阅读说明：本技术 一种晶圆电镀方法及晶圆电镀设备 (Wafer electroplating method and wafer electroplating equipment ) 是由 史蒂文·贺·汪 周志伟 于 2021-10-21 设计创作，主要内容包括：本发明提供了一种晶圆电镀方法及晶圆电镀设备,其中,晶圆电镀方法包括如下步骤：S10、将晶圆划分为多个电镀区域,计算各个电镀区域所需电量值；S20、控制晶圆夹具将晶圆放入电镀槽,控制供电装置向各个电镀区域单独供电；S30、当向某电镀区域提供的电量值累积到所需电量值时,切断对该电镀区域的供电,直至切断对所有电镀区域的供电,取出晶圆。本发明将晶圆的待镀区域划分成多个电镀区域,并为每个电镀区域配置一个供电装置进行供电,由此实现了对晶圆的分区电镀和电镀参数的单独控制,本发明可通过对各个电镀区域供电量的选择,使各个电镀区域的镀层厚度相同,从而达到电镀均匀性的要求,提升电镀品质。(The invention provides a wafer electroplating method and wafer electroplating equipment, wherein the wafer electroplating method comprises the following steps: s10, dividing the wafer into a plurality of electroplating areas, and calculating the electric quantity value required by each electroplating area; s20, controlling the wafer clamp to place the wafer into the electroplating bath, and controlling the power supply device to independently supply power to each electroplating area; and S30, when the electric quantity value supplied to a certain electroplating area is accumulated to the required electric quantity value, cutting off the power supply to the electroplating area until the power supply to all the electroplating areas is cut off, and taking out the wafer. The invention divides the area of the wafer to be plated into a plurality of electroplating areas, and allocates a power supply device for each electroplating area to supply power, thereby realizing the independent control of the subarea electroplating and the electroplating parameters of the wafer.)

1. A wafer electroplating method is characterized by comprising the following steps:

s10, dividing the wafer into a plurality of electroplating areas, and calculating the electric quantity value required by each electroplating area;

s20, controlling the wafer clamp to place the wafer into the electroplating bath, and controlling the power supply device to independently supply power to each electroplating area;

and S30, when the electric quantity value supplied to a certain electroplating area is accumulated to the required electric quantity value, cutting off the power supply to the electroplating area until the power supply to all the electroplating areas is cut off, and taking out the wafer.

2. The wafer plating method as claimed in claim 1, wherein in step S10, the required electric quantity value is a theoretical required electric quantity value, and the calculation formula of the theoretical required electric quantity value is: the theoretical required electrical value (preset coating thickness metal density plated area)/(electrochemical equivalent current efficiency).

3. The wafer plating method as claimed in claim 1, wherein in step S10, the required electric quantity value is an actual required electric quantity value, and the calculation formula of the actual required electric quantity value is: the actual required electric quantity value (preset coating thickness metal density plating area) a/(electrochemical equivalent current efficiency), and a is a correction coefficient.

4. The wafer electroplating method as claimed in claim 3, wherein the correction coefficient a is calculated by: a ═ actual coating thickness/preset coating thickness.

5. The wafer plating method as claimed in claim 1, wherein in step S10, the wafer is divided into a plurality of plating areas by the following method: providing a plurality of power supply devices, wherein the cathodes of the plurality of power supply devices are connected with the wafer clamp, and the anodes of the plurality of power supply devices are connected with an anode assembly arranged in the electroplating bath; the anode assembly comprises a plurality of anode bodies, and anodes of the power supply devices are respectively connected with the anode bodies in a one-to-one correspondence manner.

6. The wafer plating method as claimed in claim 5, wherein the power supply devices are rectifiers, the number of the rectifiers is the same as the number of the anode bodies, the negative electrode of each rectifier is electrically connected with the wafer holder, and the positive electrode is electrically connected with the corresponding anode body.

7. A method of electroplating a wafer according to claim 6, comprising the steps of:

s10: dividing the wafer into a plurality of electroplating areas, calculating the electric quantity value required by each electroplating area, and according to a formula: determining the current and time required by each electroplating area;

s20, inputting the determined current and time into the rectifiers which correspondingly supply power to each electroplating area, controlling the wafer clamp to put the wafer into the electroplating bath, and starting each rectifier;

and S30, collecting the feedback current of each electroplating area in real time, accumulating the electric quantity value, and when the accumulated electric quantity value reaches the required electric quantity value, closing the corresponding power supply rectifier of the electroplating area until all the rectifiers are closed, and taking out the wafer.

