Abstract:
A method for operating one or more electronic device manufacturing systems is provided, including the steps 1) performing a series of electronic device manufacturing process steps with a process tool, wherein the process tool produces effluent as a byproduct of performing the series of process steps; 2) abating the effluent with an abatement tool; 3) supplying an abatement resource to the abatement tool from a first abatement resource supply; 4) changing an abatement resource supply from the first abatement resource supply to a second abatement resource supply, wherein changing the abatement resource supply comprises: i) interrupting a flow of the abatement resource from the first abatement resource supply; and ii) beginning a flow of the abatement resource from the second abatement resource supply; and 5) continuing to perform the series of process steps with the process tool, while changing, and after changing, the abatement resource supply.

Description:
The present application claims priority to U.S. Provisional Patent Application Ser. No. 60/931,731, filed May 25, 2007 and entitled “Methods and Apparatus for Abating Effluent Gases Using Modular Treatment Components”, which is hereby incorporated herein by reference in its entirety for all purposes. 
     The present application also claims priority to U.S. Provisional Patent Application Ser. No. 61/026,432 filed Feb. 5, 2008 and entitled “Abatement Systems”, which is hereby incorporated herein by reference in its entirety for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to electronic device manufacturing methods and systems, and is more particularly directed to methods and apparatus for assembling and operating such systems. 
     BACKGROUND OF THE INVENTION 
     Electronic device manufacturing systems, such as process tools and abatement tools, etc., may be complex assemblies of subsystems or components, and each component may itself be a complex system. Typically, assembly of an electronic device manufacturing system may take a significant amount of time. In addition, prior to being placed into service, an assembled system, and many subsystems must be separately tested to determine whether each meets industry standards. The certification process adds to the amount of time required to ship an electronic device manufacturing system. 
     Furthermore, such systems produce a valuable product. When a system is out of service due to the maintenance requirements of a component of the system or of a supporting sub-system, the manufacturer may have to forego significant revenues due to product which is not being manufactured while the system is out of service. The same is true of a manufacturer which is waiting for delivery of a new system. 
     Methods and apparatus for simplifying and reducing the build/test time of electronic device manufacturing systems and for keeping such systems in operation, despite the need to take a component or sub-system out of service, are desirable. 
     SUMMARY OF THE INVENTION 
     In one aspect, a method for operating one or more electronic device manufacturing systems is provided, including the steps 1) performing a series of electronic device manufacturing process steps with a process tool, wherein the process tool produces effluent as a byproduct; 2) abating the effluent with an abatement tool; 3) supplying an abatement resource to the abatement tool from a first abatement resource supply; 4) changing an abatement resource supply from the first abatement resource supply to a second abatement resource supply, wherein changing the abatement resource supply comprises: i) interrupting a flow of the abatement resource from the first abatement resource supply; and ii) beginning a flow of the abatement resource from the second abatement resource supply; and 5) continuing to perform the series of process steps with the process tool, while changing, and after changing, the abatement resource supply. 
     In a second aspect, a method for assembling an electronic device manufacturing system is provided, including the steps 1) stocking one or more pre-certified, modular, electronic device manufacturing system components; 2) identifying performance requirements of the electronic device manufacturing system; 3) selecting one or more of the stocked components to satisfy the performance requirements; 4) constructing the electronic device manufacturing system from components which comprise one or more of the stocked components; and 5) certifying the constructed electronic device manufacturing system. 
     In a third aspect, an electronic device manufacturing system is provided, including 1) a process tool; 2) an abatement tool; 3) a first abatement resource supply, containing an abatement resource; and 4) a second abatement resource supply, containing the abatement resource, wherein the second abatement resource supply is adapted to flow the abatement resource to the abatement tool after a flow of the abatement resource from the first abatement resource supply is interrupted. 
     Numerous other aspects are provided in accordance with these and other aspects of the invention. Other features and aspects of the present invention will become more fully apparent from the following detailed description, the appended claims and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic drawing of a first embodiment of an electronic device manufacturing system of the present invention. 
