TWI790526B - Substrate holder, plating device, plating method, and memory medium - Google Patents

Abstract

The invention aims at suppressing or preventing the plating solution from intruding into the sealed space of the substrate holder, and early detection of the plating solution intrusion. The substrate holder of the present invention is used to hold a substrate and perform plating by contacting the substrate with a plating solution, and includes: sealing the substrate from the outside of the substrate holder in a state where the substrate holder holds the substrate The inner space of the outer periphery of the aforementioned substrate is accommodated in the state; the first passage connecting the outside of the aforementioned substrate holder and the aforementioned inner space, and introducing the liquid into the aforementioned inner space; A detector for detecting leakage of the plating solution 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 storage medium

This application relates to a substrate holder, a plating device, a plating method, and a memory medium storing a program for enabling a computer to execute the control method of the plating device.

In electrolytic plating, when the plating solution leaks into the substrate holder due to some defects (substrate unevenness, sealing aging, etc.), the seed layer will be corroded and/or dissolved due to the plating solution intruding into the holder, And poor conduction occurs, which reduces the uniformity of plating.

US Patent No. 7,727,366 (Patent Document 1) and US Patent No. 8,168,057 (Patent Document 2) describe that the sealed side of the substrate is pressurized with a fluid to prevent fluid from entering from the opposite side of the seal. Japanese Unexamined Patent Application Publication No. 2020-117763 (Patent Document 3) and Japanese Patent Application Publication No. 2020-117765 (Patent Document 4) disclose that the penetration of the plating solution is prevented by injecting liquid into the internal space of the outer peripheral portion of the sealed housing substrate. The internal space prevents the plating from separating out to the outer periphery of the substrate and the contact members. [Prior Art Literature] [Patent Document]

[Patent Document 1] Specification of US Patent No. 7727366 [Patent Document 2] Specification of US Patent No. 8168057 [Patent Document 3] Japanese Patent Laid-Open No. 2020-117763 [Patent Document 4] Japanese Patent Laid-Open No. 2020-117765

(Problem to be solved by the invention)

Even if the technical countermeasures described in the above patent documents are adopted, the plating solution may still invade the internal space depending on the degree of unevenness of the substrate and the aging of the seal. Countermeasures.

An object of the present invention is to suppress or prevent the plating solution from intruding into the sealed space of the substrate holder, and to detect the plating solution intrusion at an early stage. In addition, an object of the present invention is to prevent the uniformity of the plating film thickness from decreasing even when the plating solution invades the sealed space of the substrate holder. (technical means to solve the problem)

One embodiment provides a substrate holder for holding a substrate and performing plating by contacting the substrate with a plating solution, 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; the first passage connects the outside of the substrate holder with the internal space and introduces liquid into the internal space; and the detector is It is arranged in the internal space and is used to detect leakage of the plating solution into the internal space by monitoring the current flowing into the liquid during plating or the resistance of the liquid when the liquid is introduced into the internal space.

One embodiment is that the substrate holder can be equipped with: a contact, which is arranged in the aforementioned inner space, contacts the seed layer formed on the surface of the aforementioned substrate, and flows the plating current into the aforementioned substrate; and a dissolving electrode, which is connected to the aforementioned The contacts are 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 attached to the same or similar elements, and repeated description of the same or similar elements will be omitted in the description of various embodiments. In addition, the features shown in various embodiments can be applied to other embodiments as long as they do not contradict 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 elements, micromechanical elements, or partially produced Integrated circuits, and any other objects to be processed. The substrate includes any shape including polygon and circle. In addition, expressions such as "front", "rear", "front", "rear", "upper", "lower", "left", and "right" are used in this manual, but these are for convenience The positions and directions on the paper of the illustrations shown for illustration may be different from the actual arrangement when the device is used.

Fig. 1 is an overall configuration diagram of a plating apparatus according to an embodiment. The plating apparatus 100 performs a plating process on a substrate while holding the substrate on a substrate holder 200 ( FIG. 2 ). The plating apparatus 100 is roughly divided into: a loading/unloading station 110 for loading or unloading substrates on or from the substrate holder 200; a processing station 120 for processing the substrates; and a cleaning station 50a. The processing station 120 is configured with: a pre-processing and post-processing module 120A for performing pre-processing and post-processing of the substrate; and a plating module 120B for performing plating 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 . A cassette 25 a for accommodating substrates is mounted on the cassette table 25 . The substrate loading and unloading module 29 is configured to load and unload the 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.

In a position surrounded by the cassette stage 25, the substrate loading and unloading module 29, and the cleaning station 50a, a transfer robot 27 for transferring substrates between these units is arranged. The transfer robot 27 is configured to be able to travel by a traveling mechanism 28 . The transfer robot 27, for example, takes out the pre-plating substrate from the cassette 25a and transfers it to the substrate loading and unloading module 29, and receives the coated substrate from the substrate loading and unloading module 29, and transfers the coated substrate to the cleaning module. 50, the cleaned and dried substrates are taken out from the cleaning module 50 and stored in the cassette 25a.

