Anode assembly and application thereof

Abstract

The present invention discloses an anode assembly and its application. The anode assembly comprises a conductive substrate and an anode body arranged on the conductive substrate, and the surface of the conductive substrate has a protective layer. By arranging the protective layer on the surface of the conductive substrate, the resistance change caused by oxidation and passivation of the conductive substrate during the electroplating process is effectively avoided, the uniformity of the circuit current distribution and the stability of the electroplating process are improved, thereby improving the uniformity of the electroplating layer of the electroplated workpiece.

Description

Technical Field

[0001] The invention relates to an anode assembly and application thereof. Background Art

[0002] In electroplating equipment, there are two types of anodes: soluble anodes and insoluble anodes. Generally, the anode assembly of the soluble anode usually uses a conductive substrate to stably transmit current. There are two types of anode structures: integral anodes and segmented anodes. When the soluble anode is a segmented anode, the conductive substrate is usually segmented, and each segmented area corresponds to and matches the area of ​​each segmented anode in the anode assembly.

[0003] When electroplating copper, the anode material is usually copper or phosphor copper. The corresponding conductive substrate is usually made of inert conductive materials such as titanium, platinum, and indium. When the inert conductive metal material is titanium, it is easy to oxidize and passivate during the electroplating process. The formed oxide layer or passivation layer will not fall off by itself, and will change the resistance of each segmented conductive substrate, making its resistance unstable, and at the same time causing uneven and unstable resistance distribution at each point on the surface of each segmented conductive substrate.

[0004] The segmented anodes are usually separated by insulating materials (such as PTFE). The segmented conductive substrates are also usually separated by insulating materials (such as PTFE). These insulating materials are usually connected together to play the role of insulation and support.

[0005] Since the segmented anode, segmented conductive substrate, plating solution and cathode are interconnected during electroplating, the uneven and unstable resistance of the segmented conductive substrate and its resistance distribution will affect the uneven and unstable current distribution of the entire circuit, and ultimately affect the uneven and unstable cathode electroplating deposition. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an anode assembly in order to overcome the defect that the conductive substrate of the electroplating equipment in the prior art is easily oxidized and passivated during the electroplating process, resulting in uneven and unstable resistance distribution of the conductive substrate, which ultimately affects the uneven and unstable cathode electroplating deposition.

[0007] The present invention solves the above technical problems through the following technical solutions:

[0008] The present invention provides an anode assembly, which comprises a conductive substrate and an anode body arranged on the conductive substrate, wherein the surface of the conductive substrate has a protective layer.

[0009] Preferably, the anode assembly is composed of a conductive substrate and an anode body disposed on the conductive substrate, and the surface of the conductive substrate has a protective layer.

[0010] In this solution, the anode assembly is preferably an anode assembly for electroplating.

[0011] The material of the conductive substrate can be a conventional conductive material in the art. Preferably, the material of the conductive substrate is one or more of titanium, platinum, iridium and indium. More preferably, the material of the conductive substrate is titanium.

[0012] In this solution, the protective layer is used to prevent oxidation and passivation on the surface of the conductive substrate. Its material can be conductive or non-conductive. Technical personnel in this field can set it on the surface of the conductive substrate as needed. The specific setting is only required to inhibit oxidation and passivation on the surface of the conductive substrate.

[0013] For example, when the protective layer is non-conductive, the protective layer covers the area outside the contact surface between the conductive substrate and the anode body.

[0014] When the protective layer is conductive, the protective layer may cover the entire surface of the conductive substrate, or may cover a portion of the surface of the conductive substrate (for example, covering the area outside the contact surface between the conductive substrate and the anode body).

[0015] The material of the protective layer is preferably one or more of an inert metal, an oxide and an insulating material. By forming a protective layer on the surface of the conductive substrate, oxidation and passivation of the conductive substrate surface can be effectively prevented.

