Electroplating device and cleaning method

Abstract

The invention discloses an electroplating device and a cleaning method. The electroplating device comprises a substrate clamp which comprises a clamp body, a conductive contact and a sealing piece, the bottom of the clamp body extends inwards in the radial direction to form a substrate supporting part, the sealing piece is arranged on the surface of the substrate supporting part, and the tail end of the substrate supporting part protrudes upwards to form a sealing lip part; the sealing element and / or the clamp main body are / is provided with a groove for accommodating the conductive contact on one side, which is radially outward, of the sealing lip part; the cleaning system is used for injecting cleaning liquid into the groove to soak and clean the conductive contact; and the control system is used for controlling the substrate clamp and the cleaning system to periodically perform soaking cleaning and spin-drying treatment on the conductive contact, so that the cleaning effect of the substrate clamp is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor devices, and further relates 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 electroplating solution onto the surface of the substrate to form metal interconnections during chip manufacturing.

[0003] In the existing electroplating device, the substrate fixture includes conductive pins and seals that contact the substrate. Among them, the conductive pins should uniformly contact the seed layer on the front surface of the substrate. At the same time, the conductive pins cannot directly contact the electroplating solution. Therefore, seals are needed to isolate the electroplating solution so that it 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, residues such as residual electroplating solution and even photoresist often remain on the conductive pins and seals. This part of the residue will affect the substrate manufacturing process, such as causing uneven electric field distribution on the substrate, substrate seal failure, and wafer pick-up failure when the manipulator transfers the substrate after electroplating.

[0004] The document with the patent application number 201911077619.1 provides an electroplating device and a cleaning method. By arranging the middle section of the cleaning tube in contact with the electroplating solution in the electroplating solution storage tank, the middle section of the cleaning tube is heated by the electroplating solution with a preset temperature to obtain heated cleaning liquid, and then the cleaning liquid is heated by the electroplating solution with a preset temperature for spraying and cleaning the substrate fixture to remove residues. Summary of the Invention

[0005] Aiming at the above technical problems, the purpose of the present application is to improve the cleaning effect of the substrate fixture of the electroplating device.

[0006] To achieve the above purpose, the present application provides an electroplating device and a cleaning method.

[0007] In some embodiments, the above electroplating device includes: a substrate fixture, including a fixture body, conductive contacts, and seals. The bottom of the fixture body extends radially inward to form a substrate support portion. The seal is disposed on the surface of the substrate support portion and protrudes upward at the end of the substrate support portion to form a sealing lip. The seal and / or the fixture body has a groove for accommodating the conductive contacts on the radially outward side of the sealing lip; a cleaning system for injecting cleaning liquid into the groove to soak and clean the conductive contacts; a control system for controlling the substrate fixture and the cleaning system to periodically soak and dry the conductive contacts.

[0008] In some embodiments, the above cleaning method includes:

[0009] Step S01: Lift the substrate fixture without load to a preset height so that the substrate fixture is higher than the nozzles of the cleaning system; Step S02: Rotate the substrate fixture at a first rotation speed, and the nozzles spray cleaning liquid into the grooves for a first preset duration at a preset flow rate to soak and clean the conductive contacts. Before the volume of the cleaning liquid injected into the grooves exceeds the maximum water storage capacity of the grooves, the nozzles stop spraying the cleaning liquid; Step S03: Rotate the substrate fixture at a second rotation speed for a second preset duration, and the second rotation speed is greater than the first rotation speed to spin-dry the cleaning liquid in the grooves.

[0010] Compared with the prior art solution of spraying and cleaning the substrate fixture with nozzles, in this application, by performing periodic soaking cleaning and spin-drying treatment on the conductive contacts, the contact between the cleaning liquid and the conductive contacts is more sufficient, and it is easier to remove the residues on the surface of the conductive contacts, thereby enhancing the cleaning effect of the substrate fixture. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0013] Figure 2a is a Figure 1 partial enlarged view of area a according to an embodiment of the present application;

[0014] Figure 2b is a Figure 1 partial enlarged view of area a according to another embodiment of the present application;

[0015] Figure 3 is a schematic diagram of an electroplating device according to an embodiment of the present application;

[0016] Figure 4 is Figure 3 partial enlarged view of area b;

[0017] Figure 5 is Figure 2a schematic diagram of the cleaning liquid in the shown groove in the state of maximum water storage capacity;

[0018] Figure 6 is a step diagram of a cleaning method according to an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will describe the specific embodiments of the present invention 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 embodiments can also be obtained.

