Patent Publication Number: US-7591902-B2

Title: Recirculation and reuse of dummy dispensed resist

Description:
REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. patent application Ser. No. 10/000,208, which was filed Oct. 23, 2001 now U.S. Pat. No. 7,153,364, entitled “RE-CIRCULATION AND REUSE OF DUMMY-DISPENSED RESIST”, the entirety of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention generally relates to semiconductor processing, and in particular to an apparatus for dispensing resist. 
     BACKGROUND OF THE INVENTION 
     In the semiconductor industry, there is a continuing trend toward higher device densities. To achieve these higher densities, there have been, and continue to be, efforts toward scaling down the device dimensions (e.g., at submicron levels) on semiconductor wafers. In order to accomplish such high device packing density, smaller and smaller features sizes are required. This may include the width and spacing of interconnecting lines, spacing and diameter of contact holes, and the surface geometry such as corners and edges of various features. 
     The requirement of small features with close spacing between adjacent features generally requires high resolution lithographic processes. In general, lithography refers to processes for pattern transfer between various media. It is a technique used for integrated circuit fabrication in which a silicon slice, the wafer, is coated uniformly with a radiation-sensitive film, the resist, and the film exposed with a radiation source (such as optical light, x-rays, or an electron beam) that illuminates selected areas of the surface through an intervening master template, the mask, forming a particular pattern. The lithographic coating is generally a radiation-sensitive coating suitable for receiving a projected image of the subject pattern. Once the image is projected, it is indelibly formed in the coating. The projected image may be either a negative or a positive image of the subject pattern. Exposed portions of the coating become either more or less soluble (depending on the coating) in a particular solvent developer. The more soluble areas are removed in the developing process to leave the pattern image or its negative in the remaining coating. 
     Uniform and consistent resist coating is important to obtaining extremely fine patterns after exposure of the resist. For example, a coating thickness should vary by no more than ±100 across the wafer surface and from wafer to wafer. Although spray coating, meniscus coating, roller coating, curtain coating, extrusion coating, plasma deposition, and electrophoresis have all been used to apply resist coatings, spin coating is the usual method. 
     In a typical spin coating process, a small quantity of resist solution is dripped or sprayed onto a semiconductor substrate. The resist may be applied to the center of the substrate or in a pattern from center to edge. The resist may be applied in a helix pattern, for example, by slowly turning the wafer while scanning a dispense head from center to edge. The resist is initially spread across the surface by spinning the substrate at low speeds, (e.g., 200 rpm for 1 second). Then the spin rate is rapidly ramped up to a final spin speed in the 3000 to 7000 rpm range. The thickness of the final coating can depend on many parameters such as volume of solution dispensed, substrate diameter, resist solution viscosity, spin speed during dispense, rate of acceleration to final spin-speed, and final spin speed. Small changes, caused for example by the evaporation of solvent during spin-speed ramp-up, can significantly affect coating thickness. 
     Clean conditions must be maintained to avoid defects in the resist coating. The resist should be clean and free of particles above 0.2 m in diameter. Because the resist is sticky, it can easily entrap airborne particles. Therefore, resist coating should be carried out in a Class-100 or better environment. Defects can also be caused by air bubbles entrapped in the resist. 
     A common cause of defects and variability in resist coatings is the tendency of resists to dry rapidly and form residues on the dispense head. These residues can occlude the dispense head orifice, affecting the amount and pattern in which the resist is dispensed. In addition, flakes of dried resist and particles that crystallize from the resist solution as it dries may contaminate the resist solution or fall directly onto the substrates. 
     One way to avoid having resist solution dry at the dispense head is to maintain a steady flow of resist through the dispense head in between applications. This is called dummy dispensing. This method can be effective, but resist solutions are expensive and the amount of wasted resist involved in dummy dispensing cause this method to be prohibitive. 
