WO2025207366A1

WO2025207366A1 - Leak detection for a separated anode chamber

Info

Publication number: WO2025207366A1
Application number: PCT/US2025/020353
Authority: WO
Inventors: Kristof TOTH; Tanner Drew MALONE; Steve L PEACE; Nirmal Shankar SIGAMANI; Lee Peng Chua
Original assignee: Lam Research Corp
Current assignee: Lam Research Corp
Priority date: 2024-03-28
Filing date: 2025-03-18
Publication date: 2025-10-02
Anticipated expiration: 2026-09-28

Abstract

A method for detecting a leak in an electrodeposition system comprising a separated anode chamber is presented. The method comprises isolating a separated anode chamber. A static pressure in the separated anode chamber is modified. Pressure change is monitored in the separated anode chamber. Whether the leak is present is determined based on the pressure change monitored being greater than a threshold pressure change.

Description

LEAK DETECTION FOR A SEPARATED ANODE CHAMBER

BACKGROUND

[0001] Electroplating can be used in integrated circuit manufacturing processes to deposit electrically conductive films onto substrates. Electroplating involves the electrochemical reduction of dissolved ions of a selected metal to an elemental state on a substrate to form a film of the selected metal. Electroplating systems comprise a cathode chamber through which a catholyte solution circulates, and an anode chamber through which an anolyte solution circulates. A membrane is positioned between the catholyte chamber and anolyte chamber. The membrane can allow protons and ions of the selected metal to pass from the anode chamber to the cathode chamber while preventing the reverse passage of anions and organic additives.

SUMMARY

[0002] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.

[0003] Examples are disclosed that relate to systems and methods for leak detection in electrodeposition systems. In one example, a method for detecting a leak in an electrodeposition system comprising a separated anode chamber is presented. The method comprises isolating a separated anode chamber. A static pressure in the separated anode chamber is modified. Pressure change is monitored in the separated anode chamber. Whether the leak is present is determined based on the pressure change monitored being greater than a threshold pressure change.

[0004] In some such examples, modifying static pressure in the separated anode chamber additionally or alternatively comprises operating a pump coupled to the separated anode chamber.

[0005] In some such examples, the pressure change is additionally or alternatively monitored for a predetermined amount of time. [0006] In some such examples, the pressure change is additionally or alternatively monitored at a pressure measurement device fluidically coupled to the separated anode chamber.

[0007] In some such examples, the method additionally or alternatively comprises evacuating fluid from the separated anode chamber prior to isolating the separated anode chamber.

[0008] In some such examples, modifying a static pressure in the separated anode chamber additionally or alternatively comprises flowing gas from a gas source into the separated anode chamber.

[0009] In some such examples, isolating the separated anode chamber line additionally or alternatively comprises inserting a vent plug into a vent port in a separated anode chamber line.

[0010] In some such examples, isolating the separated anode chamber additionally or alternatively comprises operating a valve to isolate the separated anode chamber.

[0011] In some such examples, modifying a static pressure in the separated anode chamber comprises operating one or more hydraulic cylinders.

[0012] Another example provides a system for detecting a leak in an electrodeposition system comprising a separated anode chamber. The system comprises a pressure modifying mechanism fluidically coupled to the separated anode chamber. A pressure measurement device is fluidically coupled to the separated anode chamber to measure a pressure change of the separated anode chamber.

[0013] In some such examples, the system additionally or alternatively comprises one or more vent plugs configured to insert into a separated anode chamber line.

[0014] In some such examples, the system additionally or alternatively comprises an overpressure relief valve.

[0015] In some such examples, the system additionally or alternatively comprises a shutoff valve.

[0016] In some such examples, the system additionally or alternatively comprises a separated anode chamber inlet fitting configured to couple to a separated anode chamber loop. [0017] In some such examples, the separated anode chamber inlet fitting additionally or alternatively couples to the separated anode chamber loop at a separated anode chamber tower.

[0018] Another example provides an electrodeposition system. The electrodeposition system comprises a separated anode chamber. A pressure measurement is fluidically coupled with the separated anode chamber. A controller is configured with instructions to cause modification of a pressure within the separated anode chamber. The controller is further configured with instructions to cause monitoring of a pressure change at the pressure measurement device, and to cause determination as to whether a leak is present in the separated anode chamber based on the monitored pressure change being greater than a threshold pressure change.

[0019] In some such examples, the instructions for causing the modification of the pressure within the separated anode chamber additionally or alternatively comprises instructions for causing coupling the separated anode chamber to a gas source.

[0020] In some such examples, the controller is additionally or alternatively configured with instructions to cause evacuation of fluid from the separated anode chamber loop prior to modifying the pressure within the separated anode chamber.

[0021] In some such examples, the pressure change is additionally or alternatively monitored for a predetermined amount of time.

