Vapor phase alkali metal removal for in-SITU cleaning of processing chamber

Abstract

An alkali-metal removal system and method for in-situ vapor phase removal and downstream reclamation of metallic lithium from reusable lithium deposition process kit parts are provided. The system and method include preparing a cleaning gas containing vapor phase fluorinated alcohol. The system and method further include exposing parasitic lithium deposits to the cleaning gas containing the vapor phase fluorinated alcohol and etching metallic lithium from parts coated with parasitic lithium deposition. The system and method further include collecting reaction byproducts and unreacted cleaning gas. The system and method further include separating lithium compounds from the reusable cleaning gas.

Description

VAPOR PHASE ALKALI METAL REMOVAL FOR IN-SITU CLEANING OF PROCESSING CHAMBERBACKGROUNDField

[0001] The present disclosure generally relates to systems and methods for removing alkali-metal deposits from an alkali-metal deposition system. More particularly, the present disclosure generally relates to systems and methods for vapor phase removal of alkali-metal deposits and preventative maintenance for web coating equipment.Description of the Related Art

[0002] Processing of flexible substrates, such as plastic films or foils, is in high demand in the packaging industry, semiconductor industries and other industries. Processing may include coating of a flexible substrate with a material, such as a metal. The economical production of these coatings is frequently limited by the thickness uniformity necessary for the product, the reactivity of the coating material, the cost of the coating materials, and the deposition rate of the coating materials. The most demanding applications generally entail that the deposition occur in a vacuum chamber for precise control of the coating thickness and the optimum optical or other material properties. The high capital cost of vacuum coating equipment necessitates a high availability and high throughput of coated area for large-scale commercial applications. The coated area per unit time is typically proportional to the coated substrate width and the vacuum deposition rate of the coating material. High availability offsets high capital cost and facilitates economically viable commercial manufacturing.

[0003] A process that can utilize a large vacuum chamber has tremendous economic advantages. Vacuum coating chambers, substrate treating and handling equipment, and pumping capacity, increase in cost less than linearly with chamber size; therefore, the most economical process for a fixed deposition rate and coating design will utilize the largest width and length substrate available. A larger substrate can generally be fabricated into discrete parts after the coating process is complete. In the case of products manufactured from a continuous web, the web is slit or sheetcut to either a final product dimension or a narrower web suitable for the subsequent manufacturing operations.

[0004] One flexible substrate coating technique used is resistive or electron beam thermal evaporation. Thermal evaporation readily takes place when a source material is heated in an evaporation source assembly within a vacuum chamber. Above a minimum temperature, there is a sufficient vapor flux from the evaporation source assembly for material condensation on a cooler substrate. The ratio of material condensation on a cooler substrate versus the evaporation source assembly itself can be difficult to control and can lead to parasitic deposition on various chamber components. In the case of manufacturing alkali-metal, for example, metallic lithium coated foils and films, parasitic lithium deposits internal and adjacent to the evaporation source assembly can adversely affect the yield and quality of subsequently deposited lithium films. Coating large substrates necessitates using large chamber components wider than the substrate. Some components are impractical to frequently remove for ex-situ cleaning and are thus manually cleaned in-situ, which can be hazardous due to confined space combustible metal handling. Further, some aqueous solutions typically used to wet clean chamber components can produce undesirable corrosive neutralization byproducts such as lithium hydroxide which can damage chamber components. In addition, some aqueous solutions can contaminate battery grade (high purity) lithium contained in the source charge resulting in source assembly thermal drift due to the formation of higher melting point lithium oxide. In addition, lithium oxide particles formed and liberated during hazardous manual preventative maintenance can nucleate coating defects on the lithium coated web which can adversely impact energy storage device safety and cycle life.

[0005] Thus, there is a need for methods and systems for removing unwanted parasitic alkali-metal deposits from chamber components that automate hazardous preventative maintenance operations, increase equipment availability via turnaround duration decrease, and maximize manufacturing economy.SUMMARY

[0006] The present disclosure generally relates to systems and methods for removing alkali-metal deposits from an alkali-metal deposition system. Moreparticularly, the present disclosure generally relates to systems and methods for vapor phase removal of alkali-metal deposits and preventative maintenance for web coating equipment.

[0007] In one aspect, a method of in-situ removal of parasitic alkali-metal from a deposition chamber component is provided. The method includes delivering a cleaning gas including fluorinated alcohol to a processing environment of a deposition chamber, the processing environment including one or more chamber components at least partially coated with alkali-metal. The method further includes exposing the one or more chamber components to the cleaning gas for a time period during which the alkali-metal reacts with the fluorinated alcohol to form a gaseous reaction byproduct. The method further includes removing the gaseous reaction byproduct from the processing environment.

[0008] Implementations may include one or more of the following. The fluorinated alcohol has the formula RfRf’CHOH, wherein Rf and Rf’ represents a pefluoroalkyl group having 1 to 10 carbon atoms. The fluorinated alcohol has the formula RfRf’Rf’COH, where Rf, Rf’, and Rf” represent a pefluoroalkyl group having 1 to 10 carbon atoms. The fluorinated alcohol is selected from hexafluoroisopropanol, nonafluoro-tert-butyl alcohol, or a combination thereof. The one or more chamber components include at least one of a coating drum and a deposition source. The one or more chamber components include a thermal evaporator. The gaseous reaction byproduct includes lithium alcoholate and excess fluorinated alcohol. The lithium alcoholate is separated from the excess fluorinated alcohol via a distillation process. Fluorinated alcohol is regenerated from the lithium alcoholate by treating the lithium alcoholate with phosphoric acid. Removing the gaseous reaction byproduct from the processing environment includes purging the processing environment of the deposition chamber to remove to remove the gaseous reaction byproduct.

[0009] In another aspect, a deposition system for coating a flexible substrate with a stack of layers, at least one of which includes alkali-metal is provided. The deposition system including a deposition chamber that defines a processing environment and one or more chamber components positioned in the processing environment. The one or more chamber components include a drum positioned in the processing environment over which a flexible substrate is processed and a depositionsource positioned in the processing environment for depositing lithium metal over the flexible substrate. The deposition system further includes a cleaning precursor delivery system fluidly coupled with the processing environment. The cleaning precursor delivery system includes a source for supplying a cleaning gas including a fluorinated alcohol. The deposition system further includes a system controller configured to cause the deposition system to perform a process, including delivering the cleaning gas to the processing environment, the one or more chamber components at least partially coated with alkali-metal; exposing the one or more chamber components to the cleaning gas for a time period during which the alkali- metal reacts with the fluorinated alcohol to form a gaseous reaction byproduct; and removing the gaseous reaction byproduct from the processing environment.

[0010] Implementations may include one or more of the following. The fluorinated alcohol has the formula RfRf’CHOH, wherein Rf and Rf’ represents a pefluoroalkyl group having 1 to 10 carbon atoms. The fluorinated alcohol has the formula RfRf’Rf’COH, where Rf, Rf’, and Rf” represent a pefluoroalkyl group having 1 to 10 carbon atoms. The fluorinated alcohol is selected from hexafluoroisopropanol, nonafluoro-tert-butyl alcohol, or a combination thereof. The drum is a coating drum or a calendering drum. The deposition source is a thermal evaporator. The deposition chamber is a vacuum-assisted deposition chamber.