     Another approach is to flush the dispense head with solvent between uses. One difficulty with this approach is that solvent in the dispense head may dilute subsequently dispensed resist solution. Diluting the resist solution affects its viscosity and results in variable coating thickness. The dispense head can be flushed with resist solution before dispensing on substrates, but as with dummy dispensing this involves the waste of expensive resist solution. The dispense head can also be submerged in a solvent between uses, with similar consequences. 
     Another idea is to place the dispense head, between uses, under an atmosphere saturated with solvent. Unfortunately, it is difficult to maintain the correct solvent atmosphere, particularly in a location in which the dispense head can be easily placed and removed. Additionally, the required apparatus is complicated and residues may still form. 
     Other measures can be taken to reduce the extent to which resist dries on the dispense head. A vacuum suck-back in the resist solution supply line can reduce the amount of resist drying on the dispense head. A non-stick coating can improve the effectiveness of the vacuum suck-back. However, some resist remains in the dispense head and the remaining resist tends to dry very quickly. 
     Dispense heads may also be constructed so that they can be frequently changed. This approach may be employed to avoid defective coatings, but only at the price of expense, equipment downtime, and inconvenience. 
     In view of the above, there remains an unsatisfied need for an apparatus and method of dispensing resist that is convenient, uncomplicated, does not waste expensive resist solution, and keeps the dispense head relatively free of residues and contaminates. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a system and methodology to facilitate dispensing a resist while promoting a relatively free-flow of the resist through a dispense head, yet mitigating waste associated with a dummy-dispensing process. This can be achieved by employing a dummy-dispensed resist through the dispense head to facilitate a substantially unimpeded application of the resist in the dispense head in support of a lithographic process, wherein dummy-dispensing of the resist can occur at times other than when the lithographic process occurs. Resist that is employed in the dummy-dispense process can then be captured in a reservoir and returned to the dispense head in a re-circulative manner in order to mitigate waste. 
     Between substrate applications of the resist for example, the dispense head can be positioned to dispense resist into a return line, wherein the flow of resist from the dispense head mitigates having the resist dry at the dispense head. By funneling the dummy-dispensed resist into a return line with low volume, for example, the dispense head can generally be kept free of residues while the dummy-dispensed resist can be substantially preserved and reused. 
     In one aspect, the invention provides a system for dispensing resist including a reservoir, a nozzle in fluid communication with the reservoir, and a return line in fluid communication with the reservoir, wherein the nozzle is moveable between first and second positions, in the first position, the nozzle is positioned to dispense liquid from the reservoir onto a substrate, and in the second position the nozzle is positioned to dispense liquid from the reservoir into the return line. 
     In another aspect, the invention provides a system for dispensing resist solution including a reservoir, means for dispensing resist solution from the reservoir onto a substrate, and means for capturing resist solution dispensed by the dispensing means and returning the dispensed fluid to the reservoir. 
     In a further aspect, the invention provides method of dispensing resist, including the steps of drawing resist from a reservoir, dispensing resist through a dispense head onto a substrate, dummy dispensing resist to reduce or eliminate residues on the dispense head, capturing dummy dispensed resist; and returning dummy dispensed resist to the reservoir. 
     To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a system for dispensing resist according to the present invention. 
         FIG. 2  is schematic of an apparatus according to the present invention with the dispense head in a first position. 
         FIG. 3  is schematic of the apparatus of  FIG. 2  with the dispense head in a second position. 
         FIG. 4  is another schematic of the apparatus of  FIG. 2  with the dispense head in a first position. 
         FIG. 5  is another schematic of the apparatus of  FIG. 2  with the dispense head in a second position. 
         FIG. 6  is an illustration of a nozzle and coupling of the present invention. 
         FIG. 7  is an illustration of the nozzle and coupling of  FIG. 6  with the two mated together. 