[0022] In some such examples, the controller is further configured with instructions to cause operation of one or more valves to isolate the separated anode chamber from atmosphere prior to modifying the pressure within the separated anode chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 shows a block diagram of an example electrodeposition system. [0024] FIG. 2 shows a block diagram of an example electrodeposition system comprising a separated anode chamber tower fluidically coupled to multiple separated anode chambers.

[0025] FIG. 3 schematically shows a method of leak testing an electrodeposition system based on fluid levels.

[0026] FIG. 4 shows a block diagram of an example system for detecting a leak in an electrodeposition system comprising a separated anode chamber. [0027] FIG. 5 shows a flow diagram depicting an example method for detecting a leak in an electrodeposition system comprising a separated anode chamber.

[0028] FIG. 6 shows an example plot of pressure decay as a function of time for an example implementation of the method of FIG. 5.

[0029] FIG. 7 shows a block diagram of an example electrodeposition system comprising a separated anode chamber and an integrated leak testing system.

[0030] FIG. 8 schematically shows an example computing system.

DETAILED DESCRIPTION

[0031] The term “anode chamber” generally represents a physical structure configured to hold at least an anode and anolyte and that provides selective separation from a cathode chamber.

[0032] The term “anolyte” generally represents a solution used in an anode chamber during an electroplating process.

[0033] The term “cathode chamber” generally represents a physical structure configured to hold at least a cathode and catholyte and that provides selective separation from an anode chamber.

[0034] The term “cation exchange membrane” generally represents a membrane that selectively passes one or more cationic species while blocking the transport of other species, such as anionic species and organic species.

[0035] The term “clean dry air line” generally represents a conduit fluidically coupled to a source of pressurized air.

[0036] The terms “electroplating”, “plating”, “deposition”, and variants thereof generally represent a process in which dissolved ions of one or more metals are reduced on a substrate surface to form a film of the one or more metals.

[0037] The term “electrodeposition system” generally represents a machine configured to perform electroplating.

[0038] The term “gas source” generally represents a pressurized source of a gaseous species, such as an inert gas.

[0039] The term “inlet fitting” generally represents a device that couples an apparatus to an inlet port of a container.

[0040] The term “membrane frame” generally represents a device that supports an ion-exchange membrane. [0041] The term “pressure change” generally represents a return towards atmospheric pressure in a container that has been subjected to an increase or decrease in pressure.

[0042] The terms “pressure measurement device” and “pressure gauge” generally represent devices that measure the pressure of a fluid or gas in a container.

[0043] The term “pump” generally represents a device configured to move a fluid or gas.

[0044] The term “separated anode chamber” generally represents an anode chamber that is separated from a cathode chamber by a membrane.

[0045] The term “separated anode chamber line” generally represents a conduit configured to supply anolyte to a separated anode chamber.

[0046] The term “separated anode chamber loop” generally represents a path along which anolyte is recirculated through a separated anode chamber over time.

[0047] The term “separated anode chamber tower” generally represents a reservoir of anolyte that is fluidically coupled to one or more separated anode chambers. [0048] The term “vent plug” generally represents a device that inserts into a vent on a container to seal the container from atmosphere.

[0049] The term “vent port” generally represents an opening on a container that couples the inside of the container to atmosphere.

[0050] The term “valve” and associated valve types, such as “inlet valve”, “overpressure relief valve”, “sealing valve”, and “shutoff valve” generally represent devices that regulate, direct, or control the flow of a fluid through a conduit.

[0051] Some electrodeposition systems comprise a separated anode chamber (SAC) that separates the cathode plating solution (e.g., catholyte) from the anode plating solution (e.g., anolyte). The SAC is separated from the cathode plating solution by a membrane that allows cations (e.g., metal ions, acid, water) to pass but does not allow organic additives from the plating solution to pass into the SAC, which could form unwanted biproducts and passivate the anode.

[0052] During tool startup and regular preventative maintenance of the anode and/or membrane, the SAC is taken apart and reassembled. If the membrane frame and membrane are installed incorrectly, leaks may occur. As such, unwanted fluid components could move between the anolyte and catholyte, potentially damaging the anode. [0053] Accordingly, examples are disclosed that relate to a leak test in which SAC pressure change is monitored over time. In some examples, a reassembled but empty SAC is pressured with air or other gas. Then, the pressure change monitored for a period of time. Such a leak test can help to reduce preventative maintenance downtime by providing efficient and accurate methods and systems for leak detection.

