Abstract:
A heat exchanger is disclosed having multiple temperature outputs. The heat exchanger may have a body and a heating system. The body may have a first end, a second end, a first side, and a second side. The first end may oppose the second end and the first side may oppose the second side. The body may define a plurality of fluid channels, a plurality of input ports, a plurality of output ports, and each of the fluid channels may be accessible by an input port on either the side of the body and an output port on the opposed side of the body. The heating system may be configured to deliver thermal energy to the first end of the body. The body may be configured to allow the thermal energy to substantially flow from the first end to the second end, thereby producing a temperature gradient across the body.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Modern integrated circuits contain millions of individual elements that are formed by patterning the materials, such as silicon, metal and/or dielectric layers, which make up the integrated circuit, to sizes that are small fractions of a micrometer. The technique used throughout the industry for forming such patterns is photolithography. A typical photolithography process sequence generally includes depositing one or more uniform photoresist (resist) layers on the surface of a substrate, drying and curing the deposited layers, patterning the substrate by exposing the photoresist layer to electromagnetic radiation that is suitable for modifying the exposed layer, and then developing the patterned photoresist layer.  
         [0002]     It is common in the semiconductor industry for many of the steps associated with the photolithography process to be performed in a multi-chamber processing system (e.g., a cluster tool) that has the capability to sequentially process semiconductor wafers in a controlled manner. One example of a cluster tool that is used to deposit (i.e., coat) and develop a photoresist material is commonly referred to as a track lithography tool.  
         [0003]     Track lithography tools typically include a mainframe that houses multiple chambers (which are sometimes referred to herein as stations) dedicated to performing the various tasks associated with pre- and post-lithography processing. There are typically both wet and dry processing chambers within track lithography tools. Wet chambers include coat and/or develop bowls, while dry chambers include thermal control units that house bake and/or chill plates. Track lithography tools also frequently include one or more pod/cassette mounting devices, such as an industry standard FOUP (front opening unified pod), to receive substrates from and return substrates to the clean room, multiple substrate transfer robots to transfer substrates between the various chambers/stations of the track tool, and an interface that allows the tool to be operatively coupled to a lithography exposure tool in order to transfer substrates into the exposure tool and receive substrates from the exposure tool after the substrates are processed within the exposure tool.  
         [0004]     At various locations throughout track lithography tools, chambers may have plates which hold the substrates while they are processed. The temperature of these plates may be closely associated with the temperature of the substrate held. The temperature of the substrate may be a critical variable in production of circuits from the substrate. Additionally, the temperature of materials applied to the substrate at various chambers may also be critical. The desired temperatures for optimum operation may be different for each chamber and each material to be applied to the substrate. Consequently, complex systems employing multiple cooling sources and/or multiple heating sources are required to deliver optimum temperatures to each chamber and material. Embodiments of the present invention provide solutions to these and other issues.  
       BRIEF SUMMARY OF THE INVENTION  
       [0005]     A heat exchanger with multiple temperature outputs is disclosed which may be included and used in a process module of a track lithography tool. The heat exchanger may have a body and a heating system. The body may have a first end, a second end, a first side, and a second side. The first end may oppose the second end and the first side may oppose the second side. The body may further define a plurality of fluid channels, a plurality of input ports, and a plurality of output ports. Each of the plurality of fluid channels may be accessible by an input port on either the first side or second side of the body, and an output port on the opposed side of the body. Each of the plurality of fluid channels may have a length which extends from the input port to the output port. The body may substantially be made from a thermally conductive material such as copper, brass, stainless steel, or bronze.  
         [0006]     In some embodiments, the lengths of the fluid channels may be substantially parallel to each other and/or be substantially perpendicular to the temperature gradient. In various embodiments, at least one porous insert may be disposed within at least one fluid channel and in conductive thermal communication with the body. The porous insert(s) may substantially be made from a variety of materials such as titanium, copper, brass, stainless steel, and bronze.  
