusting the total through-hole area of ​​certain annular regions within the diffuser plate model, the apertures of all through-holes in the annular region are not uniformly adjusted. Instead, the sizes of a specific number of through-holes within the annular region are selectively adjusted to achieve the purpose of adjusting the total through-hole area. The method of the present invention allows the required dimensions to be concentrated on a preset number of through-holes, facilitating actual processing of the diffuser plate in a physical system and facilitating control of processing precision, thereby effectively ensuring uniformity in electroplating thickness.

[0078] In addition, the present application chooses to evenly arrange the through holes that need to adjust the aperture size in the adjustment ring area of ​​the diffuser plate model, or distribute the through holes that need to adjust the aperture size in at least two quadrants of the diffuser plate model, and the through holes for adjusting the aperture size are arranged symmetrically about the center of the diffuser plate model. This can ensure that the diffuser plate prepared according to the optimized diffuser plate model can receive a more suitable flow of plating solution as much as possible during the electroplating process of the wafer, thereby further ensuring the uniformity of the electroplating thickness.

[0079] In another embodiment, when adjusting the total area of ​​through-holes in a ring region, the diameter of the through-holes in the ring region is fixed, and the number of through-holes that need to be adjusted in the ring region is calculated so that the adjusted electroplating height of the corresponding ring region on the wafer model 400' reaches the reference value. The following formula 2 is used to calculate the number N of through-holes that need to be adjusted in the ring region:

[0080] Where N is the number of through holes required in the adjusted ring area;

[0081] s i is the initial total area of ​​the through holes in the ring region;

[0082] h i is the electroplating height of the ring area and the corresponding ring area of ​​the wafer model;

[0083] h0 is the wafer electroplating height reference value;

[0084] r is the radius of the through hole on the diffuser plate model;

[0085] n0 is the initial number of through holes in the adjusted ring area.

[0086] After calculating the number N of through holes required in the adjusted ring region, adjustments are made based on the initial number n0 of through holes in the adjusted ring region. For example, if the number N of through holes required in the adjusted ring region is 105 and the initial number n0 of through holes in the adjusted ring region is 100, then when adjusting the through hole area of ​​the adjusted ring region, the number of through holes in the adjusted ring region needs to be adjusted from 100 to 105.

[0087] By optimizing the diffusion plate model in the present invention, that is, optimizing the structure of the diffusion plate in the physical system, it is helpful for the electroplating equipment to perform the electroplating process on the wafer to improve the electroplating effect and make the electroplating thickness of the wafer more uniform.

[0088] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements 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 method for improving the uniformity of wafer electroplating thickness, characterized in that: include: Performing an electroplating process on a wafer in an electroplating chamber provided with a diffusion plate; Detect the electroplating height on the wafer surface after the electroplating process is completed; Inputting the electroplating height into a wafer model, dividing the wafer model into a plurality of concentric ring regions along a radial direction, and setting a plurality of concentric ring regions corresponding to the wafer model on a diffusion plate model corresponding to the diffusion plate, wherein through holes with uniform apertures are evenly distributed on the diffusion plate model; Taking the electroplating height value of any ring area of ​​the wafer model as a reference value, calculating the difference between the electroplating height values ​​of other ring areas of the wafer and the reference value, and determining the electroplating height adjustment rate of each ring area of ​​the wafer; The total area adjustment rate of each ring area through hole on the diffusion plate model is made equal to the electroplating height adjustment rate of each ring area on the wafer model, and the total area adjustment value of the through holes in each ring area of ​​the diffusion plate model is determined to obtain an optimized diffusion plate model.

2. The method for improving the uniformity of wafer electroplating thickness according to claim 1, characterized in that: The reference value is the maximum value, minimum value or average value of the electroplating height in each ring area of ​​the wafer model.

3. The method for improving the uniformity of wafer electroplating thickness according to claim 1, characterized in that: The plurality of concentric ring regions on the wafer model are adjacent to each other and do not overlap each other, and the common center of the plurality of concentric ring regions on the wafer model is at the center of the wafer model.

4. The method for improving the uniformity of wafer electroplating thickness according to claim 1, characterized in that: Also includes: Based on the determined value of the total area of ​​the through holes in each ring area of ​​the diffusion plate model to be adjusted, when the total area of ​​the through holes in a certain ring area is adjusted, the total number of through holes in the ring area is fixed unchanged, and the through holes in the ring area that need to adjust the aperture are defined as second through holes, and the aperture of the second through holes is preset, and the aperture of the second through holes is larger or smaller than the aperture of the first through holes; the number of second through holes in the ring area is calculated so that the adjusted electroplating height of the corresponding ring area of ​​the ring area on the wafer model reaches the reference value.

5. The method for improving the uniformity of wafer electroplating thickness according to claim 4, characterized in that: The calculating the number of through holes that need to be adjusted in the ring area includes: The number n of the second through holes whose apertures need to be adjusted is calculated using the following formula: Wherein, n is the number of second through holes whose apertures need to be adjusted; s i is the initial total area of ​​the through holes in the ring region; h i is the electroplating height of the ring area and the corresponding ring area of ​​the wafer model; h0 is the wafer electroplating height reference value; r2 is the radius of the second through hole after adjustment; r1 is the radius of the first through hole in the ring area.

6. The method for improving the uniformity of wafer electroplating thickness according to claim 5, characterized in that: The number of through holes that need to be adjusted is less than the number of through holes in the ring area.

7. The method for improving the uniformity of wafer electroplating thickness according to claim 6, characterized in that: The method also includes uniformly distributing the through holes whose apertures need to be adjusted in the ring area where the adjustment is needed.

8. The method for improving the uniformity of wafer electroplating thickness according to claim 6, characterized in that: The method also includes uniformly distributing the through holes whose apertures need to be adjusted in at least two quadrants of the diffuser plate, and the second through holes in each quadrant are symmetrically arranged about the center of the diffuser plate.

9. The method for improving the uniformity of wafer electroplating thickness according to claim 1, characterized in that: Also includes: Based on the determined value of the total area of ​​the through holes in each ring area of ​​the diffusion plate model to be adjusted, when adjusting the total area of ​​the through holes in a certain ring area, the aperture of the through holes in the ring area is fixed unchanged, and the number of through holes required in the ring area is calculated so that the adjusted electroplating height of the corresponding ring area of ​​the ring area on the wafer model reaches the reference value.

10. The method for improving the uniformity of wafer electroplating thickness according to claim 9, characterized in that: The calculating the number of through holes required in the ring area includes: The number of through holes N required in the ring area is calculated using the following formula 2: Wherein, N is the number of through holes required in the adjusted ring area; s i is the initial total area of ​​the through holes in the ring region; h i is the electroplating height of the ring area and the corresponding ring area of ​​the wafer model; h0 is the wafer electroplating height reference value; r is the radius of the through hole on the diffuser plate model; n0 is the initial number of through holes in the adjusted ring area.

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