         FIG. 8  illustrates a feedback based resist control system according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring initially to  FIG. 1 , a block diagram of a system  10  illustrates resist dispensing according an aspect of the present invention. The system  10  provides a closed loop system that reduces and mitigates drying of resist in a dispense head, for example. The system  10  maintains dispensing of resist at a slow rate, even between resist depositing steps, to reduce drying and yet, mitigates waste of resist by capturing at least some dispensed resist. The system  10  includes a controller  14 , dispensing system  12 , substrate  30 , reservoir  20 , holding tank  16  and a solvent reservoir  18 . 
     The controller  14  is operatively coupled to the dispensing system  12 , the holding tank  16 , the solvent reservoir  18  and the reservoir  20 . The controller  14  is adapted to control the operation of the dispensing system  12 , the holding tank  16 , the solvent reservoir  18  and the reservoir  20 , wherein the controller  14  includes at least one processor (not shown) and a memory (not shown) to direct the process. It is noted that the memory within the controller serves to store program code executed by the processor for carrying out operating functions of the system as described herein. The memory may include read only memory (ROM) and random access memory (RAM). The ROM contains, among other code, the Basic Input-Output System (BIOS) which controls the basic hardware operations of the system  10 . The RAM is the main memory into which the operating system and application programs are loaded. The memory also serves as a storage medium for temporarily storing information such as monitoring data, acceptable values of static charge, threshold values of static charge, other data and algorithms that may be employed in carrying out the present invention. The memory may additionally include a hard disk drive or other mass storage device. It is also noted that the controller  14  may additionally include an input device and a display (also not shown). 
     The dispensing system  12  is operatively coupled to the holding tank  16  and the reservoir  20  and generally includes a nozzle and pump, illustrated and described below, to permit delivery of resist to the holding tank  16  or substrate  30  from the reservoir  20 . The dispensing system  12  can be configured and controlled to dispense resist at a controllable rate. It is to be appreciated that other characteristics of dispensing resist are also directed by the controller  14 . For example, the dispensing system  12  can move or position the nozzle to substantially any location by use of a movable and controllable swing arm (See e.g, reference  813  in  FIG. 8 ). Generally, the dispensing system  12  selectably dispenses resist to the substrate  30  or the holding tank  16  during normal operation. 
     The dispensing system  12  also provides dispensing feedback data to the controller  14 . The feedback data may include information such as, but not limited to, resist flow rate, resist composition, temperature, arm position, nozzle position, errors and the like. For example, if the pump were to become defective, the feedback data may indicate the pump error along with a reduced flow rate. 
     The holding tank  16  is operative with the dispensing system  12 , the reservoir and the solvent reservoir  18 , the controller  14  and is employed to capture resist dispensed by the dispensing system  12 . The captured resist may be obtained directly from the dispensing system  12 , such as by a nozzle of the dispensing system  12  dispensing resist into a coupling of the holding tank or indirectly from a housing that captures extra resist that is received from the substrate  30 . The captured resist can also be referred to as a dummy-dispense resist. It is appreciated that a tube or other device may be movably connected to the nozzle of the dispensing system  12  instead of having the nozzle moved to a coupling of the holding tank  16 . The holding tank  16  generally keeps a minimum amount of resist in the holding tank  16  and is able to receive a solvent from the solvent reservoir  18  to reduce or mitigate drying of resist. The holding tank  16  can also include a filter to filter out contaminants and air particles from captured resist. The holding tank  16  also provides captured resist to the reservoir  20  at a controllable flow rate as directed by the controller  14 . This may be achieved by, for example, via a pump or gravity feed system. 
     The holding tank  16  also provides holding tank feedback data to the controller  14 . This feedback information may include, but is not limited to, information such as tank capacity, filter status, solvent percentage, amount of captured resist, resist capture rate and the like. 
     The solvent reservoir  18 , as stated above, is operative with the holding tank  16  and the controller  14 . The solvent reservoir  18  can include a solvent that reduces or prevents drying of resist, for example, and provides the solvent, as needed to the holding tank  16 . The solvent reservoir  18  can also provide solvent feedback data to the controller  14 . The feedback data may include information such as, tank capacity, solvent remaining, solvent composition and the like. It is appreciated that the solvent reservoir  18  can include one or more types of solvents and can select at least one of the solvents to be provided. Further, the solvent reservoir  18  can control ratios of the at least one solvent to be provided. 