[0054] FIG. 1 schematically shows a block diagram of an example electrodeposition system 100. Electrodeposition system 100 comprises an electroplating cell 102 comprising an anode chamber 104 and a cathode chamber 106. Electrodeposition system 100 further comprises a cation exchange membrane 108 separating the anode chamber 104 and the cathode chamber 106, and a high resistance virtual anode (HRVA) 109 within cathode chamber 106. Anode chamber 104 comprises an anode 110. Anode chamber 104 further comprises an anolyte. Cathode chamber 106 comprises a catholyte. The catholyte comprises an ionic species to be deposited on a cathode layer of a substrate 111 as a metal by electrochemical reduction. [0055] In some examples, anode 110 may comprise a consumable anode formed from the metal being deposited or may comprise an inert anode. Where anode 110 comprises the metal being deposited, electrochemical oxidation of anode 110 at least partially replenishes the ionic species consumed by the electroplating process. Bulk anolyte and/or catholyte solutions may be added at times to replenish the ionic species. When anode 110 is configured as an inert anode, the metal being deposited may be provided in the anolyte solution.

[0056] Cation exchange membrane 108 prevents organic species and anionic species from crossing between cathode chamber 106 and anode chamber 104, while allowing metal ions to cross from anode chamber 104 to cathode chamber 106. As mentioned above, HRVA 109 comprises an ionically resistive element that approximates a suitably constant and uniform current source in proximity to a substrate cathode. In other configurations, cation exchange membrane 108 may be replaced with another type of suitable membrane.

[0057] Substrate holder 112 is coupled to a substrate holder movement system 113 comprising a lift 114 that is configured to adjust a spacing between substrate holder 112 and HRVA 109. For example, lift 114 may lower substrate holder 112 to position substrate 111 within the catholyte for electroplating. Lift 114 further may raise substrate holder 112 from the catholyte after electroplating. Substrate holder movement system 113 further may comprise components to control the opening and closing of substrate holder 112.

[0058] The catholyte may be circulated between cathode chamber 106 and a catholyte reservoir 120 via a combination of gravity and one or more pumps 122. Likewise, the anolyte may be circulated through anolyte reservoir 124 and anode chamber 104 via a combination of gravity and one or more pumps 126.

[0059] In some electrodeposition systems, plating operations may be performed in parallel on multiple substrates using multiple plating cells. In some such examples, central catholyte and/or anolyte reservoirs may supply multiple plating cells with catholyte and/or anolyte. In other such examples, separate catholyte and/or anolyte reservoirs may be used to supply multiple plating cells. In yet other examples, an electrodeposition system may comprise a single plating cell. Where an electrodeposition system comprises multiple plating cells, a single lift may be configured to lift two or more substrate holders for two or more different plating cells. [0060] FIG. 2 shows an example electrodeposition system 200 comprising a central anolyte reservoir fluidically coupled to multiple plating cells comprising separated anolyte chambers. Central anolyte reservoir 202 is also referred to herein as a SAC tower. SAC tower 202 comprises an internal circulation pump 204. SAC tower 202 is fluidically coupled to electroplating cells 210 and 212. In other examples, additional electroplating cells may be included. In yet further examples, a SAC tower can be omitted.

[0061] Similar to electroplating cell 102, electroplating cell 210 comprises an anode chamber 214 and a cathode chamber 216. Anode chamber 214 is separated from cathode chamber 216 by membrane 218. Membrane 218 is supported by membrane frame 219. Anode chamber 214 comprises anode 220 which is supplied an anodic potential via charge plate 225. Cathode chamber 216 comprises a catholyte and a substrate 221 loaded into a substrate holder 222.

[0062] Anode chamber 214 further comprises an anolyte. The anolyte can be circulated through SAC tower 202 and anode chamber 214 via a combination of gravity and one or more pumps 226. SAC tower 202, anode chamber 214, pump 226, and accompanying fluid lines may comprise a SAC loop 228.

[0063] Similar to electroplating cell 210, electroplating cell 212 comprises an anode chamber 234 and a cathode chamber 236. Anode chamber 234 is separated from cathode chamber 236 by membrane 238. Membrane 238 is supported by membrane frame 239. Anode chamber 234 comprises anode 240 which is supplied an anodic potential via charge plate 245. Cathode chamber 236 comprises a catholyte and a substrate 241 loaded into a substrate holder 242.

[0064] Anode chamber 234 further comprises an anolyte. The anolyte can be circulated through SAC tower 202 and anode chamber 234 via a combination of gravity and one or more pumps 246. SAC tower 202, anode chamber 234, pump 246, and accompanying fluid lines may comprise a SAC loop 248.

[0065] Returning to FIG. 1, substrate holder 112 is lowered by lift 114 toward HRVA 109 after substrate 111 is loaded into substrate holder 112. Substrate 111 faces a surface of the HRVA 109 and is spaced from HRVA 109 by a plating gap during electroplating. An electric field is established between anode 110 and substrate 111. This electric field drives dissolved metal cations from anode chamber 104 into cathode chamber 106. At the substrate 111, the metal cations are electrochemically reduced to deposit on substrate 111. An anodic potential is applied to anode 110 via charge plate 115 and a cathodic potential is provided to the cathode of substrate 111 via a cathode electrical connection 116 to form a circuit. In some examples, substrate holder 112 may be rotated via a rotational motor 117 during electroplating.

