Abstract:
The present invention is directed towards a method and a system of patterning first and second opposed sides of a substrate. The method and system may employ a mold assembly and obtaining a desired spatial relationship between the first and second opposed sides of the substrate and the mold assembly. In a further embodiment, the method and system may employ a first and a second mold assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Application No. 60/748,430, filed on Dec. 8, 2005, entitled “Apparatus for and Methods for Imprinting, Aligning, and Separation for Double Side Imprinting,” the entirety of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The field of the invention relates generally to nano-fabrication of structures. More particularly, the present invention is directed to a method and a system of double-sided patterning of a substrate. 
     BACKGROUND INFORMATION 
     Nano-fabrication involves the fabrication of very small structures, e.g., having features on the order of nanometers or smaller. One area in which nano-fabrication has had a sizeable impact is in the processing of integrated circuits. As the semiconductor processing industry continues to strive for larger production yields while increasing the circuits per unit area formed on a substrate, nano-fabrication becomes increasingly important. Nano-fabrication provides greater process control while allowing increased reduction of the minimum feature dimension of the structures formed. Other areas of development in which nano-fabrication has been employed include biotechnology, optical technology, mechanical systems and the like. 
     An exemplary nano-fabrication technique is commonly referred to as imprint lithography. Exemplary imprint lithography processes are described in detail in numerous publications, such as United States patent application publication 2004/0065976 filed as U.S. patent application Ser. No. 10/264,960, entitled, “Method and a Mold to Arrange Features on a Substrate to Replicate Features having Minimal Dimensional Variability”; United States patent application publication 2004/0065252 filed as U.S. patent application Ser. No. 10/264,926, entitled “Method of Forming a Layer on a Substrate to Facilitate Fabrication of Metrology Standards”; and U.S. Pat. No. 6,936,194, entitled “Functional Patterning Material for Imprint Lithography Processes,” all of which are assigned to the assignee of the present invention. 
     The imprint lithography technique disclosed in each of the aforementioned United States patent application publications and United States 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 positioned upon a motion stage to obtain a desired position to facilitate patterning thereof. To that end, a template is employed spaced-apart from the substrate with a formable liquid present between the template and the substrate. The liquid is solidified to form a solidified layer that has a pattern recorded therein that is conforming to a shape of the surface of the template in contact with the liquid. The template is then separated from the solidified layer such that the template and the substrate are spaced-apart. The substrate and the solidified layer are then subjected to processes to transfer, into the substrate, a relief image that corresponds to the pattern in the solidified layer. 
     In some applications, it may be desirable to form a relief pattern on first and second opposed sides of the substrate. Forming a pattern on first and second opposed sides of the substrate, i.e. double-sided patterning, may be beneficial in the area of patterned media imprinting. To that end, a need therefore exists to provide a method and a system of double-sided patterning of substrates. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a simplified side view of a lithographic system having a template spaced-apart from a substrate, the substrate having first and second opposed sides; 
         FIG. 2  is a top down view of the template shown in  FIG. 1 ; 
         FIG. 3  is a side view of the template shown in  FIG. 1 ; 
         FIG. 4  is an exploded view of a portion of  FIG. 2 , the template having an alignment mark; 
         FIG. 5  is a side view of the substrate shown in  FIG. 1 , and an optical detection system for detecting the substrate; 
         FIG. 6  is a top down view of the substrate shown in  FIG. 1 , and an optical detection system for detecting the substrate; 
         FIG. 7  is a top down view of a robot handling the substrate shown in  FIG. 1 ; 
         FIG. 8  is a flow diagram showing a method of patterning the first and second opposed sides of the substrate shown in  FIG. 1 , in a first embodiment; 
         FIG. 9  is a side view of the system shown in  FIG. 1 , with a robot positioning the substrate on a substrate chuck in a first position; 
