Substrate holder, plating apparatus, plating method, and storage medium

Abstract

The present invention inhibits or prevents plating liquid from invading a sealed space of a substrate holder, and early detects a case where plating liquid has invaded. A substrate holder for holding a substrate and bringing the substrate into contact with plating liquid to perform plating, wherein the substrate holder has: an internal space that houses a peripheral portion of the substrate in a state of being sealed from the outside of the substrate holder in a state where the substrate is held by the substrate holder; a contact member that is disposed in the internal space, contacts a seed layer formed on a surface of the substrate in a state where liquid is introduced into the internal space, and causes plating current to flow into the substrate; and an electrode that is disposed in the internal space and is biased to a high potential side with respect to the contact member.

Description

[0001] This application is a divisional application of the invention patent application with patent application number 202180053463.2 (international filing date: January 8, 2021, entitled "substrate support, plating apparatus, plating method and storage medium"). Technical Field

[0002] This invention relates to a substrate support, a plating apparatus, a plating method, and a storage medium storing a program that enables a computer to execute a control method for the plating apparatus. Background Technology

[0003] In electroplating, if the plating solution leaks into the substrate support due to certain defects (such as unevenness of the substrate or aging of the seal), the seed layer may be corroded and / or dissolved due to the intrusion of the plating solution into the support, resulting in poor conductivity and reduced plating uniformity.

[0004] U.S. Patent No. 7,727,366 (Patent Document 1) and U.S. Patent No. 8,168,057 (Patent Document 2) describe a method of pressurizing one side of a substrate seal with a fluid to prevent fluid from entering from the opposite side of the seal. Japanese Patent Application Publication Nos. 2020-117763 (Patent Document 3) and 2020-117765 (Patent Document 4) describe injecting liquid into the internal space of the outer periphery of a sealed substrate to prevent plating liquid from entering the internal space, thereby preventing plating from depositing on the outer periphery of the substrate and contact parts.

[0005] Patent Document 1: US Patent No. 7,727,366

[0006] Patent Document 2: US Patent No. 8,168,057

[0007] Patent Document 3: Japanese Patent Application Publication No. 2020-117763

[0008] Patent Document 4: Japanese Patent Application Publication No. 2020-117765

[0009] Even if countermeasures such as those described in the aforementioned patent documents are adopted, there is still a possibility that the plating liquid may penetrate into the internal space due to the unevenness of the substrate and the degree of aging of the seal. However, the aforementioned patent documents do not describe any effective countermeasures in the event that the plating liquid has penetrated into the internal space. Summary of the Invention

[0010] One objective of this invention is to suppress or prevent plating solution from intruding into the sealed space of the substrate support, and to detect plating solution intrusion at an early stage. Another objective of this invention is to prevent a decrease in the uniformity of the plating film thickness even if plating solution intrudes into the sealed space of the substrate support.

[0011] According to one embodiment, a substrate holder is provided for holding a substrate and bringing the substrate into contact with a plating solution for plating. The substrate holder includes: an internal space that, while holding the substrate, contains the outer periphery of the substrate in a sealed manner relative to the outside of the substrate holder; a first passage that connects the outside of the substrate holder to the internal space and introduces liquid into the internal space; and a detector disposed in the internal space for monitoring the current flowing into the liquid during plating or the resistance of the liquid while the liquid is introduced into the internal space, thereby detecting leakage of the plating solution into the internal space.

[0012] According to one embodiment, the substrate support may include: a contact disposed in the internal space, in contact with a seed layer formed on the surface of the substrate, and to allow plating current to flow into the substrate; and a soluble electrode biased toward a high potential side relative to the contact. Attached Figure Description

[0013] Figure 1 This is an overall configuration diagram of a plating apparatus according to one embodiment.

[0014] Figure 2 This is a simplified diagram representing the plating module.

[0015] Figure 3 This is a simplified diagram showing the front panel of the substrate support as viewed from the inside.

[0016] Figure 4 This is a simplified diagram showing the back panel of the substrate support as viewed from the inside.

[0017] Figure 5 This is a simplified diagram of the substrate support in the pre-humidification module.

[0018] Figure 6A It is a simplified cross-section of the internal space of the substrate support in the plating tank, magnified.

[0019] Figure 6B It is a simplified cross-section of the internal space of the substrate support in the plating tank, magnified.

[0020] Figure 6C This is a simplified cross-sectional view of the interior space of the substrate support of the comparative example in the plating bath, magnified.

[0021] Figure 7 This is an illustration of how dissolved oxygen concentration causes the seed layer to dissolve.

[0022] Figure 8A This is an illustration of the dissolution of the seed layer caused by the shunt current.

[0023] Figure 8B This is an equivalent circuit diagram illustrating the shunt current. Detailed Implementation

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, there are instances where the same or similar elements are labeled with the same or similar reference numerals, and repeated descriptions related to the same or similar elements are omitted in the description of each embodiment. Furthermore, features shown in each embodiment can also be applied to other embodiments, provided they do not contradict each other.

[0025] In this specification, "substrate" includes not only semiconductor substrates, glass substrates, liquid crystal substrates, and printed circuit boards, but also magnetic recording media, magnetic recording sensors, mirrors, optical elements, micro-mechanical components or locally fabricated integrated circuits, and other arbitrary objects to be processed. Substrate includes substrates of any shape, including polygons and circles. Furthermore, although expressions such as "front surface," "rear surface," "front," "back," "upper," "lower," "left," and "right" are used in this specification, they are for convenience of explanation to indicate the position and orientation on the paper of the illustrated drawings, and may differ from the actual configuration during device use.

[0026] Figure 1 This is an overall configuration diagram of a plating apparatus according to one embodiment. The plating apparatus 100 is located on a substrate support 200 ( Figure 2 The plating apparatus 100 is generally divided into a loading / unloading station 110 for loading or unloading substrates from a substrate support 200, a processing station 120 for processing the substrates, and a cleaning station 50a. The processing station 120 is equipped with a pre-processing module 120A for pre-processing and post-processing the substrates, and a plating module 120B for plating the substrates.