[0066] Electrodeposition system 100 further comprises a computing system 130, aspects of which are described in more detail below with regard to FIG. 8. Computing system 130 may comprise instructions executable to control any suitable functions of electrodeposition system 100. Example functions include electroplating processes, substrate loading/unloading processes, and precipitate dissolution processes. In some examples, computing system 130 may be configured to communicate with a remote computing system 140 via a suitable computer network. Remote computing system 140 may comprise any suitable computing system. Examples include a networked workstation computer, an enterprise computing system, and/or a cloud computing system. It will be understood that remote computing system 140 may be in communication with and control a plurality of electrodeposition systems in some examples.

[0067] FIG. 3 schematically shows a schematic depiction of an example method of leak testing an electrodeposition system based on fluid levels. In the depicted example, electrodeposition system 300 comprises a SAC tower 302. SAC tower 302 comprises at least internal circulation pump 304, a vent port 306, and an inlet port 308. A portion of an example electroplating cell 310 is shown. Electroplating cell 310 comprises separated anode chamber 312, which is configured to hold anode 314 and plating solution 316. A membrane 318 is supported by a membrane frame 320, which separates separated anode chamber 312 from cathode chamber 322. Cathode chamber 322 is configured to hold a substrate and catholyte (not shown). Plating solution 316 circulates between SAC tower 302 and separated anode chamber 312 via SAC loop 324, which comprises one or more pumps 326. As mentioned above, in other examples, the SAC tower can be omitted.

[0068] As described, membrane 318 serves to separate the catholyte from the anolyte, thus preventing crossover of specific additives within the catholyte that would corrode or passivate anode 314. Membrane installation may occur at setup, during preventative maintenance, during anode changes, and/or during a chemistry change (for example, from copper to tin-silver). A proper membrane fit is desired to prevent leakage of catholyte into the anode chamber. As such, a leak check is performed following membrane installation to determine if the assembled separated anode chamber is fluid tight.

[0069] One possible method of performing a leak check is by filling the SAC tower and separated anode chamber with plating solution 316, circulating plating solution 316, and looking for a physical fluid level drop at the SAC tower (as shown at 330). A fluid level drop thus signifies a leak. Leaks can occur, for example, due to plating solution flowing through small cracks or holes in and around the membrane frame, leaky pipe fittings, an improperly torqued membrane frame, gasket degradation, or a defect in the membrane itself (e.g., tears, punctures). The fluid level drop at the SAC tower is monitored over an extended duration. If the initial monitoring period shows a larger than expected level drop, the SAC is inspected and reassembled, then the monitoring period may be repeated as necessary. As such, this type of leak test may result in significant amounts of tool downtime.

[0070] Further, as shown at 332, there are often air bubbles that remain in the SAC loop when the SAC and SAC tower are filled with plating solution. Such a SAC leak check circulates the solution and purges any air bubbles from the SAC into the SAC tower which also lowers the solution level on the SAC tower. A modest fluid leak in the SAC is thus indistinguishable from air bubble purging with this method and often leads to incorrect SAC leak check failures. Such methodology thus may miss active leaks that are below the expected level drop. [0071] As such, it is desirable for a leak test that is more sensitive, more robust, and less time consuming than such fluid level drop tests. FIG. 4 shows a block diagram of an example system 400 for detecting a leak in an electrodeposition system comprising a separated anode chamber. In this example, system 400 is used to detect leaks in electrodeposition system 300 comprising separated anode chamber 312.

[0072] System 400 may be utilized to perform a relatively quick pressure change test by changing the pressure within the SAC, then observing pressure change over time. In some examples, such a system may couple directly to SAC 312, the SAC line, or the SAC loop 324. In this example, system 400 reversibly couples to SAC tower 302. Pressurizing the SAC components allows for the determination of the viability of membrane 318, membrane frame 320, and associated componentry. System 400 may be made to be compatible with numerous SAC configurations and with a plurality of cationic exchange membrane types (e.g., membranes used in copper electroplating or tin/ silver electroplating).

[0073] System 400 comprises a pressure modifying mechanism 402 and a pump fitting 404 which fluidically couples pressure modifying mechanism 402 to a conduit 405. In some examples, pressure modifying mechanism 402 can be a pump. Conduit 405 is fluidically coupled to shutoff valve 406. A pressure gauge 408 is fluidically coupled to shutoff valve 406 via conduit 407. An overpressure relief valve 410 is fluidically coupled to pressure gauge 408 via conduit 409. Conduit 411 is coupled to overpressure relief valve 410. Conduit 411 is coupled to one or more vent plugs 412 and fluidically coupled to a separated anode chamber line inlet fitting 414. In this way, pressure modifying mechanism 402 and pressure gauge 408 are fluidically coupled to the separated anode chamber line inlet fitting 414. Fittings and conduits may be made from any suitable material, such as metal (e.g., stainless steel), plastic (e.g., PTFE), rubber, etc.