[0011] In yet another aspect, a deposition system for coating a flexible substrate with a stack of layers, at least one of which includes alkali-metal is provided. The deposition system including a deposition chamber that defines a processing environment, one or more chamber components positioned in the processing environment, a cleaning precursor delivery system fluidly coupled with the processing environment, a chamber foreline fluidly coupled with the processing environment, an exhaust system fluidly coupled with the processing environment via the chamber foreline, and a system controller configured to cause the deposition system to perform a process. The one or more chamber components, including a drum positioned in the processing environment over which a flexible substrate is processed and a deposition source positioned in the processing environment for depositing lithium metal over the flexible substrate. The cleaning precursor delivery system includes a source for supplying a cleaning gas including a fluorinated alcohol. The chamber foreline positioned to route gaseous effluent leaving the deposition system. The exhaustsystem includes a byproduct collection system, a distillation system positioned downstream from the byproduct collection system, and a regeneration system positioned downstream from the distillation system. The system controller is configured to cause the deposition system to perform a process, including delivering the cleaning gas including fluorinated alcohol to the processing environment, the processing environment including the one or more chamber components at least partially coated with alkali-metal, exposing the one or more chamber components to the cleaning gas for a time period during which the alkali-metal reacts with the fluorinated alcohol to form a gaseous effluent stream including a gaseous reaction byproduct, and removing the gaseous effluent stream from the processing environment via the exhaust system.

[0012] Implementations may include one or more of the following. The fluorinated alcohol is selected from hexafluoroisopropanol, nonafluoro-tert-butyl alcohol, or a combination thereof. The byproduct collection system separates excess fluorinated alcohol and the gaseous reaction byproduct from the gaseous effluent stream. The distillation system separates the fluorinated alcohol from the gaseous reaction byproduct. The regeneration system regenerates fluorinated alcohol from the gaseous reaction byproduct by chemically treating the gaseous reaction byproduct with an aqueous acidic solution to produce regenerated fluorinated alcohol.

[0013] In another aspect, a non-transitory computer readable medium has stored thereon instructions, which, when executed by a processor, causes the process to perform operations of the above apparatus and / or method.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] So that the manner in which the above-recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, and may admit to other equally effective embodiments.

[0015] FIG. 1 illustrates a schematic diagram of a processing system including an alkali-metal removal system in accordance with one or more implementations of the present disclosure.

[0016] FIG. 2 illustrates a schematic diagram of a precursor delivery system in accordance with one or more implementations of the present disclosure.

[0017] FIG. 3 illustrates a schematic side view of a deposition system incorporating an alkali-metal removal system in accordance with one or more implementations of the present disclosure.

[0018] FIG. 4 illustrates a schematic side view of an exhaust system in accordance with one or more implementations of the present disclosure.

[0019] FIG. 5 illustrates a flow chart of a method for removing parasitic lithium in accordance with one or more implementations of the present disclosure.

[0020] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.DETAILED DESCRIPTION

[0021] The present disclosure generally relates to systems and methods for removing alkali-metal deposits from an alkali-metal deposition system. More particularly, the present disclosure generally relates to systems and methods for vapor phase removal of alkali-metal deposits and preventative maintenance for web coating equipment.

[0022] Parasitic metallic lithium deposition on chamber components can adversely affect uniform lithium deposition yield and quality in a roll-to-roll deposition system. For example, unwanted parasitic lithium deposition on chamber components can react with moisture outgassing from the flexible web substrate and can induce chamber component emissivity drift due to metallic lithium oxide formation. Radiation heat transfer from thermal evaporators to a drum-cooled web increases due to unwanted parasitic lithium deposition on chamber components, for example, the deposition source, the radiation shield, and the edge mask, reacting with moisture and forminghigh emissivity lithium oxide coatings.. It is difficult to measure and to compensate change in the ratio of radiation versus condensation energy received by the substrate over long coating campaigns between turnarounds. Reducing radiation energy is generally preferred to avoid exceeding the substrate thermal budget, for example, to avoid melting the web, while maximizing deposition rate. However, for some applications, at lower lithium deposition rates and slightly elevated substrate temperatures, it useful to produce metallic lithium coatings characterized by fine lithium crystals and thus necessary to prevent radiation energy drift. On rare occasions, web defects or recipe errors cause the web to tear and lithium to condense directly on the cooling drum. Some cooling drums have fine features for providing a high and uniform gap pressure for high heat transfer between the web and substrate. It is useful to remove metallic lithium from these fine features on the drum surface without risk of fouling or corrosion. Evaporator source lithium oxide contamination was evidenced by increasing heater power entailed to maintain the source assembly at the same temperature over time. Further, parasitic deposition of lithium reduces roll-to-roll uniformity due to edge mask-and-web baffle fouling with metallic lithium which further causes pump conductance decrease and lithium vapor plume instability as evidenced by within roll transverse thickness nonuniformity. Manual removal of unwanted parasitic lithium deposits is not only hazardous but also increases chamber turnaround duration, which in turn increases the cost of ownership of the tool. For example, manual cleaning of evaporator parts can lead to lithium metal fires and necessitates complex fire protection systems that may be avoided if manual cleaning operations were automated within the isolated vacuum system. Further, conventional aqueous cleaning methods produce hazardous waste which is costly to dispose and in turn increases operating costs.

[0023] In one or more implementations, which can be combined with other implementations, an alkali-metal removal system and method for in-situ vapor phase removal and downstream reclamation of metallic lithium from reusable lithium deposition process kit parts are provided. In at least one implementation, the system and method include preparing a cleaning gas containing vapor phase fluorinated alcohol. The system and method further include exposing parasitic lithium deposits to the cleaning gas containing the vapor phase fluorinated alcohol and etching metallic lithium from parts coated with parasitic lithium deposition. The system and methodfurther include collecting reaction byproducts and unreacted cleaning gas. The system and method further include separating lithium compounds from the reusable cleaning gas. The systems and methods described can also be used to remove lithium metal from unusable scrap lithium metal coated flexible substrates, for example, flexible PET substrates coated with lithium metal or flexible copper substrates coated with lithium metal. Some lithium coated PET substrates are used for transfer laminating metallic lithium coatings onto graphite coated copper to prepare lithiated electric vehicle anodes or onto four to six micron thick metal foil to prepare solid metal anodes. After transfer lamination, it is useful to reclaim excess lithium from the lithium coated PET substrates in order to reduce PET carrier disposal expense and to minimize lithium waste.

[0024] In one or more implementations, which can be combined with other implementations, fluorinated alcohols, for example, hexafluoroisopropanol (HFIP) and Nonafluoro-tert-butyl alcohol (NFTB), are used to remove alkali-metals (e.g., lithium metals) and passivated alkali-metal compounds (e.g., lithium hydroxide) at a faster rate than traditional organic alcohols such as IPA. Volatile reaction byproducts of the fluorinated alcohols facilitate removal of the byproduct at temperatures of 50 degrees Celsius or greater under reduced pressure. These processes and systems can be extended to other alkali and alkali earth metals, for example, sodium, potassium, and calcium, as well as passivated alkali-metal compounds.

[0025] In one or more implementations, which can be combined with other implementations, the alkali-metal removal system further includes further includes a system and method for regeneration of the fluorinated alcohol and reclamation of metallic lithium. Recovery and recycling of the fluorinated alcohol precursor after the alkali-metal removal process can substantially reduce overall alkali-metal removal expenses. In one or more implementations, which can be combined with other implementations, the recovery process includes separating excess unused fluorinated alcohol, for example, HFIP, from the reaction byproducts including lithium alcoholate, for example, excess HFIP and Li-HFIP, of the alkali-metal removal process, regenerating pure fluorinated alcohol from the reaction byproducts via chemical treatment of the reaction byproducts. The recovered fluorinated alcohol can be reused in the next batch of alkali-metal removal processes, which reduces consumption of the fluorinated alcohol and improves the overall cost of the alkali-metal removalprocess. For example, consider a 90% recovery of HFIP via recycling & regeneration. Only 10% of new HFIP needed in the next batch of cleaning which will reduce the overall cost of the HFIP chemical to 90%. Thus, the cost of the effective HFIP price will be reduced to $3 / kg from $30 / kg of the actual price.

