Systems and methods for removing contaminants within electroplating systems

Abstract

An electroplating system in accordance with the present technology may include a dual bath electroplating chamber including a separator configured to provide fluid separation between a first bath configured to retain catholyte during operation and a second bath configured to retain catholyte during operation and a second bath configured to retain catholyte during operation. The second bath is configured to hold an anolyte during operation. The system may include a catholyte bath fluidly coupled with the first bath of the bath plating chamber. The system may also include a contaminant extraction system configured to remove contaminant ions of the catholyte.

Description

[0001] This application is a divisional application of the invention patent application with application date of May 9, 2019, application number 201980031370.2, and invention name “System and method for removing contaminants in electroplating system”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to U.S. Provisional Patent Application No. 62 / 669,180 filed on May 9, 2018, which is hereby incorporated by reference in its entirety. Technical Field

[0004] The present technology relates to systems and methods for semiconductor processing. More particularly, the present technology relates to systems and methods for reducing or removing contaminants from electroplating electrolyte solutions. Background Art

[0005] Integrated circuits are made by processes that create intricately patterned layers of material on a substrate surface. During the electroplating operation, contamination can occur in the form of metal ions incorporated into the electrolyte solution used in the electroplating system. Even if the electrolyte in the system can be replaced, such replacement can be expensive and require extended system offline time.

[0006] Therefore, there is a need for improved systems and methods that can be used to manufacture high-quality devices and structures. These and other needs are addressed by the present technology. Summary of the invention

[0007] An electroplating system according to the present technology may include a dual bath electroplating chamber including a divider configured to provide fluid separation between a first bath and a second bath, the first bath configured to hold a catholyte during operation and the second bath configured to hold an anolyte during operation. The system may include a catholyte tank fluidically coupled to the first bath of the bath electroplating chamber. The system may also include a contaminant extraction system configured to remove contaminant ions from the catholyte.

[0008] In some embodiments, the contaminant extraction system includes a container that is fluidly embedded between the first bath and the catholyte tank. The container includes an anode and a cathode, and the anode and the cathode are electrically coupled to a power supply. The anode may include a first material that is consumable or inert to the catholyte. The catholyte includes a solution that includes tin, and the contaminant ions may include copper, and thus the first material may be or may include tin. The first material may be or may include a material that is inert to the catholyte and more inert than copper. The power supply is configured to apply a voltage that is lower than the electroplating potential for tin in the electroplating system. The power supply is configured to apply a voltage that is higher than the electroplating potential for copper in the electroplating system. The container may include a packed bed of tin-containing particles. The contaminant extraction system may be or may include a packed bed of tin-containing particles that is placed in the catholyte tank.

[0009] Some embodiments of the present technology may further include a method of removing copper contaminants from a tin-containing catholyte in an electroplating system. The method may include flowing the catholyte from an electroplating chamber to a catholyte tank. The method may include passing the catholyte through a tin-containing material. The method may further include reducing copper contaminants from the catholyte.

[0010] In some embodiments, the tin-containing material can be an anode of an anode-cathode pair of electrically coupled electrodes. The anode and cathode are driven at a voltage that is lower than the tin plating potential and higher than the copper plating potential. The cathode comprises tin or a material that is more inert than copper. The tin-containing material can be held in a container that is located between the electroplating chamber and the cathode electrolyte tank and fluidically couples the electroplating chamber and the cathode electrolyte tank. The tin-containing material can be or can include a filling column of the tin-containing material. The tin-containing material is disposed in the cathode electrolyte tank.

[0011] Embodiments of the present technology may further include an electroplating system. The system may include an electroplating chamber. The system may include an electrolyte tank, which is fluidically coupled to the electroplating chamber and configured to hold an electrolyte. The system may include a tin-containing electrolyte, which includes copper ions. The system may also include a contaminant extraction system, which is configured to remove copper ions from the electrolyte. The contaminant extraction system may include a single-component system of a tin-containing material, or a dual-component system of the tin-containing material or a material that is more inert than copper on the electromotive force series. The contaminant extraction system may include a container, which is located between the electroplating chamber and the electrolyte tank, and the container may accommodate the single-component system or the dual-component system. The contaminant extraction system is configured to maintain an increase in the concentration of copper ions in the electrolyte below about 1 ppm per five thousand wafers processed during operation.

[0012] This technology can provide many advantages over conventional technologies. For example, the present system provides a cost-effective solution to reduce the level of contaminants in an electrolyte of the system. In addition, the present system and method can improve quality while having limited impact on bath chemistry and process parameters. These and other embodiments, as well as many of their advantages and features, are described in more detail in conjunction with the following description and the accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A further understanding of the nature and advantages of the disclosed embodiments may be realized by referring to the remainder of the description and drawings.

[0014] Figure 1 A schematic diagram of an electroplating system according to some embodiments of the present technology is shown.

[0015] Figure 2A A schematic diagram of a contaminant extraction system according to some embodiments of the present technology is shown.