[0074] Vent plug 412 is configured to insert into the separated anode chamber line at vent port 306, thus separating the SAC loop from atmosphere and maintaining pressure therewithin. Vent plug 412 may be omitted in examples where the SAC or SAC line is not open to atmosphere, or where other mechanism of isolating the SAC from atmosphere are present (e.g., valves). Separated anode chamber line inlet fitting 414 is configured to couple to separated anode chamber loop 324 at inlet port 308 of SAC tower 302. In other examples, the inlet fitting can be a fitting for a T-junction or other opening in the SAC or SAC line. In yet further examples, an inlet fitting can take any other suitable form.

[0075] When separated anode chamber line inlet fitting 414 is coupled to inlet port 308, and when vent plug 412 is inserted into vent port 306, pressure modifying mechanism 402 may be operated to change the pressure in SAC loop 324. Pressure modifying mechanism 402 may be employed to increase (pressurize) or decrease (draw a vacuum) pressure within SAC loop 324. When pressure modifying mechanism 402 is a pump, the pump may be a motorized pump or pneumatic hand pump, as examples.

[0076] Shutoff valve 406 may be operated to decouple pressure modifying mechanism 402 from SAC loop 324 when a predetermined pressure change has been affected (e.g., at 1 pound per square inch (PSI)), thus isolating SAC loop 324. Overpressure relief valve 410 may serve to release pressure (or vacuum) above a predetermined level (e.g., 3-5 PSI) to prevent damage to components in SAC loop 324. Overpressure relief valve can be located within system 400 on the opposite side of shutoff valve 406 from pressure modifying mechanism 402. Pressure gauge 408 may be digital or analog and may serve to monitor pressure while pressure modifying mechanism 402 is changing the pressure in SAC loop 324 and during a subsequent pressure change phase. In other examples, pressure gauge 408 may be augmented or replaced by other pressure sensing mechanisms, such as indirect pressure sensing mechanisms coupled within SAC loop 324.

[0077] FIG. 5 shows a flow diagram depicting an example method 500 for detecting a leak in an electrodeposition system comprising a separated anode chamber. Method 500 will be described with regard to system 400 and electrodeposition system 300 but may be performed with any suitable leak detection system and electrodeposition system comprising a separated anode chamber (see FIG. 7 for an additional example).

[0078] At 510, method 500 comprises isolating a separated anode chamber. In some examples, sealing the separated anode chamber comprises inserting a vent plug (e.g., vent plug 412) into a vent port (e.g., 306) into a separated anode chamber line. In other examples, sealing the separated anode chamber comprises operating a valve to seal the separated anode chamber.

[0079] In some examples, method 500 comprises evacuating fluid from the separated anode chamber prior to sealing the separated anode chamber. For example, some or all of the fluid in the separated anode chamber can be evacuated. In some examples, sealing the separated anode chamber is performed in response to changing a membrane. In other examples, sealing the separated anode chamber is performed in response to changing an anode, initially setting up the electrodeposition system, responsive to performance issues, etc. Method 500 may also be used to validate leak tightness of individual parts during tool manufacturing or to evaluate vendor spare parts.

[0080] At 520, method 500 comprises modifying a static pressure in the separated anode chamber. In some examples, modifying the static pressure in the separated anode chamber comprises generating a predetermined change in static pressure. The predetermined change in static pressure may be determined empirically during a calibration process. For example, the predetermined change may be a change in static pressure that generates a return to atmospheric pressure within an desired time interval even when no leak is present. The predetermined change in static pressure may be less than a pressure or vacuum which is known to damage the SAC. In other examples, a predetermined change may be defined differently. Modifying a static pressure in the separated anode chamber may comprise increasing a static pressure or decreasing a static pressure (e.g., generating a vacuum). For example, modifying a static pressure in the separated anode chamber may comprise operating a pump coupled to the separated anode chamber (e.g., pressure modifying mechanism 402). In other examples, modifying the static pressure in the separated anode chamber comprises flowing gas from a gas source into the separated anode chamber. Such a configuration is discussed further herein and with regard to FIG. 7. In still further examples, modifying the static pressure in the separated anode chamber comprises operating one or more hydraulic cylinders, a fluid reservoir with a larger hydraulic head, etc. In some examples, modifying the static pressure in the separated anode chamber can comprise generating a predetermined change in pressure in the separated anode chamber. As a non-limiting example, the predetermined change in pressure may be 1 PSI above atmosphere.