         FIG. 10  is a side view of the system shown in  FIG. 9 , with the substrate having a material positioned on a first side thereof; 
         FIG. 11  is a side view of the system shown in  FIG. 10 , with the template contacting the fluid positioned on the first side of the substrate; 
         FIG. 12  is a side view of the system shown in  FIG. 11 , with the robot positioning the substrate on the substrate chuck in a second position; 
         FIG. 13  is a side view of the system shown in  FIG. 12 , with the template contacting a fluid positioned on the second side of the substrate; 
         FIG. 14  is a side view of a lithographic system having a first template opposed a second template and a substrate, the substrate having first and second opposed sides, in a further embodiment; 
         FIG. 15  is a flow diagram showing a method of patterning the first and second opposed sides of the substrate shown in  FIG. 14 , in a further embodiment; 
         FIG. 16  is a side view of the system shown in  FIG. 14 , with a robot positioning the substrate on a substrate chuck in a first position; 
         FIG. 17  is a side view of the system shown in  FIG. 16 , with the substrate having a material positioned on the first side thereof; 
         FIG. 18  is a side view of the system shown in  FIG. 17 , with the first template contacting the fluid positioned on the first side of the substrate; 
         FIG. 19  is a side view of the system shown in  FIG. 18 , with the substrate being coupled to the first template and the substrate having a material positioned on the second side thereof; 
         FIG. 20  is a side view of the system shown in  FIG. 19 , with the second template contacting the fluid positioned on the second side of the substrate; 
         FIG. 21  is a side view of the system shown in  FIG. 20 , with the second template being spaced-apart from the substrate; 
         FIG. 22  is a side view of the system shown in  FIG. 21 , with the substrate being positioned on the substrate chuck having a pattern formed on the first and second sides thereof; 
         FIG. 23  is a side view of a lithographic system having a first template opposed a second template and a substrate, the substrate having first and second opposed sides, in a further embodiment; 
         FIG. 24  is a flow diagram showing a method of patterning the first and second opposed sides of the substrate shown in  FIG. 23 , in a further embodiment; 
         FIG. 25  is a side view of the system shown in  FIG. 23 , with the substrate having a material positioned on the first and second sides thereof; 
         FIG. 26  is a side view of the system shown in  FIG. 25 , the substrate being in a desired spatial relationship with a pin; 
         FIG. 27  is a side view of the system shown in  FIG. 26 , the substrate being positioned on the pin; 
         FIG. 28  is a side view of the system shown in  FIG. 27 , with the second template contacting the fluid positioned on the second side of the substrate; 
         FIG. 29  is a side view of the system shown in  FIG. 28 , with the first template contacting the fluid positioned on the first side of the substrate; 
         FIG. 30  is a side view of the system shown in  FIG. 29 , with the first template being spaced-apart from the substrate; and 
         FIG. 31  is a side view of the system shown in  FIG. 30 , with the first and second templates being spaced-apart from the substrate. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a system  10  is shown to form a relief pattern on a first side  12  and a second side  14  of a substrate  16 . In an example, substrate  16  may be substantially absent of an alignment mark. Substrate  16  may be coupled to a substrate chuck  18 , with substrate chuck  18  being any chuck including, but not limited to, vacuum and electromagnetic. Substrate chuck  18  may further comprise a cavity  19  facing substrate  16 . Substrate  16  and substrate chuck  18  may be supported on a first stage  20  and a second stage  22 , with first stage  20  being positioned between substrate chuck  18  and second stage  22 . Further, first and second stages  20  and  22  may be positioned on a base  23 . First stage  20  may provide motion about a first axis while second stage  22  may provide motion about a second axis, the second axis being orthogonal to the first axis, i.e. the first and second axes being the x and y axes. Exemplary stages in the present invention are available under part number XM2000 from Newport Corporation of Irvine, Calif. Substrate  16  further comprises a throughway  25  having an aperture  27  about first side  12  of substrate  16  and an aperture  29  about second side  14  of substrate  16 . However, in a further embodiment, substrate  16  may be substantially absent of throughway  25 . 