8. The wafer plating method as claimed in claim 1, wherein the wafer plating method is adapted for horizontal plating or vertical plating.

9. A wafer plating apparatus for carrying out the wafer plating method according to any one of claims 1 to 8, comprising a driving device, a plating tank, a wafer holder, and a power supply device; the driving device is connected with the wafer clamp and can drive the wafer clamp to move into or out of the electroplating bath;

the electroplating bath is internally provided with an anode assembly, the anode assembly comprises a plurality of anode bodies, the number of the power supply devices is multiple, the cathodes of the power supply devices are electrically connected with the wafer clamp, and the anodes of the power supply devices are respectively connected with the anode bodies in a one-to-one correspondence manner.

10. The wafer plating apparatus as claimed in claim 9, wherein the plurality of anode bodies are coaxially disposed and nested with each other, and adjacent anode bodies are separated from each other by an insulating layer.

11. The wafer plating apparatus as claimed in claim 9, further comprising a controller connected to the plurality of power supply devices for controlling the power supply devices to supply or cut off power to the anode body electrically connected to the anode thereof.

12. The wafer plating apparatus as claimed in claim 11, wherein the controller comprises a storage unit for storing plating parameters of the wafer plating apparatus.

13. The wafer plating apparatus as claimed in claim 12, wherein the controller further comprises a determining unit for determining whether the amount of power supplied by the power supply device reaches a desired amount of power in real time, and automatically cutting off the power supply device when the determination is reached.

Technical Field

The invention relates to the technical field of electroplating, in particular to a wafer electroplating method and wafer electroplating equipment.

Background

The wafer refers to a silicon wafer used for manufacturing a silicon semiconductor integrated circuit, and the original material is silicon, and the wafer is called a wafer or a silicon wafer because the shape is a circle. In the production process, an electroplating process is required to be performed on the wafer, that is, a layer of conductive metal is electroplated on the wafer, and then the conductive metal layer is processed to form a conductive circuit. The wafer is used as a basic material of a chip, and the requirement on electroplating and plating is extremely high, so the requirement on the process is also high. The uniformity of the plating layer must be ensured during the wafer electroplating process so as to ensure the quality of the wafer.

At present, wafer electroplating equipment is mainly divided into two types according to the positions of a cathode and an anode, wherein one type is a vertical electroplating device, and the other type is a horizontal electroplating device. In the case of a vertical electroplating device, when a wafer is vertically placed during electroplating, because a certain pressure difference exists between an upper area and a lower area of the wafer, a difference of an upper flow velocity and a lower flow velocity may exist in solution flow, which has a certain influence on the appearance and uniformity of electroplating, thereby causing the reduction of the electroplating quality of the wafer.

In the case of the horizontal electroplating device, when the wafer is electroplated, the wafer is horizontally placed, the surface to be plated of the wafer is downward, so that the wafer is convenient to load and unload, and because the surfaces to be plated of the wafer are positioned in the plating solution at the same depth and the pressure at each position is the same, compared with the vertical electroplating device, the horizontal electroplating device can ensure better electroplating uniformity. However, the horizontal electroplating device still has the problem of uneven wafer electroplating under the influence of factors such as an electric field, a flow field and the like.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a novel wafer electroplating method and wafer electroplating equipment adopting the wafer electroplating method, the wafer is divided into a plurality of electroplating areas according to a preset proportion, and a power supply device is configured for each electroplating area, so that the power supply amount of each electroplating area is independently controlled, the plating layer thickness of each electroplating area is the same, and the requirement on electroplating uniformity is met.

In order to achieve the purpose, the invention provides the following technical scheme:

a wafer electroplating method comprises the following steps:

s10, dividing the wafer into a plurality of electroplating areas, and calculating the electric quantity value required by each electroplating area;

s20, controlling the wafer clamp to place the wafer into the electroplating bath, and controlling the power supply device to independently supply power to each electroplating area;

and S30, when the electric quantity value supplied to a certain electroplating area is accumulated to the required electric quantity value, cutting off the power supply to the electroplating area until the power supply to all the electroplating areas is cut off, and taking out the wafer.

In the technical scheme, the area to be plated of the wafer is divided into a plurality of electroplating areas through the design of the steps of the method, and a power supply device is configured for each electroplating area to supply power, so that the subarea electroplating of the wafer and the independent control of electroplating parameters are realized.

Preferably, in step S10, the required electric quantity value is a theoretical required electric quantity value, and the calculation formula of the theoretical required electric quantity value is as follows: the theoretical required electrical value (preset coating thickness metal density plated area)/(electrochemical equivalent current efficiency).