[0016] Figure 2B A schematic diagram of a contaminant extraction system according to some embodiments of the present technology is shown.

[0017] Figure 3 A schematic diagram of an electroplating system according to some embodiments of the present technology is shown.

[0018] Figure 4 Selected operations of a method of removing copper contaminants from a tin-containing catholyte within an electroplating system are illustrated in accordance with some embodiments of the present technology.

[0019] Several figures are included as schematic diagrams. It will be understood that the figures are for illustrative purposes and are not to be considered to be to scale unless specifically noted to be to scale. Furthermore, as schematic diagrams, the figures are provided to aid understanding and may not include all aspects or information compared to actual representations and may include exaggerated material for illustrative purposes.

[0020] In the various figures, similar parts and / or features may have the same numerical reference designation. Furthermore, several parts of the same form may be distinguished by a letter following the reference designation that distinguishes the similar parts and / or features. If only the first numerical reference designation is used in the description, the description may apply to any of the similar parts and / or features having the same first numerical reference designation, regardless of the letter suffix. DETAILED DESCRIPTION

[0021] In the semiconductor industry, electrodeposition is performed using a variety of systems. For example, electroplating can be performed in a single-bath electrolyte system, which has a single electrolyte in contact with the anode and cathode. Electroplating can also be performed in a dual-bath electrolyte system that includes an anolyte and a catholyte. This dual-bath chamber typically includes a separator or membrane that separates the two fluids while allowing specific ions to permeate through the membrane and cause electroplating at the cathode.

[0022] In a dual bath system, the catholyte may contact the substrate on which deposition may be performed, while the anolyte is physically separated from the substrate by a membrane or separator. During some electroplating operations, one metal may be plated on a second metal, which may have been deposited in an upstream or previous operation. The upstream electroplating system may act as a source of metal ion contamination for the subsequent electroplating system. For example, when forming a solder connection, a solder material (such as tin, tin-silver alloy, or lead-free material) may be deposited on another metal (such as copper), which may have been formed in a previous operation. The process of depositing the solder material may use a catholyte including ions of a solder metal (such as tin), and a number of additives, acids, and other materials to provide a specific balanced solution configured to reduce tin ions to produce a layer of solder material on an exposed area of ​​the first material in the electroplating chamber.

[0023] Copper may have been formed in any number of previous operations, including in previous electro-deposition operations. When formed in upstream or previous electro-deposition operations, the residual electrolyte containing copper ions may be transferred to a tin-containing electrolytic bath together with the substrate, and this tin-containing electrolytic bath is to mix a certain amount of copper ion pollutants in the tin-containing electrolyte. In addition, due to the properties or conditions of the tin-containing electrolyte, copper may be naturally corroded, etched, or undergo oxidation reactions during the subsequent electroplating operation or before the electroplating operation, so that ions can be sent to the subsequent tin-containing electrolyte. This can also mix a certain amount of copper pollutants in the tin-containing electrolyte. If not resolved, when the electroplating operation is carried out, and hundreds or thousands of substrates are processed, the copper ion concentration in the tin-containing electrolyte may continue to rise. If not resolved, the accumulation of pollutants can cause many problems, including chemical reactions between electroplating solutions and pollutant materials. In addition, it has been shown that the increase of copper pollution concentration in the tin-containing electrolyte can produce a rough surface on the electroplating material, and there will be other defects or gaps between the electroplating materials.

[0024] Some conventional techniques attempt to address contaminant concentrations in the electrolyte by performing bath changes, wherein when the contaminant concentration is too high, the tin-containing electrolyte is replaced with new electrolyte in the system. This process can be expensive based on the cost of electrolyte additives and materials, and tool downtime may need to be increased during the exchange. Alternatively, the electrolyte can be replaced by routinely removing some of the electrolyte and mixing in new electrolyte, which can replenish a certain percentage of the electrolyte in the system in a given cycle, and the electrolyte can be continuously exchanged over multiple such cycles. Depending on how often the exchanges occur and the volumes involved in the exchanges, these replenishments can also become expensive over time.

[0025] The present technology improves these conventional technologies by performing the following operations, wherein contaminants can be removed from the system by advanced filtering or removal techniques, wherein contaminant ions can be electrochemically removed from a tin-containing electrolyte. The present technology can provide reduced contamination concentrations by continuously or intermittently removing copper ions from the electrolyte without the need for physical exchange of the electrolyte. These operations can reduce the replacement cost of the electrolyte, and can increase the operating time of the system by allowing removal in a functional system during the electroplating operation. It should be understood that although the present disclosure will routinely describe the removal of copper ions from a tin-containing electrolyte, the present technology is not limited thereto. For example, any electroplating material including contaminant ions can benefit from the present technology by performing an operation based on the electroplating potential difference between the metal components, as described below. For example, other applications of the present technology may include copper contamination into nickel-containing chemicals, nickel contamination into tin-silver alloy chemicals, or any other application, wherein the upstream formation of the first material can provide a contamination source into a downstream electrolyte. Therefore, the present technology should not be considered to be limited to the exemplary materials discussed.