     Spaced-apart from substrate  16  is a template  24  having a mesa  26  extending therefrom towards substrate  16  with a patterning surface  28  thereon. Mesa  26  may also be referred to as a mold  26 . However, in a further embodiment, template  24  may be substantially absent of mold  26 . Template  24  and/or mold  26  may be formed from such materials including but not limited to, fused-silica, quartz, silicon, organic polymers, siloxane polymers, borosilicate glass, fluorocarbon polymers, metal, and hardened sapphire. As shown, patterning surface  28  comprises features defined by a plurality of spaced-apart recesses  30  and protrusions  32 . However, in a further embodiment, patterning surface  28  may be substantially smooth and/or planar. Patterning surface  28  may define an original pattern that forms the basis of a pattern to be formed on first and second sides  12  and  14  of substrate  16 , described further below. Template  24  may be coupled to a template chuck  34 , template chuck  34  being any chuck including, but not limited to, vacuum and electromagnetic. Further, template chuck  34  may be coupled to an imprint head  36  to facilitate movement of template  24  and mold  26 . 
     Referring to  FIGS. 2 and 3 , a top down view of template  24  is illustrated. As shown, template  24  comprises a circular shape. However, in a further embodiment, template  24  may comprise any geometric shape desired. Further, template  24  may comprise a first region  38 , a second region  40 , and a third region  42 , with the second region  40  being positioned between first region  38  and third region  40 . Second region  40  may be referred to as an active region  40 . Furthermore, as shown, third region  42  may be positioned at a center of template  24 ; however, in a further embodiment, third region  42  may be positioned at any location of template  24  desired. Mold  26 , shown in  FIG. 1 , may be in superimposition with active region  40 . Active region  40  and third region  42  may have a height h 1 . In an example, height h 1  may be in the range of 5-15 microns. In a further embodiment, the height of active region  40  and third region  42  may differ. Furthermore, there may be a recession  44  positioned between active region  40  and third region  42 . 
     Referring to  FIGS. 2 and 4 , third region  42  may comprise an alignment mark  46 . In an example, alignment mark  46  may be a standard universal alignment target (UAT). Alignment mark  46  may be employed to obtain a desired spatial relationship between template  24  and substrate  16 , shown in  FIG. 1 . 
     Referring to  FIG. 1 , system  10  further comprises a fluid dispenser  48 . Fluid dispenser  48  may be in fluid communication with substrate  16  so as to position a polymeric material  50  on substrate  16 , described further below. As shown, fluid dispenser  48  is coupled to template chuck  34 ; however, in a further embodiment, fluid dispenser  48  may be coupled to any part of system  10 , i.e., template  24  or imprint head  36 . Further, system  10  may comprise any number of fluid dispensers and fluid dispenser  48  may comprise a plurality of dispensing units therein. Polymeric material  50  may be positioned on substrate  16  using any known technique, e.g., drop dispense, spin-coating, dip coating, thin film deposition, thick film deposition, and the like. As shown, polymeric material  50  may be positioned upon substrate  16  as a plurality of spaced-apart droplets  52 . 
     System  10  further comprises a source  54  of energy  56  coupled to direct energy  56  along a path  58 . In an example, source  54  may be an ultraviolet emitting lamp coupled with either a liquid guide or an ultraviolet fiber guide. An exemplary source of energy in the present invention is available under part number BlueWave™ 200 Spot Lamp from DYMAX Corporation of Torrington, Conn. Imprint head  36  and first and second stages  20  and  22  are configured to arrange mold  26  and substrate  16 , respectively, to be in superimposition and disposed within path  58 . Either imprint head  36 , first and second stages  20  and  22 , or a combination of the above, may vary a distance between mold  26  and substrate  16  to define a desired volume therebetween that is filled by polymeric material  50 , described further below. 
     System  10  further comprises an optical detection system having imaging units  60   a  and  60   b . As shown, imaging unit  60   a  may be coupled to fluid dispenser  48 ; however, in a further embodiment, imaging unit  60   a  may be coupled to any part of system  10 , i.e., template  24 , template chuck  34 , or imprint head  36 . Furthermore, as shown, imaging unit  60   b  is coupled to second stage  22 ; however, in a further embodiment, imaging unit  60   b  may be coupled to any part of system  10 , i.e., substrate chuck  18  or first stage  20 . Further, system  10  may comprise any number of imaging units  60   a  and  60   b . Imaging units  60   a  and  60   b  may be a microscope in data communication with an image processing module (not shown). In a further embodiment, imaging units  60   a  and  60   b  may be a laser edge detecting sensor. 