The pre-processing and post-processing module 120A has a pre-wetting module 32 , a pre-soaking module 33 , a first rinsing module 34 , an air blowing module 35 , and a second rinsing module 36 . The pre-wetting module 32 replaces the air inside the pattern formed on the surface of the substrate with the processing liquid by wetting the surface to be plated of the substrate before plating with processing liquid such as pure water or degassed water. The pre-wetting module 32 is configured to replace the processing solution inside the pattern with the plating solution during plating, so as to facilitate the pre-wetting process of supplying the plating solution inside the pattern. The pre-dipping module 33, for example, uses a treatment solution such as sulfuric acid or hydrochloric acid to etch away the high-resistance oxide film on the surface of the seed layer formed on the surface of the substrate before the plating treatment to clean or activate the plating substrate. The way of pre-preg treatment of the surface constitutes. The first rinsing module 34 cleans the pre-soaked substrate together with the substrate holder 200 with a cleaning solution (pure water, etc.). The air blowing module 35 is for draining the cleaned substrate. The second rinsing module 36 cleans the plated substrate together with the substrate holder 200 with a cleaning solution. The pre-wetting module 32 , the pre-soaking 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 configuration is an example, and is not limited to the above-mentioned configuration, and the pre-processing and post-processing module 120A may also adopt other configurations.

The plating module 120B has: a plurality of plating tanks (plating chambers) 39 and an overflow tank 38 . Each plating tank 39 accommodates one substrate inside, immerses the substrate in the plating solution held inside, and performs plating such as copper plating on the surface of the substrate. Here, the type of plating solution is not particularly limited, and various plating solutions can be used depending on the application. The configuration of the coating module 120B is an example, and the coating module 120B may adopt other configurations.

The plating apparatus 100 has, for example, a linear motor-type conveyance device 37 that is positioned on the side of each of these devices and that is conveyed together with the substrate holder 200 between the respective devices. The conveying device 37 is connected with the substrate loading and unloading module 29, the temporary storage box 30, the pre-wetting module 32, the pre-soaking module 33, the first rinsing module 34, the air supply module 35, the second rinsing module 36, and the coating module 120B to transport the substrate holder 200.

The plating apparatus 100 comprised as mentioned above has the control module (controller) 175 as a control part comprised so that each part may be controlled. The control module 175 has: a memory 175B storing a designated program; and a CPU 175A executing the program in the memory 175B. The storage 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 of the plating process and the program of the control of the cleaning station 50a. Memory media can include non-volatile and/or volatile memory media. Memory media such as computer-readable ROM (read-only memory), RAM (random access memory), flash memory and other memory, hard disk, CD-ROM (disc read-only), DVD-ROM (read-only diversified digital disc) and disk-shaped memory media such as floppy disks.

The controller 175 can communicate with an upper-level controller (not shown) that overall 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 constituted by hardware such as 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 disposed inside and/or outside the casing of the coating device 100 . Part or all of the controller 175 is communicably connected to each part of the plating apparatus 100 by wire and/or wirelessly. (plating module)

FIG. 2 shows a schematic diagram of the plating module 120B. As shown in the figure, the plating module 120B is provided with: a plating tank 39 holding a plating solution inside; an anode 40 disposed opposite to a substrate holder 200 in the plating tank 39; and an anode holder holding 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 solution Q in the plating tank 39 . The plating apparatus 100 of this embodiment is an electrolytic plating apparatus for plating the surface of the substrate W with a metal by flowing an electric current into the plating solution Q. The anode 40 is an insoluble anode formed by coating titanium which is insoluble in a plating solution, such as iridium oxide or platinum. The anode 40 can also use a soluble anode. 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 for copper plating.

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, in other embodiments, a configuration in which the anode 40 and the substrate W are arranged so as to extend in the horizontal direction (cup type) may also be employed. The anode 40 is connected to the positive pole of the power supply 90 through the anode holder 60 , and the substrate W is connected to the negative pole of the power supply 90 through 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 a plating solution.

The coating module 120B further includes an overflow tank 38 adjacent to the coating tank 39 . The plating liquid in the plating tank 39 flows out over the side wall of the plating tank 39 and can flow into the overflow tank 38 . One end of the circulation line 58 a of the plating solution is connected to the bottom of the overflow tank 38 , and the other end of the circulation line 58 a is connected to the bottom of the plating tank 39 . Installed in the circulation pipeline 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 58 a. Therefore, the plating liquid Q circulates between the plating tank 39 and the overflow tank 38 through the circulation line 58a.

The plating apparatus 100 further includes: a regulation plate (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 adjustment plate 14 has an opening 14 a 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 coating bath 39 near the surface of the substrate W held by the substrate holder 200 . The paddle 16 is made of, for example, titanium (Ti) or resin. The paddle 16 agitates the plating solution Q so that sufficient metal ions are uniformly supplied to the surface of the substrate W during the plating of the substrate W by reciprocating in parallel with the surface of the substrate W.

In addition, the above-mentioned structure is an example, and the structure of the plating apparatus 100, the plating module 120B, etc. can 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 plate of the substrate holder viewed from the inside. The substrate holder 200 includes a front panel 210 and a rear panel 220 , and holds the substrate W by being sandwiched between the front panel 210 and the rear panel 220 .

