Electroplating apparatus and cleaning method

Abstract

The present application discloses an electroplating apparatus and a cleaning method. The electroplating apparatus comprises: a process chamber, used to store an electroplating solution; a substrate fixture, comprising a fixture body and a sealing member; a driving system, used to drive the substrate fixture to raise, lower and rotate; a cleaning system, comprising a nozzle, a cleaning liquid tank and a cleaning liquid supply tube, the nozzle having an upwardly inclined spraying direction used to spray a cleaning liquid to a preset position of a substrate and / or the sealing member, so as to clean the sealing member, the spraying direction having a component consistent with a tangential direction of a rotation direction of the substrate fixture passing through the preset position; and a control system, used to, during cleaning of the sealing member, control the driving system to lift the substrate fixture to a preset height above the nozzle and rotate it at a preset speed, and control the cleaning system to cause the nozzle to spray the cleaning liquid at a preset flow rate. The present application implements a cleaning function for a sealing member, and reduces the amount of cleaning liquid dripping during the cleaning of the sealing member.

Description

Electroplating device and cleaning method Technical Field

[0001] The present application relates to the field of semiconductor equipment, and further to an electroplating device and a cleaning method. Background Art

[0002] The substrate electroplating process refers to the process of electroplating metal ions in the plating solution onto the surface of the substrate to form metal interconnections during the chip manufacturing process, such as electroplating copper, nickel, and tin-silver alloy.

[0003] In existing electroplating equipment, the substrate fixture includes a conductive stylus and a seal that contacts the substrate. The stylus should evenly contact the seed layer on the front surface of the substrate while preventing direct contact with the plating solution. Therefore, a seal is required to prevent the plating solution from reaching the edges of the front surface of the substrate. Otherwise, the edges of the front surface of the substrate would be plated with metal, resulting in poor uniformity of the metal film deposited on the substrate. After the electroplating process is complete, residues such as residual plating solution and plated metal deposits often remain on the seal.

[0004] Taking the electroplating of tin-silver alloy as an example, during the electroplating of tin-silver alloy, the residue on the seal of the substrate fixture occurs due to the significantly different reduction potential of atomic tin compared to atomic silver. The residue is generated first by plating tin (low silver content) on the seal surface, and then by the replacement reaction (Sn+2Ag + →Sn 2+ +2Ag), resulting in the reduction of silver ions to silver atoms, thereby forming a metallic silver deposit on the surface of the seal.

[0005] The document with patent application number 201911077619.1 provides an electroplating device and a cleaning method, which provides an electroplating liquid storage tank with a middle section of a cleaning tube in contact with the electroplating liquid, and uses the electroplating liquid with a preset temperature to heat the middle section of the cleaning tube to obtain a heated cleaning liquid, and then uses the electroplating liquid with a preset temperature to heat the cleaning liquid for spray cleaning of the substrate fixture to remove residues. Summary of the Invention

[0006] In order to solve the problem that residues may be left on the sealing component of a substrate clamp after an existing electroplating device electroplates a substrate, the present application provides an electroplating device and a cleaning method.

[0007] In order to achieve the above objectives, the present application provides an electroplating device and a cleaning method.

[0008] In some embodiments, the electroplating device includes: a process chamber for storing electroplating liquid to perform electroplating on a substrate; a substrate clamp for moving the substrate into or out of the process chamber, the substrate clamp including a clamp body and a seal, the clamp body for carrying the substrate, and during the electroplating process, the seal isolates the edge of the substrate from the electroplating liquid, and the bottom of the seal is in contact with the electroplating liquid; a drive system for driving the substrate clamp to rise and fall and rotate; a cleaning system including a nozzle, a cleaning liquid tank and a cleaning liquid supply pipeline, the cleaning liquid tank is supplied with cleaning liquid through the cleaning liquid supply pipeline. A cleaning liquid is supplied to the nozzle, and the nozzle has a spraying direction inclined upward, and is used to spray the cleaning liquid to a preset position of the substrate and / or the seal to clean the seal, wherein the spraying direction has a component consistent with a tangential direction of the rotation direction of the substrate clamp through the preset position; a control system is communicatively connected to the drive system and the cleaning system, and is used to control the drive system to lift the substrate clamp to a preset height above the nozzle and rotate at a preset speed during cleaning of the seal, and control the cleaning system to make the nozzle spray the cleaning liquid at a preset flow rate.

