TWI822514B - Substrate holder, plating device, plating method, and memory medium - Google Patents

Abstract

The invention suppresses or prevents the plating liquid from intruding into the sealed space of the substrate holder, and detects the intrusion of the plating liquid at an early stage. The substrate holder of the present invention is used to hold a substrate and make the substrate contact a plating liquid to perform plating. an internal space that accommodates the outer peripheral portion of the substrate in a state; a first passage that connects the outside of the substrate holder and the internal space and introduces liquid into the internal space; and is disposed in the internal space to introduce the liquid into the internal space. A detector for detecting leakage of the plating liquid into the internal space by monitoring the current flowing into the liquid during plating or the resistance of the liquid in the state of the internal space.

Description

Substrate holder, plating device, plating method, and memory medium

The present application relates to a substrate holder, a plating device, a plating method, and a memory medium that stores a program that causes a computer to execute a control method of the plating device.

In electrolytic plating, when the plating liquid leaks into the substrate holder due to certain defects (substrate unevenness, seal aging, etc.), the plating liquid that invades the inside of the holder will cause corrosion and/or dissolution of the seed layer. And poor conduction occurs, resulting in reduced plating uniformity.

U.S. Patent No. 7727366 (Patent Document 1) and U.S. Patent No. 8168057 (Patent Document 2) describe pressurizing the sealed side of the substrate with fluid to prevent the fluid from intruding from the side opposite to the seal. Japanese Patent Application Laid-Open No. 2020-117763 (Patent Document 3) and Japanese Patent Application Laid-Open No. 2020-117765 (Patent Document 4) describe preventing intrusion of plating liquid by injecting liquid into the internal space of the outer peripheral portion of the sealed housing substrate. internal space to prevent plating from depositing to the outer periphery of the substrate and contact components. [Prior technical literature] [Patent Document]

[Patent Document 1] U.S. Patent No. 7727366 Specification [Patent Document 2] U.S. Patent No. 8168057 Specification [Patent Document 3] Japanese Patent Application Publication No. 2020-117763 [Patent Document 4] Japanese Patent Application Publication No. 2020-117765

(Invent the problem you want to solve)

Even if technical countermeasures such as those described in the above-mentioned patent documents are adopted, the plating liquid may still invade the internal space depending on the degree of unevenness and sealing aging of the substrate. However, the above-mentioned patent documents do not describe any effectiveness when the plating liquid invades the internal space. Countermeasures.

An object of the present invention is to suppress or prevent plating liquid from intruding into the sealed space of the substrate holder, and to detect the intrusion of plating liquid at an early stage. In addition, an object of the present invention is to prevent the uniformity of the plating film thickness from being reduced when the plating liquid invades the sealed space of the substrate holder. (Technical means to solve problems)

One embodiment provides a substrate holder for holding a substrate and bringing the substrate into contact with a plating liquid to perform plating, and having an internal space in which the substrate is held by the substrate holder. The outer peripheral portion of the substrate is accommodated in a sealed state from the outside of the substrate holder; a first passage connects the outside of the substrate holder and the internal space, and introduces liquid into the internal space; and a detector, which is It is disposed in the internal space and is used to detect leakage of the plating liquid into the internal space by monitoring the current flowing into the liquid during plating or the resistance of the liquid in a state where the liquid is introduced into the internal space.

In one embodiment, the substrate holder may be provided with: a contact disposed in the internal space, in contact with the seed layer formed on the surface of the substrate, and allowing plating current to flow into the substrate; and a soluble electrode that is connected to the substrate. The contact is biased to the high potential side.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or similar reference signs are assigned to the same or similar elements, and repeated descriptions of the same or similar elements will be omitted in the description of various embodiments. In addition, features shown in various embodiments may also be applied to other embodiments as long as they are not inconsistent with each other.

In this specification, "substrate" includes not only semiconductor substrates, glass substrates, liquid crystal substrates, and printed circuit substrates, but also magnetic recording media, magnetic recording sensors, mirrors, optical components, micro mechanical components, or locally manufactured components. Integrated circuits, and any other objects to be processed. The substrate includes any shape including polygon and circle. In addition, in this manual, expressions such as "front", "back", "front", "back", "upper", "lower", "left", "right", etc. are used. However, these are for convenience. The position and orientation of the illustrations shown on the paper may differ depending on the actual configuration of the device used.

FIG. 1 is an overall layout diagram of a plating device according to one embodiment. The plating apparatus 100 performs a plating process on a substrate while holding the substrate on the substrate holder 200 (Fig. 2). The plating apparatus 100 is roughly divided into: a loading/unloading station 110 that loads substrates on the substrate holder 200 or unloads substrates from the substrate holder 200; a processing station 120 that processes the substrate; and a cleaning station 50a. The processing station 120 is configured with: a pre-processing and post-processing module 120A that performs pre-processing and post-processing of the substrate; and a plating module 120B that performs plating processing on the substrate.

The loading/unloading station 110 has one or a plurality of cassette stations 25 and a substrate loading and unloading module 29 . The cassette 25a for storing the substrate is mounted on the cassette table 25. The substrate loading and unloading module 29 is configured to load and remove a substrate from the substrate holder 200 . In addition, a temporary storage box 30 for accommodating the substrate holder 200 is provided near (for example, below) the substrate loading and 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 rinse dryer.

A transfer robot 27 that transfers substrates between these units is disposed at a position surrounded by the cassette table 25, the substrate loading and unloading module 29, and the cleaning station 50a. The transfer robot 27 is configured to travel by the traveling mechanism 28 . For example, the transfer robot 27 takes out the substrate before plating from the cassette 25 a and transfers it to the substrate loading and unloading module 29 , receives the plated substrate from the substrate loading and unloading module 29 , and transfers the plated substrate to the cleaning module. 50, and then take out the cleaned and dried substrate from the cleaning module 50 and store it in the cassette 25a.