[0016] The inert metal may be a conventional inert metal in the art. Preferably, the chemical activity or electrochemical activity of the inert metal is lower than that of the conductive substrate. For example, when the conductive substrate is made of titanium, the material of the protective layer may be one or more of indium, iridium and platinum. More preferably, the inert metal is one or more of indium, iridium and platinum.

[0017] Preferably, the inert metal forms an inert metal layer on the surface of the conductive substrate by coating or plating.

[0018] The oxide may be a conventional oxide in the art, preferably, the oxide is a metal oxide, and the metal is preferably the material of the conductive substrate. More preferably, the oxide is titanium dioxide.

[0019] Preferably, the oxide forms an oxide layer on the surface of the conductive substrate by a passivation treatment (such as high temperature oxidation, etc.) or a coating method.

[0020] The insulating material may be a conventional insulating material in the art. Preferably, the insulating material is Teflon (PTFE).

[0021] Preferably, the insulating material forms an insulating protective layer on the surface of the area outside the contact surface between the conductive substrate and the anode body by spraying or coating.

[0022] The thickness of the protective layer may be a conventional thickness in the art. Preferably, the thickness of the protective layer is 0.5 to 1.0 micrometers.

[0023] Preferably, the conductive substrate has one or more through holes to prevent the conductive substrate from being deformed during processing.

[0024] In this embodiment, the material of the anode body can be a conventional anode material in the art, such as a soluble anode material or an insoluble anode material. Preferably, the material of the anode body is a soluble anode material. The soluble anode material is related to the material of the electroplated layer to be formed, such as copper or phosphor copper in the case of copper electroplating.

[0025] Preferably, the side surface of the anode body also has the protective layer. When the material of the anode body is a soluble anode material, a person skilled in the art can determine the coverage of the protective layer without affecting the electrolytic dissolution of the anode body, for example, only covering the lower half of the side surface of the anode body, the lower half refers to the side in contact with the conductive substrate, and the other side is the upper half. The thickness of the protective layer on the side surface of the anode body is preferably 0.5 to 1.0 microns.

[0026] In this solution, the anode assembly can be an integral anode or a segmented anode, that is, the number of the anode bodies can be one or more, preferably 6 to 20. The number of the conductive substrates is the same as that of the anode bodies, and the shape is corresponding.

[0027] Preferably, when there are multiple anode bodies, the anode bodies are not electrically connected to each other.

[0028] When there are multiple anode bodies, the volumes of the anode bodies are the same or different. Preferably, the volumes of the anode bodies are the same, in which case the electroplating effect is better, that is, the uniformity of the coating thickness is more efficiently improved.

[0029] Preferably, when there are multiple anode bodies, the anode bodies are nested and coaxial with each other, wherein the anode body located in the center is a cylinder, and the other anode bodies are annular structures.

[0030] Preferably, the conductive substrate and the anode body are connected by one or more fasteners, and the fasteners may or may not penetrate the anode body, so that the contact between the conductive substrate and the anode body is closer, and the gap between the conductive substrate and the anode body can be ignored, usually less than 0.1 mm, to prevent oxidation and passivation of the conductive substrate at the contact surface.

[0031] More preferably, the fastener is a screw.

[0032] More preferably, the number of the fasteners is 2 to 6, and they are generally evenly distributed.

[0033] The conductive substrate is further provided with a conductive column, which is connected to the positive electrode of the power supply through the conductive column. The material of the conductive column can be a conventional conductive material in the art, such as one or more of titanium, platinum and indium. The material of the conductive column is the same as or different from that of the conductive substrate, preferably the same.

[0034] Preferably, each of the conductive substrates is provided with two conductive pillars.

[0035] Preferably, the surface of the conductive column has the protective layer.

[0036] The invention also provides an application of the anode assembly in electroplating.