In the technical scheme, through the design of the steps of the method, the theoretically required electric quantity value of each electroplating area can be quickly determined through a calculation formula, when the wafer is electroplated, when the actually accumulated electric quantity value reaches the theoretically required electric quantity value, the power supply device is closed, a user can determine whether the thickness of the wafer is different from the preset coating thickness through observing the actually accumulated coating thickness of the wafer, and if the difference exists, the theoretically required electric quantity value needs to be corrected subsequently. For example, a user presets a copper layer with a thickness of 100um on the wafer surface, calculates a theoretical required electric quantity value through a formula, and performs electroplating with the theoretical required electric quantity value, but under the influence of factors such as an electric field, a flow field, and a plating solution concentration, a thickness of a plating layer actually obtained in a part of the electroplating area may be 110um, and a thickness of a plating layer actually obtained in a part of the electroplating area may be 90 um. This shows that the actually required electric quantity value of the electroplating area should be smaller or larger than the theoretically required electric quantity value, so that the theoretically required electric quantity value needs to be corrected to meet the actually required condition, and the actually plating thickness of each electroplating area is stabilized at 100um to meet the requirement of electroplating uniformity.

Preferably, in step S10, the required electric quantity value is an actual required electric quantity value, and the calculation formula of the actual required electric quantity value is as follows: the actual required electric quantity value (preset coating thickness metal density plating area) a/(electrochemical equivalent current efficiency), and a is a correction coefficient.

According to the technical scheme, through the design of the steps of the method, the correction coefficient a is introduced, and the actually required electric quantity value of each electroplating area is quickly obtained through a calculation formula, so that the actual plating thickness of each electroplating area is ensured to be the preset plating thickness, and the requirement on the electroplating uniformity is met.

Preferably, the calculation method of the correction coefficient a is as follows: a ═ actual coating thickness/preset coating thickness.

In the technical scheme, the method is designed through the steps, and the electroplating time is calculated according to the electric quantity value, the current density and the electroplating area; and the current density (coating thickness metal density)/(electrochemical equivalent plating time current efficiency), the electric quantity value is in direct proportion to the coating thickness. This means that the actual coating thickness/the predetermined coating thickness is equal to the actual required electric quantity value/the theoretical required electric quantity value, and the actual required electric quantity value is equal to the theoretical required electric quantity value (actual coating thickness/predetermined coating thickness). Therefore, the correction coefficient a can be (actual plating thickness/preset plating thickness), and the correction coefficient a is substituted into the calculation formula, so that the actually required electric quantity value can be quickly calculated.

Preferably, in step S10, the wafer is divided into a plurality of plating areas by the following method: providing a plurality of power supply devices, wherein the cathodes of the plurality of power supply devices are connected with the wafer clamp, and the anodes of the plurality of power supply devices are connected with an anode assembly arranged in the electroplating bath; the anode assembly comprises a plurality of anode bodies, and anodes of the power supply devices are respectively connected with the anode bodies in a one-to-one correspondence manner.

In the technical scheme, through the design of the steps of the method, a user can realize the partition of the wafer electroplating area by setting the number and the structure of the anode bodies, the number of the anode bodies can be automatically set according to the actual requirement, and when the requirement on the electroplating uniformity is higher, the number of the anode bodies can be set more, so that the upper surface area of each anode body is reduced, the difference between different electroplating areas is reduced, and the electroplating uniformity is improved.

Preferably, the power supply device is a plurality of rectifiers, the number of the rectifiers is the same as that of the anode bodies, the negative electrode of each rectifier is electrically connected with the wafer clamp, and the positive electrode of each rectifier is electrically connected with the corresponding anode body.

In the technical scheme, the rectifier is used as a power supply device through the design of the steps of the method, and practice shows that the rectifier is used as a power supply, so that the maximum advantage of material saving can be absolutely embodied no matter thick plating or throwing plating is carried out, and the rectifier is convenient to operate.

Preferably, the wafer electroplating method provided by the invention comprises the following steps:

s10: dividing the wafer into a plurality of electroplating areas, calculating the electric quantity value required by each electroplating area, and according to a formula: determining the current and time required by each electroplating area;

s20, inputting the determined current and time into the rectifiers which correspondingly supply power to each electroplating area, controlling the wafer clamp to put the wafer into the electroplating bath, and starting each rectifier;

and S30, collecting the feedback current of each electroplating area in real time, accumulating the electric quantity value, and when the accumulated electric quantity value reaches the required electric quantity value, closing the corresponding power supply rectifier of the electroplating area until all the rectifiers are closed, and taking out the wafer.