[0026] Figure 1A schematic diagram of an electroplating system 100 according to some embodiments of the present technology is depicted. The electroplating system 100 shows a dual bath system, although a single bath system can similarly benefit from the present technology as will be further discussed below. The electroplating system 100 is shown as including a pair of dual bath electroplating chambers, which include chamber 105 and chamber 110. However, it should be understood that a system according to the present technology may include one or more chambers using an electrolyte bath, and may include any number of chambers. As shown, chamber 105 may include a first bath 106 configured to maintain a cathode electrolyte during operation, and a second bath 108 configured to maintain an anolyte during operation. A separator 107 can provide fluid separation between the anolyte and the cathode electrolyte while allowing ions to be transported through the separator. Similarly, chamber 100 may include a third bath 112 configured to maintain a catholyte during operation, and a fourth bath 114 configured to maintain an anolyte during operation. A separator 113 may provide fluid separation between the two baths.

[0027] The electroplating system 100 may also include a catholyte tank 120. The catholyte tank 120 is fluidly coupled to the electroplating chambers 105, 110, and may be particularly fluidly coupled to the first bath 106 of the chamber 105 and the third bath 112 of the chamber 110. Although not shown in this embodiment, the system may include a similar anolyte tank coupled to the second bath 108 of the chamber 105 and the fourth bath 114 of the chamber 110. The anolyte tank may include an additional piping or plumbing system and a dedicated pump that forms an additional loop for the chemical.

[0028] The electroplating system 100 may include a pump 125 to provide fluid communication between the catholyte tank 120, the first bath 106 of the chamber 105, and the third bath 112 of the chamber 110. In other embodiments, a dedicated pump may be provided for each dual bath electroplating system, but a single pump may be used as shown. The pump 125 may be configured to provide catholyte to the electroplating chamber to ensure consistent chemistry during the deposition process. In some embodiments, the pump 125 may be a first pump, wherein an associated anolyte tank includes a second pump for providing anolyte from the anolyte tank to the anolyte bath of the associated electroplating chamber. The electroplating system 100 may also include auxiliary equipment, such as filters, and unspecified sensors, valves, and common plumbing materials and associated components. The piping configuration shown is exemplary only and is included to illustrate potential lines including return flows 127a, 127b to the catholyte tank 120 which may intersect to provide a common return line 130. Other flow configurations are also contemplated by the present technology.

[0029] The electroplating system 100 may also include a contaminant extraction system configured to remove contaminant ions from the catholyte. The contaminant extraction system may include one or more components that can be operated to remove specific metal ions from the catholyte. For example, in an exemplary system using a tin-containing catholyte, the contaminant extraction system may be configured to remove copper or other metal ions from the tin-containing catholyte. The contaminant extraction system may include a container 135 that is fluidly embedded and located between the first bath 106, the third bath 112, and the catholyte tank 120. In a system according to the present technology, a single catholyte tank can be used to provide the catholyte and circulate it to multiple chambers. The container 135 can be located on a common pipeline, which includes a common return line 130 or a common delivery line 129, although, for example, individual containers 135 can be located in the return 127a, 127b.

[0030] The container 135 may include one or more materials that may be configured or operated to remove copper ions from a tin-containing cathode electrolyte, or other metal contaminants from an electrolyte containing metal ions. The contaminant extraction system may additionally or alternatively include a device 140 that may be configured or located in the cathode electrolyte tank 120. For example, the device 140 may include materials similar to the container 135, or may include additional materials that are configured to operate on similar or different mechanisms for removing metal ion contaminants from an electrolyte containing metal ions. As shown, the container 135 may be placed in a bypass line, which in some embodiments may allow intermittent operation of the contaminant extraction system, although the present technology also includes other bypass or embedded combination schemes. The container 135 will be described in detail below with reference to FIG. 2, as well as an exemplary operating mechanism for removing contaminants from an electroplating system.

[0031] Turn Figure 2A , shows a schematic diagram of an exemplary contaminant extraction system 200 according to some embodiments of the present technology. System 200 can be similar to, or include a container 205 similar to container 135 described above, and the system or components can be located in a catholyte fluid system, which is between a catholyte cell and a processing chamber catholyte bath in any position as described above. In some embodiments, a single system 200 can be utilized in a multi-chamber system by incorporating system 200 into a common return line between a chamber catholyte bath and a catholyte cell. In addition, when incorporated in the return line, the catholyte can flow under pressure, which can help drive the flow of catholyte within system 200.