[0026] Prior metallic lithium deposition systems rely on hazardous manual cleaning and are unable to coat multiple long rolls between turnarounds. Cleaning is often performed ex-situ. In one or more implementations, which can be combined with other implementations, the systems and methods described enable high rate and high efficiency in-situ vapor phase cleaning to remove metallic lithium while reducing the risk of lithium hydroxide or other solids contaminating the deposition system. Economical lithium reclaim from the cleaning byproducts is also included. In addition, one or more implementations described provide an automatable in-situ cleaning process that reduces metallic lithium fire and contamination risks which are otherwise likely while using traditional low-rate and low-efficiency aqueous solutions.

[0027] FIG. 1 illustrates a schematic diagram of a processing system 100 including an alkali-metal removal system 105 in accordance with one or more implementations of the present disclosure. The alkali-metal removal system 105 includes at least one of a cleaning precursor delivery system 110, a byproduct collection system 150, and an abatement system 170. The alkali-metal removal system 105 can be a portable alkali-metal removal system. Although shown as a component of the processing system 100, it should be understood that the processing system 100 is only an example, and the alkali-metal removal system 105 can be used with other systems which can benefit from vapor phase removal of alkali-metals. As shown in FIG. 1 , the processing system 100 includes an alkali-metal coating system 120 fluidly coupled with the cleaning precursor delivery system 110 and an exhaust system 130. The alkali-metal coating system 120 can be generally configured to perform an alkali-metal deposition process or other energy storage device manufacturing process. The process performed in the alkali-metal coating system 120 can be a physical vapor deposition (PVD) process. For example, the process performed in the alkali-metal coating system 120 can be a PVD process for depositing lithium metal on a flexible substrate.

[0028] The alkali-metal coating system 120 can be fluidly coupled with the byproduct collection system 150 and the abatement system 170 via a foreline 175. The foreline 175 serves as a conduit that routes gaseous effluent leaving the alkali- metal coating system 120 to the byproduct collection system 150 and the abatement system 170. The gaseous effluent may contain material, which is undesirable for release into the atmosphere or may damage downstream equipment, such as, for example, vacuum pumps. For example, the gaseous effluent may contain lithium hydroxide compounds from the alkali-metal removal process.

[0029] A pump 160, for example, a vacuum pump, can be positioned along the foreline 175. The pump 160 can be positioned downstream from the alkali-metal coating system 120 and upstream from the abatement system 170. In one or more implementations, as shown in FIG. 1 , the pump 160 is positioned downstream from the byproduct collection system 150 and upstream from the abatement system 170. The alkali-metal coating system 120 has a chamber exhaust port 122 coupled with the foreline 175. A throttle valve 140 can be positioned proximate the chamber exhaust port 122 for controlling the pressure inside the alkali-metal coating system 120. The foreline 175 includes one or more ports, for example, a sampling port through which gaseous effluent emitted by the alkali-metal coating system 120 can be sampled and monitored.

[0030] The processing system 100 further includes the cleaning precursor delivery system 110 for generating and supplying a cleaning gas include a vapor phase fluorinated alcohol, for example, vapor phase HFIB or vapor phase NTFB, to the alkali- metal coating system 120. In the implementation shown in FIG. 1 , the cleaning precursor delivery system 110 is positioned to provide vapor phase fluorinated alcohol to the alkali-metal coating system 120. The alkali-metal coating system 120 can be fluidly coupled with the alkali-metal coating system 120 via a cleaning precursor supply conduit 112. The cleaning precursor supply conduit 112 can be fluidly coupled with the alkali-metal coating system 120 through an adaptor port. The processing system 100 can further include an exhaust conduit 172 that can be connected to or fluidly coupled with, for example, a facility exhaust system 180. The exhaust system 130 can be connected to or fluidly coupled with the facility exhaust system 180 via the exhaust conduit 172.

[0031] The processing system 100 can further include a controller 190 employed to control operation of various components of the processing system 100. For example, the controller 190 can be electronically coupled with one or more of flow control devices and valves to monitor and control the flow of inert gases and the cleaning gas comprising the fluorinated alcohol from the cleaning precursor delivery system 110 to the alkali-metal coating system 120. The controller 190 may be connected (e.g., networked) to a personal computer or laptop, or to other machines in a Local Area Network (LAN), an intranet, an extranet, or the Internet. Further, while only a single controller 190 is illustrated, the term “controller” shall also be taken to include any collection of controllers that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies described herein. For example, any component of the processing system 100 can include a separate controller. The controller 190 can include a central processing unit (CPU) (not shown), memory (not shown), and support circuits for inputs and outputs (I / O) (not shown). The CPU may be one of any form of computer processors that are used in industrial settings for controlling various system functions, substrate movement, chamber processes, and control support hardware (e.g., sensors, motors, heaters, etc.), and monitor the processes performed in the system. The memory is connected to the CPU, and may be one or more of a readily available non-volatile memory, such as random access memory (RAM), flash memory, read only memory (ROM), or any other form of digital storage, local or remote. Software instructions and data can be coded and stored within the memory for instructing the CPU. The support circuits are also connected to the CPU for supporting the processor in a conventional manner. The support circuits may include cache, power supplies, clock circuits, input / output circuitry, subsystems, and the like. A program or a non-transitory computer readable medium has stored thereon instructions readable by the controller 190 to determine which tasks are performable by the components in the cleaning precursor delivery system 110. The program may be software readable by the controller 190 that includes code to perform tasks relating to the delivery of inert gas and the source gas comprising fluorinated alcohol to the alkali-metal coating system 120. The controller may contain instructions configured to perform the method 500 or portions of the method 500 shown in FIG. 5.

[0032] FIG. 2 illustrates a schematic diagram of the cleaning precursor delivery system 110 in accordance with one or more implementations of the present disclosure. As shown in FIG. 1 , the cleaning precursor delivery system 110 can be used with the processing system 100. The cleaning precursor delivery system 110 can be a gas panel. The cleaning precursor delivery system 110 can be used with other systems. The cleaning precursor delivery system 110 may contain a housing, for example, a housing 202. The housing 202 defines an interior region 204. The cleaning precursor delivery system 110 includes a source 210 for supplying a cleaning gas comprising fluorinated alcohol, an inert gas injection channel 216, a dilution system 220, a pump 240, and a controller 250.

[0033] The source 210 for supplying the cleaning gas comprising fluorinated alcohol can be positioned internal or external to the interior region 204 of the housing 202. In some implementations, where the source 210 is internal to the housing 202, the housing 202 includes a compartment for holding the source 210. The compartment can have one or more gas sensors 260 for detecting a leak in the compartment. In some implementations where the source 210 is external to the housing 202, the housing 202 includes an inlet (not shown) for fluidly coupling with the external gas source for supplying the cleaning gas comprising fluorinated alcohol. In one or more implementations, the source 210 for supplying the cleaning gas comprising fluorinated alcohol is a gas cylinder with a regulator. In one or more other implementations, the source for supplying the cleaning gas comprising fluorinated alcohol is an ampoule, which may be heated to form the cleaning gas comprising fluorinated alcohol.