In the technical scheme, the power supply amount of each electroplating area is definitely controlled to be the control of the electroplating current and the electroplating time of each electroplating area by adopting the step design of the method, and according to a formula: the electric quantity is the current x time, under the condition that the power supply volume is the definite value, the user can select electroplating current and electroplating time according to the actual required condition, for improving electroplating efficiency, can improve electroplating current to shorten electroplating time, and when electroplating, through the electric current accumulation electric quantity value of each electroplating regional feedback, through the control to electroplating time realization to electroplating regional required electric quantity value that provides, it is very simple and convenient to operate.

Preferably, the wafer plating method is suitable for horizontal plating or vertical plating.

According to the technical scheme, through the design of the steps of the method, when the wafer electroplating method provided by the invention is suitable for horizontal electroplating, the anode assembly is arranged below the wafer and is arranged in parallel relatively; when the wafer electroplating method provided by the invention is adopted for vertical electroplating, the anode assembly is arranged on the left side or the right side of the wafer and is arranged in parallel relatively.

A wafer electroplating device is used for implementing any one of the wafer electroplating methods, and comprises a driving device, an electroplating bath, a wafer clamp and a power supply device; the driving device is connected with the wafer clamp and can drive the wafer clamp to move into or out of the electroplating bath;

the electroplating bath is internally provided with an anode assembly, the anode assembly comprises a plurality of anode bodies, the number of the power supply devices is multiple, the cathodes of the power supply devices are electrically connected with the wafer clamp, and the anodes of the power supply devices are respectively connected with the anode bodies in a one-to-one correspondence manner.

In this technical scheme, through above structural design, the user accessible sets up the quantity and the structure of anode body, realizes the subregion to the wafer electroplating area to supply power alone to each anode body through utilizing a plurality of power supply unit, realize the regulation to each anode body power supply volume, thereby reduce or avoid because of the difference between the different electroplating areas that external factors such as flow field, electric field caused, improve the electroplating homogeneity.

Preferably, the plurality of anode bodies are mutually sleeved and coaxially arranged, and adjacent anode bodies are isolated by an insulating layer.

In the technical scheme, through the structural design, the two adjacent anode bodies are isolated by the insulating layer, so that the anode bodies are not conducted with each other when the anode assembly is electrified. The material of the insulating layer can adopt PVD or PFA.

Preferably, the power supply device further comprises a controller, the controller is connected with a plurality of the power supply devices, and the controller is used for controlling the power supply devices to supply power to or cut off power from the anode body electrically connected with the anode of the power supply devices.

In the technical scheme, the controller is arranged, so that the switching of a plurality of power supply devices between two states of power supply and power failure is realized, the automatic management is improved, and the process efficiency is improved.

Preferably, the controller comprises a storage unit, and the storage unit is used for storing the electroplating parameters of the wafer electroplating equipment.

In the technical scheme, parameters such as the electroplating speed, the electroplating time, the voltage value and the current value applied to the anode body by the power supply device during electroplating are stored through the design of the storage unit, and a basis is provided for data analysis and intelligent management.

Preferably, the controller further comprises a judging unit, wherein the judging unit is used for judging whether the electric quantity provided by the power supply device reaches a required electric quantity value in real time, and when the electric quantity reaches the required electric quantity value, the power supply device is automatically cut off.

In the technical scheme, the power supply device is automatically powered off when power supply needs to be stopped through the design of the judging unit, so that automatic management is realized, and compared with a manual operation mode, the timeliness of power off can be ensured, so that the electroplating uniformity is ensured.

Compared with the prior art, the invention has the following beneficial effects: the wafer electroplating method and the wafer electroplating equipment provided by the invention have the advantages that the to-be-plated area of the wafer is divided into a plurality of electroplating areas, and each electroplating area is provided with one power supply device for supplying power, so that the subarea electroplating of the wafer and the independent control of electroplating parameters are realized.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

fig. 1 is a schematic view of an overall structure of a wafer electroplating apparatus according to embodiments 1 and 3 of the present invention;

fig. 2 is a first schematic structural diagram of an anode body according to embodiments 1 and 3 of the present invention;

fig. 3 is a second schematic structural diagram of the anode body according to embodiments 1 and 3 of the present invention;

fig. 4 is a schematic circuit diagram of a wafer electroplating apparatus according to embodiments 1 and 3 of the present invention;

FIG. 5 is an exploded view of the plating bath according to examples 1 and 3 of the present invention;

fig. 6 is a schematic circuit diagram of a wafer electroplating apparatus according to embodiment 3 of the present invention;

FIG. 7 is a flowchart of a wafer plating method according to embodiment 1 of the present invention;

fig. 8 is a flowchart of a wafer electroplating method according to embodiment 2 of the present invention.