[0032] The system 200 may include an inlet line 210 and an outlet line 215, which may be a common return line for the electroplating system, or may be a bypass from a common or other fluid line for the electroplating system. Valves 212, 214 may be used to allow or prevent flow through the contaminant extraction system 200. An optional drain line 220 may also be incorporated with the contaminant extraction system 200, and may also include an optional drain valve 222. For example, the drain line may be used to remove electrolyte material contained in the container 205 during maintenance operations, and the drain line 220 may extend as an extraction line back to the cathode electrolyte tank (e.g., cathode electrolyte tank 120), or the fluid may be transported to an alternative extraction or treatment location. In some embodiments, an optional flow controller or diffuser 213 may be incorporated in the container 205 to direct flow to the anode and cathode settings, rather than simply bypassing the outlet line 215. However, in other embodiments, the dimensions of the container 205 may simply be designed to create a pressure drop configured to draw fluid through the chamber to limit unintended bypass. Any other mechanical or fluidic mechanism may also be used to direct or maintain flow within the container 205.

[0033] Within the vessel 205 of the contaminant extraction system 200 may be one or more devices or apparatuses configured to perform a removal operation to remove copper or other metal ions from a tin-containing or other metal-containing electrolyte while limiting or preventing the removal of tin or metal ions from the electrolyte. Figure 2A and Figure 2B As shown, two such options may be included individually or in combination. Figure 2A As shown, the container 205 may include an electrode system including an anode 230, a cathode 235, and a power source 240, wherein the power source 240 may be electrically coupled to the anode 230 and the cathode 235. The power source 240 is illustrated as a multi-cell source, but it should be understood that any number of power sources may be used to provide a voltage configured to drive the electrochemical operation between the anode 230 and the cathode 235. It should also be understood that the anode and cathode are schematically illustrated and are not limited to the configuration shown. For example, in some embodiments, the positions of the anode and cathode may be reversed within the container, with the cathode located above the anode. In addition, the anode and cathode may be configured in a planar configuration and positioned adjacent to or in a straight line with each other. In some embodiments, the anode and cathode may have curved characteristics and may be aligned close to each other along a common radius passing through the central axis of the container, or one of the anode or cathode may be concentrically or radially positioned outwardly from the other. Any other configuration possible within the container is also included in the present technology.

[0034] Anode 230 can be made of a first material, and cathode 235 can be made of a second material. In some embodiments, the first material and the second material can be similar or identical to each other. In some embodiments, one or both of anode 230 or cathode 235 can be or can include tin or a tin-containing material, but this material can be based on different elements, and this element can be selected to cooperate with the ions of the cathode electrolyte. As previously mentioned, an exemplary application of the present system is that a tin-containing material can be electroplated on a second material, and this second material can be or can include copper. In this electroplating operation, the cathode electrolyte of the dual-bath system can include metal ions of the material to be plated or deposited, and in this case, this metal ion can be tin. In other embodiments where different metals are to be electroplated, the anode and / or cathode can include different metals in the electrode composition. In some embodiments, the anode and / or cathode can be a more inert material and can be a material that is more inert in the electromotive force series than one or both of the metal ions of the electrolyte or the metal ions of the contaminant. Continuing to exemplify throughout the specification, the material of the anode or cathode can be more inert than one or both of tin or copper. For example, materials including platinum, silver, palladium, steel, chromium, nickel, titanium, vanadium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, ruthenium, rhodium, technelium, rhenium, osmium, iridium, antimony, tellurium, or other transition metals or other elements, including compounds (such as oxides), or any combination of materials may be used.

[0035] Although many determined materials can be used in embodiments of the present technology, in some embodiments, materials can be selected to limit interference with the electroplating system. For example, materials can be selected to limit side reactions with the composition or additives of the electrolyte, maintain conductivity, limit oxidation or passivation in the electrolyte system, and tolerate the environment of the electrolyte. Anode 230 can be consumable or inert in the cathode electrolyte. An exemplary inert material can be or can include platinum, which can be used as one or both of the anode or cathode in various embodiments. A consumable material can be or can include tin or tin-containing materials, which can also be combined as one or both of the anode or cathode in various embodiments. In some embodiments, the anode can be or can include tin or tin-containing materials, which can be consumed to provide tin ions to the cathode electrolyte. Specific inert electrode materials may not oxidize metal materials into the cathode electrolyte, but if the potential is high enough, gaseous substances may be produced or released in the cathode electrolyte, and therefore, it is possible to limit the gas from passing through the bubble separator or other collection mechanism and entering the cathode electrolyte. Accordingly, in some embodiments, tin or tin-containing materials may be used, which may be relatively or substantially neutral to the catholyte by providing metal ions, and which may at least partially supplement the plating ions to the catholyte.

[0036] As previously described, in other embodiments where the alkali ions of the catholyte are different metals, the anode can be or can include such a material, which can at least partially replenish the electrolyte during operation of the contaminant extraction system. The anode or cathode can be of a variety of designs, shapes, or configurations, including plate materials, granular materials, or other configurations to provide surface area characteristics that can be configured for a variety of system designs. For example, in one embodiment, tin particles can be contained within a conductive sleeve, and the power supply 240 can be coupled to the conductive sleeve. Such a configuration can be positioned substantially perpendicular to the flow direction within the container, and can provide an amount or tortuosity of the flow to improve contact of resident copper ions with tin or other materials to increase extraction from the system.