The pre-treatment and post-treatment module 120A has a pre-wet module 32, a prepreg module 33, a first rinse module 34, an air supply module 35, and a second rinse module 36. The prewet module 32 moistens the plated surface of the substrate before plating treatment with 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 prewetting module 32 is configured in such a manner that the treatment liquid inside the pattern is replaced with the plating liquid during plating so as to facilitate prewetting treatment by supplying the plating liquid inside the pattern. The prepreg module 33 is, for example, etched with a treatment solution such as sulfuric acid or hydrochloric acid to remove the highly resistive oxide film on the surface of the seed layer formed on the plated surface of the substrate before the plating treatment, thereby cleaning or activating the plated substrate. The surface is pre-impregnated. The first cleaning module 34 cleans the presoaked substrate and the substrate holder 200 together with a cleaning solution (pure water, etc.). The air supply module 35 is used for draining the cleaned substrate. The second cleaning module 36 cleans the plated substrate and the substrate holder 200 with cleaning fluid. The prewetting module 32, the prepreg module 33, the first flushing module 34, the air supply module 35, and the second flushing module 36 are arranged in this order. In addition, this structure is an example and is not limited to the above-mentioned structure. The pre-processing and post-processing module 120A may also adopt other structures.

The plating module 120B has a plurality of plating tanks (plating chambers) 39 and an overflow tank 38 . Each plating tank 39 accommodates a substrate inside, immerses the substrate in a plating liquid held inside, and performs plating such as copper plating on the surface of the substrate. Here, the type of plating liquid is not particularly limited, and various plating liquids can be used depending on the purpose. The structure of the plating module 120B is an example, and the plating module 120B may adopt other structures.

The plating apparatus 100 has a conveying device 37 , for example, using a linear motor, which is located on the side of each of these devices and transports the substrate holder 200 between the respective devices. The transport device 37 is connected with the substrate loading and unloading module 29, the temporary storage box 30, the pre-wetting module 32, the prepreg module 33, the first flushing module 34, the air supply module 35, the second flushing module 36, The substrate holder 200 is transported between the substrate holder 200 and the plating module 120B.

The plating apparatus 100 configured as above includes a control module (controller) 175 as a control unit configured to control each of the above-mentioned components. The control module 175 has: a memory 175B that stores a specified program; and a CPU 175A that executes the program in the memory 175B. The memory medium constituting the memory 175B stores various setting data, various programs including programs for controlling the plating apparatus 100, and the like. The program includes, for example, the transfer control of the transfer robot 27 , the loading and unloading control of the substrate to the substrate holder 200 in the substrate loading and unloading module 29 , the transfer control of the transfer device 37 , the processing control in each processing module, and the processing control in each plating tank 39 . The control program of the plating process and the control of the cleaning station 50a. Memory media may include non-volatile and/or volatile memory media. Examples of memory media include computer-readable ROM (read-only memory), RAM (random access memory), flash memory and other memories, hard disks, CD-ROM (compact disc-read only), and DVD-ROM. Those who are familiar with disc-shaped memory media such as read-only diversified digital optical discs and floppy disks.

The controller 175 can be configured to communicate with an upper-level controller (not shown) that controls the plating apparatus 100 and other related devices, and can exchange data with a database owned by the upper-level controller. Part or all of the functions of the controller 175 may be configured by hardware such as an ASIC (Application Specific Integrated Circuit). Part or all of the functions of the controller 175 may also be constituted by a sequencer. Part or all of the controller 175 may be configured inside and/or outside the frame of the plating device 100 . Part or all of the controller 175 is communicably connected to various parts of the plating device 100 through wired and/or wireless connections. (Plating module)

FIG. 2 shows a schematic diagram of the plating module 120B. As shown in this figure, the plating module 120B includes: a plating tank 39 that holds a plating liquid inside; an anode 40 that is disposed facing the substrate holder 200 in the plating tank 39; and an anode holder that holds the anode 40. 60. The substrate holder 200 is configured to detachably hold a substrate W such as a wafer, and to immerse the substrate W in the plating liquid Q in the plating tank 39 . The plating apparatus 100 of this embodiment is an electrolytic plating apparatus that coats the surface of the substrate W with metal by flowing an electric current into the plating solution Q. The anode 40 is an insoluble anode made of titanium coated with something that is insoluble in the plating solution, such as iridium oxide or platinum. A soluble anode may also be used as the anode 40 . As the soluble anode, for example, a soluble anode made of phosphorus-containing 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), tin-silver (Sn-Ag) alloy, or cobalt (Co). The plating solution Q is an acidic solution containing the metal to be plated, for example, a copper sulfate solution when plating copper.

The anode 40 and the substrate W are arranged to extend in the vertical direction, and are arranged to face each other in the plating solution. However, other embodiments may also adopt a structure in which the anode 40 and the substrate W are arranged to extend in the horizontal direction (cup type). The anode 40 is connected to the positive electrode of the power supply 90 via the anode holder 60 , and the substrate W is connected to the negative electrode of the power supply 90 via the substrate holder 200 . When a voltage is applied between the anode 40 and the substrate W, current flows into the substrate W, and a metal film is formed on the surface of the substrate W in the presence of the plating liquid.

The plating module 120B further includes an overflow tank 38 adjacent to the plating tank 39 . The plating liquid in the plating tank 39 flows out across the side wall of the plating tank 39 and can flow into the overflow tank 38 . One end of the circulation line 58a of the plating liquid 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. Installed in the circulation line 58a are: a circulation pump 58b, a constant temperature unit 58c, and a filter 58d. The plating liquid Q overflows through the side wall of the plating tank 39 and flows into the overflow tank 38, and further returns to the plating tank 39 from the overflow tank 38 through the circulation line 58a. Therefore, the plating liquid Q circulates between the plating tank 39 and the overflow tank 38 through the circulation line 58a.