[0009] In some embodiments, the above-mentioned cleaning method includes: step S10, the substrate clamp is raised and lowered to a preset height above the nozzle and rotated at a preset speed; step S20, the nozzle sprays a first cleaning liquid to a preset position of the substrate and / or the seal at a preset flow rate, and the spraying direction has a component consistent with the tangential direction of the rotation direction of the substrate clamp through the preset position.

[0010] Compared with the prior art, the present application, on the one hand, cleans the seal through the nozzle of the cleaning system, and can promptly remove residues on the surface of the seal; on the other hand, by configuring the spray direction of the nozzle to have a component consistent with the tangential direction of the rotation direction of the substrate clamp through a preset position, combined with the rotation speed of the substrate clamp and the spray flow rate of the nozzle, the cleaning liquid sprayed onto the surface of the substrate and / or the seal is thrown radially outward to the maximum extent, reducing the amount of cleaning liquid falling into the water during the cleaning of the seal, thereby preventing the cleaning liquid from dripping into the process tank and causing contamination of the electroplating solution.

[0011] Summary of the Figures

[0012] The features and performance of the present application are further described by the following examples and accompanying drawings. The preferred embodiments will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above characteristics, technical features, advantages and implementation methods of the present invention.

[0013] FIG1 is a schematic diagram of an electroplating device according to an embodiment of the present application;

[0014] FIG2 is a partial enlarged view of area a in FIG1 ;

[0015] 3a-3d are cross-sectional views of four embodiments along the bb direction of FIG. 1 ;

[0016] FIG4 is a schematic diagram of an embodiment of FIG1 along the cc direction;

[0017] FIG5 is a flow chart of a cleaning method according to an embodiment of the present application.

[0018] Preferred embodiment of this application

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific embodiments of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings and other embodiments can be obtained based on these drawings without inventive work.

[0020] To simplify the drawings, only portions relevant to the invention are schematically depicted in each figure; they do not represent the actual structure of the product. Furthermore, to simplify the drawings and facilitate understanding, in some figures, only one component with the same structure or function is schematically depicted or labeled. In this document, "one" not only means "only one" but also "more than one."

[0021] It should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0022] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0023] As shown in FIG. 1 and FIG. 2 , an electroplating device 100 according to an embodiment of the present application is disclosed.

[0024] Specifically, the electroplating apparatus 100 includes a process chamber 110, a substrate fixture 120, a drive system 130, a cleaning system 140, and a control system 150. The process chamber 110 is used to store a plating solution 1112 for electroplating a substrate 200. The substrate fixture 120 is used to move the substrate 200 into or out of the process chamber 110. Referring to FIG. 2 , the substrate fixture 120 includes a fixture body 121 and a sealing member 123. The fixture body 121 is used to support the substrate 200. During the electroplating process, the sealing member 123 isolates the edges of the substrate 200 from the plating solution, while the bottom of the sealing member 123 contacts the plating solution.

[0025] Referring again to FIG1 , the drive system 130 is configured to drive the substrate clamp 120 to rise and fall and rotate. The cleaning system 140 includes a nozzle 141, a cleaning liquid tank 143, and a cleaning liquid supply line 142. The cleaning liquid tank 143 supplies cleaning liquid to the nozzle 141 via the cleaning liquid supply line 142. The nozzle 141 has an upwardly inclined spray direction t (see FIG4 ) for spraying the cleaning liquid onto a predetermined position 1412 of the substrate 200 and / or the seal 123 to clean the seal 123. The spray direction t has a component that is consistent with a tangential direction m (see FIG3 a ) of the rotation direction s of the substrate clamp 120 through the predetermined position 1412. The control system 150 is communicatively connected to the drive system 130 and the cleaning system 140, respectively, and is configured to control the drive system 130 to raise and lower the substrate clamp 120 to a predetermined height above the nozzle 141 and rotate it at a predetermined speed during cleaning of the seal 123, and to control the cleaning system 140 to cause the nozzle 141 to spray the cleaning liquid at a predetermined flow rate.