[0037] In some embodiments, the power supply may be applied within a specific voltage range within the battery potential difference between the contaminant metal species and the electrolyte metal species. For example, in some embodiments, the power supply may be configured to provide a voltage within a potential window, which is at least partially defined by the battery potential between the contaminant material (e.g., copper) and the electrolyte metal ion (e.g., tin). In this example, the battery potential is about 0.34 copper potential minus 0.14 negative tin potential, resulting in a battery potential of about 0.48V. Similarly, when using different electrolytes or contaminant materials, the potential may be based on the specific potential of these materials. By maintaining the power supply operating voltage within the potential window defined by the battery potential, the system can be configured to reduce or plate away the contaminant material while maintaining the electrolyte metal ion material. The system can be configured to limit or prevent the electroplating of the electrolyte metal ion material, which would otherwise reduce the concentration of the ions to be electroplated at the chamber cathode, where the chamber cathode can typically be a substrate.

[0038] In a non-limiting hypothetical scenario, chamber setup and testing may determine that in a possible contaminant extraction system, tin may begin to be plated out of the electrolyte at a voltage greater than or about 2 volts (V), and thus, in a hypothetical example, the plating potential for tin in the system may be at a voltage greater than 2V, such as 2.3V. Accordingly, in such a cell, the voltage of power supply 240 may be maintained below the hypothetical 2.3V. Continuing with this hypothetical example, based on the cell potential relative to the contaminant copper, the cell potential for copper may be about 0.5V less than the cell potential of 2.3V for plating tin, and thus, the plating potential for copper in the system may be at a voltage greater than about 1.5V, such as about 1.8V. Accordingly, in some embodiments, the voltage of power supply 240 may be maintained above the hypothetical 1.8V. These plating potentials may be system specific based on a variety of factors, including the composition of the cell, the composition of the electrolyte, or various resistors in the system, and may be predetermined by testing of a given system. However, during operation, the power supply voltage can be maintained within a potential window defined as follows, i.e., the electroplating potential for tin is within a given cell design. As the concentration of copper or other contaminants in the electrolyte continues to decrease, the potential used to electroplate additional copper may move in a more negative potential direction, which may require increasing the copper plating voltage threshold over time in addition to predetermining or precalculating the copper plating voltage threshold. However, the voltage can still be maintained below the potential of the electroplated ionic material (e.g., tin). After a period of time, the potential window may not be properly maintained without tin plating initiating, and the anode and / or cathode materials in the contaminant extraction system may be replaced.

[0039] Figure 2BAnother embodiment of a schematic diagram of an exemplary contaminant extraction system 250 according to some embodiments of the present technology is shown, which can be combined with or replace the anode 230 and cathode 235. The system 250 can be similar to or include common components as described above with respect to the system 200, and can be incorporated into the electroplating system in a similar manner. The system 200 can also include a container 205 similar to the container 135 described above, and the system or components can be positioned in the catholyte fluid system, which is anywhere between or within the catholyte tank and the process chamber catholyte bath, as previously described.

[0040] The system 200 may include an inlet line 210 and an outlet line 215, which may be a common return line for the electroplating system, or may be a bypass from a common or other fluid line for the electroplating system. Valves 212, 214 may be utilized to allow or prevent flow through the contaminant extraction system 200. Valves 212, 214 may be utilized to allow or prevent flow through the contaminant extraction system 200. An optional drain line 220 may also be incorporated with the contaminant extraction system 200, and may also include an optional drain valve 222. As previously described, for example, the drain line may be used to remove electrolyte material contained within the vessel 205 during maintenance operations, and the drain line 220 may extend as an extraction line back into the catholyte cell (e.g., the catholyte cell 120), or may deliver fluid to an alternative extraction or treatment location.

[0041] Within the container 205 of the contaminant extraction system 200 may be a granular material 260, or other filler particle design. The filler material 260 may be or may include a conductive material, and may be any of the materials identified above for the anode and cathode materials of the system 200. In some embodiments, the filler material may be tin or tin-containing particles located within the container 205. Additionally or alternatively, these particles may be contained in a device 140 such as within a cathode electrolyte tank. The system 200 may also be located within the cathode electrolyte tank 120 described above. The filler material may be a single material contained within the container, or may be a combination of the above compositions. For example, the material may be more active than the contaminant material on the electromotive force series. By incorporating the material 260 within the container 205, the system may provide a galvanic action, which may allow for electroplating and removal of contaminants from the electrolyte.

[0042] For example, when in contact with an electrolyte including contaminants, a Galvanic reaction may occur on multiple particles of material 260. For example, some particles will naturally begin to donate electrons to contaminant ions (e.g., copper ions) in a reduction reaction, which will begin to be electroplated on these particles, which may exhibit a cathode effect. Other particles may then naturally exhibit an anode effect and may donate electrons to the system, causing the particles to undergo an oxidation reaction, and wherein ions of the particle material may be transported into the electrolyte material. The particles or material 260 may not be electrically coupled, and may react directly during the flow of the electrolyte material over the surface of the material 260. In some embodiments, the same action may occur if the system is allowed to continue to circulate electrolyte over the anode and cathode materials when the power supply 240 of the system 200 is not engaged. Accordingly, one or both actions may be performed or allowed to occur to reduce the concentration of contaminant ions within the electroplating system.