The plating device 100 further includes: a Regulation Plate 14 for adjusting the potential distribution on the substrate W; and a paddle 16 for stirring the plating liquid in the plating tank 39 . The adjustment plate 14 has an opening 14a disposed between the paddle 16 and the anode 40 for limiting the electric field in the plating solution. The paddle 16 is disposed in the plating tank 39 near the surface of the substrate W held by the substrate holder 200 . The paddle 16 is made of titanium (Ti) or resin, for example. The paddle 16 stirs the plating liquid Q in such a manner that sufficient metal ions are uniformly supplied to the surface of the substrate W during plating of the substrate W by reciprocating in parallel with the surface of the substrate W.

In addition, the above-described structure is an example, and the plating device 100, the plating module 120B, etc. may adopt other structures.

FIG. 3 is a schematic view of the front panel of the substrate holder viewed from the inside. FIG. 4 is a schematic view of the back panel of the substrate holder viewed from the inside. The substrate holder 200 includes a front panel 210 and a back panel 220, and holds the substrate W sandwiched between the front panel 210 and the back panel 220.

The front panel 210 includes a holding body 211, a plurality of contacts 213, a bus bar 214, and a clamping mechanism 217. A plurality of contacts 213, bus bars 214, and clamping mechanisms 217 are provided on the inner side of the holding body 211. The holding body 211 has an opening 211A that exposes the plated surface of the substrate W. A handle 212 is installed on one end side of the holding body 211 . A plurality of contacts 213 are provided along the outer periphery of the opening 211A. The contact 213 is an electrical contact that is in contact with the seed layer of the substrate W and is used to flow current into the substrate. The bus bar 214 is electrically connected between the contact point 213 and the external connection terminal 218 provided on the handle 212 . The bus bar 214 is a wiring for connecting the contact 213 to the power supply 90 via the external connection terminal 218 . Around the opening 211A, an inner seal 215 is provided inside the contact point 213 to contact the substrate W and seal between the substrate W and the substrate holder 200 . In addition, a seal 216 is provided outside the bus bar 214 to contact the back panel 220 and seal the substrate holder 200 . The clamping mechanism 217 is disposed outside the outer seal 216 and cooperates with the clamping mechanism 227 of the back panel 220 to engage the front panel 210 and the back panel 220 with each other.

The back panel 220 includes a holding body 221 and a clamping mechanism 227 provided on the outer peripheral portion of the holding body 221 . The holding body 221 has an opening 221A. However, the opening 221A may be omitted as shown in FIG. 2 . A handle 222 is installed on one end side of the holding body 221 . The handle 222 is engaged with the handle 212 of the front panel 210 to function as an integrated handle. The two ends of the handle are hung on the wall edge of the processing tank of each module to suspend the substrate holder 200 . The holding body 221 is provided with an inner seal 225 at a position corresponding to the inner seal 215 of the front panel 210 . On the holding body 221, the position corresponding to the outer seal 216 of the front panel 210 is shown in dashed lines. When the front panel 210 and the back panel 220 hold the substrate W sandwiched therebetween, the inner seals 215 and 225 and the outer seal 216 form a sealed internal space (sealed space) 240 of the substrate holder 200 (Figs. 3, 4, 6A, and 6B). The internal space 240 corresponds to the portion between the inner seal 215 and the outer seal 216 in FIG. 3 , and corresponds to the portion between the inner seal 225 and the dotted line in FIG. 4 .

As shown in FIG. 3 , a detector 230 for detecting leakage of the plating liquid 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 located near a plurality of contacts 213 . The conductor or electrode can also be integrated or composed of multiple pieces. The detector 230 is connected to the external connection terminal 219 through wiring represented by a dotted line. The external connection terminal 219 is electrically insulated from the external connection terminal 218 . When a conductor or an electrode is composed of a plurality of pieces and each piece is connected with an individual wiring, the location where leakage of the plating solution occurs can be identified.

As shown in FIGS. 4 and 5 , the back panel 220 is provided with an introduction passage 231 and a discharge passage 232 that connect the internal space 240 of the substrate holder 200 and the outside of the substrate holder 200 . As shown in FIG. 5 , the inlet passage 231 and the discharge passage 232 are respectively provided with a valve 231A and a valve 232A for controlling conduction and interruption of each passage. The valve 231A and the valve 232A may be, for example, a solenoid valve, an on-off valve, or a flow control valve capable of controlling the flow rate. Valve 231A and valve 232A are controlled by controller 175. The valve 231A and the valve 232A may be provided inside or on the surface of the holding bodies 211 and 221 of the substrate holder 200 . Part or all of the introduction passage 231 and the discharge passage 232 may be provided as passages formed inside the holders 211 and 221 of the substrate holder 200 and/or as pipes arranged on the surfaces of the holders 211 and 221.

Figure 5 is a schematic diagram of the substrate holder in the prewet module. The prewet module 300 includes: a treatment tank 301, a circulation line 302, a pump 303 provided in the circulation line 302, and a degassing module 304. The degassing module 304 is a device that removes air from liquid (degassing) or replaces it with inert gas. Figure 5 shows an example of using a vacuum pump to depressurize the degassing module to remove air from the liquid. In addition, instead of depressurizing the vacuum pump, when inert gas is circulated in the degassing module, the air in the liquid can be replaced with inert gas. In this example, pure water (for example, DIW) is stored in the treatment tank 301 . In this embodiment, pure water degassed by the degassing module 304 or replaced with inert gas is stored in the treatment tank 301 . The pure water in the treatment tank 301 is sent to the degassing module 304 through the pump 303, degassed or replaced with inert gas by the degassing module 304, and then returned to the treatment tank 301 for circulation. Degassed water accumulates in it. Here, degassed water refers to water in which air has been removed, or water in which gas in water has been replaced with inert gas. In addition, the treatment tank 301 is provided with a supply port and a discharge port (not shown), and the pure water in the treatment tank 301 is appropriately replaced through the supply port and the discharge port. The dissolved oxygen concentration in pure water is reduced by degassing and replacing inactive gases.

