Electroplating device and cleaning method

Abstract

The invention discloses an electroplating device and a cleaning method. The electroplating device comprises a process cavity used for storing electroplating liquid; the substrate clamp comprises a clamp main body and a sealing piece; the driving system is used for driving the substrate clamp to lift and rotate; the cleaning system comprises a nozzle, a cleaning liquid tank and a cleaning liquid supply pipeline, the nozzle has an obliquely upward spraying direction and is used for spraying cleaning liquid to a preset position of the substrate and / or the sealing element to clean the sealing element, and the spraying direction has a component consistent with the tangential direction of the rotation direction of the substrate clamp passing through the preset position; and the control system is used for controlling the driving system to lift the substrate clamp to a preset height higher than the nozzle during cleaning of the sealing element, rotating the substrate clamp at a preset rotating speed and controlling the cleaning system to enable the nozzle to spray the cleaning liquid at a preset flow. According to the sealing element cleaning device, the sealing element cleaning function is achieved, and the water falling amount of cleaning liquid in the sealing element cleaning period is reduced.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor devices, and further relates to an electroplating apparatus and a cleaning method. Background Art

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

[0003] In the existing electroplating apparatus, the substrate fixture includes conductive needles and seals that contact the substrate. Among them, the conductive needles should uniformly contact the seed layer on the front surface of the substrate. At the same time, the conductive needles cannot directly contact the electroplating solution. Therefore, seals are needed to isolate it so that the electroplating solution cannot reach the edge of the front surface of the substrate. Otherwise, the edge of the front surface of the substrate will be plated with metal, and the uniformity of the metal thin film deposited on the substrate will deteriorate. After electroplating, there are often residues on the seals, such as residual electroplating solution and electroplated metal deposition, etc.

[0004] Taking the electroplating of tin-silver alloy as an example, during the electroplating of tin-silver alloy, the residues on the seals of the substrate fixture occur due to the significantly different reduction potentials of atomic tin and atomic silver. The generation of residues first involves plating tin (less silver content) on the surface of the seal, and then a displacement reaction occurs on the surface of the substrate fixture (Sn + 2Ag + →Sn 2+ + 2Ag), resulting in the reduction of silver ions to silver atoms, thereby forming a deposition of metallic silver on the surface of the seal.

[0005] The document with the patent application number 201911077619.1 provides an electroplating apparatus and a cleaning method. By arranging an intermediate section of the cleaning tube in contact with the electroplating solution in the electroplating solution storage tank, the intermediate section of the cleaning tube is heated by the electroplating solution with a preset temperature to obtain a heated cleaning solution, and then the cleaning solution is heated by the electroplating solution with a preset temperature to be used for spraying and cleaning the substrate fixture to remove residues. Summary of the Invention

[0006] Aiming at the problem that there are residues on the seals of the substrate fixture after electroplating the substrate with the existing electroplating apparatus, the present application provides an electroplating apparatus and a cleaning method.

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

[0008] In some embodiments, the above electroplating device includes: a process chamber for storing electroplating solution to perform electroplating treatment on a substrate; a substrate fixture for moving the substrate into or out of the process chamber, the substrate fixture including a fixture body and a seal, the fixture body for carrying the substrate, and during the electroplating treatment, 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 solution tank, and a cleaning solution supply pipeline, the cleaning solution tank supplies cleaning solution to the nozzle through the cleaning solution supply pipeline, the nozzle has an upwardly inclined jet direction for jetting the cleaning solution to a preset position of the substrate and / or the seal to clean the seal, wherein the jet 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, and during the cleaning of the seal, the control system controls the drive system to lift the substrate fixture to a preset height higher than the nozzle and rotate at a preset speed, and controls the cleaning system to make the nozzle jet the cleaning solution at a preset flow rate.

[0009] In some embodiments, the above cleaning method includes: Step S10, lifting the substrate fixture to a preset height higher than the nozzle and rotating at a preset speed; Step S20, the nozzle jets a first cleaning solution at a preset flow rate to a preset position of the substrate and / or the seal, and the jet direction has a component consistent with the tangential direction of the rotation direction of the substrate fixture passing through the preset position.