         [0007]     The heating system may be configured to deliver thermal energy to the first end of the body, and the body may be configured to allow the thermal energy to substantially flow from the first end to the second end thereby producing a temperature gradient from the first end to the second end. In some embodiments, the heating system may be a resistance heater adapted to be electrically coupled with a power source. When a first fluid having a first temperature is input into a first input port, thermal energy may transfer between the body and the first fluid such that the first fluid may output at a first output port at a second temperature. The second temperature may be different than the first temperature, and also different than the temperature at which the first fluid would output at a second output port if input at a second input port. When the first fluid having the first temperature is input into each of the plurality of fluid channels at their input ports, the temperature of the first fluid at each of output ports may be progressively higher at output ports closer to the first end of the body.  
         [0008]     In some embodiments of the invention, the body of the heat exchanger may be substantially flat. In other embodiments, the body may have a body which is curved such that the first end is substantially proximate to the second end, thereby forming a tube. The tube may then have an interior, a circumference substantially similar to the distance from the first end to the second end, and a length substantially the length of one of the fluid channels. In embodiments with curved bodies, there may also be a fluid conduit in conductive thermal communication with the interior of the tube. The fluid conduit may define an input port and an output port. When a second fluid is input into the input port of the fluid conduit, the second fluid may output at the output port of the fluid conduit at a different temperature than it was input.  
         [0009]     Some embodiments of the invention may also have an input manifold. The input manifold may define a primary input port; a primary leg in fluid communication with the primary input port; a plurality of secondary legs, each in fluid communication with the primary leg; and a plurality of output ports, each in fluid communication with a different secondary leg. The secondary output ports may be coupled with the input ports of the body. In some embodiments, the input manifold may also defines a plurality of secondary input ports, each in fluid communication with a different secondary leg.  
         [0010]     Various other modifications and additions to the invention may be present in some embodiments. For instance, the heat exchanger may also have a plurality of valves, each coupled with a different output port. Some embodiments may also have a heat sink, possibly with a fan, at the second end of the body. Chillers and/or pumps may also be added to the heat exchanger to provide fluid flow at certain temperatures into the input ports of the body. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The present disclosure is described in conjunction with the appended figures:  
         [0012]      FIG. 1  is a simplified plan view of an embodiment of a track lithography tool according to an embodiment of the present invention;  
         [0013]      FIG. 2  is a plan view of a heat exchanger with multi-temperature outputs according to an embodiment of the present invention;  
         [0014]      FIG. 3  is a plan view of a heat exchanger with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 2 , except having fluid channels where the lengths of such channels are not perpendicular to the sides of the heat exchanger;  
         [0015]      FIG. 4  is a plan view of a heat exchanger with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 2 , except having fluid channels where the lengths of such channels are not perpendicular to the sides of the heat exchanger and also not parallel to one another;  
         [0016]      FIG. 5  is an isometric view of a fluid channel with the top of the channel cut away for the purpose of clarity;  
         [0017]      FIG. 6  is an isometric view of a porous insert disposed in the fluid channel of  FIG. 5 ;  
         [0018]      FIG. 7  is an isometric view of a heat exchanger with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 2 , except where the body is curved rather than flat;  
         [0019]      FIG. 8  is an isometric view of a heat exchanger with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 7 , except also having a conduit running through the center of the curved heat exchanger;  
         [0020]      FIG. 9  is a plan view of a heat exchanger with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 2 , except the output lines are not shown and the input manifold has secondary input ports;  
         [0021]      FIG. 10  is a plan view of a heat exchanger with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 2 , except the input manifold is not shown and output valves are coupled to the output ports;  
         [0022]      FIG. 11  is a plan view of a heat exchanger with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 2 , except a heat sink is coupled to the second end of the heat exchanger and a fan is shown moving air over the heat sink;  
         [0023]      FIG. 12  is a plan view of a heat exchanger with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 11 , except having a body temperature control channel block instead of a heat sink and fan; and  
         [0024]      FIG. 13  is a block diagram of a system which incorporates a heat exchanger with multiple outputs according to an embodiment of the present invention with a chiller, pump, valve selector and track lithography tool. 