     Referring to  FIGS. 1 ,  5 , and  6 , imaging units  60   a  and  60   b  may be employed to detect substrate  16  and mold  26 , respectively. More specifically, imaging units may detect an edge  62  of substrate  16 . In a further embodiment, imaging unit  60   a , now shown as imaging units  64   a ,  64   a ′,  64   b , and  64   b ′ in  FIGS. 5 and 6 , may be employed to determine a center location of substrate  16 , i.e. throughway  25  about the x and y axes. More specifically, imaging units  64   a  and  64   b  may be lasers producing beams  66   a  and  66   b , respectively, with imaging units  64   a ′ and  64   b ′ being intensity sensors detecting beams  66   a  and  66   b , respectively. As shown, imaging units  64   a ,  64   a ′,  64   b ,  64   b ′ may detect aperture  25 . Imaging units  64   a  and  64   b  may be employed as off-axis or thru-the-template. Exemplary intensity sensors employed in the present invention are available under part number LV-H37 from Keyence, Inc. of Woodcliff Lake, N.J. 
     Referring to  FIGS. 1 and 7 , system  10  further comprises a robot  68  for positioning substrate  16  upon and removing substrate  16  from substrate chuck  18 . Robot  68  may be any handling robot known in the art. In an example, robot  68  comprises an arm  70  coupled to a driving means  72 . Arm  70  further has an end effecter  73  coupled thereto to handle substrate  16 . In an example, end effecter  73  may be an edge-gripping or thin air cavity chuck to hold substrate  16  without contacting an area of substrate  16  having polymeric material  50  positioned thereon, i.e. the active area of substrate  16 . Driving means  72  may extend or contract arm  70 , rotate arm  70  around its axis, move arm  70  horizontally in a circle, or provide any desired motion of arm  70 . Driving means  72  may provide motion about the first and second axes mentioned above. In an example, driving means  72  may rotate about the x axes to flip substrate  16 , described further below. Driving means  72  may also rotate about its axis. Furthermore, robot  68  may transport substrate  16  between substrate chuck  18  and a substrate cassette  74 . Substrate cassette  74  may comprise a plurality of substrates  16  therein. 
     Referring to  FIG. 1 , typically, polymeric material  50  may be positioned upon substrate  16  before the desired volume is defined between mold  26  and substrate  16 . However, polymeric material  50  may fill the volume after the desired volume has been obtained. After the desired volume is filled with polymeric material  50 , source  54  may produce energy  56 , e.g., broadband ultraviolet radiation that causes polymeric material  50  to solidify and/or cross-link conforming to a shape of first side  12  of substrate  16  and patterning surface  28  of mold  26 . Control of this process is regulated by a processor  76  that is in data communication with first and second stage  20  and  22 , imprint head  36 , fluid dispenser  48 , source  54 , imaging units  60   a  and  60   b , and robot  68 , operating on a computer readable program stored in memory  78 . 
     As mentioned above, system  10  may be employed to form a pattern on first side  12  of substrate  16 . However, it may be desired to form a pattern on second side  14  of substrate  16  such that both first and second sides  12  and  14  of substrate  16  have patterns formed thereon. To that end, described below are a system and a method of forming a pattern on first and second sides  12  and  14  of substrate  16 . 
     Referring to  FIGS. 8 and 9 , in a first embodiment, a method and a system of forming a pattern on first and second sides  12  and  14  of substrate  16  are shown. As mentioned, above, at step  100 , substrate  16  may be positioned upon substrate chuck  18 . More specifically, first and second stages  20  and  22  may position substrate chuck  18  proximate to robot  68  such that robot  68  may position substrate  16  upon substrate chuck  18 . Robot  68  may transfer substrate  16  from substrate cassette  74  and position substrate  16  on substrate chuck  18  such that a side of first and second sides  12  and  14  may be positioned opposite to that of substrate chuck  18 . In a first example, robot  68  may position substrate  16  such that first side  12  faces away from substrate chuck  18  while second side  14  faces towards substrate chuck  18 . In a second example, robot  68  may position substrate  16  such that second side  14  faces away from substrate chuck  18  while first side  12  faces towards substrate chuck  18 . At step  102 , imaging unit  60   a  may determine a position of substrate  16 . More specifically, imaging unit  60   a  may be employed to determine a center location of substrate  16 , as mentioned above with respect to  FIGS. 5 and 6 , with respect to any part of system  10 , i.e. mold  18 , dispensing unit  48 , or robot  68 . As a result, a desired spatial relationship of substrate  16  with respect to any part of system  10  may be obtained. 