         FIG. 2  is a flow chart depicting a method of designing and constructing the electronic device manufacturing system of  FIG. 1 . 
         FIG. 3  is a schematic drawing of a second embodiment of an electronic device manufacturing system of the present invention. 
         FIG. 4  is a flow chart depicting a method of operating the electronic device manufacturing system of  FIG. 3 . 
         FIG. 5  is a schematic drawing of a third embodiment of an electronic device manufacturing system of the present invention. 
         FIG. 6  is a flow chart depicting a method of operating the electronic device manufacturing system of  FIG. 5 . 
         FIG. 7  is a schematic drawing of a fourth embodiment of an electronic device manufacturing system of the present invention. 
         FIG. 8  is a flow chart depicting a method of operating the electronic device manufacturing system of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As described above, electronic device manufacturing systems may be complex assemblies. Typically, a system may include a process tool having process chambers which perform process steps such as deposition, epitaxial growth, etching, cleaning, etc., and an abatement tool. Abatement tools may consist of combinations of subsystems or components which may be designed to perform different abatement functions. The terms subsystems and components may be used interchangeably herein. The subsystems from which an abatement tool may be constructed include, but are not limited to, thermal reactors, burn boxes, catalytic units, plasma units, filters, water scrubbers, absorbing and adsorbing units, acid gas scrubbers, etc. 
     One method of constructing a system for a customer may include determining the nature of the system required by the customer, identifying the subsystems which will be required to construct the system, constructing the subsystems, and then constructing the system from the subsystems. This can be a time-consuming process, especially in light of the rigorous certifications which electronic device manufacturing systems, and subsystems, must undergo before being put into service. It is possible, of course, to pre-build systems so that a system may be delivered promptly to a customer, but the diversity of available systems combined with the high cost of systems may make such a practice prohibitively expensive. 
     After a customer has begun using a system, the subsystems which make up the system may eventually require routine maintenance, troubleshooting or removal from the system for some other reason. One known method of performing maintenance on and/or troubleshooting a subsystem, is to take the entire system out of service so that the subsystem may be maintained or inspected in a safe, non-polluting manner. Once the problem has been diagnosed and fixed or preventive maintenance has been performed on the subsystem, the system may be put back into service. When a system is out of service, however, the customer cannot make product with the system. It is thus desirable to be able to continue operating a system while a subsystem is off-line. 
     The present invention provides methods and apparatus which may reduce the time between identifying a customer&#39;s needs and delivering a suitable system to the customer. The invention may also enable a customer to remove a subsystem from the system and repair or replace the subsystem without the need to shut down the system and interrupt production. 
     In some embodiments of the invention, a manufacturer of electronic device manufacturing systems may identify a number of subsystems which are frequently incorporated into systems, and then build, pre-certify and stock an appropriate number of systems. When a customer places an order and the customer&#39;s needs have been identified, the manufacturer may then construct a system in a shorter period of time, because one or more of the subsystems which may be required in the system will be stocked and pre-certified, allowing the manufacturer to simply connect the subsystem into a system frame. In these and other embodiments of the invention, the subsystems may be modular, e.g., constructed with standard connectors in standard locations, so that the subsystems may be easily and quickly fit together in various configurations. 
     In some embodiments of the invention, a system may be constructed such that one or more of its subsystems may be disconnected from the system without the need to shut down the system. For example, a system may typically be supplied with a resource such as water. In some of these embodiments, pipes which carry the water from a water supply to the system may include valves and a connector. The valves and the connector may enable an operator to disconnect the water supply from the system and may prevent water from flowing out of the supply or back out from the system. In these embodiments, the system may be provided with an alternate water supply, or be designed to operate without the water supply for a period of time sufficient to connect a new water supply. 