[0034] In one or more implementations, which can be combined with other implementation, the source 210 includes one or more feed gases comprising fluorinated alcohol. The fluorinated alcohol can be a fluoroalkyl alcohol. The fluoroalkyl alcohol can be represented by the general formula (1 ) RfCH2OH, where Rf represents a pefluoroalkyl group having 1 to 10 carbon atoms, (2) RfRf’CHOH, where Rf and Rf represents a pefluoroalkyl group having 1 to 10 carbon atoms, (3) RfRf’Rf’COH, where Rf, Rf’, and Rf” represent a pefluoroalkyl group having 1 to 10 carbon atoms, or (4) RfRf’CFOH, where Rf and Rf” represent a pefluoroalkyl group having 1 to 10 carbon atoms. In one or more implementations, which can be combined with other implementations, the fluorinated alcohol is selected fromtrifluoroethanol (CF3CH2OH), pentafluoropropanol (CF3CF2CH2OH), hexafluoroisopropanol ((CF3)2CHOH), nonafluoro-tert-butyl alcohol ((CF3)3COH), 2,2,3,3,4,4,4-Heptafluoro-1 -butanol (CF3CF2CF2CH2OH), heptafluoropropan-2-ol ((CF3)2CFOH), Trifluoromethanol (CF3OH), Pentafluorophenol (C6F5OH), 1 ,1 ,2,2,3,3,3-heptafluoro-1 -Propanol (CF3CF2CF2OH), or a combination thereof. In particular implementations, the fluorinated alcohol is or includes hexafluoroisopropanol (HFIP).

[0035] In one or more implementations, which can be combined with other implementations, the source 210 includes one or more feed gases selected from fluoroalkyl alcohol, allyl alcohol (CH2CHCH2OH), propargyl alcohol (CHCCH2OH), trimethylsilanol ((CH3)3SiOH), trifluoroacetic acid (CF3COOH), acetic acid (CH3COOH), formic acid (HCOOH), amine compounds, or a combination thereof.

[0036] The cleaning precursor delivery system 110 further includes the inert gas injection channel 216. The inert gas injection channel 216 can be formed in and extend through the housing 202. The inert gas injection channel 216 is configured to deliver an inert gas to the cleaning precursor delivery system 110. The inert gas injection channel 216 can be fluidly coupled with an inert gas source 218. Although the inert gas source 218 is shown as external to the housing 202, it should be understood that in some implementations, the inert gas source 218 is positioned within the housing 202. In one example, the inert gas source 218 is a gas cylinder with a regulator. In another example, the inert gas source 218 is supplied by a facility source. The inert gas source 218 can provide a gas such as nitrogen (N2), argon (Ar), helium, neon, krypton, xenon, or a combination thereof. In one example, the inert gas source 218 supplies argon to the cleaning precursor delivery system 110. The inert gas can be delivered to the cleaning precursor delivery system 110 to dilute the cleaning gas comprising fluorinated alcohol. The inert gas can also be delivered to the cleaning precursor delivery system 110 as a purge gas to purge the cleaning precursor delivery system 110.

[0037] The cleaning precursor delivery system 110 further includes the dilution system 220. The dilution system 220 is configured for mixing the cleaning gas comprising fluorinated alcohol with the inert gas. In one example, the dilution system 220 is configured for mixing the fluorinated alcohol, for example, HFIP, with argon. Asshown in FIG. 2, the dilution system 220 can be disposed within the housing 202. The dilution system 220 includes a first flow control device 222 or first mass flow controller (MFC) for metering a targeted amount of inert gas to mix with the feed gas comprising fluorinated alcohol. The first flow control device 222 can be directly or indirectly connected to the inert gas injection channel 216. The first flow control device 222 can be any suitable active or passive flow control device, such as a fixed orifice, mass flow controller, needle valve or the like. The first flow control device 222 can be a mass flow controller. The first flow control device 222 can be a pressure control device, can simply incorporate a pressure control device or may regulate flow independent of pressure.

[0038] The cleaning precursor delivery system 110 can further include the pump 240. The pump 240 can be a vacuum pump. The pump 240 is positioned downstream from the dilution system 220. The pump 240 includes an inlet channel 242 for receiving the diluted fluorinated alcohol gas from the dilution system 220. In the implementation shown in FIG. 2, the inlet channel 242 of the pump 240 is fluidly coupled with the dilution system 220 via a conduit 236. The pump 240 further includes an outlet channel 244. The outlet channel 244 can include an adapter for connecting the outlet channel 244 to the alkali-metal coating system 120 via the cleaning precursor supply conduit 112. The pump 240 pulls the diluted fluorinated alcohol gas from the dilution system 220 and directs the diluted fluorinated alcohol gas to the alkali-metal coating system 120. The pump 240 can be an electrical pump or any other appropriate pump. The pump 240 can be positioned in the housing 202 as shown in FIG. 2 or can be positioned external to the housing 202.

[0039] In one or more other implementations where the pump 240 is not present, the flow of inert gas from the inert gas source 218 carries the cleaning gas comprising the fluorinated alcohol from the cleaning precursor delivery system 110 into the alkali- metal coating system 120.

[0040] The cleaning precursor delivery system 110 can further include a controller 250 employed to control operation of various components of the cleaning precursor delivery system 110. For example, the controller 250 can be electronically coupled with one or more of flow control devices and valves to monitor and control the flow ofinert gases and the source gas comprising fluorine. The controller 250 can be configured similarly to the controller 190.

[0041] A second flow control device 214 may be positioned along the source gas supply conduit 212 for metering a targeted amount of the feed gas comprising the fluorinated alcohol to mix with the inert gas. The second flow control device 214 can be a mass flow control (MFC) device. One or more valves may be positioned along the source gas supply conduit 212 between the source 210 and the dilution system 220. The second flow control device 214 may be any suitable active or passive flow control device, such as a fixed orifice, mass flow controller, needle valve or the like.

[0042] The inert gas injection channel 216 is fluidly coupled with the first flow control device 222 via an inert gas supply conduit 217 or second conduit. The inert gas supply conduit 217 is fluidly coupled with the source gas supply conduit 212 via a first purge conduit 219 or a third conduit. The first purge conduit 219 is operable to deliver the inert gas into the inert gas supply conduit 217 downstream from the source 210 and upstream of the second flow control device 214. A first valve 223 positioned at the intersection of the inert gas supply conduit 217 and the inert gas purge conduit controls the flow of inert gas from the inert gas supply conduit 217 to the source gas supply conduit 212. Inert gas delivered through the first purge conduit 219 can be used to as a purge gas to purge the cleaning precursor delivery system 110. A second valve 225 positioned along the inert gas supply conduit controls the flow of the inert gas into either the first flow control device 222 or a second purge conduit 227 or fourth conduit. The inert gas supply conduit 217 is fluidly coupled with the source gas supply conduit 212 via the second purge conduit 227. The second purge conduit 227 delivers inert gas into the source gas supply conduit 212 downstream from the second flow control device 214 and upstream of the dilution system 220.

[0043] FIG. 3 illustrates a schematic side view of a deposition system 300 that may be used with the processing system 100 in accordance with one or more implementations of the present disclosure. The deposition system 300 may be the alkali-metal coating system 120 depicted in FIG. 1. The deposition system 300 is configured for coating a flexible substrate 308 with a stack of thin layers at least one of which includes an alkali-metal layer, for example a lithium metal layer. The alkali- metal removal system 105 is configured to remove deposited alkali-metal from interiorsurfaces of the deposition system 300, from the flexible substrate 308, or from both the interior surfaces of the deposition system 300 and the flexible substrate 308.

[0044] The deposition system 300 can be a roll-to-roll system adapted for depositing coatings on web materials, for example, for depositing lithium metal containing film stacks on flexible substrates according to the implementations described herein. For example, the deposition system 300 can be used for depositing metals or metal alloys, for example, lithium metals or lithium metal alloys. Examples of metal and metal alloys include but are not limited to alkali-metals (e.g., lithium or sodium), selenium, magnesium, zinc, cadmium, aluminum, gallium, indium, thallium, tin, lead, antimony, bismuth, and tellurium, alkali earth metals, silver, or a combination thereof. These metals or metal alloys can be used for manufacturing energy storage devices, and particularly for film stacks for lithium-containing anode structures. The deposition system 300 includes a deposition chamber 302 that defines a processing environment 304 in which some or all of the processing actions for depositing coatings on web materials can be performed. In one implementation, the processing environment 304 is operable as a vacuum environment. In another implementation, the processing environment 304 is operable as an inert gas environment. In some examples, the processing environment 304 can be maintained at a process pressure of 1 x 10’3mbar or below, for example, 1 x 10’4mbar or below.