In this embodiment, the substrate holder 200 holding the substrate W is immersed in the pure water (degassed water) in the treatment tank 301, the valve 231A of the introduction passage 231 is opened, and the pure water is introduced into the substrate holder 200 through the introduction passage 231. The inner space 240 is filled with pure water. Alternatively, the substrate holder 200 holding the substrate W may be immersed in the pure water in the treatment tank 301, the valves 231A and 232A may be opened, and the pure water may be introduced into the internal space 240 of the substrate holder 200 through the introduction passage 231, and The air in the internal space 240 is discharged through the discharge passage 232, and the pure water filled in the internal space 240 is discharged through the discharge passage 232, and then the internal space 240 is filled with pure water. The valve 231A and/or the valve 232A may also be opened before the substrate holder 200 is immersed in pure water. After filling the internal space 240 with pure water, the valve 231A and the valve 232A are closed.

The internal space 240 should be completely filled with pure water to avoid residual air. However, sometimes some air or bubbles are allowed to remain depending on the degree of desired effects as described later. Hereinafter, this embodiment will be described with the internal space 240 completely filled with pure water.

In addition, another passage for connecting the internal space 240 to a pressure reducing device (such as a vacuum pump) (not shown) may be further provided. After the pressure in the internal space 240 is reduced, the additional passage is blocked and the valve 231A is opened. And pure water is introduced into the internal space 240. Furthermore, the valve 232A can also be opened to more reliably fill the internal space 240 with pure water. In addition, instead of providing another passage, a decompression device may be connected to the discharge passage 232 to reduce the pressure in the internal space 240, then close the valve 232A and open the valve 231A to introduce pure water into the internal space 240.

In addition, after plating, the valve 231A and the valve 232A can be opened again in the flushing process (second flushing module 36) or the air supply process (air supply module 35) to discharge the particles in the internal space 240 of the substrate holder 200. Pure water.

6A and 6B are schematic cross-sectional views enlarging the internal space of the substrate holder in the plating tank. 6C is a schematic cross-sectional view enlarging the internal space of the substrate holder of the comparative example of the plating tank. As shown in FIG. 6C , the internal space 240A of the substrate holder 200A of the comparative example is a cavity, and air exists. Because the internal space 240A is a cavity, once the plating liquid Q intrudes and leaks into the internal space 240A, a large amount of the plating liquid Q may invade into the seal due to the hydraulic pressure of the plating liquid Q compressing the air in the internal space 240A. . When the plating solution Q adheres to the seed layer 401 in the internal space 240A, electrolytic corrosion is caused by dissolved oxygen in the plating solution and/or the diversion of the plating current, which may cause the seed layer 401 to dissolve and become electrically insulated.

Figure 7 is an explanatory diagram illustrating dissolution of the seed layer with dissolved oxygen concentration. When the plating liquid Q invades the air-filled internal space 240A ( FIG. 6C ), the original solution of the plating liquid Q is not diluted and adheres to the exposed seed layer 401 near the contact 213 . In addition, because the air (O ₂ ) in the internal space 240A compressed by the intrusion of the plating liquid Q is dissolved in the plating liquid Q, a concentration gradient of O ₂ is generated near the gas-liquid interface, causing species to be generated due to the action of the local battery. Layer 401 dissolves. Specifically, as shown in FIG. 7 , oxygen O ₂ in the air dissolves into the plating liquid Q. At the location near the air-liquid interface where the dissolved oxygen concentration is high, O ₂ receives electrons from the seed layer 401 and becomes OH ⁻ , In addition, at the location away from the gas-liquid interface with a lower dissolved oxygen concentration, copper releases electrons from the seed layer 401 and becomes copper ions and is eluted. Through this reaction, copper may be eluted from the seed layer 401, causing the seed layer 401 to become thinner, the resistance of the seed layer 401 to increase, and the seed layer 401 to be electrically insulated. Although the case of copper plating is explained here, the same phenomenon will occur if other metals are plated.

FIG. 8A is an explanatory diagram illustrating dissolution of the seed layer by shunt current. Figure 8B is an equivalent circuit diagram illustrating the shunt current. In the figure, I _total is the total current flowing into the contact, I _cw is the current flowing through the contact part between the seed layer and the contact, and I _shunt is the shunt current. R _contact is the contact resistance between the contact 213 and the seed layer 401, R _wafer is the resistance of the seed layer, R _dissolution is the resistance of the dissolution site on the seed layer side of the shunt current path, and R _deposition is the connection between the shunt current path. The resistance of the deposited part on the point side, R _electrolyte, represents the resistance of the plating solution.

When the plating liquid Q invades the internal space 240A, the resistance R _wafer of the seed layer 401 and/or the contact resistance R _contact between the contact 213 and the seed layer 401 is high, through the ion conduction in the plating liquid Q, and The redox reaction between the surface of the seed layer 401 and the surface of the contact 213 generates a short-circuit current (shunt current) I _shunt that flows from the seed layer 401 through the plating solution Q into the contact 213 . As shown in FIG. 8A , in this shunt current, Cu changes to Cu ^{2 +} on the surface of the seed layer 401 and is eluted in the plating solution Q. The Cu ^{2 +} in the plating solution Q flows by becoming Cu on the surface of the contact 213 . Therefore, when a shunt current occurs, Cu in the seed layer 401 may be dissolved, the seed layer 401 may become thinner, the resistance of the seed layer 401 may increase, and the seed layer 401 may be electrically insulated. This shunt current also causes the resistance value of the local seed layer 401 to increase due to the above-mentioned local battery effect.

Therefore, the structure of the substrate holder 200A of the comparative example is such that when the plating liquid Q invades the internal space 240A, the seed layer 401 may be dissolved due to the local battery effect of the dissolved oxygen concentration gradient and/or the shunt current, and the seed layer 401 Electrical insulation.

