Device and method for lithography

Abstract

Apparatus and method for transferring a pattern from a template ( 10 ) having a structured surface to a substrate ( 12 ) carrying a surface layer of a radiation polymerisable fluid ( 14 ). The apparatus comprises a first main part ( 101 ) and a second main part ( 102 ) having opposing surfaces ( 104;105 ), means for adjusting a spacing ( 115 ) between said main parts, support means ( 106 ) for supporting said template and substrate in mutual parallel engagement in said spacing with said structured surface facing said surface layer, a radiation source ( 110 ) devised to emit radiation into said spacing. A cavity ( 115 ) has a first wall comprising a flexible membrane ( 113 ) devised to engage said template or substrate, and means ( 114;116 ) are provided for applying an adjustable overpressure to a medium present in said cavity, whereby an even distribution of force is obtained over the whole of the contact surface between the substrate and the template. The apparatus further includes a heater device having a surface facing said spacing, for heating either fluid layer ( 14 ).

1 . Apparatus for transferring a pattern from a template having a structured surface to a substrate carrying a surface layer of a radiation polymerisable fluid, said apparatus comprising a first main part and a second main part having opposing surfaces, means for adjusting a spacing between said main parts, support means for supporting said template and substrate in mutual parallel engagement in said spacing with said structured surface facing said surface layer, a radiation source devised to emit radiation into said spacing, a cavity having a first wall comprising a flexible membrane devised to engage said template or substrate, means for applying an adjustable overpressure to a medium present in said cavity, and a heater device having a surface facing said spacing.  
     
     
         2 . The apparatus as recited in  claim 1 , wherein said radiation source is positioned in said first main part, devised to emit radiation into said spacing from a first direction, and said heater device is positioned in said second main part, having said surface of the heater device facing said spacing from a second direction, opposite said first direction.  
     
     
         3 . The apparatus as recited in  claim 1  or  2 , wherein said heater device comprises a heating element, connected to an energy source.  
     
     
         4 . apparatus as recited in  claim 3 , wherein said heater device comprises a cooling element, connected to a cooling source.  
     
     
         5 . The apparatus as recited in claim any of the preceding claims, wherein said medium comprises a gas.  
     
     
         6 . The apparatus as recited in  claim 5 , wherein said medium comprises air.  
     
     
         7 . The apparatus as recited in any of the preceding claims, wherein said means for applying an adjustable overpressure is arranged to adjust the pressure to 1-500 bar.  
     
     
         8 . The apparatus as recited in any of the preceding claims, wherein said cavity is defined by a part of the surface of said first main part, a flexible seal member arranged in and protruding from said first main part surface, and said membrane which engages said seal member.  
     
     
         9 . The apparatus as recited in  claim 8 , wherein said membrane is disconnectable from said seal member, and devised to engage said seal member by application of pressure from said second main part.  
     
     
         10 . The apparatus as recited in any of the preceding claims, wherein said membrane is transparent to a wavelength range of said radiation, said radiation source being positioned behind said membrane.  
     
     
         11 . The apparatus as recited in  claim 8 , wherein said membrane and at least a portion of said surface of said first main part is transparent to a wavelength range of said radiation, said radiation source being positioned behind said portion of said surface of said first main part.  
     
     
         12 . The apparatus as recited in  claim 8 , wherein said portion of said surface of said first main part is made from quartz, calcium fluoride or any other pressure stable material being transparent to said radiation.  
     
     
         13 . The apparatus as recited in any of the preceding claims, wherein said radiation source is devised to emit radiation at least in a wavelength range of 100-500 nm.  
     
     
         14 . The apparatus as recited in  claim 10 , wherein said radiation source is devised to emit pulsating radiation with a pulse duration of 0.5-10 μs and a pulse rate of 1-10 pulses per second.  
     
     
         15 . The apparatus as recited in any of the preceding claims, wherein said membrane is made from a polymer material.  
     
     
         16 . The apparatus as recited in any of the preceding claims, wherein said membrane has a diameter or width of 50-1000 mm.  
     