[0045] The deposition system 300 is constituted as a roll-to-roll system including an unwinding reel 306 for supplying the flexible substrate 308 or web, a coating drum 310 over which the flexible substrate 308 is processed, and a winding reel 312 for collecting the flexible substrate 308 after processing. The coating drum 310 includes a deposition surface 311 over which the flexible substrate 308 travels while material is deposited onto the flexible substrate 308. The deposition system 300 can further include one or more auxiliary transfer reels 314, 316 positioned between the unwinding reel 306, the coating drum 310, and the winding reel 312. In one or more implementations, which can be combined with other implementations, at least one of the one or more auxiliary transfer reels 314, 316, the unwinding reel 306, the coating drum 310, and the winding reel 312, can be driven and rotated by a motor. In one example, the motor is a stepper motor. Although the unwinding reel 306, the coating drum 310, and the winding reel 312 are shown as positioned in the processing environment 304, it should be understood that the unwinding reel 306 and the windingreel 312 can be positioned in separate chambers or modules, for example, at least one of the unwinding reel 306 can be positioned in an unwinding module, the coating drum 310 can be positioned in a processing module, and the winding reel 312 can be positioned in an unwinding module. The coating drum 310 is configured for guiding the flexible substrate 308 past one or more evaporation sources 340.

[0046] The unwinding reel 306, the coating drum 310, and the winding reel 312 can be individually temperature controlled. For example, the unwinding reel 306, the coating drum 310, and the winding reel 312 can be individually temperature controlled using an internal heating / cooling source positioned within each reel or an external heating / cooling source. In one or more implementations, which can be combined with other implementations, the coating drum 310 is fluidly coupled with a temperature control fluid supply 318 for supplying a temperature control fluid to the coating drum 310. The temperature of the flexible substrate 308 may be reduced during deposition, when the flexible substrate 308 is in direct thermal contact with the coating drum 310.

[0047] In one or more implementations, which can be combined with other implementations, the deposition system 300 includes the one or more evaporation sources 340. As shown in FIG. 3, the one or more deposition sources can be an evaporation source 340, for example, a thermal evaporator. The evaporation source 340 can be removably coupled with an evaporation shield. In another implementations, which can be combined with other implementations, the evaporation source 340 can be spaced apart from the coating drum 310. The evaporation source 340 is positioned to deliver evaporated material 322 onto the flexible substrate 308 as the flexible substrate 308 travels over the deposition surface 311 of the coating drum 310. In one example, the evaporated material 322 is evaporated lithium metal.

[0048] The evaporation source 340 is positioned to perform one or more processing operations to the flexible substrate 308 or web of material. In one example, as depicted in FIG. 3, the evaporation source 340 is radially disposed about the coating drum 310. In addition, arrangements other than radial are contemplated. In one implementation which can be combined with other implementations, the evaporation source 340 includes a lithium (Li) source. Further, the evaporation source 340 can also include a source of an alloy of two or more metals. The material to be deposited can be evaporated, for example, by thermal evaporation techniques.

[0049] In operation, the evaporation source 340 emits a plume of the evaporated material 322, which is drawn to the flexible substrate 308 where a film of deposited material is formed on the flexible substrate 308.

[0050] In addition, although one evaporation source 340 is shown in FIG. 3, it should be understood that any number of deposition sources can be used. In addition, the deposition system 300 can further include one or more additional deposition sources. For example, the one or more deposition sources as described herein include an electron beam source and additional sources, which can be selected from the group of CVD sources, PECVD sources, and various PVD sources. Exemplary PVD sources include sputtering sources, electron beam evaporation sources, and thermal evaporation sources. In addition, these additional deposition sources can be positioned radially relative to the deposition surface 311 of the coating drum 310.

[0051] In one or more implementations, which can be combined with other implementations, the deposition system 300 is configured to process both sides of the flexible substrate 308. For example, additional evaporation sources similar to the evaporation source 340 can be positioned to process the opposing side of the flexible substrate 308. Although the deposition system 300 is configured to process the flexible substrate 308, which is horizontally oriented, the deposition system 300 can be configured to process substrates positioned in different orientations, for example, the flexible substrate 308 can be vertically oriented. In one or more implementations, which can be combined with other implementations, the flexible substrate 308 is a flexible conductive substrate. In one or more implementations, which can be combined with other implementations, the flexible substrate 308 includes a conductive substrate with one or more layers formed thereon. In one or more implementations, which can be combined with other implementations, the conductive substrate is a copper substrate. In another implementations, which can be combined with other implementations, the flexible substrate is a polymer substrate, for example, a polyethylene terephthalate (PET) substrate.

[0052] The processing system 100 further includes the exhaust system 130. The deposition chamber 302 includes the chamber exhaust port 122 fluidly coupled with the foreline 175 of the exhaust system 130. The deposition system 300 further includes the cleaning precursor delivery system 110. The deposition system 300 mayinclude additional gas panels which are not shown for the sake of brevity. The deposition system 300 may further include a system controller 370 operable to control various aspects of the deposition system 300. For example, the system controller 370 can be electronically coupled with the evaporation source 340 to control the temperature of the evaporation source and to monitor and control the flow of gaseous effluent into the exhaust system 130. The system controller 370 can be configured similarly to the controller 190.

[0053] Before, during, or after deposition, unwanted parasitic metallic lithium deposits may form on the flexible substrate 308, interior surfaces of the deposition system 300, or on both the flexible substrate 308 and the interior surfaces, for example, parts of the evaporation source 340, the radiation shield and the edge mask of the deposition system 300. Parasitic metallic lithium deposits can cause vapor plume instability and can cause spatial and temporal drift of the evaporated material 322 which reduces roll-to-roll coating quality and yield on subsequently processed flexible substrates. The alkali-metal removal system 105 enables an in-situ lithium metal removal process that reduces fire, corrosion and contamination risks, which are otherwise likely while performing ex-situ cleaning using traditional low-efficiency aqueous solutions. The alkali-metal removal system 105 is configured to prepare a cleaning gas, for example, the cleaning gas including the vapor phase fluorinated alcohol, expose interior surfaces contaminated with parasitic lithium to the cleaning gas and remove parasitic metallic lithium deposits from the interior surfaces of the deposition system 300, collect reaction byproducts and unreacted the vapor phase fluorinated alcohol, and separate lithium compounds from reusable vapor phase fluorinated alcohol.

[0054] FIG. 4 illustrates a schematic side view of the exhaust system 130 in accordance with one or more implementations of the present disclosure. The exhaust system 130 includes the byproduct collection system 150 and the abatement system 170. The exhaust system 130 may further include the pump 160 positioned downstream from the byproduct collection system 150 and upstream from the abatement system 170. The exhaust system 130 may further include a separation system 410 positioned downstream from the byproduct collection system 150. The exhaust system 130 may further include a regeneration system 420 positioneddownstream from the byproduct collection system 150, for example, downstream of the separation system 410 (if present).

[0055] Referring to FIG. 4, during or after the cleaning process, gaseous effluent containing the cleaning byproduct, for example, Li-HFIP, and excess vapor phase fluorinated alcohol, for example, HFIP, exits the alkali-metal coating system 120 via the chamber exhaust port 122 and enters the foreline 175. The gaseous effluent enters the byproduct collection system 150.