     The reservoir  20  is operative with the holding tank  16 , the dispensing system  12 , the controller  14  and provides resist to the dispensing system  12  at a flow rate. The reservoir  20  may have an initial amount of stored resist and receives captured resist from the holding tank  16 . The reservoir  20  may be connected to an external resist supply system (not shown) to maintain a minimum amount of resist in the reservoir  20 . Alternately, the reservoir  20  may indicate to the controller  14  that more resist needs to be added. 
     The reservoir  20  also provides reservoir feedback data to the controller  14 . The feedback data may include information such as, but not limited to, tank capacity, resist composition, temperature, flow rate, errors and the like. For example, the reservoir  20  may provide feedback data that captured resist from the holding tank  16  is not being received. 
     The substrate  30  receives dispensed resist from the dispensing system  12 . The substrate  30  is typically placed on a chuck within a housing. The chuck is operative to spin the substrate  30  to more evenly distribute resist on the substrate  30 . It is to be appreciated that the system  10  is operative to form a layer of resist on the substrate  30 . The layer of resist is typically formed having a thickness and uniformity. The formation of this layer is also controllable by the controller  14 . 
     Referring again to the controller  14 , the controller  14  can control all of the operations and functions of the system  10 . By utilizing feedback data from the other components of the system  10 , the controller  14  is responsible for the following functions, maintaining a minimum resist amount in the reservoir  20 , reducing or mitigating drying of resist in the holding tank  16 , modifying flow rates of resist between the system components and the like. It is appreciated that additional operations and functions may be associated with the system and still be in accordance with the present invention. 
       FIGS. 2-5  illustrate a system  100  in accordance with the present invention, wherein  FIGS. 2 and 3  present a side view, and  FIGS. 4 and 5  present a top view of the system. The system  100  includes reservoir  110 , swing arm  120 , dispense head  130 , and return line  140 . In operation, swing arm  120  brings dispense head  130  just above the center of substrate  150 , which is on chuck  160  within housing  170 . After a small quantity of resist from reservoir  110  is dispensed through dispense head  130 , swing arm  120  brings dispense head  130  up, over, and down into coupling  142  of return line  140 . Resist is then dummy-dispensed into return line  140 . The dummy-dispensed resist passes through filter  144  and into reservoir  110 . 
     The reservoir  110  holds resist solution ready for dispensing and receives resist solution captured by the return line  140 . If air bubbles have been trapped within the resist from the return line, they will generally separate out in the reservoir. It may be beneficial to provide reservoir  100  with a purge valve for the removal of air that has separated from the resist solution. 
     The system  100  generally includes a precision metering pump (not shown) between reservoir  110  and dispense head  130 . The pump can be, for example, a diaphragm pump, a bellows pump, or a piston actuated pump. The pump can provide a suck-back action that can be used to prevent resist from dripping while the dispense head  130  is being moved. It is noted that dummy-dispensed resist can return to reservoir  110  under the action of gravity. 
     The dispense head  130  is mounted on swing arm  120  and is in fluid communication with reservoir  110 . Swing arm  120  moves dispense head  130  between a first position, which is over the center of substrate  150 , to a second position, in which dispensed resist enters return line  140 . In the first position, dispense head  130  is preferably within about 5 mm of substrate  150  so that air bubbles are not trapped in the resist solution as it falls to substrate  150 . 
     Swing arm  120  raises, lowers, and pivots about its base  122 . Generally, the motion is first raising the dispense head to clear the wall  172  of housing  170 , then pivoting until dispense head  130  is over coupling  142 , and finally lowering until dispense head  130  mates with coupling  142 . A swing arm that operates by moving linearly, for example, in perpendicular directions X, Y, and Z, can also be used. The swing arm does not need to mate dispense head  130  with coupling  142 , but, can merely bring the dispense head to a position, wherein dummy-dispensed resist enters the return line. For example, swing arm  120  may position dispense head  130  above an entrance to return line  140 . 