[0020] To simplify the drawings, only the parts related to the invention are schematically shown in each figure, and they do not represent the actual structure of the product. Additionally, to simplify the drawings for easy understanding, in some figures, for components with the same structure or function, only one of them is schematically shown, or only one of them is labeled. In this document, "one" not only means "only this one" but also can mean "more than one" situation.

[0021] In this document, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected", and "coupled" 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.

[0022] 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.

[0023] As Figure 1 and Figure 2a shown, an electroplating apparatus 100 according to an embodiment of the present application is disclosed, including a substrate fixture 120, a cleaning system 130, and a control system 140.

[0024] Among them, the substrate fixture 120 includes a fixture body 121, a conductive contact 122, and a seal 123. A substrate support portion 1211 extends radially inward from the bottom of the fixture body 121. The seal 123 is disposed on the surface of the substrate support portion 1211, and a sealing lip 1231 protrudes upward at the end of the substrate support portion 1211. The seal 123 and / or the fixture body 121 has a groove 1232 for accommodating the conductive contact 122 on the radially outward side of the sealing lip 1231. The cleaning system 130 is used to inject cleaning liquid into the groove 1232 to soak and clean the conductive contact 122. The control system 140 is used to control the substrate fixture 120 and the cleaning system 130 to periodically soak, clean, and spin-dry the conductive contact 122. It should be noted that the fixture body 121 is usually adapted to the shape of the substrate 200. For example, when the substrate 200 is circular, the fixture body 121 is in an annular shape. Therefore, the "radial direction" in the previous text can be understood as the direction from a certain position on the fixture body towards its center line. In addition, the end of the substrate support portion 1211 in the previous text refers to the end of the substrate support portion 1211 close to the center line of the fixture body 121.

[0025] Specifically, the substrate fixture 120 further includes an inner pressure ring 126 and an outer pressure ring 127. Among them, the inner pressure ring 126 is locked on the inner peripheral surface 1212 of the fixture body 121, and the outer pressure ring 127 is locked on the outer peripheral surface 1213 of the fixture body 121. The seal 123 includes an inner end portion 1233, a seal body 1234, and an outer end portion 1235. The outer end portion 1235 is fixed between the outer pressure ring 127 and the fixture body 121, the inner end portion 1233 is fixed between the inner pressure ring 126 and the fixture body 121, and the seal body 1234 covers the upper surface, inner peripheral surface, and lower surface of the substrate support portion 1211. The sealing lip 1231 is formed on the upper surface of the seal body 1234, and the sealing lip 1231 is higher than the upper surface of the seal body 1234, so that a groove 1232 is formed between the upper surface of the seal body 1234 on the radially outward side of the sealing lip 1231 and the inner pressure ring 126, that is, the groove 1232 is located on the upper surface of the seal body 1234. In addition, one end 1221 of the conductive contact 122 is fixed between the inner end portion 1233 of the seal 123 and the inner pressure ring 126, and the other end 1222 of the conductive contact 122 extends into the groove 1232 along the surface of the seal body 1234.

[0026] As Figure 2bAs shown, in another embodiment of the present application, the substrate fixture 120 includes an inner pressure ring 129, and the inner pressure ring 129 is locked on the inner circumferential surface 1212 of the fixture body 121. The end of the substrate support portion 1211 protrudes upward, and the protruding portion 1214 is covered by the seal 123 to form a sealing lip 1231. A groove 1232 is formed between the upper surface of the substrate support portion 1211 and the inner pressure ring 129 on the radially outward side of the sealing lip 1231, and the upper surface of the substrate support portion 1211 on the radially outward side of the sealing lip 1231 is not covered by the seal 123, that is, the groove 1232 is located on the upper surface of the substrate support portion 1211. In addition, one end 1221 of the conductive contact 122 is fixed between the substrate support portion 1211 and the inner pressure ring 126, and the other end 1222 of the conductive contact 122 extends into the groove 1232 along the surface of the substrate support portion 1211.

[0027] In practical applications, when the substrate fixture 120 is in an unloaded state, as Figure 1 , Figure 2a and Figure 2b shown, the end 1222 of the conductive contact 122 far from the inner pressure ring 126 has a spring-back height greater than that of the sealing lip 1231; when the substrate fixture 120 is in a state of loading the substrate 200, as Figure 3 and Figure 4 shown, the substrate 200 is clamped between the pressing plate 128 and the substrate support portion 1211. The end 1222 of the conductive contact 122 far from the inner pressure ring 126 is deformed under the pressure of the edge of the substrate 200, so that the conductive contact 122 makes sufficient electrical contact with the substrate 200 until the edge of the substrate 200 is in sealing contact with the sealing lip 1231, isolating the conductive contact 122 from the electroplating solution in the process chamber 110.