     Referring to  FIGS. 8 and 10 , at step  104 , first and second stages  20  and  22  may translate substrate  16  such that a desired position may be obtained between substrate  16  and fluid dispenser  48 . As a result, fluid dispenser  48  may position polymeric fluid  50  upon first side  12  of substrate  16 , as mentioned above. 
     Referring to  FIGS. 8 and 11 , at step  106 , a desired position may be obtained between substrate  16  and mold  26 . More specifically, first and second stages  20  and  22  and imprint head  36  may position substrate chuck  18  such that substrate  16  may be in superimposition with mold  26  and further polymeric material  50  fills the desired volume defined between substrate  16  and mold  26 . At step  108 , as mentioned above, polymeric material  50  positioned on first side  12  of substrate  16  may be solidified and/or cross-linked conforming to first side  12  of substrate  16  and a patterning surface  28  of mold  26 . At step  110 , mold  18  may be separated from polymeric material  50  positioned on first side  12  of substrate  16 . 
     Referring to  FIGS. 8 and 12 , at step  112 , analogous to that mentioned above with respect to step  100 , first and second stages  20  and  22  may position substrate chuck  18  proximate to robot  68 . At step  114 , robot  68  may separate substrate  16  from substrate chuck  18  via robot  68 . At step  116 , substrate  16  may be analyzed to determine if first and second sides  12  and  14  of substrate  16  are patterned. To that end, at step  118 , to that end, were only one side of first and second sides  12  and  14  of substrate  16  patterned, robot  68  may rotate arm  70  around its axis to flip substrate  16  180° with respect to mold  18  slid further position substrate  16  on substrate chuck  18  such that the remaining un-patterned side of first and second sides  12  and  14  of substrate  16  may be positioned opposite to that of substrate chuck  18 . In a first example, were first side  12  of substrate  16  patterned, robot  68  would position substrate  16  such that first side  12  faces towards substrate chuck  18  and second side  14  faces away from substrate chuck  18 . In a second example, were second side  14  of substrate  16  patterned, robot  68  would position substrate  16  such that second side  14  faces towards substrate chuck  18  and first side  12  faces away from substrate chuck  18 . Furthermore, polymeric material  50  patterned on a side of first and second sides  12  and  14  of substrate  16  may be positioned within cavity  19  of substrate chuck  18  to minimize, if not prevent, damage to polymeric material  50 . To that end, the remaining side of first and second skies  12  and  14  of substrate  16  may be patterned analogous to that mentioned above in  FIGS. 8-12 , with substrate  16  having first and second sides  12  and  14  patterned shown in  FIG. 13 . 
     Referring to  FIGS. 1 and 8 , however, were both first and second sides  12  and  14  of substrate  16  patterned, at step  120  substrate  16  may be unloaded from substrate chuck  18  and robot  68  may position substrate  16  in substrate cassette  74 . In a further embodiment, fluid dispenser  48  may be positioned outside of system  10 , with first and second sides  12  and  14  of substrate  16  having polymeric fluid  50  positioned thereon outside of system  10 . Furthermore, it may be desired to remove polymeric material  50  from portions of substrate  16  in contact with robot  68  and/or substrate chuck  18 . 
     Referring to  FIG. 14 , a second embodiment of system  10  is described, shown as system  110 . System  110  may be analogous to that as system  10  described above with respect to  FIGS. 1-7 , however, system  110  may further comprise an additional patterning surface, described further below. 