Therefore, this embodiment adopts a structure in which the internal space 240 of the substrate holder 200 is filled with pure water (for example, DIW) (Fig. 5, Fig. 6A, and Fig. 6B), and is configured to detect the leakage of the plating liquid Q into the substrate holder. Detector 230 in interior space 240 of 200 (Figures 3, 6A, 6B). The detector 230 may, for example, be used as an electrode for detecting the current flowing between the contacts 213 or the bus bars 214 via the pure water in the internal space 240, that is, as an electrode for detecting the current flowing in the pure water in the internal space 240 (or The resistance of pure water) electrode.

In the example of FIG. 6A , the detector 230 uses a soluble electrode 235A that functions as a sacrificial anode or a sacrificial electrode. In the figure, symbol 401 represents a seed layer formed on the surface of the substrate W, and symbol 402 represents a resist pattern formed on the surface of the seed layer 401 . Metal is electrolytically plated on the seed layer 401 exposed from the opening of the resist pattern. The contact 213 of the substrate holder 200 contacts the seed layer 401 and is electrically connected to the seed layer 401 . The soluble electrode can use a conductor made of the same material as the plated metal. For example, an electrode made of phosphorus-containing copper can be used like the soluble anode. A DC voltage is applied between the electrode 235A and the contact point 213 (bus bar 214) by the DC power supply device 236A so that the potential of the electrode 235A is higher than that of the contact point 213 (bus bar 214). Furthermore, a current detector 237A is provided in the DC power supply device 236A or on a wiring line from the DC power supply device 236A. In this state, the controller 175 monitors the current flowing between the electrode 235A and the contact 213 (bus bar 214) or the resistance therebetween. The electric current flowing between the electrode 235A and the contact 213 (bus bar 214 ) is equivalent to the electric current flowing in the pure water in the internal space 240 . The resistance between electrode 235A and contact 213 (bus bar 214) is equivalent to the resistance of pure water in internal space 240.

The DC current applied to the electrode 235A and the detection current (resistance) are controlled by the controller 175 . The controller 175 obtains the current flowing into the electrode 235A (the current flowing into the pure water in the internal space 240) through the current detector 237A, and detects the leakage of the plating liquid into the internal space 240 based on this current. In addition, the controller 175 obtains the current flowing into the electrode 235A, calculates the resistance value of the pure water from the voltage between the electrode 235A and the contact 213 (bus bar 214) and the detected current, and then detects leakage based on the resistance value.

When the plating liquid does not leak into the internal space 240, the resistance of the pure water in the internal space 240 is extremely high, so the current does not flow (or only very weakly) between the electrode 235A and the contact 213 (bus bar 214). current flow). In addition, when leakage occurs, the pure water is mixed with the plating liquid, causing the resistance of the pure water to decrease, and current flows between the electrode 235A and the contact 213 (bus bar 214) (or the current increases). Therefore, the leakage of the plating liquid into the internal space 240 can be detected through the electrode 235A. In addition, in the event that an amount of the plating solution leaks that would corrode the seed layer 401, the electrode 235A functioning as a sacrificial anode is biased to a high potential to the contact point 213 and the seed layer 401, so the electrode (sacrificial anode) 235A takes priority. dissolve, thereby inhibiting or preventing the seed layer 401 from dissolving.

When this embodiment is adopted, since the internal space 240 of the substrate holder 200 is filled with pure water, compared with when the internal space 240 is a cavity, the pressure difference between the inside and the outside of the internal space 240 is reduced, thereby suppressing or preventing The plating liquid leaks into the internal space 240 . Thereby, it is possible to suppress or prevent the uniformity of the plating film thickness from decreasing due to leakage of the plating solution.

In this embodiment, even if the plating liquid leaks, since the internal space 240 is filled with pure water, the intrusion of the plating liquid into the internal space 240 is limited to the diffused part and can be suppressed to a very small amount, so it can be suppressed. Seed layer 401 is dissolved (corroded) due to local cell action and/or shunt current due to dissolved oxygen concentration. In addition, because the plating liquid that invades the internal space 240 is diluted by pure water, corrosion of the seed layer 401 can be further suppressed. This can suppress or prevent the uniformity of the plating film thickness from decreasing.

In addition, when this embodiment is adopted, the internal space 240 is filled with pure water. Since the oxygen concentration is low, the local battery effect caused by dissolved oxygen can be suppressed from dissolving the seed layer 401 . This can suppress or prevent the uniformity of the plating film thickness from decreasing.

In addition, according to this embodiment, if an amount of the plating solution that causes corrosion is leaked, the electrode 235A functioning as a sacrificial anode is preferentially dissolved, so that the dissolution of the seed layer 401 can be suppressed or prevented. This can suppress or prevent the uniformity of the coating film thickness from decreasing due to leakage of the plating solution.

In addition, according to this embodiment, by monitoring the current (resistance) between the electrode 235A and the contact point 213 (bus bar 214), it is possible to detect early whether the plating liquid leaks into the internal space 240. Therefore, even if the leakage of the plating liquid occurs, the leakage of the plating liquid can be detected early by the electrode 235A, and the abnormality of the substrate holder 200 and the seal replacement time can be detected early. Therefore, leakage of the plating solution can be detected early, and reduction in uniformity of the plating film thickness can be suppressed or prevented.

In addition, in the example of FIG. 6A , the electrode 235A may not be used for leakage detection, and only the electrode 235A may be used as a sacrificial anode.

In the example of FIG. 6B , the detector 230 uses a non-soluble electrode 235B. As the insoluble electrode, an electrode that is insoluble in the plating solution and is made of, for example, stainless steel or titanium coated with gold or platinum can be used. At this time, the same principle as measuring conductivity or detecting liquid leakage is used. The AC power supply device 236B applies an AC voltage between the electrode 235B and the contact 213 (bus bar 214). The AC current flowing between the contacts 213 (bus bar 214) (or the impedance as the resistance between the electrode 235B and the contact 213 (bus bar 214)) is used to detect the leakage of the plating solution. The alternating current flowing between the electrode 235B and the contact 213 (bus bar 214 ) is equivalent to the current flowing in pure water in the internal space 240 . The resistance (impedance) between the electrode 235B and the contact point 213 (bus bar 214) is equivalent to the resistance (impedance) of pure water in the internal space 240. In addition, a current detector 237B is provided in the AC power supply device 236B or on the wiring from the AC power supply device 236B. The term "resistance" in this specification includes impedance, or the resistance component of impedance.