[0026] In this embodiment, the spraying direction t of the nozzle 141 is configured to have a component that is consistent with the tangent direction m of the rotation direction s of the substrate clamp 120 passing through the preset position 1412. The purpose is to prevent the spraying direction t of the nozzle 141 from colliding with the rotation direction s of the substrate clamp 120, so that after the nozzle 141 sprays the cleaning liquid onto the substrate 200 and / or the seal 123, the cleaning liquid still has a speed component that is consistent with the tangent direction m of the rotation direction s of the substrate clamp 120 passing through the preset position 1412. Combined with the rotation speed of the substrate clamp 120 and the spray flow rate of the nozzle 141, the cleaning liquid sprayed onto the surface of the substrate clamp 120 is thrown outward, reducing the amount of cleaning liquid falling during the cleaning of the seal 123, thereby preventing the cleaning liquid from dripping into the process tank and causing contamination to the electroplating liquid 1112.

[0027] Preferably, as shown in FIG2 , the substrate fixture 120 further includes a conductive contact 122 and a pressure plate 124. The fixture body 121 is annular in structure, and the bottom portion extends radially inward to form a substrate support portion 1211. A seal 123 covers the surface of the substrate support portion 1211 and is used to isolate the conductive contact 122 and the substrate support portion 1211 from the electroplating solution 1112 during electroplating of the substrate 200. The pressure plate 124 is movable up and down by the drive system 130 to secure the substrate 200 between the pressure plate 124 and the substrate support portion 1211. While securing the substrate 200, the conductive contact 122 is electrically contacted with the edge of the substrate 200, thereby causing the substrate 200 to serve as a cathode during electroplating, thereby depositing a metal layer on its surface.

[0028] The substrate clamp 120 also includes an inner pressure ring 125 and an outer pressure ring 126. The inner pressure ring 125 is locked to the inner circumference 1212 of the clamp body 121, while the outer pressure ring 126 is locked to the outer circumference 1213 of the clamp body 121. The inner pressure ring 125 is used to secure the conductive contacts 122 and one side 1231 of the seal 123 between the inner pressure ring 125 and the upper end surface of the substrate support portion 1211, while the outer pressure ring 126 is used to secure the other side 1232 of the seal 123 between the outer pressure ring 126 and the lower end surface of the substrate support portion 1211. In this embodiment, the cleaning system 140 cleans the seal 123 in an area located at the bottom of the seal 123, including a portion 1233 of the bottom surface of the seal 123 not covered by the outer pressure ring 126, as well as an inner circumference 1234 of the seal 123. In addition, during the cleaning of the sealing member 123 , the substrate holder 120 is mounted with the substrate 200 , so as to prevent the nozzle 141 from spraying the cleaning liquid onto the substrate holder 120 .

[0029] Preferably, during the cleaning of the seal 123, the substrate 200 carried by the substrate fixture 120 is a dummy wafer (dummy wafer / test wafer). In practical applications, the substrate 200 includes a positive wafer (prime wafer) and a dummy wafer. The positive wafer is also called a product-grade wafer, which has very few surface and internal defects, an impurity content close to the pure silicon level, good electrical properties, and a high production cost. It is suitable for the manufacture of semiconductor products. For example, during the electroplating process of the substrate, the substrate 200 carried by the substrate fixture 120 is preferably a positive wafer. Relatively speaking, the dummy wafer has more surface and internal defects and a higher impurity content, and has a lower production cost, and is suitable for testing and low-end applications. It should be noted that during the electroplating process, since the purity of the dummy wafer cannot meet the process requirements, the substrate 200 can only be electroplated with the positive wafer. During the cleaning of the seal 123, if an acidic cleaning solution is used to clean the seal 123, the acidic cleaning solution may damage the coating on the surface of the positive film, so the substrate 200 is preferably a dummy film; if only pure water is used to clean the seal 123, since pure water has a lower impact on the coating on the surface of the positive film, the substrate 200 can be either a positive film or a dummy film.

[0030] Preferably, the preset rotation speed is 100 r / min to 400 r / min, and the preset flow rate is 0.5 L / min to 1.5 L / min. In addition, as shown in FIG4 , the angle α between the injection direction t and the horizontal plane L is 5° to 30°.