     
         17 . The apparatus as recited in any of the preceding claims, where said substrate acts as said membrane.  
     
     
         18 . Method for transferring a pattern from a template having a structured surface to a substrate carrying a surface layer of a radiation polymerisable fluid, comprising the steps of: 
 arranging said template and substrate mutually parallel in an imprint apparatus, with said structured surface facing said surface layer, between a stop member and a first side of a flexible membrane;    heating said surface layer by means of a heater device in said imprint apparatus;    applying an overpressure to a medium present on a second side of the membrane, opposite to said first side, for imprinting said pattern into said layer; and    exposing said layer to radiation for solidifying said layer.    
     
     
         19 . The method as recited in  claim 18 , further comprising the step of: 
 baking said layer by providing heat from said heater device after said step of exposing said layer to radiation.    
     
     
         20 . The method as recited in  claim 18  or  19 , wherein said medium comprises a gas.  
     
     
         21 . The method as recited in  claim 20 , wherein said medium comprises air.  
     
     
         22 . The method as recited in any of the preceding claims  18 - 21 , comprising the step of: 
 placing said membrane in direct engagement with said template or said substrate.    
     
     
         23 . The method as recited in  claim 18 , comprising the step of: 
 clamping said membrane at a peripheral portion thereof between said stop member and a seal member, thereby defining a peripheral wall for a cavity for said medium.    
     
     
         24 . The method as recited in  claim 18 , comprising the steps of: 
 emitting radiation to said layer through said template, which template is transparent to a wavelength range of a radiation usable for polymerising said fluid; and    heating said substrate by direct contact with said heater device.    
     
     
         25 . The method as recited in  claim 18 , comprising the steps of: 
 emitting radiation to said layer through said substrate, which substrate is transparent to a wavelength range of a radiation usable for polymerising said fluid; and    heating said template by direct contact with said heater device.    
     
     
         26 . The method as recited in any of the preceding claims  18 - 25 , comprising the step of: 
 emitting radiation to said layer through said membrane, which membrane is transparent to a wavelength range of a radiation usable for polymerising said fluid.    
     
     
         27 . The method as recited in any of the preceding claims  18 - 26 , comprising the step of: 
 emitting radiation to said layer through said membrane, and through a transparent wall opposing said membrane, defining a back wall for a cavity for said medium, which back wall and membrane are transparent to a wavelength range of a radiation usable for polymerising said fluid.    
     
     
         28 . The method as recited in any of the preceding claims  18 - 27 , wherein the step of exposing said layer comprises the step of: 
 emitting radiation from a radiation source within a wavelength range of 100-500 nm.    
     
     
         29 . The method as recited in  claim 28 , comprising the steps of: 
 emitting pulsating radiation with a pulse duration in the range of 0.5-10 μs and a pulse rate in the range of 1-10 pulses per second.    
     
     
         30 . The method as recited in any of the preceding claims  18 - 29 , comprising the step of: 
 clamping said substrate and template together prior to arranging said template and substrate between said stop member and said flexible membrane.    
     
     
         31 . The method as recited in  claim 18 , comprising the step of: 
 applying a vacuum between said template and said substrate in order to extract air inclusions from said surface layer prior to exposing said layer to radiation.    
     
     
         32 . Method for transferring a pattern from a template having a structured surface to a substrate carrying a surface layer of a radiation polymerisable fluid, wherein said template includes protrusions defining a pattern, which protrusions have non-transparent layers at outer ends, comprising the steps of: 
 arranging said template and substrate mutually parallel in an imprint apparatus, with said structured surface facing said surface layer, between a stop member and a first side of a flexible membrane;    heating said surface layer by means of a heater device in said imprint apparatus;    applying an overpressure to a medium present on a second side of the membrane, opposite to said first side, for imprinting said pattern into said layer; and    exposing said layer to radiation for solidifying said layer at portions between said protrusions.    
     
     
         33 . The method as recited in  claim 32 , further comprising the step of: 
 baking said layer by providing heat from said heater device after said step of exposing said layer to radiation.