[0027] The loading / unloading station 110 has one or more cassette worktables 25 and substrate loading / unloading modules 29. The cassette worktable 25 is equipped with a cassette 25a that holds the substrate. The substrate loading / unloading module 29 is configured to load and unload the substrate onto the substrate holder 200. Additionally, a temporary storage cassette 30 for housing the substrate holder 200 is provided near (e.g., below) the substrate loading / unloading module 29. The cleaning station 50a has a cleaning module 50 for cleaning and drying the plated substrate. The cleaning module 50 is, for example, a spin dryer.

[0028] A transport robot 27 is positioned within the enclosure of the cassette workbench 25a, the substrate loading / unloading module 29, and the cleaning station 50a. The transport robot 27 is configured to move via a travel mechanism 28. For example, the transport robot 27 is configured to remove a substrate from the cassette 25a before plating and transport it to the substrate loading / unloading module 29, receive the plated substrate from the substrate loading / unloading module 29, transport the plated substrate to the cleaning module 50, remove the cleaned and dried substrate from the cleaning module 50, and store it in the cassette 25a.

[0029] The pre-treatment and post-treatment module 120A includes a pre-wetting module 32, a pre-immersion module 33, a first rinsing module 34, an air supply module 35, and a second rinsing module 36. The pre-wetting module 32 wets the substrate surface to be plated before plating using a treatment liquid such as pure water or degassed water, thereby replacing the air inside the pattern formed on the substrate surface with the treatment liquid. The pre-wetting module 32 is configured to perform a pre-wetting treatment that replaces the treatment liquid inside the pattern with plating liquid during plating, thereby facilitating the supply of plating liquid to the pattern. The pre-immersion module 33, for example, is configured to perform a pre-immersion treatment that cleans or activates the surface of the substrate to be plated by etching away oxide films with high resistance, such as those on the seed layer surface of the substrate surface to be plated before plating, using a treatment liquid such as sulfuric acid or hydrochloric acid. In the first rinsing module 34, the pre-immersed substrate and the substrate support 200 are cleaned together with a cleaning liquid (pure water, etc.). In the air supply module 35, the cleaned substrate is dehydrated. In the second rinsing module 36, the plated substrate and the substrate support 200 are cleaned together with the cleaning solution. The pre-wetting module 32, the pre-immersion module 33, the first rinsing module 34, the air supply module 35, and the second rinsing module 36 are arranged in sequence. Furthermore, this structure is an example and is not limited to the above structure; other structures can be used for the pretreatment and posttreatment modules 120A.

[0030] The plating module 120B has multiple plating tanks (plating chambers) 39 and overflow tanks 38. Each plating tank 39 houses one substrate, and copper plating or other processes are performed on the substrate surface by immersing the substrate in a plating solution held inside. The type of plating solution is not particularly limited, and various plating solutions can be used depending on the application. This structure of the plating module 120B is an example; other structures are possible for the plating module 120B.

[0031] The plating apparatus 100 includes, for example, a conveying device 37 employing a linear motor. This conveying device 37 is located to the side of each of the aforementioned devices and conveys the substrate support 200 together with the substrate between the devices. The conveying device 37 is configured to convey the substrate support 200 between the substrate loading / unloading module 29, the temporary storage box 30, the pre-wetting module 32, the pre-immersion module 33, the first rinsing module 34, the air supply module 35, the second rinsing module 36, and the plating module 120B.

[0032] The plating apparatus 100 configured as described above includes a control module (controller) 175, which is configured to control the aforementioned components. The controller 175 includes a memory 175B storing a predetermined program and a CPU 175A executing the program in the memory 175B. The storage medium constituting the memory 175B stores various setting data and various programs, including programs controlling the plating apparatus 100. The programs include, for example, programs for controlling the transport robot 27, controlling the loading and unloading of substrates from the substrate loading / unloading module 29 to the substrate support 200, controlling the transport of the transport device 37, controlling the processing in each processing module, controlling the plating processing in each plating tank 39, and controlling the cleaning station 50a. The storage medium can include non-volatile and / or volatile storage media. For example, known storage media such as computer-readable ROMs, RAMs, flash memory, hard disks, CD-ROMs, DVD-ROMs, and floppy disks can be used.

[0033] The controller 175 is configured to communicate with a host controller (not shown) that provides unified control over the plating apparatus 100 and other related devices, and to exchange data with a database held by the host controller. Some or all of the functions of the controller 175 can be implemented using hardware such as an ASIC. Some or all of the functions of the controller 175 can also be implemented using a sequencer. Some or all of the controller 175 can be configured inside and / or outside the housing of the plating apparatus 100. Some or all of the controller 175 can be communicatively connected to various parts of the plating apparatus 100 via wired and / or wireless means.

[0034] (Platinum module)

[0035] Figure 2This is a simplified diagram showing the plating module 120B. As shown in the figure, the plating module 120B includes a plating tank 39 that holds the plating solution inside, an anode 40 disposed opposite to a substrate support 200 within the plating tank 39, and an anode support 60 that holds the anode 40. The substrate support 200 is configured to hold a substrate W, such as a wafer, in a removable manner, and to immerse the substrate W in the plating solution Q within the plating tank 39. The plating apparatus 100 of this embodiment is an electrolytic plating apparatus that uses metal to plate the surface of a substrate W by flowing an electric current into the plating solution Q. As the anode 40, an insoluble anode made of titanium coated with iridium oxide or platinum, which is insoluble in the plating solution, can be used. As the anode 40, a soluble anode can also be used. For example, a soluble anode made of phosphorus copper can be used. The substrate W is, for example, a semiconductor substrate, a glass substrate, a resin substrate, or any other object to be processed. The metal plated on the surface of the substrate W is, for example, copper (Cu), nickel (Ni), tin (Sn), Sn-Ag alloy, or cobalt (Co). The plating solution Q is an acidic solution containing the metal to be plated; for example, when plating copper, it is a copper sulfate solution.