The figures show that:

100-wafer electroplating apparatus

1-a wafer;

2-a wafer holder;

3-a drive device;

4-electroplating bath;

41-an anode assembly;

411-anode body;

412-an insulating layer;

42-a fixing frame;

43-a conductive substrate;

5-a controller;

51-a judging unit;

52-memory cell

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Further, all directional indicators in this application (such as up, down, left, right, front, back, bottom …) are only used to explain the relative positional relationship between the components, the motion, etc. at a particular attitude (as shown in the drawings), and if the particular attitude changes, the directional indicator changes accordingly. Further, the descriptions in this application referring to "first", "second", etc. are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit to the number of technical features indicated.

Example 1:

the embodiment provides a wafer electroplating method, which is used for carrying out electroplating by partitioning a to-be-plated area of a wafer 1 and independently controlling an electric quantity value so as to realize the same thickness of a plating layer of each electroplating area of the wafer 1, thereby meeting the requirement of electroplating uniformity.

The wafer electroplating method of the present embodiment can be implemented by using the wafer electroplating apparatus 100 shown in fig. 1 to 5. As shown in fig. 1, the wafer plating apparatus 100 includes a driving device 3, a plating tank 4, a wafer holder 2, and a power supply device (not shown); the driving device 3 is connected with the wafer clamp 2, and the driving device 3 can drive the wafer clamp 2 to move into or out of the electroplating bath 4; an anode assembly 41 is arranged in the electroplating bath 4, the negative electrode of the power supply device is electrically connected with the wafer clamp 2, and the positive electrode of the power supply device is electrically connected with the anode assembly 41.

The anode assembly 41 includes a plurality of anode bodies 411, the anode bodies 411 are soluble anodes, and the material of the soluble anodes is related to the material of the plating layer to be formed, such as copper in copper plating. Specifically, as shown in fig. 2 to 3, the anode bodies 411 are mutually sleeved and coaxial, wherein the anode bodies a and a ' located at the center are cylinders, and the other anode bodies are of annular structures, including annular structures (anode bodies b, e, f, b ', g ') and semi-annular structures (anode bodies c, d, c ', d ', e ', f '). The number of the anode bodies 411 can be selected according to actual needs, for example, 6 to 7 anode bodies 411 are provided. The volume of each anode body 411 may be the same or different. Tests show that if the volume of the anode body 411 is the same, the electroplating effect is better, namely the improvement efficiency of the uniform thickness of the plating layer is higher. Therefore, the volume of each anode body 411 may be set to be the same.

The wafer electroplating method of the present embodiment is applicable to horizontal electroplating and also applicable to vertical electroplating, so that for the anode assembly 41, when the wafer electroplating method of the present embodiment is used for horizontal electroplating, the horizontal anode assembly 41 shown in fig. 2 is used, and when horizontal electroplating is performed, the anode assembly 41 is disposed below the wafer 1 and is parallel to the wafer 1; when the wafer plating method of the present embodiment is used for vertical plating, the vertical anode assembly 41 shown in fig. 3 is used, and when vertical plating is performed, the anode assembly 41 is disposed on the left side or the right side of the wafer 1 and is parallel to the wafer 1.

As shown in fig. 5, the anode assembly 41 includes an insulating layer 412 and a conductive substrate 43 in addition to the anode body 411. The insulating layer 412 is used to separate two adjacent anode bodies 411, so that the anode bodies 411 are not conducted when the anode assembly 41 is energized. The anode body 411 and the insulating layer 412 are both disposed on the conductive substrate 43, and the power supply device is electrically connected to the anode assembly 41 through the conductive substrate 43. A fixing frame 42 is also arranged in the electroplating bath 4, and the anode assembly 41 is fixed on the fixing frame 42.

Specifically, as shown in fig. 4, the number of the power supply devices matches the number of the anode bodies 411, the cathodes of the power supply devices are electrically connected to the wafer holder 2, the anodes of the power supply devices are electrically connected to the anode bodies 411 through the conductive substrate 43 in a one-to-one correspondence, and when the power supply devices start to supply power, the wafer 1 on the wafer holder 2 is conducted to the corresponding anode bodies 411 to perform the electroplating process. Since the positive electrode of each power supply device is connected to one anode body 411, the purpose of individually controlling parameters such as the power supply amount and current of each anode body 411 can be achieved.