     
    
       [0025]     In the appended figures, similar components and/or features may have the same reference label. Further, various components and/or features of the same type may be distinguished by following the reference label by a letter that distinguishes among the similar components and/or features. If only the first reference label is used in the specification, the description is applicable to any one of the similar components and/or features having the same first reference label irrespective of the letter suffix.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0026]     According to the present invention, apparatuses for controlling the temperature of components in substrate processing equipment are provided. More particularly, the present invention relates to a heat exchanger comprising a body with fluid channels for a coolant fluid and a heater to produce multiple temperature outputs from a single input. The present invention may therefore be able to control temperatures in multiple various subsystems of processing equipment using one fluid source and one heater. Merely by way of example, the apparatuses of the present invention may be used to control the temperature of chambers and photoresist material prior to deposition. The apparatuses can also be applied in other processes for controlling the temperatures of fluids.  
         [0027]      FIG. 1  is a plan view of an embodiment of a track lithography tool  100  in which the embodiments of the present invention may be used. As illustrated in  FIG. 1 , track lithography tool  100  contains a front end module  110  (sometimes referred to as a factory interface or FI) and a process module  111 . In other embodiments, the track lithography tool  100  includes a rear module (not shown), which is sometimes referred to as a scanner interface. Front end module  110  generally contains one or more pod assemblies or FOUPS (e.g., items  105 A-D) and a front end robot assembly  115  including a horizontal motion assembly  116  and a front end robot  117 . The front end module  110  may also include front end processing racks (not shown). The one or more pod assemblies  105 A-D are generally adapted to accept one or more cassettes  106  that may contain one or more substrates or wafers, “W,” that are to be processed in track lithography tool  100 . The front end module  110  may also contain one or more pass-through positions (not shown) to link the front end module  110  and the process module  111 .  
         [0028]     Process module  111  generally contains a number of processing racks  120 A,  120 B,  130 , and  136 . As illustrated in  FIG. 1 , processing racks  120 A and  120 B each include a coater/developer module with shared dispense  124 . A coater/developer module with shared dispense  124  includes two coat bowls  121  positioned on opposing sides of a shared dispense bank  122 , which contains a number of nozzles  123  providing processing fluids (e.g., bottom anti-reflection coating (BARC) liquid, resist, developer, and the like) to a wafer mounted on a substrate support  127  located in the coat bowl  121 . In the embodiment illustrated in  FIG. 1 , a dispense arm  125  sliding along a track  126  is able to pick up a nozzle  123  from the shared dispense bank  122  and position the selected nozzle over the wafer for dispense operations. Of course, coat bowls with dedicated dispense banks are provided in alternative embodiments.  
         [0029]     Processing rack  130  includes an integrated thermal unit  134  including a bake plate  131 , a chill plate  132 , and a shuttle  133 . The bake plate  131  and the chill plate  132  are utilized in heat treatment operations including post exposure bake (PEB), post-resist bake, and the like. In some embodiments, the shuttle  133 , which moves wafers in the x-direction between the bake plate  131  and the chill plate  132 , is chilled to provide for initial cooling of a wafer after removal from the bake plate  131  and prior to placement on the chill plate  132 . Moreover, in other embodiments, the shuttle  133  is adapted to move in the z-direction, enabling the use of bake and chill plates at different z-heights. Processing rack  136  includes an integrated bake and chill unit  139 , with two bake plates  137 A and  137 B served by a single chill plate  138 .  