The front panel 210 includes: a holder 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 disposed on the inner side of the holding body 211 . The holder 211 has an opening 211A exposing the surface of the substrate W to be plated. A handle 212 is attached to one end side of the holding body 211 . A plurality of contacts 213 are disposed along the periphery of the opening 211A. The contact 213 is in contact with the seed layer of the substrate W, and is an electrical contact for flowing current in 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 wiring for connecting the contact point 213 to the power source 90 via the external connection terminal 218 . Around the opening 211A, an inner seal 215 that contacts the substrate W and seals between the substrate W and the substrate holder 200 is provided on the inner side of the contact point 213 . In addition, a seal 216 is provided on the outside of the bus bar 214 to contact the back plate 220 and seal the outside of 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 holder 221 has an opening 221A. However, the opening 221A can also be omitted as shown in FIG. 2 . A handle 222 is attached to one end side of the holding body 221 . The handle 222 engages 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 edge of the wall of the processing tank of each module to suspend the substrate holder 200 . In the holder 221 , an inner seal 225 is provided at a position corresponding to the inner seal 215 of the front panel 210 . On the holding body 221 , a position corresponding to the outer side seal 216 of the front panel 210 is shown by dotted lines. When the substrate W is sandwiched between the front panel 210 and the rear panel 220, the inner seals 215, 225 and the outer seal 216 form a closed internal space (sealed space) 240 of the substrate holder 200 (FIG. 3, FIG. 4, FIG. 6A, FIG. 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 solution is provided between the inner seal 215 and the outer seal 216 of the front panel 210 . The detector 230 is a conductor or an electrode disposed near the plurality of contacts 213 . The conductor or electrode can also be integrated, or can be composed of multiple sheets. The detector 230 is connected to the external connection terminal 219 by the wiring shown by the dotted line. The external connection terminal 219 is electrically insulated from the external connection terminal 218 . When a conductor or an electrode is constituted by a plurality of sheets, and each sheet is connected by an individual wiring, it is possible to specify the part where the plating solution leaks.

As shown in FIG. 4 and FIG. 5 , the introduction path 231 and the discharge path 232 connecting the inner space 240 of the substrate holder 200 and the outside of the substrate holder 200 are provided on the back plate 220 . As shown in FIG. 5 , a valve 231A and a valve 232A for controlling conduction and blocking of each passage are respectively provided in the introduction passage 231 and the discharge passage 232 . The valve 231A and the valve 232A may be, for example, solenoid valves, on-off valves, or flow control valves capable of controlling flow. The valve 231A and the valve 232A are controlled by the controller 175 . The valve 231A and the valve 232A may be provided inside or on the surface of the back plate 220 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 holder 221 of the substrate holder 200 and/or piping arranged on the surface of the holder 221 .

Figure 5 is a schematic diagram of a substrate holder in a pre-wet module. The pre-humidity module 300 includes: a treatment tank 301 , a circulation pipeline 302 , a pump 303 installed in the circulation pipeline 302 and a degassing module 304 . The degassing module 304 is a device for removing the air in the liquid (degassing) or replacing it with an inert gas. Figure 5 shows an example of decompressing the degassing module with a vacuum pump to remove air from the liquid. In addition, instead of the decompression of the vacuum pump, when the inert gas is circulated in the degassing module, the air in the liquid can be replaced by the inert gas. In this example, pure water (such as DIW) is stored in the treatment tank 301 . In this embodiment, the pure water degassed by the degassing module 304 or replaced with an inert gas is stored in the treatment tank 301 . The pure water in the treatment tank 301 is sent to the degassing module 304 by the pump 303, degassed by the degassing module 304 or replaced with an inert gas and then returned to the treatment tank 301. Degassed water is stored in the Here, deaerated water refers to water from which air has been removed, or water in which gas in water has been replaced with an inert gas. In addition, a supply port and a discharge port (not shown) are provided in the processing tank 301, and the pure water in the processing tank 301 is appropriately replaced through the supply port and the discharge port. The concentration of dissolved oxygen in pure water is reduced by degassing and replacing inert gas.

In this embodiment, the substrate holder 200 holding the substrate W is immersed in pure water (deaerated 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 pure water in the treatment tank 301, the valve 231A and the valve 232A may be opened, and the pure water may be introduced into the inner space 240 of the substrate holder 200 through the introduction path 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. Valve 231A and/or valve 232A may also be opened before substrate holder 200 is immersed in pure water. And after filling the inner 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, some air or air bubbles are sometimes allowed to remain depending on the desired degree of the effect described later. Hereinafter, this embodiment will be described by filling the internal space 240 completely with pure water.

In addition, another passage for connecting the internal space 240 to a decompression device (such as a vacuum pump) not shown in the figure may be further provided. After the internal space 240 is decompressed, the other passage is blocked and the valve 231A is opened. Instead, pure water is introduced into the inner space 240 . Furthermore, the valve 232A may 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 depressurize 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 rinsing process (the second rinsing module 36) or the air supply process (the air supply module 35), so as to discharge the gas in the inner space 240 of the substrate holder 200. pure water.