[0081] At 530, method 500 comprises monitoring pressure change in the separated anode chamber. In some examples, monitoring pressure change in the separated anode chamber can include monitoring an absolute pressure and calculating a pressure change based on an initial starting pressure. In some examples, the pressure may be monitored relative to the initial starting pressure. Pressure change may be monitored by a pressure measurement device, such as a pressure gauge, fluidically coupled to the separated anode chamber, such as pressure gauge 408. Pressure measurement devices may thus be coupled within the separated anode chamber itself, within a separated anode chamber line, within a separated anode chamber tower, or locations elsewhere that are fluidically coupled to the separated anode chamber itself when the separated anode chamber is isolated from atmosphere. Additionally or alternatively, pressure change may be monitored indirectly, such as measuring a height level of a sensor configured to measure hydraulic head. In some examples, the pressure change is monitored for a predetermined amount of time (e.g., 20 minutes). The predetermined amount of time may be determined empirically, e.g., during a calibration period. In some examples, the predetermined amount of time may represent a threshold amount of time beyond which a leak condition and a no-leak condition are indistinguishable within an amount of confidence. In some examples, the pressure change is monitored until a predetermined amount of pressure change has occurred. In some examples, a rate of pressure change over time is determined.

[0082] At 540, method 500 comprises determining whether the leak is present based on the monitored pressure change being greater than a threshold pressure change. For examples where the pressure change is a pressure increase, if the pressure drop is less than a predetermined pressure drop, the pressure change test passes. If the pressure drop is greater than the predetermined pressure drop, the pressure change test fails. In examples where a vacuum is drawn on the separated anode chamber line, the pressure change is an increase in pressure towards atmospheric pressure. In some examples, the rate of pressure change may be compared to a threshold pressure change rate. Any threshold pressure change may be determined based on repeated benchmarking through pressure decay tests on SACs with known leaks (or no leaks). The initial pressure, volume, and presence or absence of fluid may influence the threshold pressure change, as the rate of pressure decay is proportional to the overall pressure of the system and inversely proportional to the total volume of the SAC. The threshold pressure change may also depend on the type of membrane being employed.

[0083] In this way, method 500 makes it possible to distinguish between actual SAC leaks and air bubbles purging, something not possible with previous methods (e.g., as described with regard to FIG. 3). The process is more reliable, robust, and consistent for determining a SAC leak, membrane punctures, or hardware installation issues. Method 500 may be performed as quickly as 20 minutes or less, thus significantly decreasing the time from previous methods, such as the method described with regard to FIG. 3, which can take 4-12 hours in some instances.

[0084] FIG. 6 shows an example plot 600 of pressure decay as a function of time for an example implementation of the method 500. Plot 600 shows example pressure decay curves that can be observed when a SAC loop is pressurized with air then allowed to depressurize for 20 minutes. Plot 605 indicates pressure decay for an intact SAC loop with no leak. Plot 610 indicates pressure decay for a SAC loop with a leak that would produce 1-3 ml/hr. when the SAC loop is filled with plating solution. Plot 615 indicates pressure decay for a SAC loop with a leak that would produce 32 ml/hr. when the SAC loop is filled with plating solution. Plot 620 indicates pressure decay for a SAC loop with a leak that would produce 720 ml/hr. when the SAC loop is filled with plating solution. Plot 625 indicates a minimum detectable leak for a SAC loop using fluid level drop techniques. As shown, plot 610 represents a leak that is detectable through pressure decay methods, such as method 500, but would not be detected using fluid level drop techniques. Minimal pressure drop is seen in plot 605, suggesting that very small leaks can be detected using pressure decay methods. The small decrease in pressure may merely be due to settling of the SAC loop once pressurized. Such a decrease may represent the maximum pressure drop observable for a SAC loop to pass the pressure decay test.

[0085] FIG. 7 schematically shows an electrodeposition system 700 comprising a separated anode chamber and an integrated leak testing system. Electrodeposition system 700 comprises a SAC tower 702. SAC tower 702 comprises at least internal circulation pump 704 and a vent port 706. A portion of an example electroplating cell 710 is shown. Electroplating cell 710 comprises separated anode chamber 712, which is configured to hold anode 714 and anolyte. A membrane 718 is fitted to a membrane frame 720, which separates separated anode chamber 712 from cathode chamber 722. Cathode chamber 722 is configured to hold a substrate and catholyte (not shown). Plating solution 716 circulates between SAC tower 702 and separated anode chamber 712 via SAC loop 724, which comprises one or more pumps 726.

[0086] Electrodeposition system 700 further comprises one or more sealing valves 730 operable to close vent port 706 and thus seal SAC loop 724 from atmosphere. An inlet valve 732 is operable to couple SAC loop 724 to a gas source 734. Gas source 734 may be a clean dry air source, an N2 source, an inert gas source, etc. A pressure gauge 736 is coupled within the SAC loop. [0087] A controller 740 can be configured with instructions to automatically perform a pressure change leak test on SAC loop 724. The test may be performed when membrane 718 is replaced, when anode 714 is replaced, at initial tool configuration, etc. In some examples, the controller is configured with instructions to evacuate fluid from the separated anode chamber loop prior to initiating the test.