As shown in fig. 7, the wafer electroplating method according to this embodiment includes the following steps:

s10, dividing the wafer 1 into a plurality of electroplating areas, and calculating the electric quantity value required by each electroplating area;

s20, controlling the wafer clamp 2 to place the wafer 1 in the electroplating bath 4, and controlling the power supply device to independently supply power to each electroplating area;

s30, when the electric quantity value supplied to a certain plating area is accumulated to the required electric quantity value, the power supply to the plating area is cut off until the power supply to all the plating areas is cut off, and the wafer 1 is taken out.

In step S10, dividing the wafer 1 into a plurality of plating areas is achieved by dividing the anode assembly 41 into a plurality of anode bodies 411 and supplying power to each anode body 411 by one power supply device. The negative electrode of the power supply device is electrically connected with the wafer clamp 2, the positive electrode of the power supply device is electrically connected with the anode body 411, during electroplating, the wafer 1 and the anode assembly 41 are arranged in parallel relatively, each power supply device supplies power for the anode body 411 correspondingly connected with the power supply device so as to electroplate the electroplating area corresponding to the anode body 411, therefore, the purpose of partition electroplating of the wafer 1 is achieved, the power supply amount and the electroplating thickness of each electroplating area of the wafer 1 can be independently controlled, and the electroplating uniformity is improved.

Further, in step S10, the required electric quantity value is handled in two cases:

first, if the user does not know the actual required electric quantity value of each plating area yet, and only can obtain the theoretical required electric quantity value through the theoretical calculation formula, the required electric quantity value here refers to the theoretical required electric quantity value, the user obtains the actual plating condition of each plating area of the wafer 1 through the theoretical required electric quantity value, and can determine whether there is a deviation between the actual plating condition and the preset plating condition, if there is no deviation, it indicates that the theoretical required electric quantity value is the actual required electric quantity value, then the user continues to provide electric quantity according to the theoretical required electric quantity value, if there is a deviation, the theoretical required electric quantity value needs to be corrected to obtain the actual required electric quantity value, and then the second situation is entered.

Secondly, if the user knows the actual required electric quantity value of each electroplating area according to the past electroplating experience or other manners, the required electric quantity value here refers to the actual required electric quantity value, and the user can deposit a coating with a preset thickness on each electroplating area according to the actual required electric quantity value, thereby realizing the requirement of electroplating uniformity.

In practice, it may happen that the user uses the above method steps provided in this embodiment to obtain the difference between the actual plating thickness and the predetermined plating thickness from the theoretical required electric quantity, derives a correction factor using the difference, and corrects the theoretical required electric quantity by the correction factor to obtain the actual required electric quantity, and further uses the above method steps provided in this embodiment to deposit the plating layer with the predetermined thickness on each plating area of the wafer 1 by the actual required electric quantity.

Specifically, step S10 is first executed to calculate the theoretical required electric quantity value of each plating area on the wafer 1 before the wafer 1 is plated. The calculation formula of the theoretical required electric quantity value of each electroplating area of the wafer 1 is as follows: current density plating area plating time. Wherein, the calculation formula of the current density is as follows: current density (coating thickness metal density)/(galvanic equivalent plating time current efficiency). For example, when 100um copper is to be plated on the wafer 1, the plating time is 40min, assuming that the current efficiency is 100%, the galvanic equivalent of the divalent copper is 1.185g/AH, and the current density calculated is about 11.26 ASD.

When the size of the wafer 1 is 12 inches, the total plating area of the wafer 1 is 7dm²The current density and the plating area and the plating time are calculated to obtain the total current density and the plating timeThe theoretical total electric quantity value required for electroplating the wafer 1 is 3152Amin, and according to the proportion of each electroplating area of the wafer 1 to the total area of the wafer 1, if a certain electroplating area accounts for 20% of the total area of the wafer 1, the theoretical required electric quantity value is 3152Amin by 0.2-630.4 Amin.

After calculating the theoretically required electric quantity value of each electroplating area, step S20 is executed, specifically, the wafer 1 is placed in the electroplating bath 4 by using the wafer holder 2, and the power supply device is controlled to supply power to the anode assembly 41, taking the anode assembly 41 shown in fig. 2 as an example, as shown in fig. 4, totally 6 power supply devices are adopted, anodes of the 6 power supply devices are respectively connected with the 6 anode bodies 411, that is, the anode bodies a, b, c, d, e, and f, in a one-to-one correspondence manner, and cathodes of the 6 power supply devices are all connected with the wafer holder 2.

Then, step S30 is executed to accumulate the power supplied to the anode bodies 411 by each power supply device, and when the accumulated power value in a certain electroplating area reaches the theoretically required power value, the corresponding power supply device is cut off to prevent power from being supplied to the corresponding anode body 411 until all power supply devices are cut off, the electroplating of the wafer 1 is completed, and the wafer 1 is taken out.