[0028] Preferably, the cleaning system 130 includes a nozzle 131, and the nozzle 131 is configured to spray cleaning liquid into the groove 1232. Among them, during the immersion cleaning, the control system 140 controls the substrate fixture 120 to rotate at a first speed, and the nozzle 131 sprays the cleaning liquid into the groove 1232 for a first preset duration at a preset flow rate, and the cleaning liquid injected into the groove 1232 does not exceed the maximum water storage capacity of the groove 1232; during the spin-drying process, the control system 140 controls the nozzle 131 to stop spraying the cleaning liquid, and the substrate fixture 120 rotates at a second speed for a second preset duration, and the second speed is greater than the first speed to spin-dry the cleaning liquid in the groove 1232. In addition, the cleaning system 130 further includes a cleaning liquid storage tank 132, and the cleaning liquid storage tank 132 is connected to the nozzle 131 through a pipeline 133 for supplying cleaning liquid to the nozzle 131.

[0029] Preferably, the nozzle 131 is configured to have an upwardly inclined jet direction, and the fixture body 121 is located above the nozzle 131 during the immersion cleaning. In practical applications, a fixture bracket 124 (refer to Figure 1 ) is provided above the fixture body 121 for connecting the fixture body 121 to the driving device 125. If the nozzle 131 is configured to have a downwardly inclined jet direction, the fixture body 121 needs to be moved below the nozzle 131 during the immersion cleaning, and the fixture bracket 124 will obstruct the jet path of the nozzle 131, causing the cleaning liquid to be sprayed onto the surface of the fixture bracket 124, reducing the cleaning efficiency, and there is a risk of dripping into the process chamber 110 and contaminating the electroplating solution.

[0030] Specifically, referring again to Figure 2a , during the immersion cleaning, the nozzle 131 sprays the cleaning liquid along the jet path s onto the inner wall of the inner pressure ring 126, and the cleaning liquid flows from the inner wall of the inner pressure ring 126 along the conductive contact 122 into the groove 1232 until the other end 1222 of the conductive contact 122 is immersed in the cleaning liquid. It should be noted that due to the surface tension of the cleaning liquid, in some cases, the liquid level in the groove 1232 is slightly higher than the top of the groove 1232, and the other end 1222 of the conductive contact 122 can be immersed.

[0031] Preferably, as shown in Figure 3 , the electroplating device 100 further includes a process chamber 110.

[0032] Specifically, the process chamber 110 includes an inner cavity 111, an overflow tank 112, and a protective cover 113. Among them, the inner cavity 111 is used to store the electroplating solution and has an opening 1111. The substrate fixture 120 is moved into or out of the inner cavity 111 through the opening 1111. The overflow tank 112 is constructed around the periphery of the opening 1111 for collecting the electroplating solution overflowing from the inner cavity 111. The protective cover 113 is constructed around the overflow tank 112 for blocking the cleaning liquid thrown out by the substrate fixture 120 during the spin-drying process, and the nozzle 131 is constructed on the inner side wall 1131 of the protective cover 113.

[0033] Preferably, the inner side wall 1131 is constructed with an annular collecting groove 1132 for collecting the cleaning liquid thrown out by the substrate fixture 120 during the spin-drying process, and the nozzle 131 is constructed in the annular collecting groove 1132. In this embodiment, the annular collecting groove 1132 can not only collect the cleaning liquid thrown out by the substrate fixture 120 during the spin-drying process but also collect the cleaning liquid remaining on the nozzle 131, reducing the risk of contamination of the electroplating solution in the process chamber 110.

[0034] Preferably, at least two nozzles 131 are provided on the inner side wall 1131 of the protective cover 113, and the at least two nozzles 131 are spaced apart and arranged on the same circumference. In this embodiment, by increasing the number of nozzles 131, the speed of injecting the cleaning liquid into the groove 1232 can be increased, thereby reducing the first preset duration of spraying the cleaning liquid into the groove 1232 and increasing the cleaning efficiency of the equipment.