[0036] The anode 40 and the substrate W are arranged to extend vertically and to face each other in the plating solution. However, in other embodiments, a structure (cup type) in which the anode 40 and the substrate W extend horizontally can be used. The anode 40 is connected to the positive terminal of the power supply 90 via the anode support 60, and the substrate W is connected to the negative terminal of the power supply 90 via the substrate support 200. When a voltage is applied between the anode 40 and the substrate W, current flows into the substrate W, thereby forming a metal film on the surface of the substrate W in the presence of the plating solution.

[0037] The plating module 120B further includes an overflow tank 38 adjacent to the plating tank 39. The plating solution in the plating tank 39 flows over the sidewall of the plating tank 39 into the overflow tank 38. One end of a circulation line 58a for the plating solution is connected to the bottom of the overflow tank 38, and the other end of the circulation line 58a is connected to the bottom of the plating tank 39. A circulation pump 58b, a temperature control unit 58c, and a filter 58d are installed on the circulation line 58a. The plating solution Q overflows from the sidewall of the plating tank 39 and flows into the overflow tank 38, and then returns from the overflow tank 38 to the plating tank 39 through the circulation line 58a. Thus, the plating solution Q circulates between the plating tank 39 and the overflow tank 38 through the circulation line 58a.

[0038] The plating apparatus 100 further includes a regulation plate 14 for adjusting the potential distribution on the substrate W, and a paddle 16 for stirring the plating solution in the plating tank 39. The regulation plate 14 is disposed between the paddle 16 and the anode 40, and has an opening 14a for limiting the electric field in the plating solution. The paddle 16 is disposed near the surface of the substrate W held by the substrate support 200 within the plating tank 39. The paddle 16 is made of, for example, titanium (Ti) or resin. The paddle 16 stirs the plating solution Q by reciprocating parallel to the surface of the substrate W, so as to uniformly supply sufficient metal ions to the surface of the substrate W during plating.

[0039] Furthermore, the above structure is just one example; other structures can be used for the plating apparatus 100, plating module 120B, etc.

[0040] Figure 3 This is a simplified diagram showing the front panel of the substrate support as viewed from the inside. Figure 4 This is a simplified diagram of the back panel of the substrate holder viewed from the inside. The substrate holder 200 has a front panel 210 and a back panel 220, which clamp and hold the substrate W.

[0041] The front panel 210 includes a retainer 211, a plurality of contacts 213, a busbar 214, and a clamping mechanism 217. The plurality of contacts 213, the busbar 214, and the clamping mechanism 217 are disposed on the inner side of the retainer 211. The retainer 211 has an opening 211A exposing the plated surface of the substrate W. A handle 212 is mounted on one end of the retainer 211. The plurality of contacts 213 are disposed along the outer periphery of the opening 211A. The contacts 213 are electrical contacts for contacting the seed layer of the substrate W to allow plating current to flow into the substrate. The busbar 214 electrically connects the contacts 213 to an external connection terminal 218 disposed on the handle 212. The busbar 214 is a wiring for connecting the contacts 213 to a power supply 90 via the external connection terminal 218. An inner sealing member 215 is provided around the opening 211A and inside the contact member 213 to seal the substrate W and the substrate support 200. Additionally, an outer sealing member 216 is provided outside the busbar 214 to seal the substrate support 200 by contacting the back panel 220. A clamping mechanism 217 is provided outside the outer sealing member 216 and cooperates with the clamping mechanism 227 of the back panel 220 to engage the front panel 210 and the back panel 220.

[0042] The back panel 220 includes a retainer 22 and a clamping mechanism 227 disposed on the outer periphery of the retainer 221. The retainer 221 has an opening 221A. The opening 221A may also be as follows: Figure 2The details shown are omitted. A handle 222 is mounted on one end of the retainer 221. The handle 222 engages with the handle 212 of the front panel 210, functioning as an integral handle. The substrate support 200 is suspended by hanging the two ends of the handle on the edge of the processing slot wall of each module. An inner seal 225 is provided on the retainer 221 at a position corresponding to the inner seal 215 of the front panel 210. On the retainer 221, the position corresponding to the outer seal 216 of the front panel 210 is shown in dashed lines. When the substrate W is held by the front panel 210 and the back panel 220, the inner seals 215 and 225 and the outer seal 216 form a sealed internal space (sealed space) 240 of the substrate support 200. Figure 3 , Figure 4 , Figure 6A , Figure 6B The interior space is 240. Figure 3 The portion corresponding to the area between the inner seal 215 and the outer seal 216 is in Figure 4 The middle part corresponds to the portion between the inner seal 225 and the dotted line.

[0043] like Figure 3 As shown, a detector 230 for detecting plating solution leakage is provided between the inner seal 215 and the outer seal 216 of the front panel 210. The detector 230 is a conductor or electrode disposed near multiple contacts 213. The conductor or electrode can be a single piece or composed of multiple pieces. The detector 230 is connected to an external connection terminal 219 via wiring indicated by dotted lines. The external connection terminal 219 is electrically insulated from the external connection terminal 218. When the conductor or electrode is composed of multiple pieces and each piece is connected by individual wiring, the location where plating solution leakage has occurred can be specifically identified.

[0044] like Figure 4 and Figure 5 As shown, the back panel 220 is provided with an inlet passage 231 and an outlet passage 232 that connect the internal space 240 of the substrate support 200 to the outside of the substrate support 200. Figure 5 As shown, valves 231A and 232A are respectively provided in the inlet passage 231 and the outlet passage 232 for controlling the opening and closing of each passage. Valves 231A and 232A can be, for example, solenoid valves, on / off valves, or flow control valves capable of controlling flow rate. Valves 231A and 232A are controlled by controller 175. Valves 231A and 232A can be disposed inside or on the surface of the holders 211 and 221 of the substrate support 200. Part or all of the inlet passage 231 and the outlet passage 232 can be provided as passages formed inside the holders 211 and 221 of the substrate support 200 and / or as piping disposed on the surface of the holders 211 and 221.