       FIG. 1  is a schematic drawing of an electronic device manufacturing system  100  of the present invention. System  100  may include a process tool  102 . The process tool  102  may include one or more process chambers  104 . In fact, a process tool  102  may typically include up to six or more process chambers  104 . The process chambers  104  may perform any of the functions typically performed by process chambers  104 , including, for example, deposition, epitaxial growth, etching, cleaning, etc. Each process chamber  104  may produce effluent which may be pumped out of the process chamber  104  by vacuum pump  106  through conduit  108 . Effluent which is pumped out of process chamber  104  may be pumped through conduit  110  and into abatement tool  112 , and, more specifically, into abatement module  114  of abatement tool  112 . The nature of the effluent which may be produced by the process chamber  104  is discussed in more detail below. 
     The abatement tool  112  may consist of one or more abatement modules  114 ,  116 ,  118 . Although the abatement tool  112  is shown having three abatement modules, it is to be understood that fewer or more modules may be used. 
     The abatement modules  114 ,  116 ,  118  may be the same or different abatement equipment or subsystems, such as thermal reactors, burn boxes, catalytic units, plasma units, filters, water scrubbers, absorbing and adsorbing units, cooling chambers, acid-gas scrubbers, etc., or any other suitable abatement equipment which is, or may become, available. The abatement modules may be selected and then concatenated in any appropriate order to effect abatement of the effluent which is produced by the one or more process chambers  104 . The effluents which may be produced by the one or more process chambers  14  may include metals, acids, flammable or explosive gases, greenhouse gases, and other noxious, dangerous, or otherwise undesirable compounds. One of ordinary skill in the art of electronic device manufacturing system effluent abatement will be able select an appropriate combination and order of abatement modules to provide effective abatement of the effluent which may be exhausted from the one or more process chambers  104 . 
     The abatement modules  114 ,  116 ,  118  may be connected to each other by conduits  120 ,  122 . Abatement module  118  may be connected by conduit  124  to a further abatement system (not shown), to a house exhaust system (not shown) or to the atmosphere. 
     Electronic device manufacturing system  100  may further include an abatement resource connection system  126  which may include a connection panel  128  and abatement resource conduits  130 ,  132 ,  134 . Abatement resource panel  128  may include abatement resource connectors  136 , to which conduits (not shown) connected to abatement resource supplies (not shown) may be connected. While abatement resource panel  128  is shown having three connectors in communication with three conduits  130 ,  132 ,  134 , it should be understood that abatement resource panel  128  may have fewer or more connectors. For example, a typical abatement system may require abatement resources such as fuel or power, water, one or more reagents, clean dry air, and inert gas, etc. The same may be true for each individual abatement module, such as abatement modules  114 ,  116 ,  118 . Depending upon the nature of a particular abatement module, it may require one or more of the abatement resources listed above. 
     The abatement resource panel  128  may have in a number of different configurations. For example on a side of abatement resource panel  128  which is exterior to the abatement system  112 , abatement resource panel  128  may have a single abatement resource connector for each type of abatement resource which may be used by abatement system  112 . Alternatively, abatement resource panel  128  may have three abatement resource connectors for each abatement resource on the exterior side, e.g., one for each abatement module for each abatement resource which may be used by abatement system  112 . On the inside of abatement system  112 , the abatement resource panel  128  may have a connector (not shown) for each conduit  130 ,  132 ,  134 , for each abatement resource connected to the exterior of abatement resource panel  128 . Thus, for example, if a particular abatement system  112  were connected to three abatement resources, there may be three abatement resource connectors  136  on the exterior of abatement resource panel  128  and three times three, or nine, connectors (not shown) on the interior side of abatement resource panel  128 . It is to be understood that there may be more or fewer abatement resources than three used by the abatement system  112 , just as there may be more or fewer than three abatement modules included in the abatement system  112 . 
     In operation, the process tool  102  may perform electronic device manufacturing steps within process chamber  104 . During and after the manufacturing steps, effluent may be evacuated from process chamber  104  by vacuum pump  106  and introduced into the abatement system  112 . Within abatement system  112 , the effluent may be treated in abatement modules  114 ,  116 ,  118  to render the effluent acceptable for eventual release to the atmosphere. For example, abatement modules  114 ,  116 ,  118  may be used to remove particulate matter from the effluent, to neutralize acid gases, to oxidize dangerous, harmful or undesirable compounds, and to remove water soluble chemicals for further treatment in liquid form, etc. Other suitable treatments may be employed. Following treatment in abatement tool  112 , the effluent may pass through conduit  124  as described above. During the abatement of the effluent in abatement modules  114 ,  116 ,  118 , the abatement modules may receive abatement resources from abatement resource supplies (not shown) through connection panel  128  and conduits  130 ,  132 ,  134 . The abatement modules  114 ,  116 ,  118 , may use the abatement resources to abate the effluent. 