     To that end, system  110  further comprises a template  224  having a mold  226  extending therefrom towards template  24  with a patterning surface  228  thereon. Template  224  may be coupled to a template chuck  234 . Template  224 , mold  226 , and template chuck  234  may be analogous to that of template  24 , mold  26 , and template chuck  34 , respectively, described above with respect to  FIG. 1 . Mold  226  may have substantially the same patterning surface  228  as patterning surface  28  of mold  26 ; however, in a further embodiment, patterning surface  228  may differ from patterning surface  28 . Template  224 , mold  226 , and template chuck  234  may be coupled to second stage  22 , with second stage  22  providing motion of template  224 , mold  226 , and template chuck  234  about the second axis, as mentioned above with respect to  FIG. 1 . As a result, mold  226  may be positioned in superimposition with mold  26  to facilitate patterning of first and second sides  12  and  14  of substrate  16 , described further below. In a further embodiment, template  224 , mold  226 , and template chuck  234  may be further coupled to first stage  20 . 
     System  110  further comprises a fluid dispenser  248 , with fluid dispenser  248  being analogous to fluid dispenser  48  mentioned above with respect to  FIG. 1 . As shown, fluid dispenser  248  is coupled to template chuck  234 ; however, in a further embodiment, fluid dispenser  248  may be coupled to any part of system  210 ; i.e. template  224  or second stage  22 . Furthermore, imagining unit  60   b  is shown coupled to fluid dispenser  248 ; however, in a further embodiment, imaging unit  60   b  may be coupled to any part of system  110 , i.e., second stage  22 , template  224 , or template chuck  234 . Control of fluid dispenser  248  may be regulated by processor  76  that is in data communication with fluid dispenser  248 . 
     Referring to  FIGS. 15 and 16 , a second embodiment of a method and a system of forming a pattern on first and second sides  12  and  14  of substrate  16  are shown. As mentioned above, at step  300 , substrate  16  may be positioned upon substrate chuck  18 . More specifically, first and second stages  20  and  22  may position substrate chuck  18  proximate to robot  68  such that robot  68  may position substrate  16  upon substrate chuck  18 . Robot  68  may transfer substrate  16  from substrate cassette  74  and position substrate  16  on substrate chuck  18  such that a side of first and second sides  12  and  14  may be positioned opposite to that of substrate  18 . Please note for simplicity of illustration, coupling between processor  76  and first stage  20 , imaging unit  60   b , and fluid dispenser  248  is not shown. 
     At step  302 , imaging units  60   a  and  60   b  may determine a position of substrate  16 . More specifically, imaging units  60   a  and  60   b  may be employed to determine a center location of substrate  16 , as mentioned above with respect to  FIGS. 5 and 6 , with respect to any part of system  10 , i.e., molds  26  and  226 , dispensing units  48  and  248 , or robot  68 . As a result, a desired spatial relationship of substrate  16  with respect to any part of system  10  may be obtained, described further below. 
     Referring to  FIGS. 15 and 17 , at step  304 , first and second stages  20  and  22  may translate substrate  16  such that a desired position may be obtained between substrate  16  and fluid dispenser  48 . As a result, fluid dispenser  48  may position polymeric fluid  50  upon first side  12  of substrate  16 , as mentioned above. 
     Referring to  FIGS. 15 and 18 , at step  306 , a desired position may be obtained between substrate  16  and mold  26 . More specifically, first and second stages  20  and  22  and imprint head  36  may position substrate chuck  18  such that substrate  16  may be in superimposition with mold  26  and further polymeric material  50  positioned on first side  12  of substrate  16  fills the desired volume defined between substrate  16  and mold  26 . At step  308 , as mentioned above, polymeric material  50  positioned on first side  12  of substrate  16  may be solidified and/or cross-linked conforming to first side  12  of substrate  16  and patterning surface  28  of mold  26 . At step  310 , substrate  16  may be separated from substrate chuck  18  such that substrate  16  is coupled to mold  26 . 
     Referring to  FIGS. 15 and 19 , at step  312 , first stage  20 , or in a further embodiment, first and second stages  20  and  22 , may translate fluid dispenser  248  such that a desired position may be obtained between substrate  16  and fluid dispenser  248 . As a result, fluid dispenser  248  may position polymeric fluid  50  upon second side  14  of substrate  16 , analogous to that mentioned above with respect to first side  12  of substrate  16  shown in  FIG. 17 . 
