Abstract:
This disclosure describes a module web coating system and components thereof including a more uniform atmospheric control pumping mechanism and gas curtain separation system. A modular web coating system may include an unwind module, any number of process modules, and a rewind module. The process modules are interchangeable and independently operable. In addition, this disclosure describes a more uniform pumping system in which process gas is removed from multiple locations or slits spaced around a process chamber and, in an example, around a process device such as a deposition source. The gas curtain system utilizes a zone between process chambers into which separation gas is injected. Gas from the chambers is continuously removed thereby operating the chambers under negative pressure and preventing process gas from one chamber bleeding into an adjacent chamber.

Description:
This application is a National Stage Application of PCT/US2012/067052, filed 29 Nov. 2012, which claims priority to U.S. Provisional Patent Application No. 61/564,728, filed Nov. 29, 2011 and U.S. Provisional Patent Application No. 61/635,748, filed Apr. 19, 2012, the disclosures of which are hereby incorporated by reference herein in their entireties. To the extent appropriate, a claim of priority is made to each of the above disclosed applications. 
    
    
     INTRODUCTION 
     Thin film materials are used in a variety of different applications. In some applications, thin film materials are deposited onto flexible substrates, such as polymeric or metallic substrates, referred to herein as the substrate or “web.” For example, in some solar applications, photovoltaic materials are deposited onto flexible substrates for use on rooftops, in mobile solar devices, and other applications. In addition to photovoltaics, other thin films are deposited onto flexible substrates for use in batteries, electrochromics, and other flexible electronics. Thin film materials are used in a variety of applications such as photovoltaic cells or semiconductor fabrication. 
     Current systems and processes for depositing thin film lack modularity. This lack of modularity causes certain process problems. For example, in certain applications there is a need to deposit on both sides of the web substrate. Current systems require multistep batch processing to deposit thin films on both sides of a web. Typically, one side of the web substrate is processed first. The web substrate is then removed from the system and reoriented such that the opposite side can then be processed. This step not only takes time, but the web must be removed from the system. This may cause exposure to air. Such actions may cause a variety of deleterious results including oxidation of the web. This may result in the finished product having different material properties than intended. 
     Current systems and processes for depositing thin film also lack the ability to optimize process conditions. Temperature is one of these process conditions. Current systems and processes may need to control temperature when depositing thin film materials onto a flexible substrate. These systems and methods may use a drum or a free span deposition chamber to deposit the thin film materials. When using a drum, the temperature of the drum may not be hot or cold enough to effectively heat or cool the flexible substrate. When using a free span deposition chamber, precise temperature control is a problem. 
     Additionally, current systems and methods fail to adequately control gas pressure and flow in process chambers. Certain applications require pressure control. Current systems may have a single pump for gas delivery and evacuation. These pumping schemes, and others like them, cause non-optimal pressure and flow rate differential within the system. For example, horizontal and vertical pressure may be unbalanced because of current pumping schemes. 
     Moreover, some multiple chamber processes fail to adequately regulate gas mixing. Specific partial pressures of gaseous mixtures may be necessary for certain applications. Current multiple chamber processes may disturb the homogeneity of these partial pressures within a system. This effect is exacerbated when an individual chamber requires a different gaseous mixture than other chambers. 
     It is with respect to these and other considerations that embodiments have been made. Also, although relatively specific problems have been discussed, it should be understood that the embodiments should not be limited to solving the specific problems identified in the background. 
     Multi-Zone Modular Coater 
     This disclosure describes a module web coating system and components thereof including a more uniform atmospheric control pumping mechanism and gas curtain separation system. A modular web coating system may include an unwind module, any number of process modules, and a rewind module. The process modules are interchangeable and independently operable. In addition, this disclosure describes a more uniform pumping system in which process gas is removed from multiple locations or slits spaced around a process chamber and, in an example, around a process device such as a sputtering cathode or similar deposition source. The gas curtain system utilizes a zone between process chambers into which separation gas is injected. Gas from the chambers is continuously removed. This operates the chambers under negative pressure and prevents the process gas of one chamber, potentially containing trace airborne materials, from bleeding into and contaminating an adjacent chamber. 
     In one aspect, the present disclosure describes a multi-zone modular coating system that includes two or more independently controllable modules mechanically coupled together, wherein one of the two or more modules is one of: an unwind module, a rewind module, a deposition module, a thermal evaporation module, or a differential pumped isolation module. One or more of the modules may include a camel hump and/or a radiant roller, as described further below. One or more of the modules may be further provided with an open slit chamber wall and an integrated linear inter-cell and background pumping configuration. The system may further include a multiple chamber module having at least a first web processing chamber and a second web processing chamber, in which each web processing chamber including a process gas transport system through which process gas is removed from or injected into the chamber. The system may also include a multiple-chamber gas curtain separation system configured to pump curtain gas into a zone between and in fluid communication with the first chamber and the second chamber, wherein the gas curtain separation system, if necessary, removes mixed process and curtain gas from the zone and maintains the pressure of process gas in the zone at a level lower or higher than process gas pressures in the first and second chambers, thereby preventing transport of process gas between the first chamber and the second chamber. 
     In another aspect, the disclosure describes a gas curtain system for use with a coater that includes a drum for moving a web; at least a first web processing chamber and a second web processing chamber, each web processing chamber adjacent to the drum and adapted to perform a process on a surface of the web, each web processing chamber including a process gas transport system through which a flow of process gas is injected into the chamber; an interstitial space between and in fluid communication with the first and second web processing chambers; one or more curtain gas injection ports through which a flow of curtain gas is injected directly into the interstitial space; and a gas removal system that removes the curtain gas injected into the interstitial space and at least a portion of the process gases injected into the first and second web processing chambers. The gas curtain system may further include a curtain gas injection system that injects the curtain gas into the interstitial space through the curtain gas injection ports and a control system that monitors the pressures in the interstitial space and the first and second web processing chambers and controls the operation of one or more of the gas removal system, in which the curtain gas injection system and the process gas transport system. In an embodiment of the gas curtain system the control system controls the flow of at least one of the curtain gas and the process gases to maintain a pressure in the interstitial space below process gas pressures in the first and second web processing chambers. The curtain gas, the process gas injected into the first web processing chamber, and the process gas injected into the second web processing chamber may be the same or different gases. In the gas curtain system, the first web processing chamber may include at least one cathode body and a plurality of linear openings adjacent to and spaced about the cathode body and the process gas flow injected into the first web processing chamber may be at least partially injected through the linear openings so that the process gas flow is distributed around the cathode body. The linear openings may be integrated into the cathode body. A process gas transport chamber may be provided that is in fluid connection with the plurality of linear openings and a pumping system that pumps process gas into the process gas transport chamber, thereby injecting process gas into the first web processing chamber through the plurality of linear openings, may be used. 