         [0030]     One or more robot assemblies (robots)  140  are adapted to access the front-end module  110 , the various processing modules or chambers retained in the processing racks  120 A,  120 B,  130 , and  136 , and the scanner  150 . By transferring substrates between these various components, a desired processing sequence can be performed on the substrates. The two robots  140  illustrated in  FIG. 1  are configured in a parallel processing configuration and travel in the x-direction along horizontal motion assembly  142 . Utilizing a mast structure (not shown), the robots  140  are also adapted to move in a vertical (z-direction) and horizontal directions, i.e., transfer direction (x-direction) and a direction orthogonal to the transfer direction (y-direction). Utilizing one or more of these three directional motion capabilities, robots  140  are able to place wafers in and transfer wafers between the various processing chambers retained in the processing racks that are aligned along the transfer direction.  
         [0031]     Referring to  FIG. 1 , the first robot assembly  140 A and the second robot assembly  140 B are adapted to transfer substrates to the various processing chambers contained in the processing racks  120 A,  120 B,  130 , and  136 . In one embodiment, to perform the process of transferring substrates in the track lithography tool  100 , robot assembly  140 A and robot assembly  140 B are similarly configured and include at least one horizontal motion assembly  142 , a vertical motion assembly  144 , and a robot hardware assembly  143  supporting a robot blade  145 . Robot assemblies  140  may be in communication with a system controller  160 . In the embodiment illustrated in  FIG. 1 , a rear robot assembly  148  is also provided.  
         [0032]     The scanner  150 , which may be purchased from Canon USA, Inc. of San Jose, Calif., Nikon Precision Inc. of Belmont, Calif., or ASML US, Inc. of Tempe, Ariz., is a lithographic projection apparatus used, for example, in the manufacture of integrated circuits (ICs). The scanner  150  exposes a photosensitive material (resist), deposited on the substrate in the cluster tool, to some form of electromagnetic radiation to generate a circuit pattern corresponding to an individual layer of the integrated circuit (IC) device to be formed on the substrate surface.  
         [0033]     Each of the processing racks  120 A,  120 B,  130 , and  136  contain multiple processing modules in a vertically stacked arrangement. That is, each of the processing racks may contain multiple stacked coater/developer modules with shared dispense  124 , multiple stacked integrated thermal units  134 , multiple stacked integrated bake and chill units  139 , or other modules that are adapted to perform the various processing steps required of a track photolithography tool. As examples, coater/developer modules with shared dispense  124  may be used to deposit a bottom antireflective coating (BARC) and/or deposit and/or develop photoresist layers. Integrated thermal units  134  and integrated bake and chill units  139  may perform bake and chill operations associated with hardening BARC and/or photoresist layers after application or exposure.  
         [0034]     In one embodiment, a system controller  160  is used to control all of the components and processes performed in the cluster tool  100 . The controller  160  is generally adapted to communicate with the scanner  150 , monitor and control aspects of the processes performed in the cluster tool  100 , and is adapted to control all aspects of the complete substrate processing sequence. The controller  140 , which is typically a microprocessor-based controller, is configured to receive inputs from a user and/or various sensors in one of the processing chambers and appropriately control the processing chamber components in accordance with the various inputs and software instructions retained in the controller&#39;s memory. The controller  140  generally contains memory and a CPU (not shown) which are utilized by the controller to retain various programs, process the programs, and execute the programs when necessary. The memory (not shown) is connected to the CPU, and may be one or more of a readily available memory, such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, or any other form of digital storage, local or remote. Software instructions and data can be coded and stored within the memory for instructing the CPU. The support circuits (not shown) are also connected to the CPU for supporting the processor in a conventional manner. The support circuits may include cache, power supplies, clock circuits, input/output circuitry, subsystems, and the like all well known in the art. A program (or computer instructions) readable by the controller  140  determines which tasks are performable in the processing chamber(s). Preferably, the program is software readable by the controller  160  and includes instructions to monitor and control the process based on defined rules and input data.  