[0035] Preferably, the first rotation speed is configured such that during the rotation of the substrate clamp 120 at the first rotation speed, the nozzle 131 sprays the cleaning liquid into the groove 1232 for a first preset duration at a preset flow rate, and the substrate clamp 120 does not throw out the cleaning liquid; the second rotation speed is configured such that during the rotation of the substrate clamp 120 at the second rotation speed, the substrate clamp 120 throws out the cleaning liquid.

[0036] Preferably, the first rotation speed is 100 r / min to 150 r / min, the first preset duration is 3 s to 4 s, and the preset flow rate is 150 ml / min to 200 ml / min; the second rotation speed is 300 r / min to 400 r / min, and the second preset duration is 4 s to 5 s.

[0037] Specifically, to avoid excessive cleaning liquid being injected into the groove 1232, resulting in the cleaning liquid overflowing from the groove 1232 and dripping into the inner cavity 111, causing contamination of the plating solution, the first preset duration T1, the preset flow rate Q, and the maximum water storage capacity V max should satisfy: T1 * Q ≤ V max .

[0038] In addition, the groove 1232 has an annular structure, and the bottom surface of the groove 1232 is circular. When the volume of the cleaning liquid injected into the groove 1232 approaches the maximum water storage capacity V max of the groove 1232, as Figure 5 shown, the cross-section of the cleaning liquid remaining in the groove 1232 is approximately triangular 1321. If the center line of the substrate clamp 120 is taken as the Y-axis upward and the straight line 1322 passing through the inner bottom surface of the groove 1232 in the radial direction of the substrate clamp 120 is taken as the X-axis to establish a two-dimensional coordinate system, that is, the maximum water storage capacity V max is approximately equal to the volume of the triangle 1321 rotating one week around the Y-axis. Additionally, assuming that the coordinates of the three vertices of the triangle 1321 are (m, 0), (n, 0), and (n, h) respectively, then:

[0039] V max = (πn 2 * h - πm 2 * h) / 2 = π(n 2 - m 2 ) * h / 2; where

[0040] m: the inner circle radius of the bottom surface of the groove;

[0041] n: The outer circle radius of the bottom surface of the groove;

[0042] h: The height of the conductive contact from the bottom surface of the groove.

[0043] If the measured data are m = 148 mm, n = 153 mm, and h = 5 mm;

[0044] Substituting into the above formula gives V max ≈ 11.820 ml;

[0045] Under the premise of satisfying T1 * Q ≤ V max Multiple tests are carried out, and the best value of the first preset duration T1 is 3.5 s, and the best value of the preset flow rate Q is 180 ml / min.

[0046] Further, based on the preset flow rate Q = 180 ml / min for testing, it is obtained that when the first rotation speed is 150 r / min, the cleaning liquid is most stable when injected into the groove 1232. If the first rotation speed is too high, the centrifugal force on the cleaning liquid will be relatively large, resulting in the cleaning liquid being thrown out of the groove 1232. If the first rotation speed is too low, too much cleaning liquid will be injected into the same area of the groove 1232, resulting in the cleaning liquid overflowing from the groove 1232.

[0047] In addition, based on V max ≈ 11.820 ml for testing, it is obtained that when the second rotation speed is 400 r / min and the first preset duration T1 is 4 s, all the cleaning liquid in the groove 1232 can be thrown out.

[0048] As Figure 6 shown, a cleaning method according to an embodiment of the present application is disclosed. This method is applicable to the electroplating device 100 in any of the above embodiments, including:

[0049] Step S01: Lift the empty substrate fixture 120 to a preset height so that the substrate fixture 120 is higher than the nozzle 131 of the cleaning system 130;

[0050] Step S02: Rotate the substrate fixture 120 at a first rotation speed, and the nozzle 131 sprays the cleaning liquid into the groove 1232 for a first preset duration at a preset flow rate to soak and clean the conductive contact 122, and before the volume of the cleaning liquid injected into the groove 1232 exceeds the maximum water storage capacity of the groove 1232, the nozzle 131 stops spraying the cleaning liquid;

[0051] Step S03, rotate the substrate fixture 120 at a second rotation speed for a second preset duration, and the second rotation speed is greater than the first rotation speed to spin-dry the cleaning liquid in the groove 1232.

[0052] Wherein, the steps S02 and S03 are repeatedly executed at least once to complete the cleaning of the conductive contact.