     In yet another aspect, this disclosure describes a drum coater system for processing a web. The drum coater system includes a rotatable drum having an exterior drum surface adapted to engage a web; a camel hump adjacent to the rotatable drum, the camel hump being a non-moving body having a drum-facing surface adjacent to the exterior drum surface and a web contact surface spaced facing away from the exterior drum surface adapted so that a web on the rotating drum travels across the web contact surface during drum rotation. In the drum coater system, the temperature of the rotatable drum and the camel hump are independently controlled. In the drum coater system the camel hump and the drum may each include one or more of a resistive heating element, a thermal fluid transfer element, and a conductive transfer element. At least a portion of the camel hump may be made of an insulating material and wherein the insulating material is located adjacent to the exterior drum surface to insulate the web contact surface of the camel hump from the exterior drum surface. The drum coater system may include multiple camel humps and a control system configured to independently control the temperature of each web contact surface of each of the plurality of camel humps. Each of the camel humps may be in a different web processing chamber performing a different web processing operation at least partially affected by the temperature the web contact surface of the camel hump. The distance between the camel hump and the exterior drum surface may be fixed and the shape of the drum-facing surface is complementary to the curvature of the exterior drum surface so that the distance between the drum-facing surface and the exterior drum surface does not vary. 
     These and various other features as well as advantages which characterize the systems and methods described herein will be apparent from a reading of the following detailed description and a review of the associated drawings. Additional features are set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the technology. The benefits and features of the technology will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments are described with reference to the following figures: 
         FIG. 1A  illustrates an embodiment of a Flexible Integrated Modular Coater Deposition System. 
         FIG. 1B  illustrates an alternative embodiment of a Flexible Integrated Modular Coater Deposition System. 
         FIG. 2  illustrates an embodiment of a multiple-chamber deposition module with a camel hump. 
         FIG. 3  illustrates an embodiment of elements of a free span chamber. 
         FIG. 4  illustrates an embodiment of elements of a radiant roller chamber. 
         FIG. 5  illustrates an embodiment of a pumping scheme. 
         FIG. 6A  illustrates an embodiment of an open slit chamber wall of a module. 
         FIG. 6B  illustrates an alternative embodiment of an open slit chamber wall of a module. 
         FIG. 7  illustrates an integrated linear inter-cell and background pumping configuration. 
         FIG. 8  illustrates an embodiment of a multiple-chamber gas curtain separation system. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments are described more fully below with reference to the accompanying drawings and attached documents, which form a part hereof, and which show specific exemplary embodiments. However, embodiments may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the embodiments to those skilled in the art. Embodiments may be practiced as methods, systems or devices. The following detailed description is, therefore, not to be taken in a limiting sense. 
     Embodiments are directed to a Flexible Integrated Modular Coater Deposition System (hereinafter the “System”). The System may be designed to apply coatings to one or both sides of a web in a single process. The embodiments of the System described herein increase material through-put while reducing downtime associated with roll change-out, target and roller replacement, routine debris removal, and system maintenance. Further, the System may be designed to facilitate control of temperature, flow rates, partial pressures, and gas separation of one or more process chambers and modules in a variety of deposition systems including but not limited to an integrated drum roll-to-roll coating system. 
     One embodiment of the System may be seen in  FIG. 1A . The System  100 A is an example of a modular design comprised of an unwind module  102 A, a web  104 A, a back-side deposition module  106 A, a front-side deposition module  108 A, and a rewind module  110 A. The four modules are shown separated for illustration purposes. In a standard embodiment, however, the modules may be connected so that the web is not exposed to the external environment as it passes through the different environments of each module. 
     In embodiments, the System  100 A may have processes and equipment to pressurize modules and chambers to the appropriate pressure. The pressure in each module may be controlled independently of the pressure in other modules. Additionally, each module may have various chambers within the module. These chambers may each be pressurized to a particular set point, and the pressure in one chamber may be independently controlled, or the pressure and temperature of the module may be maintained as a single unit. Furthermore, the pressure within each module or chamber may vary over time depending on the process requirements. Pressurizing the system may include evacuating the system, or it may include increasing the pressure in the system. Additionally, the temperature of each module or chamber within each module may be controlled. This may occur prior to, during, or after the pressurizing of each module or chamber. 
     One skilled in the art would appreciate that it may be desirous to create low pressure conditions within a module and within chambers of a module. This may be facilitated by using certain hardware components in combination with vacuum pump piping. For example, chamber and module walls may be fabricated from 304 or 304L stainless steel. For connections to external components and between modules, O-rings may be used such as BUNA-N, Viton or other materials as necessary for the desired applications. In embodiments, individual leaks in the System are preferably kept below 5×10 −9  sccm/sec. 
     In embodiments, a vacuum pumping system may be designed for attaining a low pressure environment. Pump piping may be welded 304 or 316L stainless steel or any other suitable material. A roughing pump may be employed at early stages to achieve very low pressures within the system. A variable speed control pump may be used. Other pump types may be used. Working pressure may be controlled by adjusting the exhaust. Working pressure may also be controlled by adjusting the pumping rate. Vacuum pump piping may use various types of flanges in order to facilitate rapid removal of the flanges. These flanges may be KF ISO style flanges. Less frequently removed flanges may be conflate style flanges. 
     Additionally, the System  100 A may incorporate features to allow for maintenance and cleaning. Module and chamber facets may use removable plates to provide access to the interior of the modules or to remove components from the module. This may allow for major maintenance or modification. 
     Further, the chamber may have the ability to be heated or cooled during the processing. The chamber walls, flanges, doors, and deposition shielding may be temperature controlled. This may use a fluid heat exchanger. The fluid heater-cooler unit may use a water glycol blend. 
     Process gas may be distributed to the module or to individual chambers within a module. In embodiments, incoming process gas pressure may be regulated to 20 and 40 psig. Other pressure set points may be used. Pressures may be controlled using an automated PID exhaust conductance controller and mass flow controllers. In an example embodiment, control of pressure within a chamber or module may be controlled to within 0.1 torr of an absolute pressure set within the range of 2.0 to 50.0 torr. Control of process gas flow to a chamber or module may be controlled to within 0.1 sccm within a range of 0 to 200 sccm. In an embodiment, distribution systems may use Cajon VCR or similar type fittings to reduce leakage gas. 
     The System  100 A may cause translation of the web  104 A from the unwind module  102 A to the rewind module  110 A in a continuous motion. In this process the web  104 A may pass through the back-side deposition module  106 A and the front-side deposition module  108 A. This may continue until a substantial amount of one or both sides of the web  102 A are coated. The web system may be stopped. The deposition zones  106 A and  108 A may be cooled. The System  100 A may be vented, and the coated web  104 A may be removed from a rewind spindle  112 A. In the web path there may be multiple idler rollers, sensors and load cells that keep the web aligned and tracking in a defined lateral space thru the multiple deposition chambers and modules. 
     Though System  100 A depicts only four modules, other embodiments may have as little as one module. Still other embodiments may have greater than four modules. Further, other types of modules such as thermal evaporation modules, differential pumped isolation modules, in-situ coating diagnostic modules, in situ-process metrology module, thermal annealing modules free-span deposition modules, and temperature controlled drum deposition modules may be used in embodiments of the System. An individual module may have a single chamber or it may have multiple chambers. Each module may contain multiple chambers, and this may be referred to as a multiple chamber module. 
     In embodiments, module interfaces are typically high vacuum seal interface designed to mechanically couple together. An o-ring groove may be present on one or more interfaces of the module interfaces. An o-ring may be fitted into the o-ring grove. An adjacent module may have a flat mat surface. The o-ring interface may be mechanically coupled to the flat-mat surface using external or internal mounting hardware. Translation of the web may pass through a flange, a hole, or other opening. These openings may have a hi-vacuum seal around the perimeter. 