[0010] Compared with the prior art, on the one hand, the present application cleans the seal through the nozzle of the cleaning system, which can timely remove the residues on the surface of the seal; on the other hand, by configuring the jet direction of the nozzle to have a component consistent with the tangential direction of the rotation direction of the substrate fixture passing through the preset position, combined with the rotation speed of the substrate fixture and the jet flow rate of the nozzle, the cleaning solution jetted onto the surface of the substrate and / or the seal is radially thrown out to the maximum extent, reducing the amount of cleaning solution dropping during the cleaning of the seal, thereby preventing the cleaning solution from dropping into the process tank and contaminating the electroplating solution. Description of the Drawings

[0011] The following will further illustrate the above characteristics, technical features, advantages and their implementation manners of the present invention in a clear and understandable manner in combination with the drawings of the preferred embodiments.

[0012] Figure 1 is a schematic diagram of an electroplating device according to an embodiment of the present application;

[0013] Figure 2 is Figure 1 a partial enlarged view of area a;

[0014] Figures 3a - 3d is Figure 1 Cross-sectional views of four implementation manners along the b-b direction;

[0015] Figure 4 is Figure 1 Schematic diagram of one implementation manner along the c-c direction;

[0016] Figure 5 Is a flowchart of a cleaning method according to an embodiment of the present application. Specific implementation manners

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation manners of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings, and other implementation manners can also be obtained.

[0018] To make the drawings concise, only the parts related to the invention are schematically shown in each drawing, and they do not represent the actual structure of the product. In addition, to make the drawings concise and easy to understand, in some drawings, parts with the same structure or function are only schematically shown as one of them, or only one of them is marked. In this article, "one" not only means "only this one", but also means "more than one" situation.

[0019] In this article, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0020] In addition, in the description of the present application, the terms "first", "second", etc. are only used for distinguishing descriptions, and cannot be understood as indicating or implying relative importance.

[0021] As Figure 1 and Figure 2 shown, a plating device 100 according to an embodiment of the present application is disclosed.

[0022] 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. Among them, the process chamber 110 is used to store the electroplating solution 1112 for electroplating the substrate 200. The substrate fixture 120 is used to move the substrate 200 into or out of the process chamber 110. Refer to Figure 2 , the substrate fixture 120 includes a fixture body 121 and a seal 123. The fixture body 121 is used to carry the substrate 200, and during the electroplating process, the seal 123 isolates the edge of the substrate 200 from the electroplating solution, and the bottom of the seal 123 contacts the electroplating solution.

[0023] Refer to again Figure 1 , the drive system 130 is used to drive the substrate fixture 120 to lift and rotate. The cleaning system 140 includes a nozzle 141, a cleaning liquid tank 143, and a cleaning liquid supply pipeline 142. The cleaning liquid tank 143 supplies the cleaning liquid to the nozzle 141 through the cleaning liquid supply pipeline 142. The nozzle 141 has an upwardly inclined spraying direction t (refer to Figure 4 ), and is used to spray the cleaning liquid to a preset position 1412 of the substrate 200 and / or the seal 123 to clean the seal 123. Among them, the spraying direction t has a component consistent with the tangent direction m of the rotation direction s of the substrate fixture 120 passing through the preset position 1412 (refer to Figure 3a ). The control system 150 is respectively communicatively connected to the drive system 130 and the cleaning system 140, and is used to control the drive system 130 to lift the substrate fixture 120 to a preset height higher than the nozzle 141 and rotate at a preset speed during the cleaning of the seal 123, and control the cleaning system 140 to make the nozzle 141 spray the cleaning liquid at a preset flow rate.

[0024] In this embodiment, the spraying direction t of the nozzle 141 is configured to have a component consistent with the tangent direction m of the rotation direction s of the substrate fixture 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 fixture 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 consistent with the tangent direction m of the rotation direction s of the substrate fixture 120 passing through the preset position 1412. Combining the rotation speed of the substrate fixture 120 and the spraying flow rate of the nozzle 141, the cleaning liquid sprayed onto the surface of the substrate fixture 120 is thrown outwards, reducing the amount of cleaning liquid falling during the cleaning of the seal 123, and further preventing the cleaning liquid from dropping into the process tank and contaminating the electroplating solution 1112.