[0043] Other materials that can be used may include resins or other coated particles, which include active exchange materials within the resin or coating. The exchange material can be configured to perform proton exchange relative to copper ions bound to the electrolyte. The material can be configured to preferentially interact with copper or contaminant ion species relative to other metal species, such as ions of the electrolyte used in electroplating. In operation, such as continuing the examples throughout the present disclosure, when tin ions and other materials flow through or pass through the particle bed, the tin ions and other materials may not interact with the particles. However, copper ions can be absorbed by the resin or coating material, and copper ions can be collected by the internal active exchange material, which can discharge protons in response to the collected copper. These particles can be operated for a period of time, or a certain amount of material can be consumed before the particles are saturated. Once saturated, or close to saturation, new materials can be replaced or replaced for additional use. The resin or coating can be any material configured to operate within the electrolyte and system environment, and allow the transmission of copper or contaminant ion species while limiting or preventing the transmission of other metals or some other ionic species.

[0044] By performing operations according to the present technology and systems using the present technology, the concentration of contaminant ions can be reduced and / or maintained below a specific threshold. For example, the present technology can provide a neutral contaminant configuration that allows the incorporation of contaminants to be maintained during substrate processing and routine replacement or replacement of new contaminant extraction system components. The amount of contaminants that the system may be able to tolerate incorporation into the electrolyte is, for example, less than or approximately 10 parts per million (ppm), less than or approximately 8 ppm, less than or approximately 5 ppm, less than or approximately 3 ppm, less than or approximately 2 ppm, less than or approximately 1 ppm, less than or approximately 100 parts per billion (ppb), less than or approximately 10 ppb, or less. The present technology can be configured to limit additional contaminant accumulation during multiple substrate processing operations. For example, the present technology can limit additional incorporation of contaminants and / or reduce the original contaminant concentration to below any of the stated limits at any time during operation, including after processing more than or about 1,000 substrates, processing more than or about 5,000 substrates, processing more than or about 10,000 substrates, or more. For example, if the natural concentration of a contaminant in the electrolyte solution may be 5 ppm, the present technology can maintain the contaminant concentration below 6 ppm, below 5.1 ppm, and further reduce the contaminant concentration to below 5 ppm, below 4 ppm, or less during processing of any of the stated numbers of substrates. Accordingly, the present technology can maintain or improve the contaminant concentration within the electrolytic material.

[0045] In some embodiments, the present technology can be similarly used in a single bath system. Figure 3 A schematic diagram of an electroplating system 300 according to some embodiments of the present technology is shown. The electroplating system 300 may include some or all of the aforementioned components, although a single electrolyte may be used in the system to replace separate catholyte and anolyte. The components of the electroplating system 300 may operate similarly to the above-mentioned components and may be configured to limit the accumulation of pollutants to any previously determined range. As shown, the electroplating system 300 may include a plating chamber 305 and another plating chamber 310. Similar to the aforementioned system, the electroplating system 300 may include any number of plating chambers in the system. The plating chambers 305, 310 may be configured to accommodate electrolytes 306, 312 distributed in the system. The electroplating system 300 may include an electrolyte tank 320, which is fluidly coupled to the plating chambers 305, 310 and is configured to maintain the distributed electrolyte.

[0046] The electroplating system 300 may include a pump 325 fluidly coupled between the electrolyte tank 320 and the electroplating chamber 310. The pump may be configured to provide electrolyte from the electrolyte tank to the electroplating chamber 305. In some embodiments, the electroplating system 300 may also include any other auxiliary equipment that may be used in the electroplating chamber design. The electroplating system 300 can be used for any number of electroplating operations and can be configured with materials to perform operations related to multiple metals and materials. In one example included in the present technology, the system can be used for tin electroplating operations and can use a tin-containing electrolyte. A number of contaminants, such as copper ion contaminants, may be present in the electrolyte.

[0047] The electroplating system 300 may also include one or more contaminant extraction system components, which may include a container 335 or an apparatus 340. The container 335 and the apparatus 340 may be or may include any of the materials or compositions described above, and may be configured to operate to reduce the concentration of copper ions in the electrolyte. The contaminant extraction system may include a single component system, such as a particle packing configuration as described above. The contaminant extraction system may also include a dual component system, such as an anode / cathode electrode configuration with a power source to drive the electroplating operation as described above. The system may be operated to maintain or reduce the contaminant concentration to any of the concentrations described above during processing of any number of substrates.