     Referring to  FIGS. 15 and 20 , at step  314 , a desired position may be obtained between substrate  16  and mold  226 . More specifically, second stage  22 , or in a further embodiment, first and second stages  20  and  22 , and imprint head  26  may position mold  226  to be in superimposition with substrate  16  with polymeric material  50  positioned on second side  14  of substrate  16  filling the desired volume defined between substrate  16  and mold  226 . At step  316 , polymeric material  50  positioned on second side  14  of substrate  16  may be solidified and/or cross-linked conforming to second side  14  of substrate  16  and patterning surface  228  of mold  226 . In a further embodiment, step  308 , mentioned above, may be omitted where substrate  16  substantially transparent to the actinic radiation mentioned above such that material  50  positioned on first and second sides  12  and  14  of substrate  16  may be solidified and/or cross-linked concurrently. 
     Referring to  FIGS. 15 and 21 , at step  318 , mold  226  may be separated from polymeric material  50  positioned on second side  14  of substrate  16  such that substrate  16  remains coupled to mold  26 . To facilitate separation of mold  226  from polymeric material  50 , mold  226  may be bowed towards substrate  16  while concurrently imprint head  36  provides motion of mold  26  in a direction away from mold  226 . 
     Referring to  FIGS. 15 and 22 , at step  320 , first and second stage  20  and  22  and imprint head  36  may position substrate chuck  18  such that substrate chuck  18  may be in superimposition with substrate  16 . At step  322 , mold  26  may be separated from polymeric material  50  positioned on first side  12  of substrate  16  such that substrate  16  may be positioned upon substrate chuck  18 . To facilitate separation of mold  26  from polymeric material  50 , mold  26  may be bowed towards substrate  16  while concurrently imprint head  36  provides motion of mold  26  in a direction away from substrate  16 . Polymeric material  50  positioned on second side  14  of substrate  16  may be positioned within cavity  19  of substrate chuck  18  to minimize, if not prevent, damage to polymeric material  50 . At step  324 , substrate  16  may be unloaded from substrate chuck  18  and robot  68  may position substrate  16  in substrate cassette  74 . 
     In a further embodiment, fluid dispensers  48  and  248  may be positioned outside of system  110 , with first and second sides  12  and  14  of substrate  16  having polymeric fluid  50  positioned thereon outside of system  110 . Furthermore, it may be desired to remove polymeric material  50  from portions of substrate  16  in contact with robot  68  and/or substrate chuck  18 . 
     Referring to  FIG. 23 , a third embodiment of system  10  is described, shown as system  210 . System  210  may be analogous to that as system  10  described above with respect to  FIGS. 1-7 , however, system  210  may further comprise an additional patterning surface and a pin  80  to hold substrate  16 , described further below. 
     System  210  further comprises a template  324  having a mold  326  extending therefrom towards template  24 . Template  324  may be coupled to a template chuck  334 . Template  324 , mold  326 , and template chuck  334  may be analogous to that of template  24 , mold  26 , and template chuck  34 , respectively, described above with respect to  FIG. 1 . Mold  326  may have substantially the same patterning surface  328  as patterning surface  28  of mold  26 ; however, in a further embodiment, pattering surface  328  may differ from patterning surface  28 . In a further embodiment, template chuck  324  may be a spherical chucking unit having a curvature in the range of 2 microns to 100 microns over an area of template chuck  324  in superimposition with mold  326 . Pin  80  may provide motion of template  324  and mold  326  in the first axis and second axis, as mentioned above with respect to  FIG. 1 . Further pin  80  may provide motion along a third axis orthogonal to the first and second axis, i.e. along the x axis. In an example, pin  80  may provide motion about the x and y axis of approximately 50-200 microns and along the z axis of approximately 2 millimeters. 
     System  210  further comprises a fluid dispenser  348 , with fluid dispenser  348  being analogous to fluid dispenser  48  mentioned above with respect to  FIG. 1 . Fluid dispenser  348  and imaging unit  60   b  are shown coupled to base  23 ; however, fluid dispenser  348  and imaging unit  60   b  may be coupled to any part of system  210 . Control of fluid dispenser  348  may be regulated by processor  76  that is in data communication with fluid dispenser  348 . 