[0056] The byproduct collection system 150 separates unused or excess vapor phase fluorinated alcohol, for example, excess HFIP, and reaction byproduct, for example, a lithium alcholate such as Li-HFIP, from the gaseous effluent stream. The byproduct collection system 150 may be or include a cold trap 152. The cold trap 152 condenses the reaction byproduct and the excess vapor phase fluorinated alcohol from the gaseous effluent stream. The cold trap 152 may be placed adjacent to the alkali-metal coating system 120 so that most of the excess vapor phase fluorinated alcohol condenses out in the cold trap 152 and not in the foreline 175. The reaction byproduct and the excess vapor phase fluorinated alcohol can be retrieved from the cold trap 152 and recycled / reused. After exiting the byproduct collection system 150, the remaining gaseous effluent travels through the foreline 175 via pump 160 into the abatement system 170. The remaining gaseous effluent may contain material, which is undesirable for release into the atmosphere. For example, the remaining gaseous effluent may contain additional fluorine-containing compounds from the cleaning process. In the abatement system 170, the remaining gaseous effluent reaction can be treated to remove additional undesirable material.

[0057] In one or more implementations, which can be combined with other implementations, the byproduct collection system 150 includes two or more containers. HFIP and LiHFIP can be collected in two or more containers by maintaining a temperature gradient in the successive containers, for example, gradually decreasing temperature in a series, inlet and outlet pressure of the container can be altered to achieve maximum byproduct collection without mixing the two components. Multiple containers can increase byproduct trapping efficiency and also provide primary level of separation between HFIP & LiHFIP due to differences in boiling and sublimation temperature respectively.

[0058] The exhaust system 130 may further include the separation system 410 for separating the excess vapor phase fluorinated alcohol from the reaction byproduct. The separation system 410 may include a distillation system 412, for example, a distillation column for separating the excess vapor phase fluorinated alcohol from the reaction byproduct. The excess vapor phase fluorinated alcohol may be collected and recycled / reused.

[0059] In one or more implementations, which can be combined with other implementations, the distillation system 412 includes two or more containers. The excess vapor phase fluorinated alcohol and the reaction byproduct can be collected in two or more containers by maintaining a temperature gradient in the successive containers, for example, gradually decreasing temperature in a series, inlet and outlet pressure of the container can be altered to achieve maximum byproduct collection without mixing the two components. Multiple containers can provide primary level of separation between the excess vapor phase fluorinated alcohol and the reaction byproduct due to differences in boiling and sublimation temperature respectively.

[0060] The exhaust system 130 may further include the regeneration system 420. The regeneration system 420 regenerates fluorinated alcohol from the reaction byproducts using an acid / base catalyzed process. In one or more implementations, which can be combined with other implementations, fluorinated alcohol can be regenerated from the reaction byproduct by chemically treating the reaction byproduct with an aqueous acidic solution to produce regenerated fluorinated alcohol. For example, Li-HFIP is treated with phosphoric acid to produce regenerated fluorinate alcohol. The regenerated fluorinated alcohol can be reused in subsequent cleaning processes. The regeneration system 420 can include a heat source 422 for heating the reaction mixture containing the reaction byproduct and the aqueous acidic solution and a condenser 424. The condenser 424 is fluidly coupled to a cooling fluid and configured to condense a gaseous product flowing through the regeneration system 420. The condenser 424 converts the regenerated fluorinated alcohol from the gas phase into the liquid phase.

[0061] FIG. 5 illustrates a flow chart of a method 500 for removing parasitic alkali- metal in accordance with one or more implementations of the present disclosure. Although the systems disclosed in FIGS. 1 -4 are described in relation to the method500, it will be appreciated that the systems disclosed in FIGS. 1 -4 are not limited to the method 500, but instead may stand alone independent of the method 500. Similarly, although the method 500 is described in relation to the systems disclosed in FIGS. 1-4, it will be appreciated that the method 500 is not limited to the systems disclosed in FIGS. 1 -4, but instead may be performed using other systems.

[0062] At operation 502, a lithium metal-containing layer is formed over a flexible substrate disposed in a deposition chamber. The deposition chamber may be the deposition chamber 302. Deposition of the lithium metal-containing layer may be by PVD processes, such as evaporation, a sputtering process, a slot-die process, a transfer process, for example, a substrate independent direct transfer (SIDT) process or a laser lift-off (LLO) process, or a three-dimensional lithium printing process. The chamber for depositing the thin film of lithium metal may include a PVD system, such as an electron-beam evaporator, a thermal evaporator, or a sputtering system, a thin film transfer system (including large area pattern printing systems such as gravure printing systems) or a slot-die deposition system. During deposition of the lithium metal-containing layer over the flexible substrate, the lithium metal may be deposited over interior surfaces including the chamber components, for example, the deposition source, radiation shields, edge masks, coating drum, calendering drum, and chamber sidewalls. In one or more implementations which can be combined with other implementations, the lithium metal-containing layer is formed over the flexible substrate 308 by evaporated lithium from the evaporation source 340 in the processing environment 304.

[0063] At operation 504, the processed flexible substrate is transferred out of the processing environment of the depositions chamber. In one or more implementations which can be combined with other implementations, the flexible substrate remains in the processing environment during the parasitic alkali-metal removal process.

[0064] Optionally, after depositing the lithium-metal containing layer, the processing environment 304 of the deposition chamber 302 may be purged. For example, any remaining process gases and byproducts, which are in a gaseous state, are purged out of the deposition chamber. The deposition chamber may be actively purged by flowing a purge gas into the processing environment 304. Any suitable purge gas, for example, an inert gas, may be used. Alternatively, or in addition topurging, other gases for deposition or etching may be delivered from the cleaning precursor delivery system 110 to neutralize, remove or condition the deposition chamber 302. Alternatively, or in addition to introducing the purge gas, the deposition chamber may be depressurized in order to remove any residual processing gas as well as any byproducts from the processing environment 304. The deposition chamber may be purged by evacuating the processing environment 304 of the deposition chamber 302. The time-period of purge gas flow should be generally long enough to remove volatile products from the processing environment 304 of the deposition chamber 302. In one or more implementations, which can be combined with other implementations, an argon purge gas is delivered from the cleaning precursor delivery system 110 to the processing environment 304 and vented from the processing environment 304 via the chamber exhaust port 122 and the foreline 175 to the exhaust system 130, which includes the abatement system 170.

[0065] At operation 508, the temperature of the components in the deposition chamber 302 can be adjusted. The temperature of the components may be increased, decreased or maintained relative to the temperature of the components during the deposition process of operation 502. In addition, the pressure within the processing environment 304 may be adjusted. The pressure within the processing environment 304 may be increased, decreased, or maintained relative to the pressure in the processing environment 304 during the deposition process of operation 502. In one or more implementations, which can be combined with other implementations, the pressure is adjusted to a range from about 10 Torr to about 200 Torr. In order to maintain the cleaning gas in vapor phase, the components of the deposition chamber 302 may be increased, decreased, or maintained to a temperature of 50 degrees Celsius or greater. One or more components of the deposition chamber 302 may be increased, decreased, or maintained to a temperature at or above the boiling point of the fluorinated alcohol in the cleaning gas. For example, one or more components such as the coating drum 310 and the evaporation source 340 are cooled. The coating drum 310 may be cooled using temperature control fluid from the temperature control fluid supply 318. The operation 508 may be performed subsequent to the operation 502 and either prior to, simultaneously, or sequentially relative to the operation 504. In one or more implementations which can be combined with other implementations, where the cleaning gas includes HFIP, at least one of the coating drum 310 and theevaporation source 340 are adjusted to a temperature of 50 degrees Celsius or more, for example, in a range from about 80 degrees Celsius to about 150 degrees Celsius.

[0066] At operation 510, cleaning gas including fluorinated alcohol is delivered to the processing region of the deposition chamber. For example, the cleaning gas including fluorinated alcohol is delivered from the from the cleaning precursor delivery system 110 to the processing environment 304. In one or more implementations, which can be combined with other implementations, the cleaning gas includes an inert gas and fluorinated alcohol. For example, the cleaning gas comprises, consists of, or consists essentially of argon and HFIP. The cleaning gas may be pressurized using a push gas, for example, argon. The pressurized cleaning gas is then delivered to the processing region where the component, for example, the evaporator is exposed to the cleaning gas.