[0053] In this embodiment, by performing periodic immersion cleaning and spin-drying treatment on the conductive contact 122, the contact between the cleaning liquid and the conductive contact 122 is made more sufficient, and it is easier to remove the residues on the surface of the conductive contact 122, thereby increasing the cleaning effect of the substrate fixture 120.

[0054] It should be noted that the above embodiments can be freely combined as needed. The above are only the preferred embodiments of the present invention. For those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An electroplating device, characterized in that, Including: A substrate fixture, comprising a fixture body, a conductive contact, and a seal. A substrate support portion extends radially inward from the bottom of the fixture body. The seal is disposed on the surface of the substrate support portion and protrudes upward at the end of the substrate support portion to form a sealing lip. The seal and / or the fixture body has a groove on the radially outward side of the sealing lip for accommodating the conductive contact; A cleaning system for injecting a cleaning liquid into the groove to soak and clean the conductive contact; A control system for controlling the substrate fixture and the cleaning system to periodically soak and clean and spin-dry the conductive contact.

2. The electroplating device according to claim 1, wherein, The cleaning system includes: A nozzle configured to spray the cleaning liquid into the groove; wherein, During the soaking and cleaning, the control system controls the substrate fixture to rotate at a first speed, the nozzle sprays the cleaning liquid into the groove at a preset flow rate for a first preset duration, and the cleaning liquid injected into the groove does not exceed the maximum water storage capacity of the groove; During the spin-drying process, the control system controls the nozzle to stop spraying the cleaning liquid, and the substrate fixture rotates at a second speed for a second preset duration, and the second speed is greater than the first speed to spin-dry the cleaning liquid in the groove.

3. The electroplating device according to claim 2, wherein, The maximum water storage capacity V max =(πn 2 *h - πm 2 *h) / 2; Wherein, m: the inner circle radius of the bottom surface of the groove; n: the outer circle radius of the bottom surface of the groove; h: the height of the conductive contact from the bottom surface of the groove.

4. The electroplating device according to claim 2, wherein, The nozzle is configured to have an inclined upward spraying direction, and the fixture body is located above the nozzle during the soaking and cleaning.

5. The electroplating device according to claim 2, wherein It further includes a process chamber, and the process chamber includes: An inner cavity for storing electroplating liquid. The inner cavity has an opening, and the substrate fixture moves into or out of the inner cavity through the opening; An overflow tank constructed around the opening for collecting the electroplating liquid overflowing from the inner cavity; A protective cover constructed around the overflow tank for blocking the cleaning liquid thrown out by the substrate fixture during the spin-drying process. The nozzle is constructed on the inner side wall of the protective cover.

6. The electroplating device according to claim 5, wherein, The inner side wall is constructed with an annular collecting groove for collecting the cleaning liquid thrown out by the substrate fixture during the spin-drying process. The nozzle is constructed in the annular collecting groove.

7. The electroplating device according to claim 5, wherein, At least two nozzles are provided on the inner side wall of the protective cover, and the at least two nozzles are spaced apart on the same circumference.

8. The electroplating device according to claim 2, wherein, The first speed is configured such that when the substrate fixture rotates at the first speed, if the nozzle sprays the cleaning liquid into the groove at a preset flow rate for a first preset duration, the substrate fixture does not throw out the cleaning liquid; The second rotation speed is configured such that during the rotation of the substrate fixture at the second rotation speed, the substrate fixture flings out the cleaning liquid.

9. The electroplating apparatus according to claim 8, wherein the first rotation speed is 100 r / min to 150 r / min, the first preset duration is 3 s to 4 s, and the preset flow rate is 150 ml / min to 200 ml / min; the second rotation speed is 300 r / min to 400 r / min, and the second preset duration is 4 s to 5 s.

10. A cleaning method, characterized in that, Applicable to the electroplating apparatus according to any one of claims 1-9, comprising: Step S01: Lift the empty substrate fixture to a preset height so that the substrate fixture is higher than the nozzle of the cleaning system; Step S02: Rotate the substrate fixture at the first rotation speed, and the nozzle sprays the cleaning liquid into the groove for a first preset duration at a preset flow rate to soak and clean the conductive contact, and before the volume of the cleaning liquid injected into the groove exceeds the maximum water storage capacity of the groove, the nozzle stops spraying the cleaning liquid; Step S03, the substrate fixture rotates at the second rotation speed for a second preset duration, and the second rotation speed is greater than the first rotation speed to spin-dry the cleaning liquid in the groove; wherein, steps S02 and S03 are repeatedly executed at least once to complete the cleaning of the conductive contact.

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