The actual plating thickness of each plating area of the wafer 1 is measured and compared with the preset plating thickness, and since the plating of the wafer 1 is affected by various factors such as a flow field, an electric field and the like, there may be a deviation between the actual plating thickness and the preset plating thickness, for example, it may be the case that 100um copper is plated on the surface of the wafer 1 in advance, after the theoretically required electric quantity value is obtained through formula calculation, the plating is performed with the theoretically required electric quantity value, and the actually obtained plating thickness is 110um or 90 um. This means that the actually required electric quantity value should be smaller or larger than the theoretically required electric quantity value, so that the theoretically required electric quantity value needs to be corrected to meet the actually required condition, and a correction coefficient a needs to be introduced into the calculation formula.

Further, the method is carried out. Plating area and plating time according to the electric quantity value and the current density; and the current density (coating thickness metal density)/(electrochemical equivalent plating time current efficiency), the electric quantity value is in direct proportion to the coating thickness. This means that, in a more ideal state, the actual plating thickness/the preset plating thickness is equal to the actual required electric quantity value/the theoretical required electric quantity value, that is, the actual required electric quantity value is equal to (actual plating thickness/preset plating thickness) × the theoretical required electric quantity value. Therefore, the correction coefficient a can be (actual plating thickness/preset plating thickness), and the actual plating thickness is obtained by measuring according to multiple times of electroplating experiences.

Re-executing the step S10, substituting the correction coefficient into a theoretical calculation formula, and calculating the actually required electric quantity value of each electroplating area on the wafer 1; then, step S20 is executed, the wafer clamp 2 is controlled to place the wafer 1 in the electroplating tank 4, and the power supply device is controlled to supply power to each electroplating area separately; step S30 is further executed, when the electric quantity value provided to a certain electroplating area is accumulated to the actually required electric quantity value, the power supply to the electroplating area is cut off until the power supply to all the electroplating areas is cut off, and the wafer 1 is taken out, thereby completing the uniform electroplating to each electroplating area on the wafer 1.

Example 2

The present embodiment still provides a wafer electroplating method, which has a substantially same design as that of embodiment 1, except that the present embodiment specifically defines the power supply device as a rectifier, and clearly controls the power supply amount of each electroplating area as the current and time control. As shown in fig. 8, the wafer electroplating method provided in this embodiment includes the following steps:

s10: dividing the wafer 1 into a plurality of electroplating areas, calculating the electric quantity value required by each electroplating area, and according to a formula: determining the current and time required by each electroplating area;

s20, inputting the determined current and time into the rectifiers which correspondingly supply power to each electroplating area, controlling the wafer clamp 2 to place the wafer 1 into the electroplating tank 4, and starting each rectifier;

and S30, collecting the feedback current of each electroplating area in real time, accumulating the electric quantity value, and when the accumulated electric quantity value reaches the required electric quantity value, closing the corresponding power supply rectifiers of the electroplating area until all the rectifiers are closed, and taking out the wafer 1.

Specifically, in step S10, the required electric quantity value is the same as that described in embodiment 1, that is, both the theoretical required electric quantity value and the actual required electric quantity value are included. The relevant calculation method is clearly described in embodiment 1. Furthermore, according to the electric quantity, namely the current-time, under the condition that the electric quantity value is a fixed value, a user can select the electroplating current and the electroplating time according to the actual required condition, and in order to improve the electroplating efficiency, the electroplating current can be increased, so that the electroplating time is shortened.

In step S20, the plating time and current determined in step S10 are input to the rectifiers, specifically, the number of the rectifiers is the same as the number of the anode bodies 411, the anodes of the rectifiers are connected to the anode bodies 411 in a one-to-one correspondence, the cathodes of the rectifiers are connected to the wafer chuck 2, and after the rectifiers start to supply power, the wafer 1 on the wafer chuck 2 and the corresponding anode bodies 411 are conducted with each other, and plating is performed on the corresponding plating areas.

In step S30, the feedback currents of the electroplating areas are collected in real time, the electric quantity values are accumulated, and when the accumulated electric quantity values reach the required electric quantity values, the rectifiers which supply power to the electroplating areas correspondingly are turned off. It should be noted here that the user inputs the plating current and the plating time into the rectifier before the rectifier starts to supply power, but the actual plating time may not be the input plating time because there may be a difference between the current input by the user and the actual current fed back from the plating area, in which case the plating time needs to be adjusted to ensure that the power value is not changed. Therefore, when the feedback power value provided for a certain electroplating area reaches the required power value, the power supply of the rectifier is cut off no matter whether the actual electroplating time reaches the input electroplating time or not.