       FIG. 2  is a flow chart depicting a method  200  of designing and constructing an electronic device manufacturing system of  FIG. 1 . Method  200  begins in step  202 . In step  204 , an electronic device manufacturing system manufacturer may select one or more abatement subsystems which are frequently incorporated into abatement systems, construct one or more of each selected abatement subsystem, certify each constructed abatement subsystem and place the certified abatement subsystem in stock. In an alternate embodiment, an electronic device manufacturing system constructor, who may not build abatement subsystems, may purchase and stock one or more pre-certified abatement subsystems. In step  206 , the manufacturer or constructor may determine a customer&#39;s requirements for an abatement system. In step  208 , the manufacturer or constructor may select appropriate abatement subsystems. In step  210 , the manufacturer or constructor may assemble the selected abatement subsystems, using at least one stocked, pre-certified abatement subsystem, and then certify the constructed abatement system. In step  212  the abatement system may be delivered to the customer. Method  200  ends in step  214 . The stocking of certified abatement subsystems may enable the manufacturer to deliver abatement systems in a shorter period of time. 
       FIG. 3  is a schematic drawing of a second embodiment of an electronic device manufacturing system  300  of the present invention. System  300  may include a process tool  302  which may be connected through conduit  304  to vacuum pump  306 . Vacuum pump  306  may, in turn, be connected through conduit  308  to abatement tool  310 . Abatement tool  310  may be in fluid connection with abatement resource supply  312  through conduit  314 , valve assembly  316 , and conduit  318 . Valve assembly  316  may include two shut off valves,  320 ,  322  which may be connected by connector  324 . This valve design may enable an operator to prevent the flow of fluids from the abatement resource supply  312  through conduit  314  and also prevent any back flow of fluids from the abatement tool  310  through conduit  318 . The connector  324  may enable the operator to disconnect the abatement resource supply  312  from the system  300 . Any suitable valve assembly may be utilized. 
     System  300  may also include an backup abatement resource supply  326 , which may contain the same abatement resource as is contained by abatement resource supply  312 . The backup abatement resource supply  326  may be in fluid connection with abatement tool  310  through conduit  328 , valve assembly  330 , and conduit  332 . Valve assembly  330 , like valve assembly  316 , may include two shut off valves,  334 ,  336  which may be connected through connector  338 . Abatement tool  310  may be connected through conduit  340  to further treatment (not shown), the house exhaust (not shown) or directly to the atmosphere. 
     In operation, process tool  302  may exhaust effluent through conduit  304 , through vacuum pump  306 , through conduit  308  and into abatement tool  310 , which may be adapted to abate the effluent. Abatement tool  310  may receive an abatement resource from abatement resource supply  312 . The abatement resource may flow from abatement resource supply  312  through conduit  314 , valve assembly  316 , conduit  318 , and into abatement tool  310 . Abated effluent may then flow from abatement tool  310  through conduit  340  and into a house exhaust (not shown), to further treatment (not shown), or directly to the atmosphere. Backup abatement resource supply  326  may contain the same abatement resource as is contained by abatement resource supply  312 . In the event that the abatement resource from abatement resource supply  312  is no longer available to abatement tool  310 , abatement tool  310  may receive the abatement resource from backup abatement resource supply  326 . The abatement resource from backup abatement resource supply  326  may flow through conduit  328 , valve assembly  330 , and conduit  332  into abatement tool  310 . The function of valve assemblies  316  and  330  will be described in more detail below with reference to  FIG. 4 . 
