Die Imprint By Double Side Force-Balanced Press For Step-And-Repeat Imprint Lithography

Abstract

In accordance with the invention, step-and-repeat imprint lithography is effected by applying balanced pressing forces from both sides of a substrate. The pressing forces are substantially equal in amplitude and opposite in direction. With the pressing forces thus balanced, the fixture that steps and holds the substrate does not bear the load of imprinting. The balance allows use of a high resolution aligning stage to carry the substrate and to maintain high accuracy of positioning without being shifted by change of load. With this method, sufficient imprint pressure can be used to obtain high quality patterning, a thin and uniform residual layer, and a high fidelity pattern.

1 . Apparatus for performing imprint lithography on a substrate having a moldable surface comprising, in operative relationship:
 a mold having a molding surface for imprinting the moldable surface with a pattern having microscale or nanoscale features;   a moveable positioner for holding and positioning the substrate or the mold with the molding surface adjacent the moldable surface; and   a press for pressing together the mold and the substrate with the substrate or mold on the positioner by opposing transverse forces that are balanced to minimize the net transverse force on the positioner.   
     
     
         2 . The apparatus of  claim 1  wherein the molding surface is smaller in lateral area than the moldable surface and the moveable positioner comprises as step-and-repeat positioner for imprinting a plurality of different positions on the moldable surface. 
     
     
         3 . The apparatus of  claim 1  further comprising a controller for directing the positioner and the press to imprint the moldable surface at a plurality of different positions. 
     
     
         4 . The apparatus of  claim 1  wherein the press comprises a source of pressurized fluid for pressing together the mold and the substrate. 
     
     
         5 . A method of imprint lithography to provide step-and-repeat imprint replication of a pattern having microscale or nanoscale features on a moldable surface of a substrate comprising the steps of:
 a). providing the substrate having the moldable surface;   b). providing the mold having a molding surface for molding the pattern, the molding surface smaller in lateral area than said substrate;   c). providing a body facing said molding surface of said mold;   d). disposing said substrate between said mold and said body wherein said moldable surface faces said molding surface;   e). pressing both sides of said substrate at opposing locations with said mold and said body by opposing transverse forces that are balanced;   f). at least partially hardening the moldable surface;   g). removing said mold and said body from said substrate;   h). moving said substrate laterally relative to said mold and said body;   i). repeating step e to step g at least once.   k). disposing said mold and said body transversely close to the substrate by predetermined distances;   l). pressing said substrate with said body to bend said substrate into contact with said mold; and   m). pressing said substrate further with said body while holding said mold.   
     
     
         6 . An apparatus for performing imprint lithography on a substrate having a moldable surface comprising, in operative relationship:
 providing a mold having a molding surface with a pattern having microscale or nanoscale features;   a body A to have said mold attached to one end;   a body B disposed to face body A wherein one end of body B faces the molding surface of said mold;   a fixture to attach the substrate at its edge so that most area of the substrate is accessible from both sides, and to be positioned so that the substrate is between said body A and said body B;   a press to move said body A and said body B transversely to contact and press the substrate with balanced opposing transverse forces;   a positioner to move said fixture laterally relative to said body A and said body B.   
     
     
         7 . The apparatus of  claim 6  further comprising a controller to direct transverse movements of said body A and said body B. 
     
     
         8 . The apparatus of  claim 6  further comprising a controller to direct said body A and said body B to press the substrate with balanced opposing transverse forces. 
     
     
         9 . The apparatus of  claim 6  further comprising a controller to direct lateral movement of said fixture relative to said body A and said body B. 
     
     
         10 . The apparatus of  claim 6  further comprising a controller to direct said body A and said body B to press a partial area on the substrate with balanced opposing transverse forces, then, direct said body A and said body B to press another partial area on the substrate with balanced opposing transverse forces, and repeat as desired. 
     
     
         11 . The apparatus of  claim 6  further comprising a plurality of distance sensors to detect bending of the substrate, and, a controller to use the sensing of said sensors. 
     
     
         12 . The apparatus of  claim 6  wherein said press comprises magnetic sources attached to each said body that are ON/OFF switchable. 
     
     
         13 . The apparatus of  claim 12  wherein at least one of said magnetic sources comprises a conductive coil attached close to peripheral of said body. 
     
     
         14 . The apparatus of  claim 6  wherein said press comprises a blowing of fluid from a pressurized fluid source. 
     
     
         15 . The apparatus of  claim 6  wherein said press comprises a sealed membrane of a cavity that can be inflated by pressurizing the cavity with fluid. 
     
     
         16 . The apparatus of  claim 6  wherein said press comprises a voltage driven piezo body. 
     
     
         17 . The apparatus of  claim 6  wherein said press comprises a hydraulic piston. 
     
     
         18 . The apparatus of  claim 6  wherein said body B has a mold with a molding surface including a second pattern having microscale or nanoscale features, attached to the end facing said body A. 
     
     
         19 . The apparatus of  claim 6  wherein the substrate has a moldable surface on each side. 
     
     
         20 . The apparatus of  claim 6  wherein the substrate is held onto said fixture by a plurality of mechanical clamps. 
     
     
         21 . The apparatus of  claim 6  wherein the substrate is held onto said fixture by a plurality of inflatable capsules. 
     
     
         22 . The apparatus of  claim 6  wherein areas on the substrate to contact with said fixture are optimized to optimally use the area unused by multiple die distribution.