[0037] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0038] The positive progressive effect of the present invention is that by providing a protective layer on the surface of the conductive substrate, the change in resistance of the conductive substrate due to oxidation and passivation during the electroplating process is effectively avoided, the uniformity of the circuit current distribution and the stability of the electroplating process are improved, thereby improving the uniformity of the electroplating layer of the electroplated workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic structural diagram of the anode assembly of Example 1 of the present invention.

[0040] Figure 2 Schematic diagram of the structure of the anode assembly of Example 4 of the present invention.

[0041] Figure 3 It is a three-dimensional schematic diagram of the anode assembly of Example 4 of the present invention.

[0042] Description of reference numerals:

[0043] 1- anode body, 2- conductive substrate, 3- protective layer, 4- conductive column, 5- fastener. DETAILED DESCRIPTION

[0044] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0045] Example 1

[0046] like Figure 1As shown, this embodiment provides an anode assembly for electroplating, the anode assembly comprising a conductive substrate 2 and an anode body 1 arranged on the conductive substrate 2, and the surface of the conductive substrate 2 has a protective layer 3.

[0047] In this embodiment, the protective layer 3 covers the entire surface of the conductive substrate 2. During specific production, if the material of the protective layer 3 is conductive, it can be provided on the entire surface or a portion of the surface of the conductive substrate 2 (for example, the area outside the contact surface between the conductive substrate 2 and the anode body 1) as required; if the material of the protective layer 3 is non-conductive, the protective layer 3 covers the area outside the contact surface between the conductive substrate 2 and the anode body 1.

[0048] In this embodiment, the material of the protective layer 3 is inert metal indium. During the specific manufacturing process, it can be selected from inert metals, oxides and insulating materials as needed.

[0049] In this embodiment, the inert metal indium is plated on the surface of the conductive substrate 2 by a plating method to form an indium layer with a thickness of 0.5 micrometers. During specific production, the thickness of the protective layer 3 can be selected within the range of 0.5 to 1.0 micrometers as required.

[0050] In this embodiment, the anode body 1 is a soluble anode, and the material of the soluble anode is related to the material of the electroplating layer to be formed, such as copper in the case of copper plating.

[0051] In this embodiment, the number of anode bodies 1 is 7, and the volume of each anode body is the same. The anode bodies are mutually nested and coaxial, wherein the anode body located in the center is a cylinder, and the other anode bodies are annular structures, including circular ring structures and semi-annular structures (only the anode body located in the center is shown in the figure, and the anode bodies of other annular structures are not shown). When the anode assembly is powered, these anode bodies are not connected to each other.

[0052] During specific production, the number of anode bodies 1 can be selected in the range of 6 to 20 as required. Of course, the more the number is set, the smaller the area of ​​the upper surface of each anode body is, and the higher the accuracy of the correction of electroplating uniformity is.

[0053] Correspondingly, the number of the conductive substrates 2 in this embodiment is also 7, and the shape thereof corresponds to that of the anode body 1 .

[0054] In this embodiment, the material of the conductive substrate 2 is titanium. During the specific production, one or more of titanium, platinum and indium can be selected according to needs.

[0055] In this embodiment, the conductive substrate 2 has 20 through holes, which can effectively prevent the conductive substrate 2 from deforming during processing and can also make the flow of the electroplating solution more sufficient and uniform during the electroplating process.

[0056] The conductive substrate 2 is connected to the positive electrode of the power supply through the conductive column 4. In this embodiment, two conductive columns 4 are provided on each conductive substrate. The material of the conductive column 4 is titanium. When it is made specifically, it can be selected from one or more of titanium, platinum and indium as needed. The surface of the conductive column 4 is also plated with a layer of inert metal indium (not shown in the figure), and the thickness of the indium layer is 0.5 microns.

[0057] The anode assembly for electroplating provided in this embodiment is recorded as anode assembly-1.