[0067] The fluorinated alcohol can be a fluoroalkyl alcohol suitable for removal of alkali-metals, for example, lithium.

[0068] The fluoroalkyl alcohol can be represented by the general formula (1 ) RfCH2OH, where Rf represents a pefluoroalkyl group having 1 to 10 carbon atoms, (2) RfRf’CHOH, where Rf and Rf’ represents a pefluoroalkyl group having 1 to 10 carbon atoms, (3) RfRf’Rf’COH, where Rf, Rf’, and Rf” represent a pefluoroalkyl group having 1 to 10 carbon atoms, or (4) RfRf’CFOH, where Rf and Rf” represent a pefluoroalkyl group having 1 to 10 carbon atoms. In one or more implementations, which can be combined with other implementations, the fluorinated alcohol is selected from trifluoroethanol (CF3CH2OH), pentafluoropropanol (CF3CF2CH2OH), hexafluoroisopropanol ((CF3)2CHOH), nonafluoro-tert-butyl alcohol ((CF3)3COH), 2,2,3,3,4,4,4-Heptafluoro-1 -butanol (CF3CF2CF2CH2OH), heptafluoropropan-2-ol ((CF3)2CFOH), Trifluoromethanol (CF3OH), Pentafluorophenol (C6F5OH), 1 ,1 ,2,2,3,3,3-heptafluoro-1 -Propanol (CF3CF2CF2OH), or a combination thereof. In particular implementations, the fluorinated alcohol is or includes hexafluoroisopropanol (HFIP).

[0069] In one or more implementations, which can be combined with other implementations, the cleaning gas includes one or more feed gases selected from fluoroalkyl alcohol, allyl alcohol (CH2CHCH2OH), propargyl alcohol (CHCCH2OH),trimethylsilanol ((CH3)3SiOH), trifluoroacetic acid (CF3COOH), acetic acid (CH3C00H), formic acid (HCOOH), amine compounds, or a combination thereof.

[0070] In some implementations, where the cleaning gas includes HFIP, lithium metal is removed according to the following reaction (I):Li(s) + HFIP (g) Li-HFIP (g) + Excess HFIP (g) + 0.5 H2(g) (I)

[0071] Parasitic lithium metal is converted to gaseous Li-HFIP via reaction (I).

[0072] At operation 512, the chamber components positioned in the processing region are exposed to the cleaning gas for a time period during which the parasitic lithium metal is converted to a gas. In one or more implementations, which can be combined with other implementations, where the cleaning gas includes HFIP, the parasitic lithium metal is reduced to Li-HFIP as shown in reaction (I). The fluorinated alcohol in the cleaning gas reacts with the parasitic alkali-metal on the component parts. The component is exposed to or “soaked” in the cleaning gas for a suitable time period to remove a targeted amount of the parasitic alkali-metal from the component. For example, parasitic lithium metal disposed on the chamber component reacts with the fluorinated alcohol in the cleaning gas to form a reaction byproduct, for example, Li-HFIP, which is removed from the processing environment 304 in gaseous form. In one or more implementations, which can be combined with other implementations, pressure within the processing environment 304 can be cycled during operation 512.

[0073] The soaking process of operation 512 may be performed for any suitable time period. The endpoint of the soaking process may be detected by a cleaning endpoint detection system 380 positioned in the processing environment 304. In one or more implementations, the soak process of operation 512 is performed for a time period that is suitable for removing a targeted amount of parasitic lithium metal from the chamber component.

[0074] At operation 514, after removing the parasitic lithium metal from the chamber, gaseous effluent including gaseous reaction byproducts are removed from the processing environment 304 and delivered to the exhaust system 130 for byproduct removal and abatement. In one or more implementations, which can becombined with other implementations, the processing environment 304 of the deposition chamber 302 is purged to remove any gaseous effluent including byproducts from the processing environment 304. The byproducts, which are in a gaseous state, are purged out of the processing environment 304 of the deposition chamber 302. For example, in some implementations where the cleaning gas includes fluorinated alcohol, the byproducts may include lithium alcoholate, for example, an alkali-metal-fluorinated alcohol, and excess fluorinated alcohol. The deposition chamber 302 may be actively purged by flowing a purge gas into the processing environment 304. Any suitable purge gas, for example, an inert gas, may be used. Alternatively, or in addition to introducing the purge gas, the deposition chamber 302 may be depressurized in order to remove any residual processing gas as well as any byproducts from the deposition chamber 302. The deposition chamber 302 may be purged by evacuating the processing environment 304. The time-period of the purge process should be long enough to remove the volatile products from the processing environment 304. The time-period of purge gas flow should be generally long enough to remove the volatile products from the processing environment 304 of the deposition chamber 302. In one or more implementations which can be combined with other implementations, an argon purge gas is delivered from the cleaning precursor delivery system 110 to the processing environment 304 and removed with any gaseous effluent including byproducts from the processing environment 304 via the chamber exhaust port 122 and the foreline 175. The foreline 175 serves as a conduit that routes gaseous effluent leaving the deposition chamber 302 to the exhaust system 130 where the byproducts are removed from the gaseous effluent using, for example, the exhaust system 130 depicted in FIG. 4 and abatement takes place.

[0075] The gaseous effluent may be processed in the exhaust system 130 as described in relate to FIG. 4. Excess fluorinated alcohol and the gaseous reaction byproduct may be separated from the gaseous effluent stream using a byproduct collection system, for example, the byproduct collection system 150. The fluorinated alcohol can be separated from the gaseous reaction byproduct via a distillation process performed in a separation system, for example, the separation system 410. Fluorinated alcohol can be regenerated from the gaseous reaction byproduct by chemically treating the gaseous reaction byproduct with an aqueous acidic solution toproduce regenerated fluorinated alcohol in a regeneration system, for example, the regeneration system 420.

[0076] At operation 516, a pump-purge process can be performed. The pumppurge process may be performed on any components, gas lines, and valves used during the method 500. The pump-purge may include pumping down the appropriate conduits, valves, and other fittings one or more times with a high, medium, or rough vacuum source depending on the leaching solution and byproducts produced during the parasitic lithium removal process. Between pump-downs, the lines and valves may be purged with a gas, such as an inert gas. In some cases a liquid purge of conduits and valves may be performed to more efficiently remove unwanted and toxic residues present therein, particularly solid residues or residues with a very low vapor pressure.

[0077] The previously described implementations of the present disclosure have many advantages, including the following. The efficient in-situ vapor phase removal of parasitic lithium metal from chamber components of a lithium metal deposition system. Traditional removal of parasitic lithium metal included manual removal of lithium metal which was performed by opening the chamber and exposing the chamber components to cleaning chemicals. Manual removal of lithium metal exposed workers not only to toxic chemicals but also to lithium metal fires. The in-situ vapor phase removal of parasitic lithium described is not only more efficient than traditional manual removal of parasitic lithium metal deposits but is also much safer than known manual processes. The in-situ vapor phase removal of parasitic lithium described also reduces turnaround duration, which in turn improves the cost of ownership of the tool. In addition, system described provides for vapor phase removal of parasitic lithium and downstream facile economical reclaim of metallic lithium from reusable lithium deposition process kit parts. For example, the system and method described include collecting lithium and fluorinated alcohol reaction byproducts and unreacted fluorinated alcohols and separating lithium compounds from the reusable fluorinated alcohols. Further, the in-situ vapor phase cleaning process can be performed under vacuum to improve process throughput and reduce chamber downtime. The in-situ vapor phase cleaning process can be automated and performed inside an enclosed chamber to reduce human exposure in comparison to previous approaches. The in-situ vapor phase cleaning process uses mild organicsolvent, which will not damage the chamber parts. The fluorinated alcohols described can also remove passivated lithium compound from chamber surfaces unlike other vapor phase etchants. The previously described implementations of the present disclosure have many advantages, including those previously described. However, the present disclosure does not necessitate that all the advantageous features and all the advantages need to be incorporated into every implementation of the present disclosure.