       FIG. 4  is a flow chart which depicts a method  400  of operating the electronic device manufacturing system  300  of  FIG. 3 . In some embodiments, method  400  may provide a method for replacing an abatement resource supply  312  with a backup abatement resource supply  326 , without interrupting the operation of the process tool  302 . In some embodiments, the system  300  may include a backup abatement resource supply  326  which may be available solely to system  300  as a backup abatement resource supply to abatement resource supply  312 . 
     Method  400  begins with step  402 . In step  404 , a process tool  302  is operated to perform a series of steps in the manufacture of an electronic device. In step  406 , an abatement resource flows to an abatement tool  310  from an abatement resource supply  312 , and a backup abatement resource  326  is kept idle as the backup abatement resource supply to supply  312 . The abatement resource is used by the abatement tool  310  to abate effluent from the process tool  302 . 
     In step  408  the source of the abatement resource is changed from the abatement resource supply  312  to the backup abatement resource supply  326 . During the operation of the process tool  302  and the abatement tool  310 , there may come a time when the abatement resource supply  312  encounters a problem, or must be taken out of service for preventive maintenance or for some other reason. If it becomes necessary to take the abatement resource supply  312  out of service, an operator or a controller may disconnect the abatement resource supply  312  from the abatement tool  310 , and the operator, or controller, may connect the backup abatement resource supply  326  so that abatement tool  310  does not suffer an interruption of abatement resource. 
     The step  408  of disconnecting the abatement resource supply may include the following steps. With reference to  FIG. 3 , valves  320 ,  322  may be turned to a closed position to prevent any further flow of abatement resource from conduit  314  and to prevent any backflow of abatement resource or other contents of the abatement tool  310  through conduit  318 . At, or approximately at, the same time the backup abatement resource supply  326  may be connected to the abatement tool  310  by opening valves  334 ,  336 . After valves  320 ,  322  have been closed the connector  324  may be disconnected and the abatement resource supply  312  may be removed for service and/or troubleshooting. Any other suitable method may be used to disconnect the abatement resource supply  312  and connect the backup abatement resource supply  326 . 
     In step  410 , the operation of the process tool  302  is not interrupted during the steps of disconnecting the abatement resource supply  312  and connecting the alternate abatement resource supply  326 . In step  412 , method  400  ends. 
       FIG. 5  is a schematic drawing of a third embodiment of an electronic device manufacturing system  500  of the present invention. System  500  may include process tools  502 ,  502   a . Process tools  502 ,  502   a  may be connected to abatement tools  504 ,  504   a , respectively, by conduits  506 ,  506   a , respectively. Abatement resource supplies  508 ,  508   a  may be primary abatement resource supplies to abatement tools  504 ,  504   a , respectively. In some embodiments, abatement resource supply  508  may supply the abatement resource to the abatement tool  504  through primary conduit  510 . Similarly, abatement resource supply  508   a  may supply the same abatement resource to abatement tool  504   a  through primary conduit  510   a.    
     Secondary conduit  512  may connect to abatement resource supply  508  to abatement tool  504   a . Likewise, secondary conduit  512   a  may connect abatement resource supply  508   a  to abatement tool  504 . 
     Each of the primary conduits  510 ,  510   a  and secondary conduits  512 ,  512   a  may contain valve assemblies  514 ,  514   a  and  516 ,  516   a , respectively. The valve assemblies, and their operation on a valve assembly level, were discussed in detail with respect to  FIG. 3 , and that valve assembly level description applies equally to the valve assemblies depicted in  FIG. 5 . 
     Although a system  500  with only two parallel process tool/abatement tool/abatement resource supply lines has been depicted in  FIG. 5 , it is to be understood that three or more parallel process tool/abatement tool/abatement resource supply lines may be utilized. 
     It will be understood, for some abatement resources, that for every conduit which carries the abatement resource to an abatement tool there must be a return conduit. Return conduits are not shown in any of the figures herein for the sake of clarity. 