6A and 6B are enlarged schematic cross-sectional views of the inner space of the substrate holder in the plating tank. 6C is an enlarged schematic cross-sectional view of the inner space of the substrate holder of the comparative example in the plating tank. As shown in FIG. 6C , the inner 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 solution Q invades and leaks into the internal space 240A, a large amount of the plating solution Q may invade the seal by hydraulically compressing the air in the internal space 240A. . When the plating solution Q adheres to the seed layer 401 in the internal space 240A, the dissolved oxygen in the plating solution and/or the shunting of plating current will cause electrolytic corrosion, which may cause the seed layer 401 to dissolve and be electrically insulated.

Fig. 7 is an explanatory diagram illustrating dissolution of a seed layer at a concentration of dissolved oxygen. When the plating solution Q invades the air-filled inner space 240A ( FIG. 6C ), the stock solution of the plating solution 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 dissolves in the plating liquid Q, a concentration gradient of O ₂ is generated near the air-liquid interface, causing species due to the action of the local cell. Layer 401 dissolves. Specifically, as shown in FIG. 7 , oxygen _O2 in the air dissolves into the plating solution Q, and at a position with a high dissolved oxygen concentration near the gas-liquid interface, _O2 receives electrons from the seed layer 401 and becomes OH ⁻ , In addition, at the part away from the gas-liquid interface with a lower dissolved oxygen concentration, copper releases electrons from the seed layer 401 to become copper ions and elute. Through this reaction, copper may be eluted from the seed layer 401 to cause 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 described here, the same phenomenon will occur when other metals are plated.

Fig. 8A is an explanatory diagram illustrating dissolution of a seed layer by a shunt current. Fig. 8B is an equivalent circuit diagram illustrating a shunt current. In the figure, I _total is the sum of the current flowing into the contact, I _cw is the current flowing through the contact 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 dissolving part on the seed layer side of the shunt current path, and R _deposition is the connection of the shunt current path. The resistance of the precipitation part on the dot side, R _electrolyte represents the resistance of the plating solution.

When the plating solution 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, and the ions in the plating solution Q conduct electricity and contact with the seed layer 401. The oxidation-reduction 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 flowing from the seed layer 401 through the plating solution Q into the contact 213 . As shown in FIG. 8A , Cu becomes Cu ^{2 +} on the surface of the seed layer 401 and is eluted in the plating solution Q as shown in FIG. 8A . 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 dissolve, the seed layer 401 becomes thinner, the resistance of the seed layer 401 increases, and the seed layer 401 is electrically insulated. The shunt current also increases the resistance value of the local seed layer 401 through the above-mentioned local battery action.

Therefore, the composition of the substrate holder 200A of the comparative example is that when the plating solution Q invades the inner space 240A, the seed layer 401 may be dissolved due to the local battery action and/or shunt current of the above-mentioned dissolved oxygen concentration gradient, and the seed layer 401 Electrically insulated.

Therefore, this embodiment adopts the configuration that the inner space 240 of the substrate holder 200 is filled with pure water (such as DIW) (Fig. 5, Fig. 6A, Fig. 6B), and is equipped with a detection method for detecting the leakage of the plating solution Q to the substrate holder. Detector 230 in interior space 240 of 200 (FIGS. 3, 6A, 6B). The detector 230 can be used, for example, as an electrode that detects the current flowing between the contacts 213 or the bus bars 214 through the pure water in the internal space 240, that is, as an electrode that detects the current flowing in the pure water in the internal space 240 (or resistance of pure water) electrodes.

In the example of FIG. 6A , the detector 230 is a soluble electrode 235A that functions as a sacrificial anode or a sacrificial electrode. In this figure, reference numeral 401 denotes a seed layer formed on the surface of the substrate W, and reference numeral 402 denotes a resist pattern formed on the surface of the seed layer 401 . Metal is electric field plated on the seed layer 401 exposed from the opening of the resist pattern. The contacts 213 of the substrate holder 200 are in contact with the seed layer 401 to be electrically connected to the seed layer 401 . A conductor made of the same material as the plating metal can be used for the soluble electrode, for example, an electrode made of phosphorus-containing copper can be used like the soluble anode. Between the electrode 235A and the contact point 213 (bus bar 214 ), a DC voltage is applied by the DC power supply device 236A so that the electrode 235A has a higher potential than the contact point 213 (bus bar 214 ). Furthermore, a current detector 237A is provided in the DC power supply unit 236A or on wiring from the DC power supply unit 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 between these. The current flowing between electrode 235A and contact point 213 (bus bar 214 ) is equivalent to the current flowing in pure water in internal space 240 . The resistance between the electrode 235A and the contact point 213 (bus bar 214 ) corresponds to the resistance of pure water in the internal space 240 .