     The unwind module  102 A may give the System  100 A the ability to clean or prepare the web surface prior to coating. The web cleaning or surface modification may be done to a web prior to deposition. A plasma unit, an ion beam, or electron beam unit may be used to modify the web surface. Resistive or infra-red heaters may also be used in combination to clean or degas some web materials. 
     The unwind module  102 A may have a mandrel  114 A on which the web  104 A may be spooled or a removable web spool may be attached. For example, a fully spooled mandrel may have 20″ O.D. with a 6″ core by 1.2 meter wide, and the fully spooled web may weigh 1500 lbs. The System  100 A may include elements that shield roller bearings from deposition. The mandrel may be shielded to prevent deposition of sputtered material. Additionally, an unwind module  102 A may have the ability to process different types, widths and thicknesses of webs. For example, an unwind module  102 A, as well as the other modules, may have the components necessary to handle 1.0 meter, 1.2 meter and other widths of webs with a minimum of reconfiguration. This may allow the System to be quickly adapted to different widths and applications. 
     As the web  104 A is translated through the System  100 A, idler rollers  116 A in various modules may guide the web  104 A through the modules. Idler rollers may be designed for removal for periodic cleaning. In embodiments, the idler roller surface roughness may be 8 microinch rms. Idler rollers may spin freely, and they may have low rotational inertia. Idler rollers may be shielded to prevent deposition of sputtered material. Idler rollers may have active sensors to indicate positive motion. 
     The web  104 A may translate through the system at specified rate. The System  100 A may translate the web at a rate of 12 to 48 web-inches per minute. This speed may be set to be constant during processing or may vary as needed. A high speed web-wrapping phase may allow for wrapping at a greater speed than that of the processing speed. Acceleration and deceleration may be controlled. This may prevent slack in the spool. The web  104 A may have a tension of 10-50 lbf for a 1 meter wide web. In an embodiment in which different processes require different residence times, in order to run the System at a single speed, modules may vary in length or additionally modules may be added. 
     In the embodiment shown in  FIG. 1A , one module  106 A of System  100 A is a back-side deposition module  106 A. The web  104 A may be routed through the back-side deposition module  106 A so that the back-side of the web  104 A faces a deposition source or other processing device. The module  106 A is shown with six idler rollers  116 A for receiving and directing the web  104 A onto a drum  118 A and through the module so that the back side of the web is exposed to two processing devices  120 A, e.g., magnetron sputtering cathodes, thermal evaporation source, ION beam or electron beam source, etc. 
     The web  104 A continues through the system from the back-side deposition module  106 A to the front-side deposition module  108 A. The translation of the web  104 A through the front-side deposition module  108 A occurs in such a way that the front-side of the web substrate is exposed to the output of two depositions sources  120 A. Both the back-side deposition module  106 A and the front-side deposition module  108 A may include one or more of the following: a drum, an idler roller, a camel hump, a radiant roller, a free span, an additional transport device, and any processing devices such as a deposition source, a heater, a laser or an optical device, a process monitor or process sensors, etc., as necessary for the desired final product. In embodiments the System, sputtering techniques utilized may include ion-beam, ion-assisted, high-target-utilization reactive deposition, high-power impulse magnetron, gas flow deposition or any deposition technology now known or later developed. A web  102 A passing in proximity to a deposition cathode and target plate may cause material to be deposited onto the side exposed to the plate. 
     Cathodes may be employed in the back-side deposition module  106 A and the front-side deposition module  108 A. Power to the cathode may be supplied by radio frequency (“RF”). RF power supplies may have the capability for phase locking to avoid RF cross-talk by using one power supply as the master and by disabling the RF signal generator in the remaining power supplies. Safety systems may be provided to shut off power to the cathodes if protective covers are removed or errors are detected. 
     Cathodes may be cooled in various ways. In embodiments, the cathodes may be cooled directly. Cooling water or other cooling fluid may directly contact the deposition material&#39;s backing plate. Indirect cooling may use a cooling system that does not require direct contact with the deposition material&#39;s backing plate. 
     Deposition modules  106 A and  108 A may be designed for easy maintenance and cleaning. For example, a target plate may be removable and replaceable without requiring the modules in the System to be detached from each other. The interior may be cleaned with the cathodes mounted to the chamber frame. The chamber frame may be designed for insertion of the cathode mounting plate removal tool. 
     Direct cooling may affect maintenance of the cathode. Replacing the target may be necessary. It may be advantageous to remove the cooling water or other cooling fluid from inside the cathode body. Doing so while the cathode is in the process chamber may expose the process chamber to water. Consequently, it may be advantageous to remove the cathode from the module before servicing the cathode. 
     Indirect cooling may not require the cooling water or other cooling fluid to be removed. Thus, the target may be changed at or within the deposition module. Valving may be used to isolate the cathodes from the rest of the System  100 . This may allow for the cathode to be serviced without a total system vent. 
     A drum, idler roller, camel hump or radiant roller may be used to heat or cool the web  104 A. In embodiments of the System, any drum, idler roller, camel hump (as described in greater detail below) or radiant roller may be temperature controlled independent of the temperature of the gas environment in the interior space of the modules. The temperature control of components that physically contact the web may include the use of radio frequency, alternating current, or pulsed direct current. Additionally, plasma may be used to add energy to the System where needed. The use of magnetics in the localized drum, idler roller, camel hump or radiant roller may be used to increase the sputtered species ionization fraction and surface energy in the web. The temperature control may use a programmable logic controller (“PLC”), and it may be integrated into the Human Machine Interface (“HMI”). 
     With respect to the rewind module  110 A, the rewind module may give the system the ability to clean or modify the web surface after coating as a final processing step before the web is wound onto a rewind mandrel  112 A. A plasma unit, an ion beam, or electron beam unit may be used to modify the web surface. Resistive or infra-red heaters may also be sued in combination to clean or degas some web materials. 
     The System  100 A may be controlled by operators through the use of an integrated device control system. An input/output (I/O) control computer may compute information related to each of the modules including separate information for each piece of process equipment, various temperature, pressure and gas sensors, and switches associated with the system. This I/O computer may be a PLC. The PLC may communicate to another computing device. 
     For example, in embodiments, System  100 A may have a personal computer (PC)-based control system with distributed I/O. Software may be used to save and archive key system operation data such as chamber pressure, foreline pressure, heater temperatures, power supply powers, water flow rates. Software may be used for archiving data. In embodiments, this software may be Microsoft Excel or Microsoft Access. 
     The control computer and I/O may be housed in easily assessable 19-inch standard racks. A graphical user interface (“GUI”) may be provided to interface with process equipment in order to facilitate the control of some or all of the processing operations. Password protection may be utilized to control access to the various functionality of the GUI described below. 
     In an embodiment, the GUI may allow a user of the System  100 A to control the translation of the web  104 A through the System  100 A and its processing. The GUI may indicate control parameters, and it may allow the user to control such parameters as speed of the web  104 A, tension of the web  104 A, distance elapsed, distance remaining, time elapsed, time remaining, and other particulars related to the processing in each module. The user interface may provide real time control of system I/O with update times of less than 200 milliseconds. 