         [0035]     It is to be understood that embodiments of the invention are not limited to use with a track lithography tool such as that depicted in  FIG. 1 . Instead, embodiments of the invention may be used in any track lithography tool including the many different tool configurations described in U.S. patent application Ser. No. 11/315,984, entitled “Cartesian Robot Cluster Tool Architecture” filed on Dec. 22, 2005, which is hereby incorporated by reference for all purposes and including configurations not described in the above referenced application.  
         [0036]     Referring to  FIG. 1 , it may be desirable to control the temperature of the substrates by controlling the temperature of the plates which hold the substrates at and between various chambers in the tack lithography tool. For instance, pod assemblies  105 A-D, substrate support  127 , chill plate  132 , shuttle  133  and robot assemblies  140 A,  140 B may wish to be temperature controlled, thereby affecting the temperature of the substrate being processed at that component. One common method of controlling the temperature of each of these components is to flow fluid coolant at a certain temperature to each component. However, it is often desirable due to process parameters to maintain different components at different temperatures. In such a case, multiple sources of different temperature coolant fluid, or one source with multiple temperature adjustment systems at each component must be provided. Embodiments of the present invention allow for a single source of constant temperature coolant fluid and a single temperature adjustment system to provide coolant fluid at different, controlled temperatures to various components. In some embodiments, heat exchangers of the invention may physically be located in process module  111 , possibly in the shared dispensers  124 . Other locations in a track lithography tool may be an appropriate location for such heat exchangers depending on where coolant fluid from the heat exchanger is required.  
         [0037]     Turning now to some of the specific heat exchangers of the present invention,  FIG. 2  illustrates a plan view of a heat exchanger with multi-temperature outputs  200  according to one embodiment. A body  205  is shown having four fluid channels  210 ,  220 ,  230 ,  240  spaced equidistant between first end  250  of the body  205  and second end  255  of the body  205 . In other embodiments the spacing of the fluid channels may not be equidistant, or may be only approximately equidistant, between first end  250  and second end  255 . The body  205  may be made from any thermally conductive material, including, but not limited to, copper, brass, stainless steel and bronze. Note that the top of the body  205  is cut away for explanatory purposes in  FIG. 2  so the fluid channels may be seen more clearly. Each fluid channel has an input port  212 ,  222 ,  232 ,  242  on the first side  265  of the body  205  and an output port  214 ,  224 ,  234 ,  244  on the second side  265  of the body. These ports may be threaded, or otherwise adapted by methods known in the art, to be connected to fluid delivery equipment. In  FIG. 2  the ports are shown as threaded.  
         [0038]     A heating system  270  is shown having a power source  272 , controller  274 , and resistance heater  276 . The heating system  260  is coupled with the body  205  in any suitable manner known in the art, and a thermal paste  278  may be disposed between the heating system  260  and the body  205  (the amount of thermal paste is exaggerated for purposes of clarity). The thermal paste  268  may be a silicon paste, a ceramic paste or a metal paste known in the art. Though a resistance heater is shown for the heating system  260 , other types of heaters known in the art could also be used to deliver thermal energy to the body  205 . Heat produced by the heating system  270  is transferred to first end  250  of body  205  and flows through body  205  to second end  255 . In  FIG. 2 , the heat  299  is shown coming second end  255  for visual explanation purposes.  
         [0039]     Controller  274  of heating system  270  may, in some embodiments, be controlled by a feedback loop. The feedback loop may monitor the temperature of the body  205  and adjust controller  274  to change the amount of heat, and consequently the temperature of body  205 . In  FIG. 2 , a thermocouple  278  at the first end  250  of body  205  is shown connected with controller  274 . Controller  274  may adjust the amount of voltage across the resistance heater  276  to vary the amount of heat created based upon the temperature of body  205  at thermocouple  278 . In other embodiments, a different feedback system could be employed. For instance, temperature of body  205  could be measured at different or multiple locations, or device other than a thermocouple could be used to measure temperature.  