     In operation, process tools  502 ,  502   a  of system  500  may produce effluent which may flow through conduits  506 ,  506   a , respectively to abatement tools  504 ,  504   a , respectively, were the effluent may be abated. The abatement tools  504 ,  504   a  in turn, may receive abatement resources from abatement resource supplies  508 ,  508   a , respectively. Abatement resource supplies  508 ,  508   a  may be designed with sufficient capacity such that upon one of the abatement resource supplies becoming non-operational, the remaining operational abatement resource supply may be selected to supply abatement resource to both abatement tools  504 ,  504   a . This may enable the process tools  502 ,  502   a  to continue operating while the non-operational abatement resource supply is being replaced or repaired. 
     In some embodiments, during normal operation, secondary conduits  512 ,  512   a  may be unselected and remain closed so that no abatement resource may flow through the secondary conduits. Under circumstances where one of the abatement resource supplies  508 ,  508   a  becomes unavailable, the secondary conduit, connecting the still available abatement resource supply to the abatement tool whose primary abatement resource supply has become unavailable, may be selected. Upon selection, the valve assembly in the secondary conduit may be opened to allow the flow of abatement resource through the secondary conduit. For example, if abatement resource supply  508   a  were to become unavailable, secondary conduit  512  may be selected and valve assembly  516  placed in an open configuration. These actions would allow abatement resource to flow from abatement resource supply  508  through conduit  512  to abatement tool  504   a.    
     If one of the abatement resource supplies must be removed from the system  500 , the valve assemblies of the primary and secondary conduits which emanate from the abatement resource supply may be placed in the closed configuration and the connector portion of the valve assemblies may be disconnected. See  FIG. 3  for a description of the operation of the valve assemblies. For example, if abatement resource supply  508  must be removed from system  500 , valve assembly  514  and valve assembly  516  may be placed in the closed configuration. Thereafter, the valve assemblies may be disconnected so that the abatement resource supply  508  may be removed from the system  500 . Of course, prior to the removal of abatement resource supply  508 , valve assembly  516   a  may be placed in the open configuration so that abatement resource supply  508   a  may supply abatement resource through conduit  512   a  to abatement tool  504 . 
       FIG. 6  is a flow chart depicting a method  600  of operating the electronic device manufacturing system of  FIG. 5 . Method  600  takes advantage of the configuration of the system  500 , wherein extra capacity may be built into resource supplies  508 ,  508   a  so that upon the unavailability of one of the resource supplies the other the resource supply may be used to provide a backup resource capability to other abatement tool in the system  500 . As described above, the system  500  may include more than two parallel lines. 
     Method  600  begins in step  602 . In step  604 , process tools  502 ,  502   a , having dedicated abatement tools  504 ,  504   a , are operated to perform steps in the manufacture of electronic device. In step  606 , each abatement tool is supplied with the abatement resource from an abatement resource supply which is the primary supply for that abatement tool. For example, in  FIG. 5 , abatement tool  504  is primarily supplied by abatement resource supply  508 , and abatement tool  504   a  is primarily supplied by abatement resource supply  508   a . This may be accomplished by configuring valves  514 ,  514   a  in the open position, and by configuring valves  516 ,  516   a  in the closed position. 
     In step  608 , a first abatement resource supply is disconnected from the abatement tool which the first abatement resource supply primarily supplies. At, or about, the same time, a second abatement resource supply is connected to both abatement tools. Excess capacity built in to the abatement resource supplies enables one of the supplies to supply two abatement tools, at least for a limited time period. In step  610 , the process tools  502 ,  502   a  are operated both during and after the step of disconnecting the abatement resource supply and connecting the other abatement resource supply. Method  600  ends in step  612 . 
       FIG. 7  is a schematic drawing of a fourth embodiment of an electronic device manufacturing system  700  of the present invention. System  700  may include process tools  702 ,  702   a  which may be connected to abatement tools  704 ,  704   a  by conduits  706 ,  706   a . In some embodiments, for any particular abatement resource, each abatement tool may have a primary abatement resource supply for that abatement resource. In  FIG. 7 , for example, abatement tool  704  may receive an abatement resource from abatement resource supply  708  through conduit  710 , valve assembly  712 , and valve  714 . Likewise, abatement tool  704   a  may receive the abatement resource from abatement resource supply  708   a  through conduit  710   a  valve assembly  712   a  and valve  714   a . Resource supply  708   b  may be configured as a backup abatement resource supply, and may be connected to both abatement tools  704  and  704   a  through conduits  716  and  716   a  respectively. 