     The GUI may provide a well-designed, intuitive interface that displays key processing information. This may include: a navigation screen, a vacuum set-up screen, a water flow rate set-up screen, a web motion set-up screen, a processing set-up screen, an alarms screen, and a complete I/O status screen. 
     A main screen may display the following information: a chamber schematic screen with color coding to indicate the status of process equipment and devices including: heaters, cathodes, mass flow controllers, valves, pumps, drums, radiant heat rollers, idler rollers, camel humps, and sensors, and web motion. The GUI may also replicate a push button to choose automated, manual, or maintenance modes. The GUI may also display cathode labeling information; chamber pressure; mass flow controller set point and actual value; conductance valve set point and actual pressure; cathode set points and actual power information, e.g., power, voltage, DC current, forward power, reflected power, and DC bias for RF. A running sequence screen may display the sequence of operations with the past and pending steps in red and the current step in green. The GUI may also display a current web position, a web remaining position, an elapsed time, and a time remaining, an alarm indicator, and GUI push buttons to access water flow rates. 
     A navigation screen may have the following: a push button to access a water set point screen; a push button to access a vacuum set point screen; a push button to access a cathodes location set-up screen; a push button to enable the maintenance mode. 
     A vacuum set-up screen may display the following: an mp on foreline open delay; a foreline pressure set point; a post foreline valve close delay; a rough chamber pressure set point—cross-over pressure; a foreline leak set point; rough pressure leak time; a rough leak check set point; a low foreline pressure set point; and a process start pressure. A foreline may be the process piping from the high vacuum pump to a backing pump. The backing pump may be a mechanical pump. 
     A water or fluid set-up screen may allow the user to set up flow rate set points for one or more of the following fluid delivery control systems: cathodes, turbo pumps, chambers, modules, mechanical pumps, cathode mounting plates, and quartz crystal mircobalances (QCM). For example, information regarding to water flow to a cathode may be displayed. Water flow to a cathode may be displayed, and it may be compared to a low flow set point. A low flow flag for alarming and interlocks may be designed. The low flow set point may be configurable from a set-up screen. 
     A web set-up screen may provide the following functionality: display system mode, e.g., pre-deposition, deposition, and post-deposition; set web speed; set processing length for pre-deposition, deposition, and post-deposition modes; monitor and alter web tension; save a recipe; call a recipe; and display recipes. A recipe may be a group of software routines that are executed in series or parallel controlling all sub-systems of the entire deposition. 
     A process set-up screen may provide the following functionality: enable or select the cathodes that are displayed on the GUI, display and adjust a gas flow set point, display or adjust the exhaust valve controller or working gas set point, call a recipe, and display a recipe. 
     Hyper links, tabs, or similar elements displayed on the GUI for accessing and displaying other control screens may be provided to facilitate easy navigation within the control interface. 
     Automatic modes may be enabled from the GUI. This may facilitate process controls that step through a predetermined sequence of events. These events may relate to the control of process equipment and sensors. Processes with automatic modes may include pumping, leak-checking, processing, and venting. Initiation of an entire preprogrammed process may be facilitated by the use of a single user input. Manual mode may be enabled to allow a user to manually control process equipment or sensors. 
     Automated pumping may include the automated pumping down of a system. This may include executing sequence of events such as enabling cooling water to cathodes, turbo, water pump and chamber jacket; closing high vacuum valves and verifying limit switches have been met, starting mechanical pump; delaying for a predetermined amount of time; starting a turbo pump; waiting until the turbo pump speed has reached 80% of set point; closing vent valve and verifying it has been closed; opening roughing valve if necessary; waiting for chamber pressure to drop below a roughing chamber pressure set point; closing the roughing valve; waiting a predetermined amount of time; comparing the chamber pressure to a predetermined pressure set point; alarming and exiting sequence if change in pressure is greater than a set point; opening valves; delaying a predetermined time such as 5 seconds; opening an isolation valve; waiting for a chamber pressure to drop below a set point; and exiting the sequence. 
     Automated leak-checking may include an automated leak-check sequence. This sequence may include verifying whether a chamber is at or below the set point; close a high vacuum valve; delay a leak check time set point; alarm an exit auto leak-check sequence if chamber pressure change is greater than a set point, open a high vacuum valve; and end sequence. 
     Automated processing may include an automated process sequence. This may allow for automatic control of the process components of the machine. Process control set points may be entered into the control set-up screen. This sequence may include waiting until chamber pressure is below a set point; enabling a cathode cooling water; start a web translation and processing sequence; obtaining web set-up parameters; enable and verifying gas flows; enable and verifying the exhaust valve control; enable power supplies to cathodes; enabling heaters, waiting for process to complete or alarm, initiating shutdown, turning of cathodes, turning of heaters; opening exhaust to conduction valve; stopping working gas flow; and ending automated process. 
     Automated venting may include an automated venting sequence. An auto vent sequence may be implemented to control the valves and pumps in bringing chambers and modules to set pressures, including to atmosphere. These sequences may include: disabling cooling water to cathodes and chamber jacket; closing high vacuum valves, isolation valves roughing valves if open; turning off ion gauge; delaying for a number of seconds defined in a set point; opening vent valve; waiting for door switch to become open; closing vent valve; and ending auto vent process. 
     The GUI may provide information regarding power supplies. This may include deposition power supplies and radio frequency power supplies. This may include information regarding set points, currents, voltage, and power values. 
     Control of each power supply&#39;s on/off state or power level may either be manual or automatic depending on a machine mode. In embodiments, if automatic control is selected, during the automatic process sequence the power supplies will be started. In manual mode, operators may control the on/off status via operator interface screens. The output level may be ramped up to a set point over a 60-second time period. The logic also monitors all interlock conditions and disables the power supplies during fault conditions. 
     Certain triggers may interrupt the functioning of the cathode. This may include 3-phase alarms, emergency stops triggers, a low flow of water alarm to the cathode, a chamber pressure alarm, insufficient process gas flow, and stoppage or breakage of the web. 
     Additionally, the gas control for each machine may consist of the interlocks and the continuous control of each gas. The system may monitor the interlock conditions and shut down gas flow if required. Each gas flow can be enabled/disabled via operator controls. Certain triggers may interrupt the functioning of gas flow. These may include a 3-phase alarm and an emergency stop. 
     Heaters may be controlled through the GUI. Each device, process equipment, and/or module may utilize independent temperature controllers to maintain temperature. The temperature may be retransmitted from the controller for display on the software. Certain triggers may interrupt the functioning of heaters. These include 3-phase alarm, emergency stops, temperature at a location being over or below predetermined thresholds, chamber or module pressure being too high, the web stopping or the web breaking. 
     A GUI may accept and scale all the systems pressure inputs including the roughing foreline, turbo foreline, process, and chamber pressure gages. It may also accept the atmosphere switch that is used for indication only. 
     Mechanical pumps may be controlled via the GUI, and through a manual pushbutton control. The pumps may be controlled automatically via the auto pump-down. The pump run status may be used to interlock the roughing, foreline, and HiVac valves. 