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

Since no plating solution leaks into the inner space 240, the resistance of the pure water in the inner space 240 is extremely high, so the current does not flow between the electrode 235A and the contact 213 (bus bar 214) (or there is only a very weak current flow). In addition, when a leak occurs, the pure water is mixed with the plating solution to lower the resistance of the pure water, and the current flows (or the current increases) between the electrode 235A and the contact point 213 (bus bar 214 ). Therefore, leakage of the plating solution into the inner space 240 can be detected by the electrode 235A. In addition, in the event of leakage of the plating solution that would corrode the seed layer 401, the electrode 235A, which functions as a sacrificial anode, is biased at a high potential against the contact point 213 and the seed layer 401, so the electrode (sacrificial anode) 235A has priority dissolve, and inhibit or prevent the seed layer 401 from dissolving.

When adopting this embodiment, since the inner space 240 of the substrate holder 200 is filled with pure water, the pressure difference between the inside and the outside of the inner space 240 can be reduced compared with when the inner space 240 is a cavity, and the pressure difference can be suppressed or prevented. The plating solution leaks into the internal space 240 . Thereby, it is possible to suppress or prevent the decrease in the uniformity of the plated film thickness due to the leakage of the plating solution.

When adopting this embodiment, even if the plating solution leaks, because the inner space 240 is filled with pure water, the intrusion of the plating solution in the inner space 240 is limited to a diffused part, and can be suppressed in a very small amount, so it can be suppressed. The seed layer 401 is dissolved (corroded) by local cell action and/or current shunting due to dissolved oxygen concentration. In addition, since the plating solution that invaded the inner space 240 is diluted with pure water, corrosion of the seed layer 401 can be further suppressed. Thereby, it is possible to suppress or prevent the decrease in the uniformity of the plated film thickness.

In addition, according to the present embodiment, since the inner space 240 is filled with pure water, since the oxygen concentration is low, the seed layer 401 can be dissolved by suppressing local battery action due to dissolved oxygen. Thereby, it is possible to suppress or prevent the decrease in the uniformity of the plated film thickness.

In addition, according to this embodiment, in the event of leakage of the plating solution in an amount that would corrode, 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. Thereby, it is possible to suppress or prevent the decrease in the uniformity of the plated film thickness due to the 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 early detect whether the plating solution leaks into the internal space 240 . Therefore, even if the leakage of the plating solution occurs, the leakage of the plating solution can be detected early by the electrode 235A, and the abnormality of the substrate holder 200 and the replacement timing of the seal can be detected early. 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.

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

In the example of FIG. 6B , the detector 230 uses a non-dissolving electrode 235B. As the insoluble electrode, for example, an electrode made of gold or platinum-coated stainless steel or titanium that does not dissolve in the plating solution can be used. At this time, using the same principle as measuring conductivity or detecting liquid leakage, an AC voltage is applied between the electrode 235B and the contact point 213 (bus bar 214 ) by the AC power supply device 236B. The leakage of the plating solution is detected by an alternating current flowing between the contact 213 (bus bar 214 ) (or impedance as a resistance between the electrode 235B and the contact 213 (bus bar 214 )). The alternating current flowing between the electrode 235B and the contact point 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 wiring from the AC power supply device 236B. The resistance in this specification includes impedance, or the resistance component of impedance.

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

Since the plating solution does not leak into the inner space 240, the resistance of the pure water in the inner space 240 is extremely high, so the current does not flow between the electrode 235B and the contact 213 (bus bar 214) (or there is only a very weak current flow). When leakage occurs, the pure water is mixed with the plating solution to lower the resistance of the pure water, and the current flows (or the current increases) between the electrode 235B and the contact 213 (bus bar 214 ). Therefore, leakage of the plating solution into the inner space 240 can be detected by the insoluble electrode 235B.

Even with the configuration of the example shown in FIG. 6B , except for the function of the sacrificial anode, the same effect as that of the example shown in FIG. 6A can still be achieved. In addition, when the non-dissolving 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 is deposited to the contact, and maintenance to remove the deposited Cu is required. In addition, the sacrificial anode needs to be replaced when it is reduced. In addition, in the case of using the non-dissolving electrode 235B, such maintenance can be suppressed or prevented. In addition, when the plating solution leaks, although it is possible that the seed layer 401 dissolves (when the contact resistance between the contact point 213 and the seed layer 401 is high, or when there are bubbles remaining in the inner space of the substrate holder), because the electrode 235B can (Detector 230 ) The leakage of the plating solution is detected at an early stage, so that the defective substrate holder can be prevented from continuing to be used by replacing the substrate holder or the like, thereby suppressing or preventing degradation of the plating quality.