[0031] It should be noted that the above-mentioned preset rotational speed, preset flow rate, and angle α between the spray direction t and the horizontal plane L were measured through multiple experiments. In actual operation, multiple test values ​​for the preset rotational speed, multiple test values ​​for the preset flow rate, and test values ​​for the angle α between the spray direction t and the horizontal plane L are first set, and the above-mentioned different types of test values ​​are arranged and combined to form several groups of test values. The electroplating apparatus 100 is then tested for each of the above groups of test values ​​in sequence, and the total amount of water falling corresponding to each group of test values ​​during the cleaning of the seal 123 is recorded. Finally, the range of test values ​​in which the amount of water falling is lower than the preset value is calculated to obtain the optimal range value.

[0032] In the embodiment shown in FIG3a , during cleaning of the seal 123, the nozzle 141 sprays cleaning liquid onto a predetermined position 1412 of the seal 123. At this time, the component of the spray direction t in the horizontal plane L is in the same direction as the tangent direction m of the rotational direction s passing through the predetermined position 1412 in the horizontal plane L. In this embodiment, the cleaning liquid is sprayed onto the surface of the seal 123 in the spray direction t, and the speed of the cleaning liquid colliding with the seal 123 is minimized. While flushing the seal 123, the cleaning liquid is simultaneously thrown outward, reducing the amount of cleaning liquid falling onto the surface.

[0033] In the embodiment shown in Figure 3b, during the cleaning of the seal 123, the nozzle 141 sprays the cleaning liquid to the preset position 1412 of the seal 123. At this time, the angle β between the component of the spray direction t in the horizontal plane L and the tangent direction m of the rotation direction s in the horizontal plane L passing through the preset position 1412 is acute.

[0034] In the embodiment shown in FIG3c , during cleaning of the seal 123, the nozzle 141 is configured to spray the cleaning liquid onto an area 1413 between the center of the substrate 200 and the seal 123. Any location within the area 1413 can be used as a predetermined location. In this embodiment, the cleaning liquid does not directly flush the seal 123. However, as the cleaning liquid flows outward along the substrate 200, it passes over the surface of the seal 123, thereby cleaning the seal 123.

[0035] Preferably, in the embodiment shown in FIG3 d , during cleaning of the seal 123, the nozzle 141 is configured to spray the cleaning liquid onto an area 1414 on the surface of the substrate 200 and the seal 123. Any location within the area 1414 can be used as a predetermined location. In this embodiment, a portion of the cleaning liquid is sprayed onto the surface of the substrate 200. As this portion of the cleaning liquid flows outward along the substrate 200, it passes through the surface of the seal 123 to clean the seal 123. Another portion of the cleaning liquid directly rinses the seal 123 to clean the seal 123.

[0036] Specifically, the nozzle 141 is a linear nozzle or a fan-shaped nozzle. It should be noted that, in the embodiments shown in Figures 3a and 3b, in order to accurately spray the cleaning liquid onto the surface of the seal 123, the nozzle 141 preferably uses a linear nozzle. In the embodiment shown in Figure 3c, the cleaning liquid is sprayed onto the area between the center of the substrate 200 and the seal 123, and the nozzle 141 can use either a linear nozzle or a fan-shaped nozzle. In the embodiment shown in Figure 3d, the cleaning liquid needs to be sprayed onto the surfaces of the substrate 200 and the seal 123 at the same time, and the nozzle 141 preferably uses a fan-shaped nozzle.

[0037] Preferably, referring again to FIG. 1 , the process chamber 110 includes an inner cavity 111 and an overflow trough 112. The inner cavity 111 is configured to store the electroplating solution 1112 and has an opening 1111. The overflow trough 112 is configured to surround the opening 1111 and collect the electroplating solution 1112 that overflows from the inner cavity 111. Furthermore, a protective cover 113 is configured above the overflow trough 112. The inner sidewall of the protective cover 113 is configured to have an annular collection trough 1131. The annular collection trough 1131 is configured to collect cleaning liquid ejected from the substrate holder 120 during cleaning of the seal 123.

[0038] As shown in FIG5 , a cleaning method according to an embodiment of the present application is disclosed. The cleaning method is applicable to the electroplating device 100 of any of the above-mentioned embodiments.

[0039] Specifically, the cleaning method includes:

[0040] In step S10 , the substrate clamp 120 is raised or lowered to a predetermined height above the nozzle 141 and rotated at a predetermined speed.

[0041] In step S20 , the nozzle 141 sprays the first cleaning liquid at a preset flow rate toward a preset position of the substrate 200 and / or the sealing member 123 , wherein the spraying direction t has a component consistent with the tangent direction m of the rotation direction s of the substrate holder 120 passing through the preset position.