[0025] Preferably, as Figure 2As shown, the substrate fixture 120 further includes a conductive contact 122 and a pressing plate 124. The fixture body 121 has an annular structure, and a substrate support portion 1211 extends radially inward from the bottom. The 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 plating solution 1112 during the electroplating of the substrate 200. The pressing plate 124 can move up and down under the drive of the drive system 130 and is used to fix the substrate 200 between the pressing plate 124 and the substrate support portion 1211. While fixing the substrate 200, the conductive contact 122 is brought into electrical contact with the edge of the substrate 200, so that the substrate 200 serves as a cathode during electroplating to deposit a metal layer on its surface.

[0026] In addition, the substrate fixture 120 further includes an inner pressure ring 125 and an outer pressure ring 126. The inner pressure ring 125 is locked to the inner peripheral surface 1212 of the fixture body 121, and the outer pressure ring 126 is locked to the outer peripheral surface 1213 of the fixture body 121. The inner pressure ring 125 is used to fix one side 1231 of the conductive contact 122 and the seal 123 between the inner pressure ring 125 and the upper end surface of the substrate support portion 1211, and the outer pressure ring 126 is used to fix 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 area of the cleaning system 140 for the seal 123 is concentrated 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 and the inner peripheral side 1234 of the seal 123. In addition, during the cleaning of the seal 123, the substrate fixture 120 is provided with the substrate 200 to prevent the nozzle 141 from spraying the cleaning liquid above the substrate fixture 120.

[0027] Preferably, during the cleaning of the seal 123, the substrate 200 carried by the substrate fixture 120 is a dummy wafer / test wafer. In practical applications, the substrate 200 includes prime wafers and dummy wafers. Prime wafers are also known as product-grade wafers, which have few surface and internal defects, impurity content close to the pure silicon level, good electrical properties, high production costs, and are suitable for the manufacturing of semiconductor products. For example, during the electroplating process of the substrate, the substrate 200 carried by the substrate fixture 120 is preferably a prime wafer. In contrast, dummy wafers have more surface and internal defects and higher impurity content, lower production costs, and are 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 a prime wafer for electroplating. During the cleaning of the seal 123, if an acidic cleaning solution is used to clean the seal 123, since the acidic cleaning solution may damage the coating on the surface of the prime wafer, the substrate 200 is preferably a dummy wafer; 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 prime wafer, the substrate 200 can be either a prime wafer or a dummy wafer.

[0028] 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 Figure 4 shown, the included angle α between the injection direction t and the horizontal plane L is 5° to 30°.

[0029] It should be noted that the above preset rotation speed, preset flow rate, and the included angle α between the injection direction t and the horizontal plane L are measured through multiple experiments. In actual operation, first, multiple test values of the preset rotation speed, multiple test values of the preset flow rate, and test values of the included angle α between the injection direction t and the horizontal plane L are set respectively, and the above different types of test values are arranged and combined to be divided into several groups of test values. Then, the electroplating device 100 is tested with each group of test values in turn, and the total water drop amount corresponding to each group of test values during the cleaning of the seal 123 is recorded. Finally, the test value range with the water drop amount lower than the preset value is statistically analyzed to obtain the best range value.

[0030] In the embodiment as Figure 3a shown, during the cleaning of the seal 123, the nozzle 141 sprays the cleaning solution to the preset position 1412 of the seal 123. At this time, the component of the injection direction t in the horizontal plane L and the tangent direction m of the horizontal plane L passing through the preset position 1412 in the rotation direction s are in the same direction. In this embodiment, the cleaning solution is sprayed onto the surface of the seal 123 in the injection direction t, and the speed at which the cleaning solution impacts the seal 123 is the minimum. While flushing the seal 123, the cleaning solution is thrown outwards, reducing the water drop amount of the cleaning solution.