[0045] Figure 5 This is a simplified diagram of the substrate support in the pre-humidification module. The pre-humidification module 300 includes a processing tank 301, a circulation line 302, a pump 303 installed in the circulation line 302, and a degassing module 304. The degassing module 304 is a device for removing (degassing) air from the liquid or replacing it with an inert gas. Figure 5 The example shown illustrates the removal of air from a liquid by depressurizing the degassing module using a vacuum pump. Conversely, if inert gas is allowed to circulate in the degassing module instead of depressurizing the liquid using a vacuum pump, the air in the liquid can be replaced with inert gas. In this example, pure water (e.g., DIW) is stored in the processing tank 301. In this embodiment, pure water obtained through degassing or inert gas replacement by the degassing module 304 is stored in the processing tank 301. The pure water in the processing tank 301 is pumped to the degassing module 304 by the pump 303, and after degassing or inert gas replacement by the degassing module 304, it is circulated back to the processing tank 301, thereby accumulating degassed water in the processing tank 301. Here, degassed water refers to water from which air has been removed or water in which the gas in the water has been replaced by inert gas. Furthermore, a supply port and an outlet (not shown) are provided in the processing tank 301 to appropriately replace the pure water in the processing tank 301. The dissolved oxygen concentration in pure water can be reduced through degassing and inert gas replacement.

[0046] In this embodiment, the substrate holder 200 holding the substrate W is immersed in pure water (deaerated water) in the processing tank 301. Valve 231A of the inlet passage 231 is opened, and pure water is introduced into the internal space 240 of the substrate holder 200 through the inlet passage 231, thus filling the internal space 240 with pure water. Alternatively, the substrate holder 200 holding the substrate W can be immersed in pure water in the processing tank 301, and valves 231A and 232A can be opened to introduce pure water into the internal space 240 of the substrate holder 200 through the inlet passage 231. Air in the internal space 240 is discharged through the outlet passage 232, and pure water that has filled the internal space 240 is discharged through the outlet passage 232, thus filling the internal space 240 with pure water. Valve 231A and / or valve 232A can also be opened before the substrate holder 200 is immersed in pure water. After the internal space 240 is filled with pure water, valves 231A and 232A are closed.

[0047] The internal space 240 is preferably completely filled with pure water in a manner that leaves no air residue. However, there may be cases where some air or air bubbles may remain, depending on the desired effect described later. Hereinafter, this embodiment will be described by forming the internal space 240 completely filled with pure water.

[0048] Alternatively, other passages can be provided to connect the internal space 240 to a pressure-reducing device (e.g., a vacuum pump) not shown. After depressurizing the internal space 240, these other passages are closed, and valve 231A is opened to introduce pure water into the internal space 240. Alternatively, valve 232A can be opened to more reliably fill the internal space 240 with pure water. Alternatively, without providing other passages, the pressure-reducing device can be connected to the discharge passage 232. After depressurizing the internal space 240, valve 232A is closed, and valve 231A is opened to introduce pure water into the internal space 240.

[0049] Alternatively, after plating, valves 231A and 232A can be opened again in the rinsing process (second rinsing module 36) or the air supply process (air supply module 35) to discharge pure water from the internal space 240 of the substrate support 200.

[0050] Figure 6A and Figure 6B It is a simplified cross-section of the internal space of the substrate support in the plating tank, magnified. Figure 6C This is a simplified cross-sectional view of the interior space of the comparative example substrate support in the plating bath, magnified. (See diagram below.) Figure 6C As shown, in the comparative example substrate support 200A, the internal space 240A is a void containing air. Because the internal space 240A is void, if a leakage occurs where plating solution Q enters the internal space 240A, the air in the internal space 240A will be compressed by the hydraulic pressure of the plating solution Q, raising concerns that a large amount of plating solution Q may enter the seal. If the plating solution Q adheres to the seed layer 401 within the internal space 240A, there is a concern that the seed layer 401 may dissolve due to electrolytic corrosion caused by dissolved oxygen in the plating solution and / or the shunting of the plating current, thus compromising electrical insulation.

[0051] Figure 7 This is an illustration of how dissolved oxygen concentration causes the seed layer to dissolve. If the plating solution Q invades the air-filled internal space 240A (… Figure 6C If the plating solution Q is not diluted, the original solution will adhere to the exposed seed layer 401 near the contact 213. Furthermore, the air (O2) in the compressed internal space 240A due to the intrusion of the plating solution Q dissolves in the plating solution Q, thus creating an O2 concentration gradient near the gas-liquid interface, causing the seed layer 401 to dissolve due to the effect of local galvanic cells. Specifically, as... Figure 7 As shown, oxygen (O2) from the air dissolves into the plating solution Q. Therefore, near the gas-liquid interface where the dissolved oxygen concentration is high, O2 accepts electrons from the seed layer 401 to become OH-. －On the other hand, in areas far from the gas-liquid interface and with lower dissolved oxygen concentrations, Cu releases electrons from the seed layer 401, becoming Cu ions and dissolving. Due to this reaction, there is a concern that Cu dissolves from the seed layer 401, causing it to thin, thereby increasing its resistance and potentially leading to electrical insulation issues. This explanation pertains to copper plating, but the same phenomenon may occur with plating of other metals.

[0052] Figure 8A This is an illustration of the dissolution of the seed layer caused by the shunt current. Figure 8B This is an equivalent circuit diagram illustrating the shunt current. In the diagram, I... total It is the sum of the currents flowing into the contact elements, I cw It is the current flowing through the contact area between the seed layer and the contact element, I shunt It is the shunt current. R contact It is the contact resistance between contact 213 and seed layer 401, R wafer It is the resistance of the seed layer, R dissolution R is the resistance at the dissolution site on the seed layer side of the shunt current path. depositio It is the resistance at the condensation point on the contact side of the shunt current path, R. electrolyte This indicates the resistance of the plating solution.