     It is desirable that dispense head  130  be brought within a few millimeters of return line  140  so that air bubbles are not trapped by the dummy-dispensed resist. Bringing the dispense head close to the return line also reduces evaporation of solvent from the dummy-dispensed resist solution. In one aspect, dispense head  130  is brought within about 5 mm of return line  140 . In another aspect, dispense head  130  is brought within about 1.5 mm of return line  140 . In a further aspect, dispense head  130  is brought into a mating position with return line  140 . 
     Dispense head  130  includes one or more orifices from which resist may be dispensed. These orifices are usually circular, but can be oblong, rectangular, or any other shape. The dispense head may include a spray nozzle, for example a round spray nozzle, a wide-angle round spray nozzle, or a flat spray nozzle. Dispense head  130  may be constructed of any material, including metal, (e.g., steel or brass), or plastic, (e.g. thermoplastic or polypropylene). Dispense head  130  may be coated or constructed from a non-stick material, such as a fluoropolymer, (e.g. fluorinated ethylene propylene (Teflon®) or polytetrafluoroethylene (PTFE)). 
       FIGS. 6 and 7  illustrate an exemplary dispense head  130 . The exemplary dispense head can be designed to drip resist from a single orifice, however, it is to be appreciated that multiple orifice designs are possible. Dispense head  130  includes nozzle tip  132  that can have the shape of a truncated cone, for example. Nozzle tip  132  can be oversized in that its base  134  has a circumference at least about 10 times that of the cone&#39;s truncated tip  136  and orifice  138 . In this example, orifice  138  occupies the entire truncated tip, but orifice  138  could occupy a smaller portion of the truncated tip. Making nozzle tip  130  oversized facilitates forming a connection with the coupling  142  wherein the mating surfaces do not become fouled with resist, for example. 
     Coupling  142  has a complimentary shape to dispense head  130  in that coupling  142  and dispense head  130  can be brought together to form a seal. The seal is formed by surface  139  of dispense head  130  and surface  146  of coupling  142 , which surfaces mate together. As illustrated by  FIG. 7 , in the mated position dispense head  130  and coupling  142  form an enclosed vapor space. This space is sufficiently small that it rapidly fills with vapor from dummy-dispensed resist solution. On the other hand, the size of the space is sufficiently large that drops or resist solution forming on dispense head  130  do not contact dispense head  142  until they are released. Because of this, and the width of the space in comparison to the orifice dimensions, resist never reaches surface  146  unless it drips on that surface while dispense head  130  is being moved. Preferably, measures are taken to prevent such dripping, such as providing a suck-back to dispense head  130  after resist has been applied to substrate  150  but before dispense head  130  is moved away from its position over substrate  150 . With such measures, resist is prevented from drying and forming residues on any portion of coupling  142 . 
     The volume of return line  140  is generally kept small so that resist flows rapidly to either a holding tank or reservoir  110 . This can be facilitated by positioning coupling  142  over the holding tank or reservoir  110 . In one aspect, the volume of return line  140  is such that dummy-dispensed resist has a residence time in return line  140 , defined as volume of the return line divided by volumetric flow rate, of 100 minutes or less. In another aspect, the residence time is about 10 minutes or less. In a further aspect, the residence time is about 1 minute or less. 
     The system  100  can include additional means for preventing resist from drying within return line  140 , and in particular to prevent resist from drying within return line  140  when dispense head  130  is in its first position. Such means can include a cap for coupling  142 . The cap can be placed into mating position with coupling  142 , thereby enclosing the vapor space of return line  140  when dispense head  130  is over substrate  150 . The cap can be moved out of the way when dispense head  130  is brought to return line  140  and replaced when dispense head  130  is brought back to the area of substrate  150 . 