It is also possible to combine the configurations of FIG. 6A and FIG. 6B . In this case, 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. In the case of performing leak detection with both the electrode 235A and the electrode 235B, the redundancy of the leak detection can be improved. (Other implementation forms)

(1) The above-mentioned embodiment is described by taking a substrate holder of a square substrate as an example, but the above-mentioned embodiment can be applied to a substrate holder of a circle, a polygon other than a square, and other arbitrary shapes. (2) The above embodiment is an example of a substrate holder holding the substrate between the front panel and the back panel, but the present invention can be applied to substrates of any configuration as long as the substrate holder has an internal space in which the contacts are sealed. holder. (3) The above embodiment is described as an example of a plating apparatus (so-called immersion type) that performs plating on a substrate by immersing the substrate holder in the plating solution, but the present invention can also be applied to a substrate holder A plating device (so-called cup type) that holds the substrate downward to contact the plating solution and performs plating on the substrate. (4) In the above embodiment, in the pre-wetting module, pure water is introduced into the inner space of the substrate holder, however, another module for introducing liquid such as pure water into the inner space of the substrate holder may be provided. (5) The liquid introduced into the inner space may be a liquid other than water as long as it does not corrode the components exposed in the inner space of the substrate holder. As the liquid, for example, a metal salt-free liquid (a liquid in which the concentration of the metal salt 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. Aspect 1 provides a substrate holder for holding a substrate and performing plating by contacting the substrate with a plating solution, and having: an internal space in which the substrate is held by the substrate holder. The outer periphery of the aforementioned substrate is accommodated in a sealed state of the outer portion of the aforementioned substrate holder; the first passage connects the outer portion of the aforementioned substrate holder with the aforementioned inner space, and guides liquid into the aforementioned inner space; and the detector is configured In the internal space, in the state where the liquid is introduced into the internal space, it 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 the components exposed in the inner space of the substrate holder. As the liquid, for example, pure water used in the pre-wetting process can be used.

According to this aspect, it is possible to suppress or prevent corrosion of the seed layer of the substrate due to leakage of the plating solution, and to suppress or prevent reduction in the uniformity of the plating film thickness. Since the inner space of the substrate holder is filled with the liquid, the pressure difference between the inside and the outside of the inner space is reduced, suppressing or preventing the plating liquid from leaking into the inner space. In addition, even if the leakage of the plating solution intrudes into the sealed internal space occurs, since the internal space is filled with liquid, since the intrusion of the plating solution into the internal space is limited to the portion diffused into the liquid, it can be suppressed to a very small amount, so it can be Inhibits corrosion of the seed layer of the substrate. In addition, since the plating solution that invaded the inner space is diluted by the liquid, corrosion of the seed layer of the substrate can be further suppressed. In addition, since the oxygen concentration in the inner space is low, it is possible to suppress seed corrosion due to local cell action due to dissolved oxygen.

In addition, even if the plating solution leaks, the leakage of the plating solution can be detected early by the detector. Thereby, abnormality of the substrate holder and replacement timing of the seal can be detected early. 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 equipped with: contacts, which are arranged in the aforementioned internal space, contact with the seed layer formed on the surface of the aforementioned substrate, and flow plating current into the aforementioned substrate; and soluble electrodes, which The aforementioned contact is biased to the high potential side.

When this form is adopted, in case of leakage of the plating solution that will corrode the seed layer, the soluble electrode is preferentially dissolved because the contact point and the seed layer are biased at high potential, so the soluble electrode functions as a sacrificial anode , which can inhibit or prevent the dissolution of the seed layer.

Form 3 is the substrate holder as in Form 1, wherein the soluble electrode functions as the detector, and the detector is configured to monitor the inflow of the liquid into the contact or electrical conduction under the condition that the liquid is introduced into the internal space. The current between the wires of the aforementioned contacts and the aforementioned electrodes can detect the leakage of the plating solution into the aforementioned inner space.

In this form, since the leakage of the plating solution can be detected by monitoring the current flowing between the sacrificial anode (dissolving electrode) and the contact, it is not necessary to provide an additional electrode for detecting leakage.

Form 4 is the substrate holder as in Form 1, wherein a contact point is provided, which is arranged in the aforementioned inner space, contacts the seed layer formed on the surface of the aforementioned substrate, and flows the plating current into the aforementioned substrate, and the aforementioned detector has insolubility The electrode of the aforementioned detector is constituted by applying an AC voltage between the aforementioned contact or the wiring electrically connected to the aforementioned contact and the aforementioned non-dissolving electrode in the state where the aforementioned liquid is introduced into the aforementioned internal space, by monitoring the inflow The current of the aforementioned insoluble electrode can detect the leakage of the plating solution into the aforementioned internal space.

In this form, since an insoluble electrode is used as a detector, the metal of the electrode will not be deposited to the contact, etc., and the maintenance of the substrate holder is easy.

Form 5 is the substrate holder of form 4, which further has a soluble electrode, which is biased to the high potential side with respect to the aforementioned contact.

When this form is adopted, in addition to the effects of forms 1 and 4, the soluble electrode dissolves preferentially over the seed layer, which can suppress or prevent the seed layer from dissolving.

Aspect 6 is that the soluble electrode functions as the detector, and the detector is configured to detect leakage of the plating solution into the internal space by both the insoluble electrode and the soluble electrode.

According to this aspect, since the leakage of the plating solution is detected by both the soluble electrode (sacrificial anode) and the insoluble electrode, the detection accuracy of the leakage of the plating solution can be improved. In addition, even if one electrode is flawed, the leakage of the plating solution can still be detected, so the leakage of the plating solution can be detected more reliably, and the redundancy of detection of leakage can be improved.