         [0040]     Also shown in  FIG. 2  is a manifold  280  for delivering fluid to the input ports  212 ,  222 ,  232 ,  242  of the body  205 . The manifold has a primary input port  282  connected to a primary leg  284 . Primary leg  284  is connected to four secondary legs  286 A,  286 B,  286 C,  286 D. Each secondary leg  286 A,  286 B,  286 C,  286 D is connected to an output port  288 A,  288 B,  288 C,  288 D. By inputting a fluid at one temperature into primary input port  282 , the fluid may be delivered to each output port  288 A,  288 B,  288 C,  288 D. The manifold may be insulated in some embodiments to prevent change in temperature of the fluid prior to entry into the body  205  of the heat exchanger  200 .  
         [0041]     In an example use, a coolant fluid, perhaps chilled water at 19° C., may be sent to input manifold  280  and enter at primary input  282 . Notably, the water may perhaps be another, uncontrolled temperature. The coolant fluid may flow to each of the input ports  212 ,  222 ,  232 ,  242 . Heating system  270  may be maintaining the first end  250  of the body  205  at 25° C., and thermal convection from the second end  255  of the body  205  may cause the second end  255  of the body  205  to be at 20° C. The temperature throughout the body  205  between the first end  250  and the second end  255  may be a linear gradient between the temperatures of the ends. Therefore the temperatures at respective locations on the body  205  may be: first end  250 —25° C.; fluid channel  210 —24° C.; fluid channel  220 —23° C.; fluid channel  230 —22° C.; fluid channel  240 —21° C.; and second end  255 —20° C. If the rate of heat flow from the first end  250  to the second end  255  is more significant than the flow of coolant fluid through the body  205 , then the coolant fluid may exit the body  205  at the temperature of the of the body  205  at the same temperature of the fluid channel through which the coolant fluid flowed. In this example, the fluid might exit the body  205  at the following locations and temperatures: output port  214 —24° C.; output port  224 —23° C.; output port  234 —22° C.; and output port  244 —21° C. The coolant fluid may then flow through fluid output tubes  292 ,  294 ,  296 ,  298 , which are coupled with the output ports  214 ,  224 ,  234 ,  244  respectively.  
         [0042]     In this manner, multiple flows of a coolant fluid may be provided, each at a different temperature, while only using a single temperature fluid source and a single heating and cooling system. In some embodiments, flows from each of fluid output tubes  292 ,  294 ,  296 ,  298  may each be sent to components which require a different temperature coolant fluid for optimum performance. In other embodiments, less than all output tubes  292 ,  294 ,  296 ,  298  may be used because fewer components required coolant fluid, or fewer coolant fluids of differing temperatures are required.  
         [0043]      FIGS. 3 and 4  are plan views of two other heat exchangers  300 ,  400  with multi-temperature outputs according to alternative embodiments of the present invention, similar to that shown in  FIG. 2 , except having fluid channels  210 ,  220 ,  230 ,  240  where the lengths of such channels are not perpendicular to the sides of the heat exchanger, or parallel to each other. This figure demonstrates that the fluid channels  210 ,  220 ,  230 ,  240  need to be perpendicular in all embodiments.  
         [0044]      FIG. 5  is an isometric view of a fluid channel  500  with the top of the channel cut away for the purpose of clarity.  FIG. 6  is an isometric view of a porous insert  610  disposed in the fluid channel  500  of  FIG. 5 . The porous insert may, for example, be made from titanium, copper, brass, stainless steel and/or bronze. The inserts may be brazed into the body  205  of a heat exchanger to improve heat transfer between the body  205  and the fluid channel  500 . Coolant fluid entering the front side of the porous insert  610  would flow through the pores and exit the back side of the porous insert. In this way, the coolant fluid is in contact with more surface area at the desired temperature, increasing heat transfer between the coolant fluid and the fluid channel  500  may be increased. By adding inserts to the channels, the overall size of the fluid channel may be decreased and still obtain sufficient heat transfer.  