[0053] If the plating solution Q penetrates into the internal space 240A, and the resistance R of the seed layer 401 is... wafer and / or the contact resistance R between contact 213 and seed layer 401 contact If the conductivity is high, a short-circuit current (shunt current) I is generated from the seed layer 401 through the plating solution Q and the redox reaction at the surface of the seed layer 401 and the contact 213, flowing from the seed layer 401 through the plating solution Q into the contact 213. shunt .like Figure 8A As shown, the shunt current causes Cu to transform into Cu on the surface of the seed layer 401. 2＋ Cu dissolved in plating solution Q 2＋ The flow occurs through the surface of the contact 213, where it becomes Cu. Therefore, if a shunt current is generated, there is a risk of Cu dissolution in the seed layer 401, causing the seed layer 401 to thin and its resistance to increase, raising concerns about the electrical insulation of the seed layer 401. This shunt current also occurs when the resistance of the seed layer 401 locally increases due to the aforementioned localized cell effect.

[0054] Therefore, in the structure of the substrate support 200A in the comparative example, if the plating solution Q invades the internal space 240A, there is a concern that the seed layer 401 may be dissolved due to the local battery effect and / or shunt current caused by the dissolved oxygen concentration gradient, thereby affecting the electrical insulation of the seed layer 401.

[0055] Therefore, in this embodiment, a structure is adopted in which the internal space 240 of the substrate support 200 is filled with pure water (e.g., DIW). Figure 5 , Figure 6A , Figure 6B ), and a detector 230 is provided to detect leakage of plating solution into the internal space 240 of the substrate support 200. Figure 3 , Figure 6A , Figure 6B The detector 230, for example, can form an electrode for detecting the current flowing through the pure water in the internal space 240 between the contact 213 or the busbar 214, that is, an electrode for detecting the current (or the resistance of the pure water) flowing in the pure water in the internal space 240.

[0056] exist Figure 6A In this example, a dissolvable electrode 235A, functioning as a sacrificial anode or electrode, is used as detector 230. In this figure, reference numeral 401 indicates a seed layer formed on the surface of substrate W, and reference numeral 402 indicates a resist pattern formed on the surface of seed layer 401. Metal is electrolytically plated onto seed layer 401, exposed through openings in the resist pattern. Contact 213 of substrate support 200 contacts seed layer 401 and is electrically connected to it. The dissolvable electrode can be a conductor made of the same material as the plated metal; for example, similar to the dissolvable anode, an electrode made of phosphorus copper can be used. A DC voltage is applied between electrode 235A and contact 213 (busbar 214) via DC power supply device 236A, such that electrode 235A has a higher potential than contact 213 (busbar 214). Furthermore, a current detector 237A is provided within DC power supply device 236A or on wiring from DC power supply device 236A. In this state, the controller 175 monitors the current flowing between electrode 235A and contact 213 (busbar 214), or the resistance between them. The current flowing between electrode 235A and contact 213 (busbar 214) is equivalent to the current flowing in pure water within the internal space 240. The resistance between electrode 235A and contact 213 (busbar 214) is equivalent to the resistance of pure water within the internal space 240.

[0057] The application of DC voltage to electrode 235A and the detection of current (resistance) are controlled by controller 175. Controller 175 obtains the current flowing into electrode 235A (the current of pure water flowing into internal space 240) via current detector 237A, and detects leakage of plating solution into internal space 240 based on this current. Additionally, controller 175 obtains the current flowing into electrode 235A, calculates the resistance value of pure water based on the voltage between electrode 235A and contact 213 (busbar 214) and the detected current, and detects leakage based on the resistance value.

[0058] In the absence of leakage of plating solution into the internal space 240, the resistance of the pure water within the internal space 240 is extremely high, so current will not flow between the electrode 235A and the contact 213 (busbar 214) (or only a very weak current will flow). On the other hand, if leakage occurs, the plating solution mixes with the pure water, thereby reducing the resistance of the pure water, and thus current flows between the electrode 235A and the contact 213 (busbar 214) (or the current increases). In this way, leakage of plating solution into the internal space 240 can be detected by the electrode 235A. In addition, even if a leakage of plating solution occurs in an amount that may corrode the seed layer 401, since the electrode 235A, which functions as a sacrificial anode, is biased to a higher potential relative to the contact 213 and the seed layer 401, the electrode (sacrificial anode) 235A will preferentially dissolve, thereby suppressing or preventing the dissolution of the seed layer 401.

[0059] According to this embodiment, the internal space 240 of the substrate support 200 is filled with pure water. Therefore, compared with the case where the internal space 240 is empty, the pressure difference between the inside and outside of the internal space 240 can be reduced, thereby suppressing or preventing the leakage of plating solution into the internal space 240. As a result, the reduction in the uniformity of the plating film thickness caused by the leakage of plating solution can be suppressed or prevented.

[0060] According to this embodiment, even if leakage of the plating solution occurs, since the internal space 240 is filled with pure water, the intrusion of the plating solution into the internal space 240 is limited to the diffused portion and suppressed to a very small amount. Therefore, the local galvanic effect caused by dissolved oxygen concentration and / or the dissolution (corrosion) of the seed layer 401 caused by shunt current can be suppressed. In addition, since the plating solution that has intruded into the internal space 240 is diluted by pure water, the corrosion of the seed layer 401 can be further suppressed. Thus, the reduction in the uniformity of the plating film thickness can be suppressed or prevented.

[0061] Furthermore, according to this embodiment, since the internal space 240 is filled with pure water and has a low oxygen concentration, the dissolution of the seed layer 401 caused by localized galvanic action due to dissolved oxygen can be suppressed. Therefore, it is possible to suppress or prevent a decrease in the uniformity of the coating thickness.