[0048] The foregoing systems may be used to perform one or more methods, such as removing copper contaminants from a tin-containing catholyte or electrolyte within an electroplating system. Figure 4 Operations of an exemplary method 400 for removing contaminants from an electrolyte material according to some embodiments of the present technology are shown. Method 400 may be performed using any of the systems described above, which may include any components or configurations described elsewhere. Method 400 may include additional operations performed prior to the operations described, including a first deposition or electroplating in a first chamber. For example, an upstream process may include forming a copper-containing or other metal-containing material on a substrate. The substrate may then be transferred to a second electroplating chamber to electroplate a tin-containing or other metal-containing material. When converted to an electrolyte comprising a second material (e.g., a tin-containing material), contaminants may be introduced into the system as described above. Method 400 may include, at operation 410, allowing a catholyte or electrolyte to flow through an electroplating system. The electrolyte may include contaminants in solution. The electrolyte may flow between a processing chamber and an electrolyte tank, which in some embodiments may be a catholyte tank. At operation 420, the electrolyte is passed through a material configured to reduce or remove contaminants in the electrolyte. In one embodiment, the catholyte may be passed through a tin-containing material. At operation 430, contaminants may be reduced or removed from the electrolyte.

[0049] As previously described, the material may be any of the materials described above, and may include one or more components including an extraction vessel and / or a particulate material embedded in a fluid line of the system, such as a fluidly coupled line between a plating chamber and an electrolyte tank. In some embodiments, the material may also or alternatively be included in an electrolyte tank, such as a cathode electrolyte tank as described above. In some embodiments, the material may be tin or a tin-containing material, which is operated as an anode of an anode-cathode pair of electrically coupled electrodes. The contaminant, which may be copper, may be plated on the cathode, and the anode material may be corroded into the electrolyte solution. In some embodiments, during operation, one or more of the cathode or anode may not be consumed. When operating as a cathode and an anode, the electrode may be driven by a power supply operating at a voltage configured or tested to be lower than the tin plating potential and higher than the copper plating potential, and in other embodiments, the voltage may also be lower than the potential of the electrolyte material and higher than the potential of the contaminant material. In some embodiments, the cathode may be or include tin, or may be a material that is more inert than copper in the electromotive force series.

[0050] For example, during system setup, a sample run or test may be performed to determine a threshold voltage at which tin plating may occur in the system. For example, a power supply as described above may apply a specific voltage while monitoring the current. The current may be based on the material plated in the electrolyte. Therefore, for example, at low voltages, the current may be reduced or no current may occur. At the threshold where copper plating may occur, a certain amount of current may be observed. Based on the concentration of copper in the solution, this current may be in the range of microamps or milliamps. As the voltage further increases, a threshold may be reached at which the current may rise in a more obvious manner, which may indicate the plating of tin in the electrolyte. Due to the high concentration of tin in the system, the current generated by electroplating tin may, for example, be an order of magnitude higher than during electroplating copper.

[0051] Based on this, the threshold for electroplating tin can then be determined for individual systems, and the operating voltage can then be maintained below this threshold, but above the threshold potential for electroplating copper. As mentioned above, the voltage can be adjusted over time relative to the characteristics of the electrolyte. For example, as the copper ion concentration further decreases, the voltage can be increased to adapt to further electroplating, but it must still be maintained at a voltage below the tin electroplating threshold. In addition, due to the low concentration of copper, copper deposition may be carried out at a limited current density of mass transfer of copper or at a limited current density close to the mass transfer of copper. Therefore, the flow characteristics of the electrolytic liquid and the characteristics of the cathode material may be important factors in removing limited copper or other contaminants in the system. Therefore, a flow agitator or other mechanism can be included to promote movement in the container, such as stirring (rifling) along the container, and a combination device to increase the movement of the electrolyte in the container. In some embodiments, the cathode material can also be improved or enhanced, including by combining roughening to increase the surface area and electroplating opportunities, and including a groove, fold or waveform design, which can increase the residence time in the cathode and surface area to promote electroplating. In some embodiments applicable to any of the foregoing figures, the cathode has the characteristic of a larger surface area than the anode and has at least twice the surface area, at least three times the available surface, at least five times the available surface area, at least ten times the available surface area, or more.

[0052] In some embodiments, the system can be operated in a continuous mode to continuously reduce the copper concentration and / or provide additional tin from the anode. The system can also be operated intermittently after the electrolyte test indicates that the copper ion concentration is elevated (e.g., above a threshold). By operating the system intermittently, the balance of the electrolyte can be better maintained. For example, intermittent operation may limit the impact on other materials or additives in the electrolyte and can ensure that too many tin ions are not provided to the system.

[0053] In some embodiments, this material can be contained in a packing arrangement, within a container or a packing column arrangement, to provide sufficient surface area for interaction with the electrolyte and the contaminant species contained within the electrolyte. By utilizing the present technique, the concentration of contaminants within the electrolyte can be maintained or reduced to below a predetermined concentration. Utilizing electroplating and / or galvanic interactions, the present technique can allow for the removal of contaminant species while maintaining other ionic species within the electrolyte. These techniques can reduce operating costs while maintaining system uptime compared to conventional techniques.