[0042] Preferably, the cleaning method further comprises:

[0043] In step S30 , the first cleaning liquid is switched to a second cleaning liquid to clean the sealing member 123 , wherein the first cleaning liquid is an acidic cleaning liquid and the second cleaning liquid is pure water.

[0044] In actual application, the seal 123 is first cleaned with an acidic cleaning solution, and then the acidic cleaning solution is switched to pure water to clean the seal 123. This can remove the acidic cleaning solution attached to the surface of the seal 123, thereby preventing the acidic cleaning solution attached to the surface of the seal from corroding the seal after the seal is cleaned. The above-mentioned acidic cleaning solution includes sulfuric acid, nitric acid, and a mixed solution of sulfuric acid and nitric acid.

[0045] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. For those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be considered as the scope of protection of the present invention.

Claims

1. An electroplating device, characterized in that, Comprising: A process chamber for storing electroplating solution to electroplate a substrate; A substrate fixture for moving the substrate into or out of the process chamber. The substrate fixture includes a fixture body and a seal. The fixture body is used to carry the substrate, and during the electroplating process, the seal isolates the edge of the substrate from the electroplating solution, and the bottom of the seal contacts the electroplating solution; A drive system for driving the substrate fixture to lift and rotate; A cleaning system including a nozzle, a cleaning liquid tank, and a cleaning liquid supply pipeline. The cleaning liquid tank supplies cleaning liquid to the nozzle through the cleaning liquid supply pipeline. The nozzle has an upwardly inclined spraying direction for spraying the cleaning liquid to a preset position of the substrate and / or the seal to clean the seal. Wherein, the spraying direction has a component consistent with the tangential direction of the rotation direction of the substrate fixture passing through the preset position; A control system communicatively connected to the drive system and the cleaning system, for controlling the drive system to lift the substrate fixture to a preset height higher than the nozzle and rotate at a preset speed during cleaning the seal, and controlling the cleaning system to make the nozzle spray the cleaning liquid at a preset flow rate.

2. The electroplating apparatus according to claim 1, wherein The preset speed is 100 r / min to 400 r / min.

3. The electroplating apparatus according to claim 1, wherein The preset flow rate is 0.5 L / min to 1.5 L / min.

4. The electroplating apparatus according to claim 1, wherein The angle between the spraying direction and the horizontal plane is 5° to 30°.

5. The electroplating apparatus according to claim 1, wherein During cleaning the seal, the substrate carried by the fixture body is a dummy wafer.

6. The electroplating apparatus according to claim 1, wherein During cleaning the seal, the nozzle sprays the cleaning liquid to a preset position of the substrate and / or the seal, and at this time, the component of the spraying direction in the horizontal plane and the tangential direction of the rotation direction in the horizontal plane passing through the preset position are in the same direction.

7. The electroplating apparatus according to claim 1, wherein During cleaning the seal, the nozzle sprays the cleaning liquid to a preset position of the substrate and / or the seal, and at this time, the angle between the component of the spraying direction in the horizontal plane and the tangential direction of the rotation direction in the horizontal plane passing through the preset position is an acute angle.

8. The electroplating apparatus according to claim 1, wherein During cleaning the seal, the nozzle is configured to spray the cleaning liquid to the area between the center of the substrate and the seal.

9. The electroplating apparatus according to claim 1, wherein The nozzle is a linear nozzle or a fan-shaped nozzle.

10. A cleaning method, characterized in that, Applicable to the electroplating apparatus according to any one of claims 1-9, including: Step S10, the substrate fixture is lifted to a preset height higher than the nozzle and rotates at a preset speed; Step S20, the nozzle sprays a first cleaning liquid at a preset flow rate onto a preset position of the substrate and / or the seal, and the spraying direction has a component consistent with the tangential direction of the rotation direction of the substrate fixture passing through the preset position.

11. The cleaning method according to claim 10, wherein during the cleaning of the seal, the substrate carried by the fixture body is a dummy wafer.

12. The cleaning method according to claim 11, wherein It further includes: Step S30, switching the first cleaning liquid to a second cleaning liquid to clean the seal, wherein the first cleaning liquid is an acidic cleaning liquid and the second cleaning liquid is pure water.

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