[0088] Controller 740 can be configured with instructions to cause operation of the one or more sealing valves 730 to seal the separated anode chamber loop 724 from atmosphere. Controller 740 can be further configured with instructions to cause operation of inlet valve 732 to couple the separated anode chamber loop 724 to gas source 734. Gas from gas source 734 may be used to pressurize separated anode chamber loop 724 to a predetermined pressure. Controller 740 can be further configured with instructions to cause operation of inlet valve 732 to decouple separated anode chamber loop 724 from gas source 734. Controller 740 can be further configured with instructions to cause monitoring of pressure changes at pressure gauge 736. Pressure change may be monitored for a predetermined amount of time (e.g., 20 minutes). Controller 740 can be further configured with instructions to determine whether a leak is present in the separated anode chamber loop based on the monitored pressure change. Controller 740 can be further configured with instructions to cause operation of sealing valve 730 to recouple the SAC loop 724 to atmosphere, thus relieving any residual gas pressure.

[0089] In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can comprise semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and/or specific processing components. These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and/or the type of system, may be programmed to control any of the processes disclosed herein, including temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, flow rate settings, fluid delivery settings, and/or positional and operation settings, wafer transfers into and out of a tool and other transfer tools and/or load locks connected to or interfaced with a specific system. [0090] Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, and/or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more structures (e.g. layers, materials, metals, surfaces, circuits, and/or dies) of a wafer.

[0091] The controller, in some implementations, may be a part of or coupled to a computer that is integrated with, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and/or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

[0092] As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and/or load ports in a semiconductor manufacturing factory.

[0093] FIG. 8 schematically shows a non-limiting example of a computing system 800 that can enact one or more of the methods and processes described above. Computing system 800 is shown in simplified form. Computing system 800 may take the form of one or more personal computers, workstations, computers integrated with substrate processing tools, and/or network accessible server computers.

[0094] Computing system 800 includes a logic machine 802 and a storage machine 804. Computing system 800 may optionally include a display subsystem 806, input subsystem 808, communication subsystem 810, and/or other components not shown in FIG. 8. Computing system 130 and controller 740 are examples of computing system 800.

[0095] Logic machine 802 includes one or more physical devices configured to execute instructions. For example, the logic machine may be configured to execute instructions that are part of one or more applications, services, programs, routines, libraries, objects, components, data structures, or other logical constructs. Such instructions may be implemented to perform a task, implement a data type, transform the state of one or more components, achieve a technical effect, or otherwise arrive at a desired result.

[0096] The logic machine may include one or more processors configured to execute software instructions. Additionally or alternatively, the logic machine may include one or more hardware or firmware logic machines configured to execute hardware or firmware instructions. Processors of the logic machine may be single-core or multi-core, and the instructions executed thereon may be configured for sequential, parallel, and/or distributed processing. Individual components of the logic machine optionally may be distributed among two or more separate devices, which may be remotely located and/or configured for coordinated processing. Aspects of the logic machine may be virtualized and executed by remotely accessible, networked computing devices configured in a cloud-computing configuration.

[0097] Storage machine 804 includes one or more physical devices configured to hold instructions 812 executable by the logic machine to implement the methods and processes described herein. When such methods and processes are implemented, the state of storage machine 804 may be transformed — e.g., to hold different data.

[0098] Storage machine 804 may include removable and/or built-in devices. Storage machine 804 may include optical memory (e.g., CD, DVD, HD-DVD, Blu-Ray Disc, etc.), semiconductor memory (e.g., RAM, EPROM, EEPROM, etc.), and/or magnetic memory (e.g., hard-disk drive, floppy-disk drive, tape drive, MRAM, etc.), among others. Storage machine 804 may include volatile, nonvolatile, dynamic, static, read/write, read-only, random-access, sequential-access, location-addressable, file- addressable, and/or content-addressable devices.

[0099] It will be appreciated that storage machine 804 includes one or more physical devices. However, aspects of the instructions described herein alternatively may be propagated by a communication medium (e.g., an electromagnetic signal, an optical signal, etc.) that is not held by a physical device for a finite duration.

[00100] Aspects of logic machine 802 and storage machine 804 may be integrated together into one or more hardware-logic components. Such hardware-logic components may include field-programmable gate arrays (FPGAs), program- and application-specific integrated circuits (PASIC / ASICs), program- and applicationspecific standard products (PSSP / ASSPs), system-on-a-chip (SOC), and complex programmable logic devices (CPLDs), for example.