[0062] Furthermore, according to this embodiment, even if a potentially corrosive amount of plating solution leaks, the electrode 235A, which functions as a sacrificial anode, preferentially dissolves, thereby suppressing or preventing the dissolution of the seed layer 401. This suppresses or prevents a decrease in the uniformity of the plating film thickness caused by plating solution leakage.

[0063] Furthermore, according to this embodiment, by monitoring the current (resistance) between electrode 235A and contact 213 (busbar 214), the presence or absence of plating solution leakage into the internal space 240 can be detected early. Therefore, even if plating solution leakage occurs, it can be detected early by electrode 235A, thereby enabling early detection of abnormalities in the substrate support 200 and the replacement time of the seal. Thus, early detection of plating solution leakage can suppress or prevent a decrease in the uniformity of the plating film thickness.

[0064] In addition, Figure 6A In some cases, leakage detection based on electrode 235A may not be performed, and electrode 235A may be used only as a sacrificial anode.

[0065] exist Figure 6B In this example, an insoluble electrode 235B is used as detector 230. The insoluble electrode can be made of stainless steel or titanium coated with a substance insoluble in the plating solution, such as gold or platinum. In this case, using the same principle as conductivity measurement or leakage detection, an AC voltage is applied between electrode 235B and contact 213 (busbar 214) via AC power supply device 236B, and the AC current flowing between electrode 235B and contact 213 (busbar 214) (or the impedance as the resistance between electrode 235B and contact 213 (busbar 214)) is measured, thereby detecting leakage of the plating solution. The AC current flowing between electrode 235B and contact 213 (busbar 214) is equivalent to the current flowing in pure water within the internal space 240. The resistance (impedance) between electrode 235B and contact 213 (busbar 214) is equivalent to the resistance (impedance) of pure water in the internal space 240. Furthermore, a current detector 237B is provided within the AC power supply unit 236B or on the wiring from the AC power supply unit 236B. In this specification, resistance includes impedance or the resistive component of impedance.

[0066] The application of AC voltage to electrode 235B and the detection of current (resistance) are controlled by controller 175. Controller 175 obtains the current flowing into electrode 235B (the current of pure water flowing into internal space 240) via current detector 237B, and detects leakage of plating solution into internal space 240 based on this current. Additionally, controller 175 obtains the current flowing into electrode 235B, calculates the resistance value of pure water based on the voltage between electrode 235B and contact 213 (busbar 214) and the detected current, and detects leakage based on the resistance value.

[0067] In the absence of leakage of plating solution into the internal space 240, due to the extremely high resistance of the pure water within the internal space 240, current will not flow between the electrode 235B and the contact 213 (busbar 214) (or only a very weak current will flow). If leakage occurs, the plating solution mixes with the pure water, the resistance of the pure water decreases, and thus current flows between the electrode 235B and the contact 213 (busbar 214) (or the current increases). In this way, leakage of plating solution into the internal space 240 can be detected by the insoluble electrode 235B.

[0068] Even if Figure 6B The structure of this example, besides sacrificing the function of the anode, also serves to... Figure 6A The structure of the example has the same effect. Furthermore, when using the insoluble electrode 235B, the substrate support 200 is easier to maintain. When using a soluble electrode (sacrificial anode), if the plating solution leaks, some of the Cu dissolved from the sacrificial anode will precipitate onto the contacts, requiring maintenance to remove the precipitated Cu. Additionally, when the sacrificial anode decreases, it needs to be replaced. On the other hand, when using the insoluble electrode 235B, this maintenance can be suppressed or prevented. Moreover, while there is a concern about the dissolution of the seed layer 401 when the plating solution leaks (due to high contact resistance between the contact 213 and the seed layer 401, or residual air bubbles in the internal space of the substrate support), the plating solution leak can be detected early by the electrode 235B (detector 230). Therefore, by replacing the substrate support, the continued use of a defective substrate support can be prevented, thereby suppressing or preventing a decrease in plating quality.

[0069] You can also Figure 6A and Figure 6B The example shows a structural combination. In this case, leak detection can be performed using only electrode 235B, or it can be performed using both electrodes 235A and 235B. When leak detection is performed using both electrodes 235A and 235B, the redundancy of leak detection can be improved.

[0070] (Other implementation methods)

[0071] (1) In the above embodiment, a substrate support for a quadrilateral substrate was described as an example, but the above embodiment can be applied to substrate supports for polygons and other arbitrary shapes other than circles and quadrilaterals.

[0072] (2) In the above embodiments, a substrate support that holds the substrate by sandwiching it between the front panel and the back panel is given as an example. However, as long as the substrate support has an internal space formed by sealing the contact members, the present invention can be applied to substrate supports of any structure.

[0073] (3) In the above embodiment, a plating apparatus (so-called immersion type) is described as an example of a plating apparatus that immerses the substrate holder in the plating solution to perform plating on the substrate. However, the present invention can also be applied to a plating apparatus (so-called cup type) that holds the substrate downward by the substrate holder and contacts it with the plating solution to perform plating on the substrate.

[0074] (4) In the above embodiment, pure water is introduced into the internal space of the substrate support in the pre-wetting module, but other modules for introducing liquids such as pure water into the internal space of the substrate support may also be provided.

[0075] (5) The liquid introduced into the internal space can be any liquid that does not corrode the components exposed in the internal space of the substrate support, and can be any liquid other than water. For example, liquids that do not contain metal salts (liquids with a metal salt concentration less than the specified concentration (e.g., 5 g / L)) can be used. Such liquids include, for example, tap water, natural water, and pure water. Pure water includes, for example, deionized water (DIW), distilled water, purified water, or RO water.

[0076] The present invention can also be described in the following manner.