     In operation, process tools and  702 ,  702   a  may produce effluent which may flow through conduits  706 ,  706   a  and into abatement tools  704 ,  704   a , where the effluent may be abated. Abatement tools  704 ,  704   a  may use an abatement resource supplied by primary abatement resource supplies  708 ,  708   a , respectively. Under normal operating circumstances, abatement resource supply  708   b  may not be in fluid connection with any abatement tools and may be considered a spare abatement resource supply. By “not in fluid connection” is meant, for example, that valve assemblies  712   b ,  712   c  may be in a closed configuration, or that valves some  714  and  714   a  may be configured to prevent fluid flow from abatement resource supply  708   b . However, in the event that one or more of primary abatement resource supplies  708 ,  708   a  should become inoperative or otherwise be taken out of service, abatement resource supply  708   b  may be connected to one or more abatement tools for which the primary abatement resource supply has become unavailable. The selection and switch over from one abatement resource supply to another may be accomplished through a series of valves such as valve assemblies  712 ,  712   a ,  712   b , and  712   c , in conjunction with three-way valves  714  and  714   a . Thus for example if abatement resource supply  708  should become unavailable the valves may be operated to disconnect abatement resource supply  708  from fluid communication with abatement tool  704  and place abatement resource supply  708   b  in fluid communication with abatement tool  704 . This may be accomplished by placing valve assembly  712  in a closed configuration, by placing valve assembly  712   b  in an open configuration, and by placing three-way valve  714  in a configuration which enables abatement resource flowing through conduit  716  to flow into abatement tool  704 . While abatement resource supplies  708  is disconnected from system  700 , abatement resource supply  708  may be repaired or maintained. 
       FIG. 8  is a flow chart depicting a method  800  of operating the electronic device manufacturing system of  FIG. 7 . Method  800  makes use of a backup abatement resource supply  708   b  which is connected to more than one abatement tool  704 ,  704   b . Backup abatement tool  708   b  is idle during normal operation, and is available to serve as a backup abatement resource supply to any of the abatement tools  704 ,  704   b  to which it is connected. Although system  700  is shown with only two parallel process tool/abatement tool/abatement resource supply lines, it is to be understood that three or more parallel process lines may be used. 
     Method  800  begins with step  802 . In step  804  two process tools  702 ,  702   a  having dedicated abatement tools  704 ,  704   a  are operated to perform steps in an electronic device manufacturing process. In step  806 , each abatement tool  704 ,  704   a  receives an abatement resource from a primary abatement resource supply, respectively. In step  808 , a backup abatement resource supply is provided for use when a primary abatement resource supply may become unavailable, but is kept idle until it is needed as a backup resource supply. In step  810 , the supply of abatement resource is changed from one of the primary abatement resource supplies  708 ,  708   a  to the backup abatement resource supply  708   b . In step  812 , the process tools are operated to perform electronic device manufacturing process steps both during and following step  810  where the primary abatement resource supply is disconnected and the spare abatement resource supply is connected to the abatement tool. The method  800  ends in step  814 . 
     The foregoing description discloses only exemplary embodiments of the invention. Modifications of the above disclosed apparatus and methods which fall within the scope of the invention will be readily apparent to those of ordinary skill in the art. For example, the invention has been described with respect to abatement system components, but may be practiced with other electronic device manufacturing systems and subsystems, including, but not limited to, blowers, pumps, chillers, process chemical delivery systems, entire abatement systems, cooling towers, cryogenic pumps, etc. These systems and subsystems may have extra capacity which can be used for backup, can be duplicated to have dedicated backup, or act as a backup for a group of similar components. 
     Accordingly, while the present invention has been disclosed in connection with exemplary embodiments thereof, it should be understood that other embodiments may fall within the spirit and scope of the invention, as defined by the following claims.