     The turbo pump may be controlled in two modes, manual and automatic through the GUI. In manual, the pump may be controlled via manual pushbutton control from the screen. In automatic, the pump may be started via the auto pump-down routine. The pump running status may be used to interlock the HiVac Valve. Alarms may trigger when there is a low turbo water flow, or where the pump is below 80% of the set point speed. Certain triggers may cause the turbo pump to shut down. These include a 3-phase alarm, an emergency stop, or a low turbo water flow. 
     The GUI may allow the water pump to be controlled in two modes, manual and automatic. In manual, the pump may be controlled via manual pushbutton control from the screen. In automatic, the pump may be started and stopped via the auto pump-down routine. The pump running status may be used to interlock the HiVac Valve. The heat output may be currently not used and will be deleted if unnecessary. The water pump cooling water may be input, scaled to GPM and compared to a low flow set point to set a low flow alarm and interlock. The low flow set point may be configurable from the GUI. The turbo cooling water may be input, scaled to GPM and compared to a low flow set point to set a low flow alarm and interlock. The low flow set point may be configurable from the screen. Certain events may trigger alarms, such as the pump not running or running. Certain triggers may cause the water pump to shut down, such as a 3-phase alarm, and emergency stop alarm, and a low water flow alarm. 
     The GUI may allow the roughing valve to be operated in two modes, manual and automatic. In manual, the valve may be controlled via operator interface pushbuttons. In automatic, the valve may be opened and closed via the auto pump-down and auto vent routine. In either mode, the valve may be subject to the interlocks. The valve may be forced to close if there is a 3-phase alarm, an emergency stop, a machine pump off, a pneumatic low pressure, a chamber low process or a chamber door open. The valve may be forced open if the vent valve is open, if the foreline valve is open or the high vacuum valve is open. 
     The GUI may allow for the high vacuum valve to be controlled in two modes, manual and automatic. In manual, the valve is controlled via manual pushbutton control from the screen. In automatic, the valve may be opened and closed via the auto pump down and auto vent routine. In either mode, the valve may be subject to the interlocks. Certain triggers may cause the valve to force close or may prevent the valve from opening. These include a 3-Phase Alarm, a emergency stop, the turbo pump being off, the mechanical pump being off, the pneumatic low pressure alarm being present, the chamber door being open, the chamber low pressure set point not being met, the foreline high pressure flag being set, the vent valve being open, the roughing valve being open, the foreline valve being closed. 
     The GUI may allow for the vent valve to be controlled in two modes, manual and automatic. In manual, the pump is controlled via manual pushbutton control from the screen. In automatic, the valve is open and closed via the auto pump-down and auto vent routine. In either mode, the valve is subject to the interlocks. 
     Software may be utilized to perform logic to generate alarms and input I/O as alarms. Emergency mode will shut down the system. Software may be implemented to recognize impending emergencies. This may allow user intervention to try to correct the problem before complete system shut down. Alternatively, the alarm mode may just display the alarm state if the issue is not critical. 
     The System&#39;s electrical power may operate from a single-source 480 volt, 3 phase, 5 wire (3 primary phases, neutral, and ground) facility power. In embodiments, wire distribution within control cabinets are sized and fused according to component vendor specifications. The electrical system associated with System  100 A may have a single point breaker and/or fuse disconnect, with interchangeable maximum current ratings. The main electrical disconnect may remove power from the entire system with the exception of items powered by an uninterruptable power supply. An uninterruptable power supply (UPS) may supply power to a control computer. This power supply may last ˜20 minutes. 
     The electrical system may contain all necessary transformers, circuit breakers, relays, contractors, motor starters, and fuses necessary to allow complete system operation from the control panel. It may additionally include sufficient regulation of power fluctuations to ensure satisfactory operation under conditions of over/under-voltage variations of up to +10% in the form of either a fast immediate or gradual change. 
     In embodiments, the electrical system equipment and enclosures comply with applicable National Electrical Code (NEC) and National Electrical Manufacturer&#39;s Association (NEMA) standards for a normal industrial environment. In embodiments, the control panels are rated to NEMA 1. The electrical systems may be capable of operation without exposing personnel to dangerous electrical potentials. Wire numbers may be attached to each wire near each terminal point, using a clear and permanent marking method. The wire numbers may coincide with the numbers shown on the point-to-point and detailed wiring diagrams. Shielded terminal strips may be used for wiring which is 120 volts or greater when measured to ground or neutral. The electrical system may have a three-phase monitor, interfaced to the system I/O to provide and alarm state if all three phase are not active. Electrical components such as breakers and magnetic contactors may be aligned in a vertical fashion, mounted on DIN rails. Wires between interconnect, close proximity power components (i.e., fuse-to-breaker-magnetic contactor-SCR) may be clearly labeled and visible. Wire numbers may be attached to each wire near each terminal point, using a clear and permanent marking method. The wire numbers coincide with the numbers shown on the point-to-point and detailed wiring diagrams. 
     The system may provide a single point water supply and return, power, and dried compressed air to the system. Water and gas distribution systems may be connected to the System  100 A. 
     A chilled water utility subsystem may be connected to the System  100 A. In embodiments, this may have a single point supply and return. Independent shut off valves for each item requiring cooling may be present. The incoming water may be regulated from 30 to 65 psi. Water distribution components may be designed to withstand water pressures from 30 to 65 and up to 100 psi range. Incoming water temperature may be regulated from 55 to 70 deg F. System  100 A may provide means to regulate water flow rate to each component. In embodiments, the system may provide regulated chill water flow circuits and regulated heated water circuits. 
     In embodiments, chilled water may be used for certain systems. For example, cathodes may require 15 gallons per minute (GPM) of chilled water. Chambers may require 5 GPM, turbo pumps may require 0.5 to 1 gpm, and water vapor pumps may require 0.5 to 2 GPM. In embodiments, the total system flow may require 20 GPM of chilled water. 
     Temperature, pressure, and flow rate sensors may be used on all water inlet and outlet lines. Valve actuators for compressed air blow down of the water system for maintenance of water containing components may be utilized. 
     A dry compressed air subsystem may be connected to System  100 A. In embodiments, a single air line may be used with System  100 A. Incoming air maybe provided at 100 to 120 psi. System components may be designed to withstand maximum incoming air pressure. Additionally, a valve manifold may be provided for purposes of actuating pneumatic valves. Lockout/tagout air pressures regulators and filters may be provided. Air pressure regulators may be properly sized for valves in use in connection to the System  100 A. 
     An alternative embodiment of the System may be seen in  FIG. 1B . The System  100 B is an example of a modular design comprised of an unwind module  102 B, a deposition back-side deposition module  104 B, a front-side deposition module  106 B, a first differential pumped isolation module  108 B, a thermal evaporation module  110 B, a second differential pumped isolation module  112 B, an in-situ coating diagnostics module  114 B, and a rewind module  116 B. The eight modules are shown separated for illustration purposes, however, in a standard embodiment the modules may be connected so that the web is not exposed to the external environment as it passes through the different environments of each module. The system  100 B may include GUI&#39;s, electrical power systems, integrated device control systems, computer systems, chilled water systems, and temperature and pressure flow rate sensors as described with reference to system  100  above. 
     In embodiments, the unwind module  102 B may be configured to clean or prepare the web surface prior to coating. Cleaning unit  119 B may be used to clean or prepare the web. 