[0077] According to Method 1, a substrate holder is provided for holding a substrate and bringing the substrate into contact with a plating solution for plating. The substrate holder includes: an internal space that, while holding the substrate, houses the outer periphery of the substrate in a sealed manner relative to the outside of the substrate holder; a first passage that connects the outside of the substrate holder to the internal space and introduces liquid into the internal space; and a detector disposed in the internal space for monitoring the current flowing into the liquid during plating or the resistance of the liquid while the liquid has been introduced into the internal space, thereby detecting leakage of the plating solution into the internal space. The liquid can be, for example, water or other liquids that do not corrode components exposed in the internal space of the substrate holder. For example, pure water used in a pre-wetting process can be used.

[0078] According to this method, corrosion of the seed layer of the substrate caused by leakage of the plating solution can be suppressed or prevented, thereby suppressing or preventing a decrease in the uniformity of the plating film thickness. Since the internal space of the substrate support is filled with liquid, the pressure difference between the inside and outside of the internal space can be reduced, thus suppressing or preventing leakage of the plating solution into the internal space. Furthermore, even if leakage of the plating solution into the sealed internal space occurs, since the internal space is filled with liquid, the intrusion of the plating solution into the internal space is limited to the portion that diffuses into the liquid and is suppressed to a very small amount, thus suppressing corrosion of the seed layer of the substrate. In addition, the plating solution that has intruded into the internal space is diluted by the liquid, thus further suppressing corrosion of the seed layer of the substrate. Furthermore, since the oxygen concentration in the internal space is low, corrosion of the seed layer caused by localized galvanic action due to dissolved oxygen can be suppressed.

[0079] Furthermore, even if a leakage of the plating solution occurs, it can be detected early using a detector. This allows for early detection of substrate support abnormalities and the timing of seal replacement. Therefore, early detection of plating solution leakage can suppress or prevent a decrease in the uniformity of the plating film thickness.

[0080] According to Method 2, the substrate support of Method 1 includes: a contact disposed in the internal space and in contact with a seed layer formed on the surface of the substrate, thereby allowing plating current to flow into the substrate; and a soluble electrode biased toward a higher potential side relative to the contact.

[0081] According to this method, even if a leakage of plating solution occurs that could corrode the seed layer, the soluble electrode functions as a sacrificial anode because it is biased to a higher potential relative to the contact and the seed layer, thus preferentially dissolving and inhibiting or preventing the dissolution of the seed layer.

[0082] According to Method 3, in the substrate support of Method 1, the aforementioned soluble electrode functions as the aforementioned detector. The detector is configured to detect leakage of plating liquid into the aforementioned internal space by monitoring the current flowing into the aforementioned contact or the wiring electrically connected to the aforementioned contact and the aforementioned electrode when the aforementioned liquid is introduced into the aforementioned internal space.

[0083] According to this method, the presence or absence of leakage of plating solution can be detected by monitoring the current flowing between the sacrificial anode (dissolving electrode) and the contact, etc., so there is no need to set up an additional electrode for leakage detection.

[0084] According to Method 4, the substrate support described in Method 1 includes a contact member disposed in the internal space and in contact with a seed layer formed on the surface of the substrate, thereby allowing plating current to flow into the substrate. The detector has an insoluble electrode and is configured to detect leakage of plating liquid into the internal space by applying an alternating voltage between the contact member or a wiring electrically connected to the contact member and the insoluble electrode, and by monitoring the current flowing into the insoluble electrode, when the liquid has been introduced into the internal space.

[0085] According to this method, since insoluble electrodes are used as detectors, the metal of the electrodes will not precipitate into the contacts, etc., making it easy to maintain the substrate support.

[0086] According to method 5, the substrate support of method 4 further includes a soluble electrode that is biased toward the high potential side relative to the aforementioned contact.

[0087] According to this method, not only are the effects of methods 1 and 4 achieved, but the soluble electrode also dissolves preferentially over the seed layer, thereby inhibiting or preventing the dissolution of the seed layer.

[0088] According to method 6, in the substrate support of method 5, the soluble electrode functions as the detector, which is configured to detect leakage of plating solution into the internal space by means of both the insoluble electrode and the soluble electrode.

[0089] According to this method, since the leakage of plating solution can be detected by both the soluble electrode (sacrificial anode) and the insoluble electrode, the detection accuracy of plating solution leakage can be improved. In addition, even if one electrode malfunctions, the leakage of plating solution can still be detected, so the detection of plating solution leakage can be more reliable, thereby improving the redundancy of leakage detection.

[0090] According to method 7, in the substrate support of any of methods 3 to 6, the aforementioned wiring is a busbar. According to this method, compared to using multiple cables, the wiring setup space can be reduced, and the wiring resistance can be suppressed.

[0091] According to method 8, in any of methods 1 to 7, the substrate support further includes a valve, which is disposed in the first passage to connect or disconnect the outside of the substrate support from the internal space.

[0092] According to this method, since the internal space of the substrate support can be connected to or blocked from the outside by opening and closing the valve, the substrate plating process can be performed while the internal space of the substrate support is reliably sealed.

[0093] According to method 9, in any of methods 1 to 8, the substrate support further includes a second passage that connects the outside of the substrate support to the internal space, thereby discharging air and / or liquid from the internal space.

[0094] According to this method, when liquid is introduced through the first passage, air in the internal space is expelled through the second passage, thereby enabling efficient introduction of liquid into the internal space. Furthermore, by introducing liquid through the first passage and expelling the liquid filling the internal space through the second passage, the internal space can be filled with liquid without leaving any air bubbles. Alternatively, the second passage can be connected to a pressure-reducing device, allowing liquid to be introduced into the internal space through the first passage during or after pressure reduction. In this case, liquid can be rapidly introduced into the depressurized internal space.

[0095] According to method 10, the substrate support in any of methods 1 to 9 further includes a third passage that connects the outside of the substrate support to the internal space and is connected to a device for depressurizing the internal space.

[0096] According to this method, since liquid is introduced into the internal space from the first passage at the same time as or after decompression, liquid can be rapidly introduced into the internal space.