Form 7 is the substrate holder of any one of forms 3 to 6, wherein the aforementioned wiring is a bus bar. According to this form, compared with the case of using a plurality of cables, the installation space of wiring can be reduced, and the resistance of wiring can be suppressed.

Embodiment 8 is the substrate holder of any one of Embodiments 1 to 7, further comprising a valve disposed in the first passage to conduct or block between the exterior of the substrate holder and the internal space.

According to this aspect, 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 in a state in which the internal space of the substrate holder is reliably sealed.

Form 9 is the substrate holder of any one of forms 1 to 8, further comprising a second passage, which connects the outside of the substrate holder with the internal space, and discharges air and/or liquid from the internal space.

With this configuration, when the liquid is introduced from the first passage, the air in the inner space is exhausted through the second passage, so that the liquid can be effectively introduced into the inner space. In addition, by introducing the liquid from the first passage and discharging the liquid filling the inner space from the second passage, it is possible to avoid remaining bubbles and filling the inner space with the liquid. In addition, the second passage can also be connected to the decompression device, and the liquid can be introduced from the first passage to the inner space simultaneously with or after the decompression. At this time, the liquid can be quickly introduced into the decompressed internal space.

Form 10 is the substrate holder of any one of forms 1 to 9, further comprising a third passage connecting the outside of the substrate holder to the internal space and connected to a device for decompressing the internal space.

According to this aspect, since the liquid is introduced from the first passage into the internal space simultaneously with or after decompression, the liquid can be quickly introduced into the internal space.

Form 11 is the substrate holder of any one of forms 1 to 10, wherein the aforementioned liquid is pure water, or degassed or replaced with inert gas.

In this aspect, by introducing pure water into the internal space, corrosion of the conductor member in the internal space can be suppressed, and intrusion of the plating solution can be suppressed. In addition, when pure water, or pure water that has been degassed or replaced with an inert gas, is introduced into the inner space, the oxygen concentration in the inner space can be reduced, and when the plating solution invades, the local battery action caused by the dissolved oxygen concentration can be suppressed Causes chemical corrosion of the seed layer.

Form 12 provides a plating device, which is equipped with: the substrate holder of any one of the first to eleventh items in the scope of the patent application; the liquid supply module, which supplies the liquid through the aforementioned first channel of the aforementioned substrate holder To the aforementioned internal space; a plating module, which receives the aforementioned substrate holder and makes it contact with the plating solution to plate the aforementioned substrate; and a control module, which is in the state of introducing the liquid into the aforementioned internal space, in During plating, the output from the aforementioned detector is obtained to determine whether the plating solution has leaked into the aforementioned internal space.

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

Aspect 13 is the coating device of Aspect 12, wherein the aforementioned liquid supply module is a pre-wetting module for contacting the surface of the aforementioned substrate with pure water, or degassed or replaced pure water with an inert gas.

According to this aspect, since the liquid is introduced into the inner space of the substrate holder by the pre-wetting module, it is not necessary to provide a separate module for introducing the liquid into the inner space, and the increase in size and/or cost of the device can be suppressed.

Aspect 14 provides a method for coating a substrate, including introducing a liquid into the inner space of the substrate holder accommodated in a state of sealing the outer periphery of the substrate from the outside, and in a state where the liquid is introduced into the inner space, Leakage of the plating solution 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.

Aspect 15 provides a storage medium which memorizes a program for executing a control method of a coating device by a computer, and memorizes a liquid introduced into an inner space of the substrate holder contained in a state in which the outer periphery of the substrate is sealed from the outside, In the state after the liquid is introduced into the internal space, by monitoring the electrical resistance of the liquid, it is possible to detect the leakage of the plating solution 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, but the above-mentioned embodiments of the present invention are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention can be changed and improved within the scope not departing from the gist thereof, and the present invention of course includes the equivalents thereof. In addition, as long as at least a part of the above-mentioned problems can be solved, or at least a part of the effect can be achieved, the embodiments and modifications can be combined arbitrarily, and the elements described in the scope of claims and the specification can be combined or omitted arbitrarily.

25: box table 25a: Box 27:Transfer robot 28: Traveling mechanism 29: Substrate loading and unloading module 30: Temporary storage box 32: Pre-wet module 33: Prepreg module 34: The first flushing module 35: Air supply module 36: The second flushing module 37: Conveying device 38: overflow tank 39: Plating tank 40: anode 50: cleaning module 50a: cleaning station 14: Adjustment plate 14a: opening 16: Paddle 58a: Circulation pipeline 58b:Circulation pump 58c: Constant temperature 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: holding body 211A: opening 212: handle 213: Contact 214: bus bar 215: inner seal 216: Outer seal 217: clamping mechanism 218: External connection terminal 219: External connection terminal 220: back panel 221: Hold body 221A: opening 222: handle 225: inner seal 227: clamping mechanism 230: detector 231: Import path 231A: Valve 232: discharge channel 232A: Valve 235A, 235B: electrodes 236A: DC power supply unit 236B: AC power supply unit 237A, 237B: current detector 240, 240A: interior 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 configuration diagram of a plating apparatus according to an embodiment. Figure 2 is a schematic diagram showing 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 plate of the substrate holder viewed from the inside. Figure 5 is a schematic diagram of a substrate holder in a pre-wet module. FIG. 6A is an enlarged schematic cross-sectional view of the inner space of the substrate holder in the plating tank. Fig. 6B is an enlarged schematic cross-sectional view of the inner space of the substrate holder in the plating tank. 6C is an enlarged schematic cross-sectional view of the inner space of the substrate holder of the comparative example in the plating tank. Fig. 7 is an explanatory diagram illustrating dissolution of a seed layer at a concentration of dissolved oxygen. Fig. 8A is an explanatory diagram illustrating dissolution of a seed layer by a shunt current. Fig. 8B is an equivalent circuit diagram illustrating a shunt current.