Example 3

As shown in fig. 1 and 6, the wafer plating apparatus 100 of the present embodiment includes a driving device 3, a plating tank 4, a wafer chuck 2, a power supply device, and a controller 5; the driving device 3 is connected with the wafer clamp 2, and the driving device 3 can drive the wafer clamp 2 to move into or out of the electroplating bath 4; an anode assembly 41 is arranged in the electroplating bath 4, the cathode of the power supply device is electrically connected with the wafer clamp 2, and the anode of the power supply device is electrically connected with the anode assembly 41; the controller 5 is connected to the power supply device for sending a power supply command or a power cut command to the power supply device, thereby controlling the power supply device to supply power or cut power to the anode body 411 electrically connected to the anode thereof.

The anode assembly 41 includes a plurality of anode bodies 411, the anode bodies 411 are soluble anodes, and the material of the soluble anodes is related to the material of the plating layer to be formed, such as copper in copper plating. Specifically, as shown in fig. 2 to 3, the anode bodies 411 are mutually sleeved and coaxial, wherein the anode body 411 positioned at the center is a cylinder, and the other anode bodies 411 are of an annular structure, including a circular structure and a semi-annular structure. The number of the anode bodies 411 can be selected according to actual needs, for example, 6 to 7 anode bodies 411 are provided. The volume of each anode body 411 may be the same or different. Preferably, the volume of each anode body 411 is set to be the same.

The wafer plating apparatus 100 of the present embodiment is suitable for horizontal plating and also suitable for vertical plating, so that the anode assembly 41 is the horizontal anode assembly 41 shown in fig. 2 when the wafer plating apparatus 100 of the present embodiment is used for horizontal plating, and when horizontal plating is performed, the anode assembly 41 is disposed below the wafer 1 and parallel to the wafer 1; when the wafer electroplating apparatus according to the embodiment is used to perform vertical electroplating, the vertical anode assembly 41 shown in fig. 3 is used, and when the vertical electroplating is performed, the anode assembly 41 is disposed on the left side or the right side of the wafer 1 and is parallel to the wafer 1.

As shown in fig. 4, the anode assembly 41 includes an insulating layer 412 and a conductive substrate 43 in addition to the anode body 411. The insulating layer 412 is used to separate two adjacent anode bodies 411, so that the anode bodies 411 are not conducted when the anode assembly 41 is energized. The anode body 411 and the insulating layer 412 are both disposed on the conductive substrate 43, and the power supply device is electrically connected to the anode assembly 41 through the conductive substrate 43. A fixing frame 42 is also arranged in the electroplating bath 4, and the anode assembly 41 is fixed on the fixing frame 42.

Specifically, as shown in fig. 6, the number of the power supply devices is matched with the number of the anode bodies 411, the power supply devices may be rectifiers, the cathodes of the power supply devices are electrically connected to the wafer holder 2, the anodes of the power supply devices are electrically connected to the anode bodies 411 through the conductive substrates 43 in a one-to-one correspondence manner, and when the controller 5 controls the power supply devices to start to supply power, the wafer 1 on the wafer holder 2 is conducted to the corresponding anode bodies 411, so as to implement the electroplating process. Since the positive electrode of each power supply device is connected to one anode body 411, the purpose of individually controlling parameters such as the power supply amount and current of each anode body 411 can be achieved.

The controller 5 includes a storage unit 52 and a determination unit 51, the storage unit 52 is configured to store electroplating parameters of the wafer electroplating apparatus 100, the electroplating parameters include an electroplating rate, an electroplating duration, a voltage value and a current value applied to the anode body 411 by the power supply device during electroplating, and the storage of the electroplating parameters may provide a basis for data analysis and intelligent management. The determining unit 51 is configured to monitor the power provided by the power supply device in real time and determine whether the power provided by the power supply device reaches a required power value, and when it is determined that the power provided by the power supply device reaches the required power value, automatically cut off the power supply device to stop the power supply from being supplied to the corresponding anode assembly, thereby implementing automatic management.

In the embodiment, through the structural design, the region to be plated of the wafer 1 is divided into a plurality of electroplating regions, and each electroplating region is provided with one power supply device for supplying power, so that the partitioned electroplating of the wafer 1 and the independent control of the electroplating parameters are realized.

While the embodiments of the present invention have been described, it is clear that various changes and modifications can be made by workers in the field without departing from the technical spirit of the present invention.