     Return line  140  can also include a liquid trap to reduce evaporation of solvent and reduce the extent to which resist solution contacts air. The trap is filled with resist solution. When a trap is used, it is advantageously located near the entrance of return line  140 , whereby a large portion of return line  140 &#39;s volume is isolated from the outside air. The use of a trap is particularly beneficial when dispense head  130  does not mate with coupling  142 , but remains separated from it by some distance. 
     Return line  140  is provided with a filter  144 . This filter is intended to remove contaminants and/or dried resist that may have gotten into the system. It is also usual to place a filter between reservoir  110  and dispense head  130 . When a filter of the later type is used, filter  144  may be redundant. 
     In the system  100 , return line  140  exhausts into reservoir  110 . However, the invention includes systems in which the return line leads to a holding tank and that the resist remain in the holding tank for a period of time before being returned to reservoir  110 . If a holding tank is employed, it is preferable that it contain some resist, in order that a substantial volume of solvent is not lost from the resist. In one aspect, the holding tank contains at least about 1% resist by volume, in another aspect, the holding tank contains at least about 5% resist by volume. In another aspect, the holding tank contains at least 15% resist by volume. Returning the resist directly to reservoir  110  facilitates that the resist is being discharged into a tank containing a substantial amount of resist in comparison to the tank&#39;s volume. 
     It is noted that the resist to be dispensed can be organic or inorganic and can be a photoresist responsive to visible light, ultraviolet light, x-rays, and/or it can be an electron beam resist or an ion beam resist. Although negative tone resists tend to be high viscosity compared to positive tone resists, the invention is applicable to positive and negative tone resists whether high viscosity or low viscosity. 
     The systems for dispensing resist and methods of dispensing resist of the invention may be employed to dispense other compounds. They are useful in dispensing, in a controlled manner, substantially any compound that is prone to drying at the dispense head and which cannot be economically disposed of. 
     In a process provided by the invention, the dispense head  130  is brought to a first position, from which fluid pumped from resist  130  may be dripped or sprayed onto substrate  150 . After resist has been dispensed, a suck-back action can be applied to clear dispense head  130  of excess resist that might drip. The dispense head  130  is then moved to a second position. 
     In the second position, dispense head  130  is positioned to dispense resist into a return line. The dispense head can be positioned above the return line, or it may engage a coupling on the return line. An issue to consider is to generally avoid permitting excessive solvent loss from portions of the resist, whether on the dispense head, around the entrance to the return line, or within the return line. 
     Resist is then dummy-dispensed into the return line. In one aspect, where a pump is used, the flow rate of dummy-dispensed resist may be from about 1 to 100% of the pump&#39;s capacity. In another aspect, the flow rate can be from about 1 to about 10% of the pump&#39;s capacity. Alternatively, the flow rate of dummy-dispensed resist may be from about 1 to about 100 drops per minute. In a further aspect, the flow rate of dummy-dispensed resist can be from about 10 to about 50 drops per minute. 
     The resist from the return line can be expelled into a holding tank or into the reservoir  110 . Where a holding tank is used, the resist from the holding tank is eventually returned to reservoir  110 . Solvent may be added to the dummy-dispensed resist, or to the reservoir, to compensate for solvent loss that occurs during dummy-dispensing. For this purpose, dummy-dispensed resist can be sampled in either the return line or the holding tank. It can also be beneficial to sample the dummy-dispensed resist to facilitate it has not been contaminated. In one aspect, dummy-dispensed resist is sampled and tested before being returned to reservoir  110 . In a further aspect, dummy dispensed resist is returned to reservoir  110  when it is of acceptable quality. 
       FIG. 8  illustrates a feedback based resist control system according to the present invention. The system reduces or mitigates drying of resist in a dispense head while conserving resist during a dummy-dispense process. A processor  803  can be any of a plurality of processors, such as the AMD K6, ATHLON and/or other processors. The manner in which the processor  803  can be programmed to carry out the functions relating to the present invention will be readily apparent to those having ordinary skill in the art based on the description herein. A memory  807  is operatively coupled to the processor  803  and serves to store program code executed by the processor for carrying out operating functions of the system as described herein. 