     In embodiments, the unwind module  102 B may be configured to unwind a web  120 B as the web translates through the system  100 B. For example, the unwind module  102 B may have a mandrel  118 B on which the web  118 B may be spooled or a removable spool may be attached. For example, a fully spooled mandrel may have a 20″ O.D. with a 6″ core by 1.2 meter wide, and the fully spooled web may be 1500 lbs. The System  100 B may include elements that shield roller bearings from deposition. The mandrel may be shielded to prevent deposition of sputtered material. 
     A pump  124 B may regulate the pressure in the unwind chamber  102 B. Pump  124 B may be used in other modules as well. A single pump may be used for each module or chamber. Alternatively, all modules may be controlled by a single pump connected to a pumping manifold. Additionally, pumping configurations as described with respect to  FIG. 7  may be employed. In embodiments pump  124 B may be a variable speed pump. Other pump types may be used. A roughing pump may be employed at early stages to achieve very low pressures within the system. Working pressure may be controlled by adjusting the exhaust. Working pressure may also be controlled by adjusting the pumping rate or inlet valve opening. 
     The pump  124 B may be attached to pump piping. Pump piping may be welded 304 or 316L stainless steel or any suitable material. Vacuum pump piping may use various types of flanges in order to facilitate rapid removal of the flanges. These flanges may be KF ISO style flanges. Less frequently removed flanges may be conflate style flanges. 
     In embodiments, the unwind module  102 B contains an idler roller  122 B. The idler roller  122 B may guide the web  120 B through the unwind module. Idler rollers may also be used in other modules. Idler rollers may be designed for removal for periodic cleaning. In embodiments, the idler roller surface roughness may be 8 microinch rms. Idler rollers may spin freely, and they may have low rotational inertia. Idler rollers may be shielded to prevent deposition of sputtered material. Idler rollers may have active sensors to indicate positive motion. 
     The web  120 B may translate through a back-side deposition chamber  104 B. The web  120 B may be routed through the back-side deposition module  104 B so that the back-side of the web  120 B faces a processing device  125 B. The module  104 B is shown with six idler rollers  124 B for receiving and directing the web  120 B onto a drum  126 B and through the module so that the back side of the web is exposed to two processing devices  125 B, e.g., sputtering devices. 
     The web  120 B continues through the system from the back-side deposition module  104 B to the front-side deposition module  106 B. The translation of the web  104  through the front-side deposition module  106 B occurs in such a way that the front-side of the web substrate is exposed to the output of two process modules  125 B. Both the back-side deposition module  104 B and the front-side deposition module  106 B may include one or more of the following: a drum, an idler roller, a camel hump, a radiant roller, a free span, an additional transport device or assembly, and any processing devices such as a deposition source, a heater, a laser or an optical device, a process monitor or process sensors, etc., as necessary for the desired final product. 
     In embodiments of the System  100 B, deposition techniques utilized may include ion-beam, ion-assisted, high-target-utilization reactive sputtering, high-power impulse magnetron, gas flow sputtering or any deposition technology now known or later developed. A web  120 B passing in proximity to a sputtering cathode and target plate may cause material to be deposited onto the side exposed to the plate. 
     Cathodes may be employed in the back-side deposition module  104 B and the front-side deposition module  106 B. Power to the cathode may be supplied by radio frequency (“RF”). RF power supplies may have capability for phase locking to avoid RF cross-talk by using one power supply as the master and by disabling the RF signal generator in the remaining power supplies. Cooling and maintenance of cathodes may be performed in a similar fashion as described with respect to  FIG. 1A . 
     A drum, idler roller, camel hump or radiant roller may be used to heat or cool the web  120 B. In embodiments of the System, any drum, idler roller, camel hump (as described in greater detail above) or radiant roller may be temperature controlled independent of the temperature of the gas environment in the interior space of the modules. This temperature control of components that physically contact the web may include the use of radio frequency, alternating current, or pulsed direct current. Additionally, plasma may be used to add energy to the System where needed. The use of magnetics in the localized drum, idler roller, camel hump or radiant roller may be used to increase the sputtered species ionization fraction and surface energy in the web. The temperature control may use a programmable logic controller (“PLC”), and it may be integrated into the Human Machine Interface (“HMI”). 
     Turning now to the first differential pumped isolation module  108 B, the web  120 B may pass through a differential pumped isolation module  108 B. A vacuum pump  124 B may be used to keep the differential pumped isolation module at a set pressure. In embodiments, this pressure may be lower than that of modules that are mechanically coupled to the differential pumped isolation module. The differential pumped isolation module  108 B may be coupled to a front-side deposition module  106 B and a thermal evaporation chamber  110 B. The front-side deposition module  106 B may be at a higher pressure than the differential pumped isolation module  108 B. In addition, thermal evaporation module  110 B may be at a higher pressure than the differential pumped isolation module  108 B. This may cause process gasses associated with a module mechanically coupled to the differential pumped isolation module  108 B to flow into the differential pumped isolation module  108 B. As such, process gasses will not flow from the differential pumped isolation module  108 B into modules mechanically coupled to the differential pumped isolation module  108 B. This may preserve the partial pressure set-points for mechanically coupled modules, such as front-side deposition module  106 B and thermal evaporation module  110 B. 
     Next, the web  120 B may translate through a thermal evaporation module  110 B. The thermal evaporator module  110 B may contain thermal evaporator process equipment  132 B. This process equipment may employ a thermal method, a crucible method, a molecular beam epitaxy method, an electron beam method, a flash evaporation method, or a resistive evaporation method to facilitate evaporation of a source material. This may cause the source material to evaporate and be deposited on the web  120 B. Two idler rollers  122 B may be present to guide the web through the thermal evaporation module  110 B. Process device  130 B may aid in the process associated with evaporation module  110 B. 
     The web may then translate through a second differential pumped isolation module  112 B. A vacuum pump  124 B may be used to keep the differential pumped isolation module at a set pressure. In embodiments, this pressure may be lower than that of modules that are mechanically coupled to the differential pumped isolation module. The differential pumped isolation module  112 B may be a thermal evaporation chamber  110 B and an in-situ coating diagnostics module  114 B. The thermal evaporation chamber  110 B may be at a higher pressure than the differential pumped isolation module  108 B. In addition, in-situ coating diagnostics module  114 B may be at a higher pressure than the differential pumped isolation module  108 B. This may cause process gasses associated with a module mechanically coupled to the second differential pumped isolation module  112 B to flow into the second differential pumped isolation module  112 B. As such, process gasses will not flow from the second differential pumped isolation module  112 B into modules mechanically coupled to the second differential pumped isolation module  112 B. This may preserve the partial pressure set-points for adjacent modules, such as front-side deposition module  106 B and thermal evaporation module  110 B. 
     Next, the web  120 B may translate through an in-situ coating diagnostics module  114 B. The in-situ diagnostics module may contain process equipment that may perform thermal wave analysis, optical emission spectroscopy, and x-ray photoelectron spectroscopy. Multiple diagnostic devices such as  134 B and  136 B may be present in module  120 B. 
     With respect to the rewind module  116 B, the rewind module may give the system the ability to clean or modify the web surface after coating as a final processing step before the web is wound onto a rewind mandrel  140 . A final processing device  138  may facilitate cleaning. 