         [0045]      FIG. 7  is an isometric view of a heat exchanger  700  with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 2 , except having six rather than four fluid channels and having a body  705  which is curved rather than flat. A tube shape is thereby formed in this embodiment having a length of the distance between the first side and second side which have the input and output ports. The circumference of the tube shape is equal to the distance between the first end  710  and the second end  720  of the body  705 , plus the width of the heater  730 , plus an air space between the heater  730  and the second end  720 . Two of the fluid channels  740 ,  750  are shown as hidden in dashed line for purposes of clarity. Additionally, for explanatory purposes, heat  760  is seen coming off second end  720 . A different heating system  730  may be used in this embodiment to more completely make the assembly tubular in shape. This tubular shape may be advantageous in certain embodiments due to space constraints of related equipment.  FIG. 8  is an isometric view of the heat exchanger  700  from  FIG. 7 , except also having a conduit  810  running through the center of the curved heat exchanger. In some embodiments, this conduit  810  may be a resist line of a track lithography tool. Heat transfer between the conduit  810  and the heat exchanger  700  may be useful in adjusting the temperature of the resist fluid prior to reaching the component where it is used in the track lithography tool. This may reduce the amount of thermal adjustment performed by other components in the track lithography tool such as water jacketing and other systems used to adjust the temperature of the resist fluid. In some embodiments, multiple fluid conduits may pass through the tube shaped heat exchanger  700 .  
         [0046]      FIG. 9  is a plan view of a heat exchanger  900  with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 2 , except the output lines are not shown and the input manifold  910  has secondary input ports  912 ,  914 ,  916 ,  918 . The secondary inputs  912 ,  914 ,  916 ,  918  may be used to return coolant fluid from a component, possibly from a track lithography tool, to the heat exchanger for re-use before the fluid is returned to a chiller, pump or other coolant fluid component. This may be advantageous where the temperature of the return coolant fluid is only slightly different than one of the temperatures the heat exchanger is configured to produce.  
         [0047]      FIG. 10  is a plan view of a heat exchanger  1000  with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 2 ,except the input manifold is not shown and output valves  1002 ,  1004 ,  1006 ,  1008  are coupled to the output ports. Output valves  1002 ,  1004 ,  1006 ,  1008  may be computer controlled and connected to temperature detection and control devices such thermocouples, resistance temperature devices and valve controllers. Through the use of such systems, the heat exchanger  1000 , and other heat exchangers of the invention, may be used to change which temperature coolant fluid is being delivered to a component based on the temperature of components downstream.  
         [0048]      FIG. 11  is a plan view of a heat exchanger  1100  with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 2 ,except heat sink  1110  is coupled to the second end of the heat exchanger and a fan  1120  is shown moving air over the heat sink  1110 . A thermal paste  1130  is disposed between the body  205  and the heat sink  1110  (the amount of thermal paste is exaggerated for purposes of clarity). Some embodiments may only use heat sink  1110 , without fan  1120 . By changing the physical shape and properties of the heat sink  1110 , the rate of conductive heat transfer from the second end  255  of the body  205  can be controlled. This may change the gradient of temperatures across the body  205 , and therefore the temperature outputs of the heat exchanger  1100 . The addition of a fan  1120  may allow for greater hear transfer from the heat sink  1110 , and consequently even more pronounced temperature gradients across the body  205 . For example, in an embodiment without a heat sink  1110  and fan  1120 , the temperature difference across the body  205  may be 5° C. (for example, 20° C. to 25° C., as discussed above in reference to  FIG. 1 ). If a heat sink  1110  and fan  1120  are employed, more convective heat transfer will occur at the second end  255  of the body  205 , and the temperature difference across the body  205  may increase to 10° C. (for example, 15° C. to 25° C.). Now instead of the four temperature outputs of the body  205  being 21° C., 22° C., 23° C. and 24° C., the temperature outputs of the body  205  may be 23° C., 21° C., 19° C. and 17° C. (corresponding to the equidistant fluid channels between the first end  250  and the second end  255 ). In these embodiments, controls on the heater  270  (to control thermal heat production) and the fan  1120  (to control the speed of fan  1120 , and consequently the rate of active thermal convection at the second end  255 ) may both be adjusted to configure the heat exchanger  1100  to produce different ranges and increments of output coolant fluid temperatures. In some embodiments, a thermocouple  1140  or other temperature measuring device may be used to control fan  1120 . In this way, fan  1120  may be run at different speeds to achieve different temperatures at the second end  255  of body  205 .  