     A substrate or wafer  806  is shown on a chuck to assist in resist dispensing. A nozzle  812  is included in the system to dispense an antistatic solution. The nozzle  812  is positioned at a location above the substrate  806 . The nozzle  812  is able to adjust a flow rate of the resist and is adjustable to reduce or prevent clogging or drying of the nozzle. During resist layer depositing steps, the flow rate is adjusted to so as to deposit a suitable amount of resist on the substrate  806 . However, at other times, the resist may dispense at a slow rate. The slow rate is defined as the flow rate of resist necessary to avoid or reduce clogging of the nozzle  812 . The nozzle  812  provides feedback data to the processor  830 , through the flow rate control system  822 , to indicate early stages of clogging so that the flow rate can be adjusted. The flow rate is controlled by a flow rate control system  822 . The flow rate control system  822  is connected to the nozzle  812  and the processor  803 . The flow rate control system  822  adjusts the flow rate as determined by the processor  803  and based on the feedback data. 
     A swing arm  813  supports the nozzle  812  and connects the nozzle  812  to the nozzle base  814 . The swing arm  813  permits passage of the resist to the nozzle  812 . The nozzle base  814  positions the swing arm  813  and thereby the nozzle  812 . The nozzle base  814  is movable to adjust positioning of the swing arm  813  and the nozzle  812 , in multiple axes, so that the resist can be dispensed as required. Further, the nozzle base  814  is movable to adjust position of the swing arm  813  and the nozzle so that dispensed resist may be captured. The movement of the nozzle base  814  is controlled by the movement control system  824 . The movement control system  824  is coupled to the nozzle base  814  and the processor  803  and positions the nozzle  812  as needed during operation. The processor  803  controls the movement system  824  based on the feedback data. The nozzle base  814  receives captured resist from a delivery system  838  which can be a pipe or tubing, for example. 
     A resist capture device  836  is coupled to the delivery system  838  and can generally be implemented as described above with respect to  FIGS. 2-5 . The resist capture device  836  is shown with a coupling area able to receive the nozzle  812  and is generally placed close enough to the coupling area to form a seal. However, it is to be appreciated that the resist capture device  836  may utilize other components such as movable resist capture arm (not shown) to capture resist. The resist capture device  836  captures resist dispensed from the nozzle  812  when the nozzle  812  is appropriately located, such as above or attached to the resist capture device  836 . The captured resist may also be referred to as dummy dispense resist. The resist capture device  836  includes a reservoir for storing captured resist. The resist capture device  836  provides feedback data to the processor  803  through the resist capture control system  834 . 
     The feedback data may include information such as, but not limited to, remaining resist, resist capacity, flow rate, composition, solvent amounts and the like. The resist capture device  836  can add solvents (not shown) to captured resist to further reduce or prevent clogging or drying of the resist. The resist capture device  836  can include other components such as holding tanks, filters and the like. Further, the resist capture device  836  may be connected to an external resist source to obtain additional resist as necessary. The resist capture device  836  may include a port to expel gas released from the resist. Also, the resist capture device  836  can include a pump or gravity feed system to deliver captured resist to the nozzle  812 . 
     The resist capture control system  834  is connected to the resist capture device  836  and the processor  803 . The resist capture control system  834  is generally responsible for controlling all aspects of the resist capture device  836  and facilitating operation of the resist capture device  836 . As discussed above, the processor  803  controls the flow rate control system  822 , the movement control system  824  and the resist capture control system  834 . It is appreciated that a portion or all of the system of  FIG. 8  can be employed in other processing steps. For example, the nozzle  812  can be utilized to dispense other solutions such as anti-reflective coatings. 
     What has been described above is the present invention and several of its specific aspects. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present invention, but one of ordinary skill in the art will recognize that many further combinations and permutations of the present invention are possible. Accordingly, the present invention is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims.