Abstract:
A fluid dispense system having a coating layer applied to the fluid flow path and the external surfaces is described. The coating layer is chemically resistant to the working fluids of the fluid dispense system and prevents the leaching of a plurality of ions from the fluid dispense system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit under 35 U.S.C. §119(e)(1) of U.S. Provisional Patent Application No. 61/106,183, filed Oct. 17, 2008, which is hereby incorporated by reference herein in its entirety. 
     
    
     BACKGROUND INFORMATION 
       [0002]    Nano-fabrication includes the fabrication of very small structures that have features on the order of 100 nanometers or smaller. One application in which nano-fabrication has had a sizeable impact is in the processing of integrated circuits. The semiconductor processing industry continues to strive for larger production yields while increasing the circuits per unit area formed on a substrate, therefore nano-fabrication becomes increasingly important. Nano-fabrication provides greater process control while allowing continued reduction of the minimum feature dimensions of the structures formed. Other areas of development in which nano-fabrication has been employed include biotechnology, optical technology, mechanical systems, and the like. 
         [0003]    An exemplary nano-fabrication technique in use today is commonly referred to as imprint lithography. Exemplary imprint lithography processes are described in detail in numerous publications, such as U.S. Patent Publication No. 2004/0065976, U.S. Patent Publication No. 2004/0065252, and U.S. Pat. No. 6,936,194, all of which are hereby incorporated by reference. 
         [0004]    An imprint lithography technique disclosed in each of the aforementioned U.S. patent publications and patent includes formation of a relief pattern in a polymerizable layer and transferring a pattern corresponding to the relief pattern into an underlying substrate. The substrate may be coupled to a motion stage to obtain a desired positioning to facilitate the patterning process. The patterning process uses a template spaced apart from the substrate and a formable liquid applied between the template and the substrate. The formable liquid is solidified to form a rigid layer that has a pattern conforming to a shape of the surface of the template that contacts the formable liquid. After solidification, the template is separated from the rigid layer such that the template and the substrate are spaced apart. The substrate and the solidified layer are then subjected to additional processes to transfer a relief image into the substrate that corresponds to the pattern in the solidified layer. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0005]    So that the present invention may be understood in more detail, a description of embodiments of the invention is provided with reference to the embodiments illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of the invention, and are therefore not to be considered limiting of the scope. 
           [0006]      FIG. 1  illustrates a simplified side view of one embodiment of a lithographic system in accordance with the present invention. 
           [0007]      FIG. 2  illustrates a simplified side view of the substrate shown in  FIG. 1  having a patterned layer positioned thereon. 
           [0008]      FIG. 3  illustrates a simplified side view of an exemplary fluid dispense system. 
           [0009]      FIG. 4  illustrates a simplified side view of an exemplary fluid dispense system having a coating layer. 
           [0010]      FIG. 5  illustrates examples of compounds for use within coating layer. 
           [0011]      FIG. 6  illustrates a flow chart of an exemplary method for passivating fluid dispense system with coating layer. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Referring to the figures, and particularly to  FIG. 1 , illustrated therein is a lithographic system  10  used to form a relief pattern on a substrate  12 . Substrate  12  may be coupled to a substrate chuck  14 . As illustrated, substrate chuck  14  is a vacuum chuck. Substrate chuck  14 , however, may be any chuck including, but not limited to, vacuum, pin-type, groove-type, electromagnetic, and/or the like. Exemplary chucks are described in U.S. Pat. No. 6,873,087, which is hereby incorporated by reference. 
         [0013]    Substrate  12  and substrate chuck  14  may be further supported by a stage  16 . Stage  16  may provide motion about the x-, y-, and z-axes. Stage  16 , substrate  12 , and substrate chuck  14  may also be positioned on a base (not shown). 
         [0014]    Spaced-apart from substrate  12  is a template  18 . Template  18  generally includes a mesa  20  extending therefrom towards substrate  12 , mesa  20  having a patterning surface  22  thereon. Further, mesa  20  may be referred to as a mold  20 . Template  18  and/or mold  20  may be formed from such materials including, but not limited to, fused-silica, quartz, silicon, organic polymers, siloxane polymers, borosilicate glass, fluorocarbon polymers, metal, hardened sapphire, and/or the like. As illustrated, patterning surface  22  comprises features defined by a plurality of spaced-apart recesses  24  and/or protrusions  26 , though embodiments of the present invention are not limited to such configurations. Patterning surface  22  may define any original pattern that forms the basis of a pattern to be formed on substrate  12 . 
         [0015]    Template  18  may be coupled to a chuck  28 . Chuck  28  may be configured as, but not limited to, vacuum, pin-type, groove-type, electromagnetic, and/or other similar chuck types. Exemplary chucks are further described in U.S. Pat. No. 6,873,087, which is hereby incorporated by reference. Further, chuck  28  may be coupled to an imprint head  30  such that chuck  28  and/or imprint head  30  may be configured to facilitate movement of template  18 . 
         [0016]    System  10  may further comprise a fluid dispense system  32 . Fluid dispense system  32  may be used to position a polymerizable material  34  on substrate  12 . Polymerizable material  34  may be positioned upon substrate  12  using techniques such as drop dispense, spin-coating, dip coating, chemical vapor deposition (CVD), physical vapor deposition (PVD), thin film deposition, thick film deposition, and/or the like. Polymerizable material  34  may be disposed upon substrate  12  before and/or after a desired volume is defined between mold  22  and substrate  12  depending on design considerations. Polymerizable material 34 may comprise a monomer as described in U.S. Pat. No. 7,157,036 and U.S. Patent Publication No. 2005/0187339, all of which are hereby incorporated by reference. An exemplary composition of polymerizable coating  34 , as incorporated by reference from U.S. Pat. No. 7,157,036, may include isobornyl acrylate comprising approximately 55% of the composition, n-hexyl acrylate comprising approximately 27%, ethylene glycol diacrylate approximately comprising 15% of the composition, and the initiator 2-hydroxy-2-methyl1-phenyl-propan-1-one comprising approximately 3% of the composition. The initiator is sold under the trade name DAROCUR 1173 by CIBA of Tarrytown, N.Y. Also, less than 1% of the composition may include a surfactant with the general structure of R,R 2  where R 1 ═F(CF 2 CF 2 ) y , with y being in the range of 1 to 7, and R 2 ═CH 2 CH 2 O(CH 2 CH 2 O) x , inclusive where X is in the range of 0 to 15 inclusive. The composition above also includes stabilizers that are well known in the chemical art to increase the operational life of the composition. In one alternative embodiment, the composition above may not include the surfactant. A second exemplary composition, as incorporated by reference from U.S. Pat. Pub. 2005/0187339, has a viscosity associated therewith and including a surfactant, a polymerizable component, and an initiator responsive to a stimuli to vary the viscosity in response thereto, with the composition, in a liquid state, having the viscosity being lower than 100 centipoises, a vapor pressure of less than 20 Torr, and in a solid cured state a tensile modulus of greater than 100 MPa, a break stress of greater than 3 MPa, and an elongation at break of greater than 2%. 
         [0017]    Referring to  FIGS. 1 and 2 , system  10  may further comprise an energy source  38  coupled to direct an energy  40  along a path  42 . Imprint head  30  and stage  16  may be configured to position template  18  and substrate  12  in superimposition with path  42 . System  10  may be regulated by a processor  54  in communication with stage  16 , imprint head  30 , fluid dispense system  32 , and/or source  38 , and may operate on a computer readable program stored in a memory  56 . 
         [0018]    Either imprint head  30 , stage  16 , or both vary a distance between mold  20  and substrate  12  to define a desired volume there between that is filled by polymerizable material  34 . For example, imprint head  30  may apply a force to template  18  such that mold  20  contacts polymerizable material  34 . After the desired volume is filled with polymerizable material  34 , source  38  produces energy  40 , e.g., broadband ultraviolet radiation, causing polymerizable material  34  to solidify and/or cross-link conforming to shape of a surface  44  of substrate  12  and patterning surface  22 , defining a patterned layer  46 , as shown in  FIG. 2 , on substrate  12 . Patterned layer  46  may comprise a residual layer  48  and a plurality of features shown as protrusions  50  and recessions  52 , with protrusions  50  having thickness t 1  and residual layer having a thickness t 2 . 
         [0019]    The above-mentioned system and process may be further employed in imprint lithography processes and systems referred to in U.S. Pat. No. 6,932,934, U.S. Patent Publication No. 2004/0124566, U.S. Patent Publication No. 2004/0188381, and U.S. Patent Publication No. 2004/0211754, each of which is hereby incorporated by reference. 
         [0020]    As described above, polymerizable material  34  may be applied to the defined volume between template  18  and substrate  12  using a fluid dispense system  32 . Exemplary fluid dispense systems  32  may include, but are not limited to a printhead, a microjet tube, syringe, or similar systems that are able to eject a drop of fluid. For example, systems that are able to eject a drop of fluid ≦50 picoliters. 
         [0021]      FIG. 3  illustrates an exemplary embodiment of fluid dispense system  32 . Fluid dispense system  32  may comprise a dispense head  60  and nozzle system  62 . Nozzle system  62  may comprise a single tip  64  or a plurality of tips  64  depending on design considerations. For example,  FIG. 3  illustrates nozzle system  62  comprising a plurality of tips  64 . Generally, polymerizable material  34  enters inlet valve  61 , propagates through channel  63  along flow path  67 , and egresses from tip  64  of nozzle system  62 . Tip  64  defines a dispensing axis  65  at which polymerizable material  34  may be positioned on substrate  12 . The distance d s  between tip  64  and substrate  12  may be selected so as to minimize, or prevent splashing; minimize, or prevent gas from being present, and/or other similar design considerations. 
         [0022]    Polymerizable material  34  may be positioned by fluid dispense system  32  on substrate  12  as a droplet  66 . Exemplary droplet techniques for positioning polymerizable material  34  on substrate  12  are described in detail in 
         [0023]    U.S. Patent Publication No. 2005/0270312 and U.S. Patent Publication No. 2005/0106321, all of which are hereby incorporated by reference. 
         [0024]    Fluid dispense system  32  may also comprise a vision system  70 . Vision system may include a microscope  72  (e.g. optical microscope) to provide microscopic and/or macroscopic views of droplets  66  on substrate  12 . Dispense head  60  and/or microscope  72  may be regulated by processor  54 , and further may operate on a computer readable program stored in memory  56 . 
         [0025]    Fluid dispense system  32  may be formed of materials that leach ions into the polymerizable material  34 . Leaching may substantially alter the purity level of the polymerizable material  34  and may contaminate the imprint process as imprint process materials may be manufactured to have low ion content (e.g., ≦25 ppb electronic grade or ppb semiconductor grade for the following ions: Al, Ca, Cr, Cu, Fe, Li, Mg, Mn, Ni, K, Na, Sn, and Pb). 
         [0026]    Although use of the fluid dispense system  32  as it applies to the imprint process is discussed in detail herein, it should be noted that the fluid dispense system  32  may be used in other applications. For example, in bio related applications, bio-functional compounds that flow through fluid dispense system  32  may absorb leached containments from fluid dispense system  32 . Additionally, bio-functional compounds may adsorb on wetted surfaces of the fluid dispense system  32  and may potentially reduce concentration of the active contents of the fluid. As such, dispensing of bio-functional compounds may yield inadequate characteristics for sensing and/or detecting applications. 
         [0027]    Liquids flowing through the fluid dispense system  32  may be corrosive, clog and/or impede fluid flow. For simplicity of description, polymerizable material  34  is discussed hereinafter, however, any liquid may flow through fluid dispense system  32 . 
         [0028]    Passivating fluid dispense system  32  may protect polymerizable material  34  from contaminants of materials used to form fluid dispense system  32 . Additionally, passivating fluid dispense system  32  may protect fluid dispense system  32  from clogging. Generally, a coating layer  80  may be distributed over internal and external surfaces of fluid dispense system  32  and its associated fluid delivery components, such as tubing, fittings, valves, and liquid reservoir(s). For example, as illustrated in  FIG. 4 , coating layer  80  may be distributed on the walls of channel  63  within the flow path  67  of the fluid dispense system  32 . Additionally, coating layer  80  may be distributed over exterior portions of fluid dispense system  32 . For example, coating layer  80  may be distributed over the external portions of tips  64 , external portions of dispense head  60 , microscope  70 , processor  54 , and the like. Additionally, coating layer  80  may be distributed over communication links  83   a - c , the communication links being wired or wireless. 
         [0029]    In one example, coating layer  80  may be applied by chemical vapor deposition, however, it should be noted that other processes for applying coating layer  80  may be used. Coating layer  80  may have a thickness t 3 . For example, thickness t 3  may be less than 100 microns, or as in one embodiment, equal to or less than 15 microns. The coating layer  80  may include substituted and unsubstituted poly(p-xylylenes), such as substituted and unsubstituted poly(p-xylxylene) and poly(halo-p-xylxylenes) (e.g., poly(chloro-p-xylylene), poly(fluro-p-xylylene, and poly(iodo-p-xylxylene)). Substituted poly(p-xylxylenes) may include, for example, sulfonated, aminomethylated, and amidomethylated poly(p-xylylene) and poly(halo-p-xylylenes), plasma treated forms of poly(p-xylylene) and poly(halo-p-xylxylenes) the wet chemical modifications of poly(p-xylylene), poly(chloro-p-xylylene), and poly(fluro-p-xylylene) by sulfonation, aminomethylation, or amdiomethylation, and/or the like. 
         [0030]    Poly(p-xylylene) is also known by its trade name Parylene which is manufactured by Specialty Coating Systems of Indianapolis, Ind. Poly(chloro-p-xylylene) is also known by its trade name Parylene C or Parylene D which are manufactured by Specialty Coating Systems of Indianapolis, Indiana. One fluorine derivative of poly(p-xylylene) is also known by its trademark name Parylene HT® which is manufactured by Specialty Coating Systems of Indianapolis, Ind. Exemplary materials for coating layer  80  are illustrated in  FIG. 5 . 
         [0031]      FIG. 6  illustrates an exemplary embodiment of a method for passivating fluid dispense system  32  with coating layer  80 . In a step  82 , receiving fluid dispense system  32  that includes a fluid flow path  67  configured to provide a fluid from inlet port  61  to a plurality of nozzles  62 . In a step  84 , coating layer  80  may be applied to fluid flow path  67  and external surfaces of fluid dispense system  32 . 
         [0032]      FIG. 7  illustrates an exemplary embodiment of a method  86  for passivating fluid dispense system  32  with coating layer  80 . In a step  88 , receiving fluid dispense system  32  that includes a fluid flow path  67  configured to provide a fluid from inlet port  61  to a plurality of nozzles  62 . In a step  90 , a first film layer  80  may be applied to fluid flow path  67 . In a step  92 , a second film layer  80  may be applied to the external surfaces of fluid dispense system  32 .