[0058] Example 2

[0059] Compared with Example 1, the anode assembly for electroplating provided in this embodiment is different in that the material of the protective layer 3 is titanium dioxide, and an oxide layer is grown on the entire surface of the conductive substrate 2 by oxidation at 200°C. Similarly, an oxide layer is also grown on the surface of the conductive column 4.

[0060] The anode assembly for electroplating provided in this embodiment is recorded as anode assembly-2.

[0061] Example 3

[0062] Compared with Example 1, the anode assembly for electroplating provided in this embodiment is different in that the material of the protective layer 3 is the insulating material Teflon (PTFE), and the insulating protective layer is formed on the surface of the conductive substrate 2 outside the contact surface of the anode body 1 by spraying. Similarly, the surface of the conductive column 4 is also sprayed with an insulating protective layer.

[0063] The anode assembly for electroplating provided in this embodiment is recorded as anode assembly-3.

[0064] Example 4

[0065] like Figures 2-3 As shown, compared with Example 1, the difference in the anode assembly for electroplating provided in this embodiment is that the conductive substrate 2 and the anode body 1 are also connected by a fastener 5, so that the gap between the conductive substrate 2 and the anode body 1 is less than 0.1 mm, so that the contact between the two is closer, and the oxidation and passivation of the conductive substrate 2 on the contact surface can be effectively prevented.

[0066] In this embodiment, the fastener 5 does not penetrate the anode body 1. In actual manufacturing, it can penetrate or not penetrate, as long as its resistance does not change during electroplating.

[0067] In this embodiment, the fasteners 5 are conductive screws, and the number is 6, which are evenly distributed on the conductive substrate 2. In actual production, the fasteners 5 can be conductive or non-conductive, and the number can be selected within the range of 2 to 6 as needed.

[0068] The anode assembly for electroplating provided in this embodiment is recorded as anode assembly-4.

[0069] Example 5

[0070] Compared with Example 3, the anode assembly for electroplating provided in this embodiment is different in that the lower half of the outer side surface of the anode body 1 also has a protective layer 3, and the material of the protective layer 3 is the insulating material Teflon.

[0071] The anode assembly for electroplating provided in this embodiment is recorded as anode assembly-5.

[0072] Example 6

[0073] Compared with Example 1, the anode assembly for electroplating provided in this embodiment is different in that the thickness of the protective layer 3 (indium layer) is 0.3, 0.8 and 1.0 microns, respectively. Similarly, the thickness of the indium layer on the surface of the conductive column 4 is also 0.3, 0.8 and 1.0 microns, respectively. The corresponding anode assemblies are respectively recorded as anode assembly-6 (0.3 microns), anode assembly-7 (0.8 microns) and anode assembly-8 (1.0 microns).

[0074] Comparative Example 1

[0075] Compared with Example 1, the anode assembly for electroplating provided in this comparative example is different in that the surface of the conductive substrate 2 has no protective layer, and similarly, the surface of the conductive column 4 is not plated with inert metal indium. The anode assembly for electroplating provided in this comparative example is recorded as anode assembly-9.

[0076] Effect Example 1

[0077] The electroplating device used in this effect embodiment includes: the anode assembly, controller, power module, electroplating tank and fixed frame in embodiments 1 to 6 and comparative example 1. The anode assembly is fixed on the fixed frame, and the fixed frame has a built-in inlet tank for electroplating liquid. The fixed frame is set and fixed in the electroplating tank. The controller is electrically connected to the power module.

[0078] When electroplating is performed, the positive electrode of the power module is electrically connected to the anode body through a conductive substrate, and the negative electrode is electrically connected to the electroplating workpiece (such as a wafer). The anode assembly and the electroplating workpiece are arranged in parallel. Specifically: when horizontal electroplating is performed, the anode assembly is arranged below the electroplating workpiece; and the radius of the electroplating surface of the anode assembly is the same as the radius of the electroplating workpiece, that is, the shape and size of the anode assembly are the same as the shape and size of the electroplating workpiece. The controller sends a power supply instruction to the power module. When the power module receives the power supply instruction, it supplies power to one or several target anode bodies, and at this time, the target anode bodies are not conductive to each other.