The application of AC voltage to the electrode 235B and the detection current (resistance) are controlled by the controller 175 . The controller 175 obtains the current flowing into the electrode 235B (the current flowing into the pure water in the internal space 240) through the current detector 237B, and detects the leakage of the plating liquid into the internal space 240 based on the current. In addition, the controller 175 obtains the current flowing into the electrode 235B, calculates the resistance value of the pure water from the voltage between the electrode 235B and the contact 213 (bus bar 214) and the detected current, and then detects leakage based on the resistance value.

When the plating liquid does not leak into the internal space 240, the resistance of the pure water in the internal space 240 is extremely high, so the current does not flow (or only very weakly) between the electrode 235B and the contact 213 (bus bar 214). current flow). When leakage occurs, the pure water mixed with the plating liquid causes the resistance of the pure water to decrease, and current flows between the electrode 235B and the contact 213 (bus bar 214) (or the current increases). Therefore, the leakage of the plating liquid into the internal space 240 can be detected through the non-soluble electrode 235B.

Even with the structure of the example of FIG. 6B , in addition to the function of the sacrificial anode, the same effects as the structure of the example of FIG. 6A can be achieved. In addition, when the non-soluble electrode 235B is used, the maintenance of the substrate holder 200 is easy. When a soluble electrode (sacrificial anode) is used, when the plating solution leaks, part of the copper (Cu) eluted from the sacrificial anode will precipitate to the contact, and maintenance will be required to remove the precipitated Cu. In addition, the sacrificial anode needs to be replaced when it is reduced. In addition, by using non-soluble electrode 235B, such maintenance can be suppressed or prevented. In addition, when the plating liquid leaks, although the seed layer 401 may dissolve (when the contact resistance between the contact 213 and the seed layer 401 is high, or when bubbles remain in the internal space of the substrate holder), because the electrode 235B can (Detector 230) detects the leakage of the plating solution early, so the substrate holder can be replaced to prevent the continued use of the defective substrate holder, thereby suppressing or preventing the degradation of plating quality.

The structures of FIG. 6A and FIG. 6B can also be combined. At this time, only the electrode 235B may be used for leak detection, or both the electrode 235A and the electrode 235B may be used for leak detection. When leakage detection is performed using both the electrode 235A and the electrode 235B, the redundancy of the leakage detection can be improved. (Other implementation forms)

(1) The above embodiment is explained by taking a substrate holder for a square substrate as an example. However, the above embodiment can be applied to a substrate holder for circular, polygonal and other arbitrary shapes other than a square substrate. (2) The above embodiment is an example of a substrate holder holding the substrate sandwiched between the front panel and the back panel. However, the present invention can be applied to any structure of substrate as long as it has an internal space in which the contacts are sealed. Holder. (3) The above embodiment is explained by taking as an example a plating apparatus (so-called immersion type) that immerses a substrate holder in a plating liquid and performs plating on a substrate. However, the present invention can also be applied to a substrate holder. A plating device that holds the substrate downward and contacts the plating liquid to perform plating on the substrate (so-called cup type). (4) In the above embodiment, pure water is introduced into the internal space of the substrate holder in the prewet module. However, another module for introducing liquid such as pure water into the internal space of the substrate holder may also be provided. (5) The liquid introduced into the internal space only needs to be a liquid that does not corrode the constituent parts exposed in the internal space of the substrate holder. It may also be a liquid other than water. For example, a liquid that does not contain metal salts (a liquid whose concentration of metal salts does not reach a specified concentration (for example, 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.

The present invention can also be described as the following forms. Embodiment 1 provides a substrate holder for holding a substrate and bringing the substrate into contact with a plating liquid to perform plating, and having an internal space that allows the substrate to be moved from the substrate while the substrate holder holds the substrate. The substrate holder houses the outer peripheral portion of the substrate in a sealed state; a first passage connects the outside of the substrate holder and the internal space and introduces liquid into the internal space; and a detector is configured In the state where the liquid is introduced into the internal space, the method is used to detect leakage of the plating liquid into the internal space by monitoring the current flowing into the liquid during plating or the resistance of the liquid. The liquid may be, for example, water or other liquids that do not corrode components exposed in the inner space of the substrate holder. As the liquid, for example, pure water used in the prewetting step can be used.

When this form is adopted, corrosion of the seed layer of the substrate due to leakage of the plating solution can be suppressed or prevented, and a decrease in the uniformity of the plating film thickness can be suppressed or prevented. Since the internal space of the substrate holder is filled with liquid, the pressure difference between the inside and the outside of the internal space is reduced, thereby suppressing or preventing the plating liquid from leaking into the internal space. In addition, even if a leak occurs in which the plating liquid intrudes into the sealed internal space, since the internal space is filled with liquid, the intrusion of the plating liquid into the internal space is limited to the part that diffuses into the liquid and can be suppressed to a very small amount, so it can be Inhibits corrosion of the substrate's seed layer. In addition, since the plating liquid that invades the internal space is diluted by the liquid, corrosion of the seed layer of the substrate can be further suppressed. In addition, because the oxygen concentration in the internal space is low, the corrosion of the seed layer caused by local battery effects caused by dissolved oxygen can be suppressed.

In addition, even if the plating liquid leaks, the leakage of the plating liquid can still be detected early by the detector. This enables early detection of abnormalities in the substrate holder and the timing of seal replacement. Therefore, the leakage of the plating solution can be detected early and the decrease in the uniformity of the plating film thickness can be suppressed or prevented.

Form 2 is the substrate holder of Form 1, which is provided with: a contact disposed in the internal space, in contact with the seed layer formed on the surface of the substrate, and allowing plating current to flow into the substrate; and a soluble electrode, which The aforementioned contact point is biased to the high potential side.

In this form, if an amount of plating solution leaks that will corrode the seed layer, the soluble electrode will be biased to a high potential against the contact point and the seed layer, so the soluble electrode will function as a sacrificial anode and will be dissolved preferentially. , which can inhibit or prevent the dissolution of the seed layer.

Embodiment 3 is a substrate holder as in Embodiment 1, wherein the soluble electrode functions as the detector, and the detector is configured to monitor the flow into the contact point or electrical conduction in a state where the liquid is introduced into the internal space. The current between the wiring of the contact point and the electrode can detect the leakage of the plating liquid into the internal space.

In this form, leakage of the plating solution can be detected by monitoring the current flowing between the sacrificial anode (soluble electrode) and the contact, etc., so there is no need to install a separate electrode for detecting leakage.

Embodiment 4 is a substrate holder as in Embodiment 1, which is provided with a contact, which is disposed in the internal space, contacts the seed layer formed on the surface of the substrate, and allows plating current to flow into the substrate, and the detector has insolubility The electrode, the detector is configured by applying an AC voltage between the contact point or the wiring electrically connected to the contact point and the insoluble electrode in a state where the liquid is introduced into the internal space, and monitors the inflow. The current of the aforementioned non-soluble electrode can detect the leakage of the plating liquid into the aforementioned internal space.

In this form, since non-soluble electrodes are used as detectors, the metal of the electrodes does not precipitate to contacts, etc., making it easy to repair the substrate holder.

Form 5 is the substrate holder of Form 4, further having a soluble electrode biased to the high potential side with respect to the contact point.

When this form is adopted, in addition to the effects of Forms 1 and 4, the soluble electrode dissolves prior to the seed layer, thereby suppressing or preventing the dissolution of the seed layer.

Aspect 6: In the substrate holder of Aspect 5, the soluble electrode functions as the detector, and the detector is configured to detect leakage of the plating solution into the internal space using both the insoluble electrode and the soluble electrode.

In this form, since the leakage of the plating solution is detected using both the soluble electrode (sacrificial anode) and the non-soluble electrode, the detection accuracy of the leakage of the plating solution can be improved. In addition, even if one of the electrodes is defective, the leakage of the plating solution can still be detected, so the leakage of the plating solution can be detected more reliably, and the tediousness of detecting leakage can be improved.

Form 7 is a substrate holder of any one of Forms 3 to 6, wherein the wiring is a bus bar. When this form is adopted, the wiring installation space can be reduced and the resistance of the wiring can be suppressed compared to when using multiple cables.

Form 8 is a substrate holder of any one of Forms 1 to 7, further equipped with a valve, which is disposed in the first passage to conduct or block between the outside of the substrate holder and the internal space.

In this form, since the internal space of the substrate holder and the outside can be connected or blocked by opening and closing the valve, the plating process of the substrate can be performed while the internal space of the substrate holder is reliably sealed.

Form 9 is a substrate holder of any one of Forms 1 to 8, further provided with a second passage that connects the outside of the substrate holder and the interior space to discharge air and/or liquid from the interior space.

In this form, when the liquid is introduced from the first passage, the air in the internal space is discharged through the second passage, so that the liquid can be effectively introduced into the internal space. In addition, by introducing liquid from the first passage and discharging the liquid filling the internal space from the second passage, it is possible to prevent bubbles from remaining and filling the internal space with liquid. In addition, the second passage can also be connected to the pressure reducing device, and the liquid can be introduced from the first passage into the internal space while or after the pressure is reduced. At this time, the liquid can be quickly introduced into the depressurized internal space.

Form 10 is a substrate holder of any one of Forms 1 to 9, further provided with a third passage that connects the outside of the substrate holder and the interior space and is connected to a device for decompressing the interior space.

In this form, since the liquid is introduced from the first passage into the internal space simultaneously with or after the pressure is reduced, the liquid can be quickly introduced into the internal space.

Form 11 is a substrate holder of any one of forms 1 to 10, wherein the liquid system is pure water, or pure water after degassing or replacing it with an inert gas.

When this form is adopted, by introducing pure water into the internal space, it is possible to suppress corrosion of the conductive member in the internal space and to suppress intrusion of the plating liquid. In addition, when pure water or pure water degassed or replaced with inert gas is introduced into the internal space, the oxygen concentration in the internal space can be reduced. When the plating liquid intrudes, it can inhibit the local battery effect caused by the dissolved oxygen concentration. Cause chemical corrosion of the seed layer.

Form 12 provides a plating device, which is provided with: a substrate holder according to any one of items 1 to 11 of the patent scope; and a liquid supply module that supplies liquid through the first passage of the substrate holder. to the aforementioned internal space; a plating module that receives the aforementioned substrate holder and brings it into contact with the plating liquid to plate the aforementioned substrate; and a control module that, while introducing the liquid into the aforementioned internal space, During plating, the output from the detector is obtained to determine whether the plating liquid leaks into the internal space.

When this form is adopted, a plating device that achieves the above effects can be provided.

Aspect 13 is the plating apparatus of aspect 12, wherein the liquid supply module is a prewet module that contacts the surface of the substrate with pure water, or degasses or replaces the pure water with an inert gas.

In this form, since the liquid is introduced into the internal space of the substrate holder using the pre-wetting module, there is no need to install an additional module for introducing the liquid into the internal space, thereby suppressing an increase in the size and/or cost of the device.

Embodiment 14 provides a method for plating a substrate, including introducing a liquid into an internal space of the substrate holder housed in a state of sealing the outer peripheral portion of the substrate from the outside, and in a state in which the liquid is introduced into the internal space, Leakage of the plating liquid into the internal space is detected by monitoring the current flowing into the liquid or the resistance of the liquid. When this form is adopted, the same effects as those described in Form 1 can be achieved.

Embodiment 15 provides a memory medium that stores a program for executing a control method of a plating device using a computer, and the memory includes a liquid introduced into the internal space of the substrate holder housed in a state of sealing the outer peripheral portion of the substrate from the outside, A program for detecting leakage of the plating liquid into the internal space by monitoring the resistance of the liquid after introducing the liquid into the internal space. When this form is adopted, the same effects as those described in Form 1 can be achieved.

The embodiments of the present invention have been described above. However, the above-mentioned embodiments of the present invention are provided for easy understanding of the present invention and do not limit the present invention. The present invention can be changed and improved within the scope that does not deviate from the spirit, and the present invention naturally includes equivalents thereof. In addition, the embodiments and modifications may be arbitrarily combined within the scope that can solve at least part of the above-mentioned problems or achieve at least part of the effects, and each element described in the patent claim and the specification may be arbitrarily combined or omitted.

25:Box table 25a:Box 27:Transport robot 28: Driving mechanism 29:Substrate loading and unloading module 30: Temporary box 32: Pre-wet module 33:Prepreg module 34: First flushing module 35: Air supply module 36:Second flushing module 37:Conveying device 38:Overflow tank 39:Plating tank 40:Anode 50:Cleaning module 50a: Cleaning station 14:Adjustment plate 14a:Open your mouth 16:Paddle 58a: Circulation line 58b: Circulation pump 58c: Thermostat unit 58d: filter 60:Anode holder 100:Plating device 110:Loading/unloading station 120: Processing station 120A: Pre-processing and post-processing module 120B: Plating module 175:Controller 175A:CPU 175B:Memory 200,200A: Substrate holder 210:Front panel 211:Maintain body 211A:Open your mouth 212: handle 213:Contact 214:Bus bar 215:Inside seal 216:Outer seal 217: Clamping mechanism 218:External connection terminal 219:External connection terminal 220:Back panel 221:Maintenance body 221A:Open your mouth 222: handle 225:Inside seal 227: Clamping mechanism 230:Detector 231:Import path 231A:Valve 232:Exhaust passage 232A:Valve 235A, 235B: Electrode 236A: DC power supply unit 236B: AC power supply unit 237A, 237B: Current detector 240,240A: Internal space 300: Pre-wet module 301: Processing tank 302: Circulation pipeline 303:Pump 304: Degassing module 401: seed layer 402: Resist pattern W: substrate

FIG. 1 is an overall layout diagram of a plating device according to one embodiment. Figure 2 shows a schematic diagram of the plating module. FIG. 3 is a schematic view of the front panel of the substrate holder viewed from the inside. FIG. 4 is a schematic view of the back panel of the substrate holder viewed from the inside. Figure 5 is a schematic diagram of the substrate holder in the prewet module. 6A is a schematic cross-sectional view enlarging the internal space of the substrate holder in the plating tank. 6B is a schematic cross-sectional view enlarging the internal space of the substrate holder in the plating tank. 6C is a schematic cross-sectional view enlarging the internal space of the substrate holder of the comparative example of the plating tank. Figure 7 is an explanatory diagram illustrating dissolution of the seed layer with dissolved oxygen concentration. FIG. 8A is an explanatory diagram illustrating dissolution of the seed layer by shunt current. Figure 8B is an equivalent circuit diagram illustrating the shunt current.

175:Controller

200:Substrate holder

210:Front panel

213:Contact

214:Bus bar

215:Inside seal

216:Outer seal

220:Back panel

225:Inside seal

230:Detector

231:Import path

231A:Valve

232:Exhaust passage

232A:Valve

235A:Electrode

236A: DC power supply unit

237A:Current detector

240:Internal space

401: seed layer

402: Resist pattern

W: substrate

Claims (7)

A substrate holder is used to hold the substrate and make the substrate contact the plating liquid for plating, and has: An internal space that accommodates the outer peripheral portion of the substrate in a state of being sealed from the outside of the substrate holder while the substrate holder holds the substrate; A contact is disposed in the internal space, and in a state where the liquid is introduced into the internal space, contacts the seed layer formed on the surface of the substrate, allowing plating current to flow into the substrate; and The electrode is arranged in the internal space and is biased to a high potential side with respect to the contact point. The substrate holder of claim 1, wherein the electrode with the contact point biased to the high potential side functions as a detector, The detector is configured to detect leakage of the plating liquid into the interior by monitoring a current flowing into the contact point or between a wiring electrically connected to the contact point and the electrode in a state where the liquid is introduced into the internal space. space. The substrate holder of claim 2, wherein the wiring is a bus bar. The substrate holder of any one of claims 1 to 3, wherein the liquid system is pure water, pure water from which air has been removed, or pure water in which the gas is replaced with an inert gas. A plating device equipped with: The substrate holder according to any one of claims 1 to 4; a liquid supply device that supplies liquid to the internal space in front of the substrate holder; and A plating tank is used to plate the substrate by bringing the substrate held by the substrate holder into contact with a plating liquid. A plating method is used for plating a substrate and includes the following steps: introducing the liquid into the internal space of the substrate holder that accommodates the outer peripheral portion of the substrate in a state of being sealed from the outside, In a state where the liquid is introduced into the internal space, the contacts formed on the surface of the substrate by the pair of electrodes arranged in the internal space are biased to the high potential side, thereby suppressing the formation of species on the surface of the substrate. layer of corrosion. A memory medium is a program that memorizes a control method for executing a plating device through a computer. The control method includes the following steps: introducing the liquid into the internal space of the substrate holder that accommodates the outer peripheral portion of the substrate in a state of being sealed from the outside, In a state where the liquid is introduced into the internal space, the contacts formed on the surface of the substrate by the pair of electrodes arranged in the internal space are biased to the high potential side, thereby suppressing the formation of species on the surface of the substrate. layer of corrosion.

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