[0054] In the above description, for the purpose of explanation, many details have been set forth to understand several embodiments of the present technology. However, it will be appreciated that for those skilled in the art, certain embodiments may be implemented without some or additional details.

[0055] In the case of several embodiments disclosed, those of ordinary skill in the art will appreciate that several modifications, alternative configurations, and equivalents may be used without departing from the spirit of the embodiments. In addition, some known processes and elements are not described to avoid unnecessarily obscuring the present technology. Therefore, the above description should not be taken as a limitation on the scope of the present technology.

[0056] It will be understood that, unless the context clearly dictates otherwise, where a numerical range is provided, each intervening value between the upper and lower limits of the range that is the smallest fraction of the lower limit unit is also explicitly disclosed. Any stated value or unstated intervening value in the stated range, and any narrower range between any other stated or intervening values ​​in the stated range are included. The upper and lower limits of these smaller ranges may be independently included or excluded in the range, and subject to any specifically excluded limits in the stated range, each range containing either, neither, or both limits in the smaller range is also included in this technology. Where the stated range includes one or two limits, the range excluding either or both of these included limits is also included. Where multiple values ​​are provided in a list, any range containing or based on these values ​​is similarly specifically disclosed.

[0057] As used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the content clearly dictates otherwise. Thus, for example, reference to "a material" includes a plurality of such materials and reference to "the channel" includes reference to one or more channels and equivalents thereof known to those skilled in the art, etc.

[0058] Furthermore, the words “comprise(s), comprising, contain(s), containing, include(s), and including” used in this specification and the claims below are intended to mean the presence of stated features, integers, components, or operations, but they do not exclude the presence of one or more other features, integers, components, operations, actions, or groups or additional one or more other features, integers, components, operations, actions, or groups.

Claims

1. An electroplating system comprising: A dual bath electroplating chamber comprising a divider configured to provide fluid separation between a first bath configured to hold a catholyte during operation and a second bath configured to hold an anolyte during operation; a catholyte bath fluidly coupled to the first bath of the dual bath electroplating chamber; and A contaminant extraction system configured to remove contaminant ions from the cathode electrolyte, wherein the cathode electrolyte comprises a solution, wherein the solution comprises tin, wherein the contaminant extraction system comprises a container, wherein the container comprises an anode and a cathode, wherein the anode and the cathode are electrically coupled to a power supply, wherein the power supply is configured to operate at less than 2.3V in the contaminant extraction system, and wherein the contaminant extraction system is configured to maintain an increase in copper ion concentration in the cathode electrolyte below about 10 ppm per 1000 wafers processed.

2. The electroplating system of claim 1, wherein the anode comprises a first material that is consumable or inert to the cathode electrolyte.

3. The electroplating system of claim 2, wherein the contaminant ions include copper, and wherein the first metal includes tin.

4. The electroplating system of claim 1, wherein the power supply is configured to operate at a voltage lower than a plating potential for tin within the electroplating system.

5. The electroplating system of claim 1, further comprising: A bypass line between the dual bath electroplating chamber and the catholyte cell, wherein the bypass line allows for intermittent operation of the contaminant extraction system.

6. The electroplating system of claim 1, further comprising: A second dual bath electroplating chamber is in fluid communication with the catholyte bath and the contaminant extraction system.

7. A method for removing copper contaminants from a tin-containing catholyte in an electroplating system, the method comprising: flowing the catholyte from the electroplating chamber to the catholyte tank; Passing the catholyte through a tin-containing material in a contaminant extraction system, wherein the contaminant extraction system comprises a container, the container comprising an anode and a cathode, the anode and the cathode being electrically coupled to a power source, and wherein the power source delivers a voltage less than 2.3V; and The copper contaminant from the catholyte is reduced.

8. The method of removing copper contaminants from a tin-containing catholyte in an electroplating system as recited in claim 7, wherein said power source delivers a voltage that is lower than the plating potential for tin in said electroplating system.

9. The method of removing copper contaminants from a tin-containing catholyte in an electroplating system as recited in claim 7, wherein the cathode comprises tin or a material that is more noble than copper.

10. The method of removing copper contaminants from a tin-containing catholyte in an electroplating system as recited in claim 7, wherein the cathode comprises tin particles within a conductive sleeve.

11. The method of removing copper contaminants from a tin-containing catholyte in an electroplating system as claimed in claim 7, further comprising: Reduce copper contamination to below natural concentrations.

12. An electroplating system comprising: Electroplating chamber; an electrolyte tank fluidly coupled to the electroplating chamber and configured to hold an electrolyte; a tin-containing electrolyte comprising copper ions; and a contaminant extraction system configured to remove the copper ions from the electrolyte, wherein the contaminant extraction system comprises a vessel, the vessel comprising an anode and a cathode, the anode and the cathode being electrically coupled to a power source, wherein the power source is configured to operate at a potential lower than the electroplating potential used for tin in the electroplating system, and wherein the contaminant extraction system is configured to maintain an increase in the copper ion concentration in the cathode electrolyte below about 10 ppm per 1000 wafers processed during operation.

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