[0079] In this embodiment, the power module can supply power to one or several anode bodies separately to realize electroplating of local areas of the electroplated workpiece, thereby correcting the uneven electroplating layer after one or more electroplating (initial electroplating).

[0080] The electroplating devices including the anode assemblies in Examples 1 to 6 and Comparative Example 1 were respectively used to electroplate 12-inch wafers for a period of time to examine the electroplating uniformity of the electroplating equipment during continuous use. The parameters of each electroplating in the process were the same and the frequency of use was the same. The results of the examination are shown in Table 1.

[0081] Table 1

[0082]

[0083]

[0084] In the above table, the uniformity of the electroplated layer was obtained by testing the electroplated layer on the surface of the wafer after electroplating when the electroplating device was used for 90 days. The calculation formula for the uniformity of the electroplated layer is as follows:

[0085] H=(H max -H min ) / 2H avg ;

[0086] Among them, H is the uniformity of the electroplating layer, H max is the maximum thickness of the electroplating layer, H min is the minimum thickness of the electroplating layer, H avg is the average thickness of the electroplating layer.

Claims

1. An anode assembly, characterized in that: The anode assembly comprises a conductive substrate and an anode body arranged on the conductive substrate, and the surface of the conductive substrate has a protective layer; The thickness of the protective layer is 0.5 to 1.0 micrometers; The conductive substrate has one or more holes extending therethrough; The protective layer covers the area outside the contact surface between the conductive substrate and the anode body; The material of the protective layer is an inert metal, and the inert metal is indium.

2. The anode assembly according to claim 1, characterized in that The anode assembly consists of a conductive substrate and an anode body arranged on the conductive substrate, and the surface of the conductive substrate is provided with a protective layer.

3. The anode assembly according to claim 1 or 2, characterized in that: The anode assembly is an anode assembly used for electroplating; And / or, the material of the conductive substrate is one or more of titanium, platinum, iridium and indium.

4. The anode assembly according to claim 3, characterized in that The conductive substrate is made of titanium.

5. The anode assembly according to claim 1 or 2, characterized in that: The inert metal forms an inert metal layer on the surface of the conductive substrate by coating or plating.

6. The anode assembly according to claim 1 or 2, characterized in that: The material of the anode body is a soluble anode material; and / or, the side surface of the anode body also has the protective layer; And / or, the number of the anode bodies is one or more, the conductive substrates are the same as the number of the anode bodies and have corresponding shapes; when the number of the anode bodies is multiple, the anode bodies are not conductive to each other; when the number of the anode bodies is multiple, the anode bodies are mutually nested and coaxial, wherein the anode body located in the center is a cylinder, and the other anode bodies are annular structures.

7. The anode assembly according to claim 6, characterized in that When there are multiple anode bodies, the volumes of the anode bodies are the same.

8. The anode assembly according to claim 1 or 2, characterized in that: The conductive substrate and the anode body are connected by one or more fasteners, and the fasteners may or may not penetrate the anode body.

9. The anode assembly according to claim 8, characterized in that The fastener is a screw.

10. The anode assembly according to claim 8, characterized in that The number of the fasteners is 2 to 6.

11. The anode assembly according to claim 1 or 2, characterized in that: The conductive substrate is provided with a conductive column, and is connected to the positive electrode of the power supply through the conductive column.

12. The anode assembly according to claim 11, wherein The material of the conductive pillar is the same as that of the conductive substrate.

13. The anode assembly according to claim 11, wherein: Two conductive pillars are arranged on each of the conductive substrates.

14. The anode assembly according to claim 11, wherein: The surface of the conductive column has the protection layer.

15. Use of the anode assembly according to any one of claims 1 to 14 in electroplating.

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