     Referring to  FIGS. 24 and 25 , a third embodiment of a method and a system of forming a pattern on first and second sides  12  and  14  of substrate  16  are shown. At step  400 , robot  68  may retrieve substrate  16  from substrate cassette  74  with robot  68  holding substrate  16 . At step  402 , robot  68  may position substrate  16  such that a desired spatial relationship between substrate  16  and fluid dispensers  48  and  348  may be obtained to position polymeric fluid upon substrate  16 . More specifically, fluid dispenser  48  may position polymeric fluid  50  on first side  12  of substrate  16  and fluid dispenser  348  may position polymeric fluid  50  on second side  14  of substrate  16 . In a further embodiment, fluid dispensers  48  and  348  may be positioned outside of system  210 , with first and second sides  12  and  14  of substrate  16  having polymeric fluid  50  positioned thereon outside of system  210 . At step  404 , a distance between mold  26  and mold  326  may be increased such that substrate  16  may be positioned between mold  26  and mold  326 . Please note for simplicity of illustration, coupling between processor  76  and imaging unit  60   b , pin  80 , and fluid dispenser  348  is not shown. 
     Referring to  FIGS. 24 and 26 , at step  406 , robot  68  may translate substrate  16  and pin  80  may translate such that a desired spatial relationship between substrate  16  and pin  80  may be obtained. As a result, substrate  16  may be centered with respect to pin  80 . More specifically, throughway  25  may be in superimposition with pin  80 . However, in a further embodiment, any desired spatial relationship between substrate  16  and pin  80  may be obtained. 
     Referring to  FIGS. 24 and 27 , at step  408 , pin  80  may translate along the z axis such that substrate  16  may be positioned upon pin  80 . At step  410 , robot  68  may be retracted from holding substrate  16 . More specifically, arm  70  of robot  68  may be retracted such that end effecter  73 , shown in  FIG. 7 , is not coupled to substrate  16 . At step  412 , imaging unit  60   a  may determine a position of substrate  16 . More specifically, imaging unit  60   a  may be employed to determine a center location of substrate  16 , as mentioned above with respect to  FIGS. 5 and 6 , with respect to any part of system  10 , i.e., mold  26 , mold  326 , or robot  68 . As a result, a desired spatial relationship of substrate  16  with respect to any part of system  10  may be obtained, described further below. 
     Referring to  FIGS. 24 and 28 , at step  414 , a desired position may be obtained between substrate  16  and mold  326 . More specifically, pin  80  and chuck  334  may position substrate  16  and mold  326  such that substrate  16  may be in superimposition with mold  326  and further polymeric material  50  positioned on second side  14  of substrate  16  fills the desired volume defined between substrate  16  and mold  326 . 
     Referring to  FIGS. 24 and 29 , at step  416 , a desired position may be obtained between substrate  16  and mold  26 . More specifically, pin  80  and imprint head  36  may position substrate  16  and mold  26  such that substrate  16  may be in superimposition with mold  26  and further polymeric material  50  positioned on first side  12  of substrate  16  fills the desired volume defined between substrate  16  and mold  26 . At step  418 , as mentioned above, polymeric material  50  positioned on first side  12  of substrate  16  may be solidified and/or cross-linked conforming to first side  12  of substrate  16  and patterning surface  28  of mold  26  and polymeric material  50  positioned on second side  14  of substrate  16  may be solidified and/or cross-linked conforming to second side  14  of substrate  16  and patterning surface  328  of mold  326 . 
     Referring to  FIGS. 24 and 30 , at step  420 , mold  26  may be separated from polymeric material  50  positioned on first side  12  of substrate  16 . Furthermore, it may be desired to remove polymeric material  50  from portions of substrate  16  in contact with robot  68  and/or pin  80 . 
     Referring to  FIGS. 24 and 31 , at step  422 , robot  68  may retrieve substrate  16  such that end effecter  73 , shown in  FIG. 7 , of arm  70  holds substrate  16 . At step  424 , mold  326  may be separated from polymeric material  50  positioned on second side  14  of substrate  16  such that substrate  16  is coupled to robot  68 . At step  426 , substrate  16  may be unloaded from substrate chuck  18  and robot  68  may position substrate  16  in substrate cassette  74 . 
     The embodiments of the present invention described above are exemplary. Many changes and modifications may be made to the disclosure recited above, while remaining within the scope of the invention. Therefore, the scope of the invention should not be limited by the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.