       FIG. 2  illustrates an embodiment of a multiple-chamber deposition module with a drum and a device on the drum referred to herein as a “camel hump.” In the embodiment shown, the web  202  enters the multiple-chamber deposition module  200 . An idler roller  204  may guide the web substrate along a drum  206 . The drum  206  may be temperature controlled to a first temperature. This temperature control may include the use of radio frequency, alternating current, heated or cooled fluid, or pulsed direct current. In the embodiment shown, the camel hump  212  is a device placed adjacent to the drum such that as the drum rotates, the web lifts off from the drum, travels over a web-contact surface of the camel hump, and then returns to the drum. 
     Embodiments of the deposition module  200  may have multiple chambers, such as the three process chambers  208 ,  210  and  214  as shown in  FIG. 2 . The web  202  may enter a first deposition chamber  208 . The first deposition chamber  208  may have a temperature control process and pressure control process. The temperature in the first deposition chamber  208  may be maintained at a temperature of the drum  206  or near a temperature of the drum  206 . Entering the deposition chamber  208  may cause the temperature of the web  202  to approach the temperature of the drum  206 . The web  202  may leave the first deposition chamber  208  having had material deposited on it through a deposition process. Processing devices other than deposition devices may be used. 
     In embodiments, the web  202  may enter another chamber of the multiple-chamber deposition module  200 . This chamber may be a second deposition chamber  210  provided with a camel hump  212 . In embodiments, this camel hump-equipped deposition chamber  210  may have a different temperature and pressure profile than the first deposition chamber  208  and the drum  206 . The drum  206  may be designed to engage the web. The camel hump  212  facilitates the different temperature by causing the web  202  to contact the camel hump and not the drum while in the second deposition chamber  210 . The camel hump may be provided with its own temperature control so that, as the web  202  contacts the camel hump, the web&#39;s temperature is changed toward that of the camel hump. In embodiments, the drum  206  may be a low temperature (Δ5 deg. C. is shown in  FIG. 2 ) and the camel hump  212  may allow for the web  202  to have its temperature increased dramatically while in the second deposition chamber  210 . An opposite configuration is also possible, where the camel hump is held at a temperature lower than the drum. Greater or lower temperature differences between the drum and the camel hump may also be possible. 
     In the embodiment shown, the camel hump  212  causes the web  202  to be separated from the drum  206  for some distance. The distance may be fixed. Providing a camel hump in a separate chamber allows for the localized control of physical and chemical conditions within that chamber. For example, this may allow for localized high or low temperature in-situ process temperature control. This may be facilitated by the camel hump  212  having internal cooling elements and heating elements to control the temperature of the surface of the camel hump. In a further embodiment, these heating and cooling elements may be used in combination to create a specific temperature gradient across the camel hump  212 . Additionally, magnetic fields, radio frequency, alternating current, and/or pulsed DC power may be applied to some or all portions of the camel hump  212 . 
     In the embodiment shown, the camel hump  212  has two surfaces: a drum-facing surface that complements the curvature of the adjacent drum and a web-contact surface over which the web travels. The web-contact surface may be treated to prevent damage to the web-surface and any coatings that may be on the web surface that is in contact with the web-contact surface. The web-contact surface may have any shape depending on the needs of the design. For example, the web-contact surface may be a continuous curve as illustrated in  FIG. 2 , may include a substantially flat section adjacent to the sputtering device or process device, or may be provided with multiple planes or different surfaces as needed. The web-facing surface may be designed to engage the web. The drum-facing surface may be spaced by some nominal amount to prevent the temperature of the drum from interfering with the operation of the camel hump  212 . In an embodiment, the drum-facing surface may include or be made entirely of an insulating material such as a ceramic in order to more effectively thermally isolate the camel hump&#39;s web-contact surface from the drum. The camel hump may contain resistive heating elements and/or thermal transfer fluids in combination with a heater or chiller unit. The camel hump may also have a particular material specification of the camel hump and specialized coatings for camel hump and web interface. Temperature control of the hump  212  may be controlled by a control system. This control system may be configured to control the temperature of the web-surface. Though one camel hump is shown in  FIG. 2 , multiple camel humps may be utilized. Each camel hump may have its own control system or be independently controlled from a central control system. 
     Though  FIG. 2  depicts a multiple-chamber deposition module  200  having three chambers, the multiple-chamber deposition module may have as little as one chamber, and it may have more than three chambers. The multiple-chamber deposition module may have a drum, or it may not. The chamber types may include one or more of the following chambers: a deposition chamber, a camel hump chamber, a free span chamber, and a radiant roller chamber. Chamber components may be designed to optimize uniform process gas flow across the deposition source and process space. 
     For example,  FIG. 3  illustrates an embodiment of elements of a free span chamber. In embodiments, the web  302  passes over a camel hump  304  that is not adjacent to a drum. This camel hump may have heating and cooling elements  306 . A drum may not be present in the free span chamber. 
       FIG. 4  illustrates elements of a radiant roller chamber. The web  402  passes over the radiant roller  404 . The radiant roller may have internal heating and cooling elements  406 . These elements may be used to control the temperature of the radiant roller. Temperature of the radiant roll heater may be controlled through the use of radio frequency, alternating current, or pulsed direct current. Additionally, plasma may be used to add energy to the system. 
       FIG. 5  presents an embodiment for a pumping scheme for modules in the System  100 . In embodiments, a module may have three chambers. Gas flow of a first chamber  502  may be controlled by a pump  504 . Gas flow of a second chamber  506  may be controlled by a second pump  508 . Gas flow of a third chamber  510  may be controlled by a third pump  512 . A deposition cathode  514  may be present in the chamber. 
     Each chamber  502 ,  506 , and  508  may be provided with a process gas transport system that is attached to one or more pumps, which may be shared between chambers or may be completely independent. The process gas transport system may be provided with different assemblies for removing and/or injecting process gas as is known in the art. Such transport systems may include pressure sensors, gas analyzers and flow meters for monitoring and controlling the process gas in the chambers. They may also include valves such as check valves, flow control valves and various piping and other transport structures for directing and conveying flow of process gas. 
     Gas flow in first chamber  502  travels vertically toward the pump  504 . The gas may pass through a single orifice located at the coupling between the first chamber  502  and the inlet of the pump  504 . Pump piping may include a vacuum tight welded 304 or 316L stainless steel. Similarly, gas flow in a second chamber  506  may flow vertically through a single orifice located at the coupling between the second chamber  506  and the pump  508 . Additionally, gas flow in third chamber  508  may flow vertically through a single orifice located at the coupling between the third chamber  510  and the pump  512 . The gas used in this process may be an inert gas such as argon. Pumps and pump piping may be similar to the pumps and piping as discussed with reference to  FIG. 1A . 
       FIG. 6A  presents an embodiment of an open slit chamber wall of a module. Open volume slits  602 A line the chamber wall  604 A. The open slit  602 A may allow process gas to be pumped into the chamber. This may allow for a more vertically homogenous pressure differential across the chamber. The chamber wall  604 A may be made out of stainless steel 304 or 304L. A deposition cathode  606 A may be present. Other processing devices may also be present. The open slit  602 A may be a single open slit. In alternative embodiments the open slit may be a series of perforated holes, slits, or other openings that allow process gas to flow into the chamber. These may form essentially a vertical line, but other shapes such as s-curves, circles, intermittent vertical openings, or others may be desirable. A horizontal configuration may also be desirable in some applications. 