[0097] According to Method 11, in the substrate support of any of Methods 1 to 10, the liquid is pure water or pure water that has been degassed and replaced with an inert gas.

[0098] According to this method, by introducing pure water into the internal space, corrosion of conductive components within the internal space can be suppressed, and the intrusion of plating solution can be prevented. Furthermore, if pure water, or pure water that has been degassed and replaced with inert gas, is introduced into the internal space, the oxygen concentration within the internal space can be reduced. This, in turn, suppresses chemical corrosion of the seed layer caused by localized galvanic action due to dissolved oxygen concentration when plating solution intrudes.

[0099] According to embodiment 12, a plating apparatus is provided, comprising: a substrate support as described in any one of technical solutions 1 to 11; a liquid supply module that supplies liquid to the internal space via the first passage of the substrate support; a plating module that receives the substrate support and contacts it with the plating liquid to plating the substrate; and a control module that, while liquid is introduced into the internal space, obtains an output from the detector during plating and determines whether there is leakage of the plating liquid into the internal space.

[0100] According to this method, a plating apparatus that achieves the aforementioned effects can be provided.

[0101] According to method 13, in the plating apparatus of method 12, the liquid supply module is a pre-wetting module that brings the surface of the substrate into contact with pure water or pure water that has been degassed and replaced with inert gas.

[0102] According to this method, since liquid is introduced into the internal space of the substrate support through the pre-wetting module, there is no need to set up a separate module for introducing liquid into the internal space, which can suppress the increase in size of the device and / or the increase in cost.

[0103] According to Method 14, a plating method is provided for plating a substrate, comprising the steps of: introducing liquid into the internal space of a substrate support that houses the outer periphery of the substrate in a sealed state relative to the outside; and detecting leakage of plating liquid into the internal space by monitoring the current flowing into the liquid or the resistance of the liquid while the liquid has been introduced into the internal space. This method achieves the same effect as described in Method 1.

[0104] According to Method 15, a storage medium is provided that stores a program for executing a control method for a plating apparatus via a computer. The storage medium stores a program including the following steps: introducing liquid into the internal space of a substrate support that houses the outer periphery of the substrate in a sealed state relative to the outside; and detecting leakage of plating liquid into the internal space by monitoring the resistance of the liquid while the liquid has been introduced into the internal space. According to this method, the same effect as described in Method 1 is achieved.

[0105] The embodiments of the present invention have been described above. However, the above-described embodiments are for the purpose of easy understanding of the present invention and are not intended to limit the present invention. The present invention can be modified and improved without departing from its spirit, and its equivalents are naturally included in the present invention. In addition, within the scope of solving at least a portion of the above-mentioned problems, or within the scope of achieving at least a portion of the effects, any combination of embodiments and modifications is possible, and any combination or omission of the constituent elements described in the claims and specification is possible.

[0106] Explanation of reference numerals in the attached figures

[0107] 32…Pre-wetting module; 100…Plating apparatus; 120B…Plating module; 175…Controller; 200…Substrate support; 210…Front panel; 211…Retainer; 211A…Opening; 212…Handle; 213…Contact; 214…Busbar; 215…Inner seal; 216…Outer seal; 217…Clamping mechanism; 218…External connection terminal; 219…External connection terminal; 220…Back panel; 221…Retainer; 222…Handle; 225… 227…Clamping mechanism; 230…Detector; 231…Inlet passage; 231A…Valve; 232…Outlet passage; 232A…Valve; 235A…Electrode (sacrificial anode); 235B…Electrode; 236A…DC power supply; 236B…AC power supply; 240…Internal space; 300…Pre-humidification module; 301…Treatment tank; 302…Circulation pipeline; 303…Pump; 304…Degassing module; 401…Seed layer; 402…Resist pattern.

Claims

1. A substrate holder for holding a substrate and bringing the substrate into contact with a plating solution for plating. The substrate support is characterized in that it comprises: An internal space that, while holding the substrate by the substrate support, accommodates the outer periphery of the substrate in a sealed manner relative to the outside of the substrate support. A contact element disposed in the internal space, which, when liquid is introduced into the internal space, contacts a seed layer formed on the surface of the substrate, and a plating current flows into the substrate. as well as An electrode is disposed in the internal space and biased toward a higher potential side relative to the contact.

2. The substrate support according to claim 1, characterized in that, The electrode, biased towards the high potential side relative to the contact element, functions as a detector. The detector is configured to detect leakage of plating solution into the internal space by monitoring the current flowing into the contact or between the wiring electrically connected to the contact and the electrode when the liquid has been introduced into the internal space.

3. The substrate support according to claim 2, characterized in that, The wiring is a busbar.

4. The substrate support according to any one of claims 1 to 3, characterized in that, The liquid is pure water or pure water that has been degassed and replaced with an inert gas.

5. A plating apparatus, characterized in that, have: The substrate support according to any one of claims 1 to 4; A liquid supply device that supplies liquid to the internal space of the substrate support; as well as A plating tank, wherein the substrate held by the substrate support is brought into contact with a plating solution to perform plating on the substrate.

6. A method for plating a substrate, The method is characterized by including the following steps: Liquid is introduced into the internal space of a substrate support that houses the outer periphery of the substrate in a sealed state relative to the outside. With liquid introduced into the internal space, corrosion of the seed layer formed on the surface of the substrate is suppressed by biasing the electrodes disposed in the internal space toward a higher potential side relative to the contacts into which plating current flows into the substrate.

7. A storage medium storing a program for controlling a plating apparatus by executing a computer. The storage medium is characterized in that... Store programs for performing the following steps via a computer: Liquid is introduced into the internal space of a substrate support that houses the outer periphery of the substrate in a sealed state relative to the outside. With liquid introduced into the internal space, corrosion of the seed layer formed on the surface of the substrate is suppressed by biasing the electrodes disposed in the internal space toward a higher potential side relative to the contacts into which plating current flows into the substrate.

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