[0031] In the embodiment asFigure 3b In the illustrated embodiment, during the cleaning of the seal 123, the nozzle 141 sprays the cleaning liquid onto a preset position 1412 of the seal 123. At this time, the angle β between the component of the spraying direction t in the horizontal plane L and the tangential direction m of the rotation direction s in the horizontal plane L passing through the preset position 1412 is an acute angle.

[0032] In the embodiment as Figure 3c illustrated, during the 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 position within the area 1413 can be used as the preset position. In this embodiment, the cleaning liquid does not directly rinse the seal 123, but during the process of the cleaning liquid flowing outward along the substrate 200, the cleaning liquid passes through the surface of the seal 123 to clean the seal 123.

[0033] Preferably, in the embodiment as Figure 3d illustrated, during the cleaning of the seal 123, the nozzle 141 is configured to spray the cleaning liquid onto an area 1414 on the surfaces of the substrate 200 and the seal 123. Any position within the area 1414 can be used as the preset position. In this embodiment, a part of the cleaning liquid is sprayed onto the surface of the substrate 200. During the process of this part of the cleaning liquid flowing outward along the substrate 200, the cleaning liquid passes through the surface of the seal 123 to clean the seal 123, and another part of the cleaning liquid directly rinses the seal 123 to clean the seal 123.

[0034] Specifically, the nozzle 141 is a linear nozzle or a fan-shaped nozzle. It should be noted that in the embodiments as Figure 3a and Figure 3b illustrated, 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 as Figure 3c illustrated, it is sufficient to spray the cleaning liquid onto the area between the center of the substrate 200 and the seal 123. The nozzle 141 can use either a linear nozzle or a fan-shaped nozzle. In the embodiment as Figure 3d illustrated, the cleaning liquid needs to be sprayed onto the surfaces of both the substrate 200 and the seal 123 simultaneously, and the nozzle 141 preferably uses a fan-shaped nozzle.

[0035] Preferably, referring again to Figure 1, the process chamber 110 includes an inner cavity 111 and an overflow tank 112. Among them, the inner cavity 111 is used to store the electroplating solution 1112 and has an opening 1111. The overflow tank 112 is circumferentially configured around the periphery of the opening 1111 and is used to collect the electroplating solution 1112 overflowing from the inner cavity 111. In addition, a protective cover 113 is configured above the overflow tank 112, and an annular collection groove 1131 is configured on the inner side wall of the protective cover 113. The annular collection groove 1131 is used to collect the cleaning solution thrown out by the substrate fixture 120 during the cleaning of the seal 123.

[0036] As Figure 5 shown, a cleaning method according to an embodiment of the present application is disclosed. This cleaning method is applicable to the electroplating device 100 in any of the above embodiments.

[0037] Specifically, this cleaning method includes:

[0038] Step S10, the substrate fixture 120 is lifted to a preset height higher than the nozzle 141 and rotated at a preset speed;

[0039] Step S20, the nozzle 141 sprays a first cleaning solution at a preset flow rate to a preset position of the substrate 200 and / or the seal 123, and the spraying direction t has a component consistent with the tangential direction m of the rotation direction s of the substrate fixture 120 passing through the preset position.

[0040] Preferably, this cleaning method further includes:

[0041] Step S30, switching the first cleaning solution to a second cleaning solution to clean the seal 123, where the first cleaning solution is an acidic cleaning solution and the second cleaning solution is pure water.

[0042] In practical applications, first use an acidic cleaning solution to clean the seal 123, and then switch the acidic cleaning solution to pure water to clean the seal 123, which 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 cleaning is completed. The above acidic cleaning solution includes sulfuric acid, nitric acid, and a mixed solution of sulfuric acid and nitric acid, etc.

[0043] It should be noted that the above embodiments can be freely combined as needed. The above is only the preferred embodiment of the present invention. For those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. An electroplating device, characterized in that, Comprising: A process chamber for storing electroplating solution to perform electroplating treatment on 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 treatment, 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, configured to, during cleaning the seal, control the drive system to lift the substrate fixture to a preset height higher than the nozzle and rotate at a preset speed, and control 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. 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. 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 to 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, characterized in that, 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.

Images