[00101] When included, display subsystem 806 may be used to present a visual representation of data held by storage machine 804. This visual representation may take the form of a graphical user interface (GUI). As the herein described methods and processes change the data held by the storage machine, and thus transform the state of the storage machine, the state of display subsystem 806 may likewise be transformed to visually represent changes in the underlying data. Display subsystem 806 may include one or more display devices utilizing virtually any type of technology. Such display devices may be combined with logic machine 802 and/or storage machine 804 in a shared enclosure, or such display devices may be peripheral display devices. [00102] When included, input subsystem 812 may comprise or interface with one or more user-input devices such as a keyboard, mouse, or touch screen. In some examples, the input subsystem may comprise or interface with selected natural user input (NUI) componentry. Such componentry may be integrated or peripheral, and the transduction and/or processing of input actions may be handled on- or off- board. Example NUI componentry may include a microphone for speech and/or voice recognition, and an infrared, color, stereoscopic, and/or depth camera for machine vision and/or gesture recognition.

[00103] When included, communication subsystem 810 may be configured to communicatively couple computing system 800 with one or more other computing devices. Communication subsystem 810 may include wired and/or wireless communication devices compatible with one or more different communication protocols. As non-limiting examples, the communication subsystem may be configured for communication via a wireless telephone network, or a wired or wireless local- or wide-area network. In some examples, the communication subsystem may allow computing system 800 to send and/or receive messages to and/or from other devices via a network such as the Internet.

[00104] It will be understood that the configurations and/or approaches described herein are exemplary in nature, and that these specific examples or examples are not to be considered in a limiting sense, because numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. As such, various acts illustrated and/or described may be performed in the sequence illustrated and/or described, in other sequences, in parallel, or omitted. Likewise, the order of the above-described processes may be changed.

[00105] The subject matter of the present disclosure includes all novel and non- obvious combinations and sub-combinations of the various processes, systems and configurations, and other features, functions, acts, and/or properties disclosed herein, as well as any and all equivalents thereof.

Claims

CLAIMS:

1. A method for detecting a leak in an electrodeposition system comprising a separated anode chamber, the method comprising: isolating a separated anode chamber; modifying a static pressure in the separated anode chamber; monitoring a pressure change in the separated anode chamber; and determining whether the leak is present based on the pressure change monitored being greater than a threshold pressure change.

2. The method of claim 1, wherein modifying a static pressure in the separated anode chamber comprises operating a pump coupled to the separated anode chamber.

3. The method of claim 1, wherein the pressure change is monitored for a predetermined amount of time.

4. The method of claim 1, wherein the pressure change is monitored at a pressure measurement device fluidically coupled to the separated anode chamber.

5. The method of claim 1, further comprising: evacuating fluid from the separated anode chamber prior to isolating the separated anode chamber.

6. The method of claim 1, wherein modifying a static pressure in the separated anode chamber comprises flowing gas from a gas source into the separated anode chamber.

7. The method of claim 1, wherein isolating the separated anode chamber comprises inserting a vent plug into a vent port in a separated anode chamber line.

8. The method of claim 1, wherein isolating the separated anode chamber comprises operating a valve to isolate the separated anode chamber.

9. The method of claim 1, wherein modifying a static pressure in the separated anode chamber comprises operating one or more hydraulic cylinders.

10. A system for detecting a leak in an electrodeposition system comprising a separated anode chamber, the system comprising: a pressure modifying mechanism fluidically coupled to the separated anode chamber; and a pressure measurement device fluidically coupled to the separated anode chamber to measure a pressure change of the separated anode chamber.

11. The system of claim 10, further comprising: one or more vent plugs configured to insert into a separated anode chamber line.

12. The system of claim 10, further comprising an overpressure relief valve.

13. The system of claim 10, further comprising a shutoff valve.

14. The system of claim 10, further comprising a separated anode chamber inlet fitting configured to couple to a separated anode chamber loop.

15. The system of claim 14, wherein the separated anode chamber inlet fitting couples to the separated anode chamber loop at a separated anode chamber tower.

16. An electrodeposition system, comprising: a separated anode chamber; a pressure measurement device fluidically coupled with the separated anode chamber; and a controller configured with instructions to: cause modification of a pressure within the separated anode chamber; cause monitoring of a pressure change at the pressure measurement device; and cause determination as to whether a leak is present in the separated anode chamber based on the monitored pressure change being greater than a threshold pressure change.

17. The electrodeposition system of claim 16, wherein the instructions for causing the modification of the pressure within the separated anode chamber comprises instructions for causing coupling of the separated anode chamber to a gas source.

18. The electrodeposition system of claim 16, wherein the controller is further configured with instructions to cause evacuation of a fluid from the separated anode chamber prior to modifying the pressure within the separated anode chamber.

19. The electrodeposition system of claim 16, wherein the pressure change is monitored for a predetermined amount of time.

20. The electrodeposition system of claim 16, wherein the controller is further configured with instructions to cause operation of one or more valves to isolate the separated anode chamber from atmosphere prior to modifying the pressure within the separated anode chamber.