[0078] In the Summary and in the Detailed Description, and the Claims, and in the accompanying drawings, reference is made to particular features (including method operations) of the present disclosure. It is to be understood that the disclosure in this specification includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect, implementation, implementation, or example of the present disclosure, or a particular claim, that feature can also be used, to the extent possible in combination with and / or in the context of other particular aspects and implementations of the present disclosure, and in the present disclosure generally.

[0079] Implementations and all of the functional operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed in this specification and structural equivalents thereof, or in combinations of them. Implementations described herein can be implemented as one or more non-transitory computer program products, i.e. , one or more computer programs tangibly embodied in a machine readable storage device, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple processors or computers.

[0080] The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0081] The term “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer.

[0082] Computer readable media suitable for storing computer program instructions and data include all forms of nonvolatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0083] The term “comprises” and grammatical equivalents thereof are used herein to mean that other components, ingredients, operations, etc. are optionally present. For example, an article “comprising” (or “which comprises”) components A, B, and C can consist of (i.e., contain only) components A, B, and C, or can contain not only components A, B, and C but also one or more other components. In addition, whenever a composition, an element or a group of elements is preceded with the transitional phrase “comprising” or grammatical equivalents thereof, it is understood that it is contemplated that the same composition or group of elements may be preceded with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

[0084] Where reference is made herein to a method comprising two or more defined operations, the defined operations can be carried out in any order or simultaneously (except where the context excludes that possibility), and the method can include one or more other operations which are carried out before any of thedefined operations, between two of the defined operations, or after all of the defined operations (except where the context excludes that possibility).

[0085] When introducing elements of the present disclosure or exemplary aspects or implementation(s) thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements.

[0086] The terms “comprising,” “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0087] While the foregoing is directed to implementations of the present disclosure, other and further implementations of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

What is claimed is:1 . A method of in-situ removal of parasitic alkali-metal from a deposition chamber component, comprising: delivering a cleaning gas comprising fluorinated alcohol to a processing environment of a deposition chamber, the processing environment comprising one or more chamber components at least partially coated with alkali-metal; exposing the one or more chamber components to the cleaning gas for a time period during which the alkali-metal reacts with the fluorinated alcohol to form a gaseous reaction byproduct; and removing the gaseous reaction byproduct from the processing environment.

2. The method of claim 1 , wherein the fluorinated alcohol has the formula RfRf’CHOH, wherein Rf and Rf’ represents a pefluoroalkyl group having 1 to 10 carbon atoms.

3. The method of claim 1 , wherein the fluorinated alcohol has the formula RfRf’Rf’COH, where Rf, Rf’, and Rf” represent a pefluoroalkyl group having 1 to 10 carbon atoms.

4. The method of claim 1 , wherein the fluorinated alcohol is selected from hexafluoroisopropanol, nonafluoro-tert-butyl alcohol, or a combination thereof.

5. The method of claim 1 , wherein the one or more chamber components comprise at least one of a coating drum and a deposition source.

6. The method of claim 1 , wherein the one or more chamber components comprise a thermal evaporator.

7. The method of claim 1 , wherein the gaseous reaction byproduct comprises lithium alcoholate and excess fluorinated alcohol.

8. The method of claim 7, further comprising separating the lithium alcoholate from the excess fluorinated alcohol via a distillation process.

9. The method of claim 8, further comprising regenerating fluorinated alcohol from the lithium alcoholate by treating the lithium alcoholate with phosphoric acid.

10. The method of claim 1 , wherein removing the gaseous reaction byproduct from the processing environment comprises purging the processing environment of the deposition chamber to remove to remove the gaseous reaction byproduct.

11. A deposition system for coating a flexible substrate with a stack of layers, at least one of which includes alkali-metal, the deposition system comprising: a deposition chamber that defines a processing environment; one or more chamber components positioned in the processing environment, the one or more chamber components, comprising: a drum positioned in the processing environment over which a flexible substrate is processed; and a deposition source positioned in the processing environment for depositing lithium metal over the flexible substrate; a cleaning precursor delivery system fluidly coupled with the processing environment, comprising: a source for supplying a cleaning gas comprising a fluorinated alcohol; a system controller configured to cause the deposition system to perform a process, comprising: delivering the cleaning gas to the processing environment, the one or more chamber components at least partially coated with alkali-metal; exposing the one or more chamber components to the cleaning gas for a time period during which the alkali-metal reacts with the fluorinated alcohol to form a gaseous reaction byproduct; and removing the gaseous reaction byproduct from the processing environment.

12. The deposition system of claim 11 , wherein the fluorinated alcohol has the formula RfRf’CHOH, wherein Rf and Rf’ represents a pefluoroalkyl group having 1 to 10 carbon atoms.

13. The deposition system of claim 11 , wherein the fluorinated alcohol has the formula RfRf’ Rf’COH, where Rf, Rf’, and Rf” represent a pefluoroalkyl group having 1 to 10 carbon atoms.

14. The deposition system of claim 11 , wherein the fluorinated alcohol is selected from hexafluoroisopropanol, nonafluoro-tert-butyl alcohol, or a combination thereof.

15. The deposition system of claim 11 , wherein the drum is a coating drum or a calendering drum.

16. The deposition system of claim 11 , wherein the deposition source is a thermal evaporator.

17. The deposition system of claim 11 , wherein the deposition chamber is a vacuum-assisted deposition chamber.

18. A deposition system for coating a flexible substrate with a stack of layers, at least one of which includes alkali-metal, the deposition system comprising: a deposition chamber that defines a processing environment; one or more chamber components positioned in the processing environment, the one or more chamber components, comprising: a drum positioned in the processing environment over which a flexible substrate is processed; and a deposition source positioned in the processing environment for depositing lithium metal over the flexible substrate; a cleaning precursor delivery system fluidly coupled with the processing environment, comprising: a source for supplying a cleaning gas comprising a fluorinated alcohol; a chamber foreline fluidly coupled with the processing environment, the chamber foreline positioned to route gaseous effluent leaving the deposition system; an exhaust system fluidly coupled with the processing environment via the chamber foreline, the exhaust system, comprising: a byproduct collection system;a distillation system positioned downstream from the byproduct collection system; and a regeneration system positioned downstream from the distillation system; and a system controller configured to cause the deposition system to perform a process, comprising: delivering the cleaning gas comprising fluorinated alcohol to the processing environment, the processing environment comprising the one or more chamber components at least partially coated with alkali-metal; exposing the one or more chamber components to the cleaning gas for a time period during which the alkali-metal reacts with the fluorinated alcohol to form a gaseous effluent stream comprising a gaseous reaction byproduct; and removing the gaseous effluent stream from the processing environment via the exhaust system.

19. The deposition system of claim 18, wherein the fluorinated alcohol is selected from hexafluoroisopropanol, nonafluoro-tert-butyl alcohol, or a combination thereof.

20. The deposition system of claim 18, wherein the byproduct collection system separates excess fluorinated alcohol and the gaseous reaction byproduct from the gaseous effluent stream; the distillation system separates the fluorinated alcohol from the gaseous reaction byproduct; and the regeneration system regenerates fluorinated alcohol from the gaseous reaction byproduct by chemically treating the gaseous reaction byproduct with an aqueous acidic solution to produce regenerated fluorinated alcohol.

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