       FIG. 6B  presents an alternative embodiment of an open slit chamber wall of a module. Integrated open volume slits  602 B are integrated into the body of deposition cathode  606 B. The open slit  602 B may allow process gas to be pumped into the chamber in a uniform manner. This may allow for a more vertically homogenous pressure differential across the chamber. The chamber wall  604 B may be made out of stainless steel 304 or 304L. The open slit  602 B may be a single open slit. In alternative embodiment the open slit may be a series of perforated holes, slits, or other openings that allow process gas to flow into the chamber. These may form essentially a vertical line, but other shapes such as s-curves, circles, intermittent vertical openings, or others may be desirable. A horizontal configuration may also be desirable in some applications. 
       FIG. 7  illustrates an embodiment of an integrated linear inter-cell and background pumping configuration  700 . The integrated linear inter-cell and background pumping configuration chamber may control the gas flow into and out of a chamber. The pump configuration  700  may be used in combination with an open slit chamber wall module. The pump  702  may be centered along the chamber wall, and it may direct the gas into a module with one or more chambers. The fluid flow  704  may provide homogenous horizontal and vertical pressures. The pumping may be achieved using either an open volume or slits to develop the pressure or a plenum tapered to control streaming velocity in the vertical direction. An alternative pump configuration for integrated linear inter-cell and background pumping may have the pump positioned in an off-centered position. Exterior cell wall  706  may form an interstitial void with interior wall  708 . Gas may be delivered by pump  702  into chamber  710  through slit  712 . 
       FIG. 8  illustrates an embodiment of a multiple-chamber gas curtain separation system  800 . In embodiments, a multiple-chamber gas curtain separation system may have a first process chamber  802 , a second process chamber  804 , and a third process chamber  806 . The first process chamber  802  may have an interior first process barrier wall  808 . The second process chamber  804  may have an interior second process barrier wall  810 . The interior first process barrier wall  808  and the second process barrier wall  810  may be spaced apart to form an interstitial space  812 . A web  814  may translate through the first process chamber  802  into the second process chamber  804 . Barrier process walls may be made of stainless steel 304 or 304L. 
     In embodiments, it may be desirable to prevent process gasses from the first process chamber  802  from flowing into the second process chamber  804 . It may also be desirable to direct the flow of process gases related to the first process chamber  802 . There may be a first web-barrier wall gap  816  that may allow first process gasses to escape from the first process chamber  802 . A flow of separation gas  818  may be supplied to the interstitial space  812 . Flow of this separation gas  818  may travel the interstitial space, and the separation gas  818  may flow out through a gas removal system. This flow of separation gas  818  may entrain process gasses from the first process chamber  802 . Differential pumping may draw the separation gases and the process chamber gases from the interstitial space  812  by means of a gas removal system as described above, essentially operating the chamber  802  under positive pressure relative to that of the interstitial space  812 . 
     The flow of separation gas  818  may follow several paths. One such path may be through interstitial space  812  to a gas removal system. This gas removal system may be designed to remove the separation gas  818  and process gas out of the system. The flow of gas may not travel through a web processing chamber, such as first process chamber  802  or second process chamber  804 . 
     A web processing chamber may be a chamber where a web is processed. This process may include one or more of the following processes: deposition, cleaning, waiting, settling, preparing, or another process necessary for processing the web. Any of the modules or chambers referenced in  FIGS. 1-7  may include or be a web processing chamber. 
     Alternatively, the flow of separation gas  818  may take a different path. The flow may split. Some flow of the separation gas  818  may flow through an interstitial space  812  to a gas removal system. Flow of some of the separation gas  818  may pass through a web-barrier wall gap  820  to a second process chamber  804 . The flow may then travel to a gas removal system that may be designed to remove separation gas  818  in such a way that causes the gas flow to pass through the web processing chamber. 
     Separation gas  818  may be gas supplied through a gas curtain injection port  822 . A gas curtain injection port  822  may allow flow of separation gas  818  to flow through an interstitial space. In some embodiments, one or more gas injection ports  822  may be located proximate to the web  814 , a first web-barrier wall gap  816 , and a second web-barrier wall gap  818 . Alternatively, the gas curtain injection port  822  may be located at a point within the interstitial space  812 . Additionally, there may be multiple gas curtain injection ports located in or in proximity to the interstitial space  812  through which the curtain gas is injected into the interstitial space  812 . 
     A control system may be employed with the gas separation system  800 . This may monitor the pressure in the interstitial space. It may also monitor the pressure of web processing chambers, e.g., a first process chamber  802  and a second process chamber  804 . This may control the operation of one or more of the gas removal systems, the curtain gas injection systems, and the process gas transport systems. Various sensors may be employed to monitor flow, temperature, and pressure. Additionally, sensors may be employed to monitor the gaseous make-up of the gas at various points in the process chamber and interstitial space. The control system may allow the regulation of the flow, pressure, and temperature by monitoring and altering pump speeds, valve openings, and cooling/heating elements. 
     The process gas may be provided by a process gas transport system  824 . This process gas transport system  824  may supply a flow of process gas. The process gas transport system may be attached to a pumping manifold. Alternatively, it may be attached to a pumping system as described with reference to  FIG. 6A ,  FIG. 6B  and/or  FIG. 7 . Similarly, the gas curtain injection port  822  may supply a flow of separation gas. To supply the flow of separation gas, pumping manifolds or other pumping schemes such as those referenced in  FIG. 6A ,  FIG. 6B , and/or  FIG. 7  may be used. Separation gas may have a gas make-up similar to a process gas. It may also have another gaseous make-up such as air. 
     Additionally, in embodiments, it may be desirable to prevent process gasses from the second process chamber  804  from flowing into the first process chamber  802 . It may also be desirable to direct the flow of the second process gases. There may be a second web-barrier wall gap  820  that may allow second process gasses to escape from the second process chamber  804 . A flow of separation gas  818  may be supplied to the interstitial space  812 . Flow of this separation gas  818  may travel the interstitial space, and the separation gas  818  may flow out through a gas removal system. This flow of separation gas  818  may entrain process gasses from the second process chamber  804 . Differential pumping may draw the separation gases and the process chamber gases from the interstitial space  812  by means of a gas removal system as described above, essentially operating the chamber  804  under positive pressure relative to that of the interstitial space  812 . 
     It will be clear that the present invention is well adapted to attain the ends and advantages mentioned as well as those inherent therein. Those skilled in the art will recognize that the methods and systems of the present invention within this specification may be implemented in many manners and as such is not to be limited by the foregoing exemplified embodiments and examples. In other words, functional elements being performed by a single or multiple components, in various combinations of hardware and software, and individual functions can be distributed among software applications at either the client or server level. In this regard, any number of the features of the different embodiments described herein may be combined into one single embodiment and alternate embodiments having fewer than or more than all of the features herein described are possible. 
     While various embodiments have been described for purposes of this disclosure, various changes and modifications may be made which are well within the scope of the present invention. Numerous other changes may be made which will readily suggest themselves to those skilled in the art and are considered within the scope of this disclosure.