         [0049]      FIG. 12  is a plan view of a heat exchanger  1200  with multi-temperature outputs according to an embodiment of the present invention, similar to that shown in  FIG. 11 , except having a body temperature control channel block  1210  instead of a heat sink  1110  and fan  1120 . In this embodiment, chilled fluid is used to control the temperature of second end  255 . Body temperature control channel block  1210  is coupled to second end  255  and a thermal paste  1230  is disposed between body  205  and body temperature control channel block  1210  (the amount of thermal paste is exaggerated for purposes of clarity). Body temperature control channel block  1210  contains a fluid channel  1215  which allows fluid to travel through body temperature control channel block  1210 , thereby controlling the temperature of second end  255 . In some embodiments, body temperature control channel block  1210  may merely be another fluid channel through the body  205  near second end  255 , and thus integral with body  205 . In various embodiments, the temperature of the fluid entering the body temperature control channel block  1210  may be controlled to control the temperature of the second end (as measured by a thermocouple  1240 ), and may or may not be the same coolant fluid entering the fluid channels of block  205 . In some embodiments, thermocouple  1240 , or other temperature measuring device, may assist in controlling a flow valve  1230 , adjusting the flow of fluid through body temperature control channel block  1210  to adjust the temperature of second end  255 . Fluid exiting body temperature control channel block  1210  may be, or may not be, used by other equipment before it is returned to the fluid source. Additionally, a porous insert may be put into fluid channel  1215  to increase thermal heat transfer as described above.  
         [0050]      FIG. 13  is a block diagram of a system  1300  which incorporates a heat exchanger  1000  with multiple motorized (or otherwise remotely activated) valved outputs  1002 ,  1004 ,  1006 ,  1008  according to one embodiment of the present invention with a chiller  1310 , pump  1320 , valve selector  1330  and track lithography tool  1340 . In this embodiment, coolant fluid passes through chiller  1310 , being pressurized by pump  1320 . Coolant fluid travels to heat exchanger  1000  where it passes through four different fluid channels. At least one of the valves  1002 ,  1004 ,  1006 ,  1008  is open and allows the coolant fluid from one of the fluid channels, now at a different temperature than before entry into heat exchanger  1000 , to pass to track lithography tool  1340 . Before entering track lithography tool  1340 , a thermocouple  1350 , or other temperature detection device, informs valve selector  1330 , and based on process parameters, valve selector  1330  may change which valve  1002 ,  1004 ,  1006 ,  1008  is open, thereby changing the temperature of coolant fluid delivered to track lithography tool  1340 . In some embodiments, multiple fluid lines may be delivered from heat exchanger  1000  to multiple components in track lithography tool  1340 . These embodiments may contain more motorized valved outputs and more complex valve selector systems. Also, in various embodiments, coolant fluid may be returned to a point downstream from chiller  1310 , but upstream of heat exchanger  1000  to be reused before being chilled again. The reentry point of coolant fluid in these embodiments may be secondary input ports in a manifold coupled to the heat exchanger as described in  FIG. 9 . These secondary inputs may be valved and controlled by another valve selector system.  
         [0051]     The invention has now been described in detail for the purposes of clarity and understanding. However, it will be appreciated that certain changes and modifications may be practiced within the scope of the appended claims.