175: Controller

200: substrate holder

210: front panel

213: Contact

214: bus bar

215: inner seal

216: Outer seal

220: back panel

225: inner seal

230: detector

231: Import path

231A: Valve

232: discharge channel

232A: Valve

235A: electrode

236A: DC power supply unit

237A: Current detector

240: interior space

401: seed layer

402: Resist pattern

W: Substrate

Claims (15)

A substrate holder for holding a substrate and performing plating by contacting the substrate with a plating solution, and comprising: an internal space for holding the substrate from the substrate in a state where the substrate holder holds the substrate The outer periphery of the substrate is housed in a sealed state of the exterior of the holder; the first passage connects the exterior of the substrate holder with the interior space and introduces liquid into the interior space; and the detector is arranged in the interior The space is for detecting leakage of 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. The substrate holder as claimed in claim 1, wherein it is provided with: contacts, which are arranged in the aforementioned internal space, contact with the seed layer formed on the surface of the aforementioned substrate, and flow the plating current into the aforementioned substrate; and soluble electrodes, which are The aforementioned contact is biased to the high potential side. The substrate holder according to claim 2, wherein the soluble electrode functions as the detector, and the detector is configured to monitor the inflow of the liquid into the aforementioned contact or electrical conduction in the state where the liquid is introduced into the inner space. The current between the wiring of the aforementioned contact and the aforementioned electrode can detect the leakage of the plating solution into the aforementioned internal space. The substrate holder as claimed in claim 1, wherein there are contact points arranged in the aforementioned internal space, contacting the seed layer formed on the surface of the aforementioned substrate, so as to flow the plating current into the aforementioned substrate, and the aforementioned detector has an insoluble electrode, The detector is configured by applying an AC voltage between the contact or the wiring electrically connected to the contact and the non-dissolving electrode in the state where the liquid is introduced into the internal space, and monitors the flow of the non-dissolving liquid. The current of the polar electrode can detect the leakage of the plating solution into the aforementioned internal space. The substrate holder according to claim 4, further comprising a soluble electrode, which is biased to the high potential side for the aforementioned contact. The substrate holder according to claim 5, wherein the soluble electrode functions as the detector, and the detector is configured to detect leakage of the plating solution into the inner space by both the insoluble electrode and the soluble electrode. The substrate holder according to any one of claims 3 to 6, wherein the aforementioned wiring is a bus bar. The substrate holder according to any one of claims 1 to 6, further comprising a valve disposed in the first passage to conduct or block between the exterior of the substrate holder and the interior space. The substrate holder according to any one of claims 1 to 6, further comprising a second passage connecting the exterior of the substrate holder with the internal space, and discharging air and/or liquid from the internal space. The substrate holder according to any one of claims 1 to 6, further comprising a third passage, which connects the outside of the substrate holder and the interior space, and is connected to a device for decompressing the interior space. The substrate holder according to any one of claims 1 to 6, wherein the aforementioned liquid is pure water, pure water from which air has been removed, or pure water in which the gas has been replaced with an inert gas. A coating device, comprising: the substrate holder according to any one of claims 1 to 11; a liquid supply module, which supplies the liquid to the aforementioned internal space through the aforementioned first channel of the aforementioned substrate holder; a coating mold A set, which receives the aforementioned substrate holder and makes it contact with the plating solution to plate the aforementioned substrate; and a control module, which is used to obtain the sensor from the aforementioned detector during plating under the condition that the liquid is introduced into the aforementioned internal space. The output is used to judge whether the plating solution has leaked into the aforementioned internal space. The coating device according to claim 12, wherein the liquid supply module is used to pre-wet the surface of the substrate in contact with pure water, pure water from which air has been removed, or pure water in which the gas has been replaced with an inert gas. mod. A plating method for plating a substrate, comprising introducing a liquid into an inner space of a substrate holder housed in a state of sealing the outer periphery of the substrate from the outside, and in a state where the liquid is introduced into the inner space, by The current flowing into the liquid or the resistance of the liquid is monitored to detect leakage of the plating liquid into the internal space. A memory medium storing a program for executing a control method of a coating device by a computer, and the stored program includes: introducing a liquid into an inner space of a substrate holder housed in a state of sealing the outer periphery of a substrate from the outside, Leakage of the plating solution into the internal space is detected by monitoring the current flowing into the liquid or the resistance of the liquid in a state after the liquid is introduced into the internal space.

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