Plastic male mold for fabricating microstructures and nanostructures using imprint lithography

Abstract

Known electron beam lithography used for manufacturing male molds is cost-intensive and very time consuming. As a result, conventional highly sensitive electron beam resists have an insufficient plasma etching resistance and galvanic molding makes special demands on the structural profile and the thermal stability and solubility of the resist structures. The novel production and use of lithographically produced resist structures as male mold material for use in imprint lithography for producing microstructures and nanostructures should thus overcome the drawbacks associated with the conventional procedure for producing male molds. To this end, a negative resist system is used whose lithographically produced structures correspond to the demands made on a male mold for molding thin polymer layers. Lithographically produced structures comprised of curable materials are thus used for molding, preferably those based on photo-reactive epoxy resins. The invention, in turn, enables an economical and thereby low-cost production of male mold material.

1 . The invention relates to the fabrication of micro and nano structures by heat embossing, characterized by the fact that for copying lithographically produced structures are used which consist of curable materials, preferably based on photo-reactive epoxy resins and the structure transfer is preferably carried out in thin layers.  
     
     
         2 . according to  claim 1  characterized by the fact that preferably structured resist layers based on photo-reactive aliphatic, aromatic, cyclo-aliphatic epoxy resins and mixtures thereof are used.  
     
     
         3 . according to  claim 1  characterized by the fact that the master structures used for the micrometer range are preferably fabricated by optical lithography and for the nanometer range in particular are fabricated by electron beam lithography.  
     
     
         4 . According to  claim 1  characterized by the fact that the structure transfer is preferably carried out in polymeric layers the layer thicknesses of which are less than 1 micrometer.  
     
     
         5 . according to  claim 3  characterized by the fact that following the development process the master structures are after-treated by UV surface irradiation in the dosage range of 200-2,000 mJ/cm 2 , preferably between 500-1,000 mJ/cm 2  and at a temperature of 50-180° C., preferably between 120-150° C.  
     
     
         6 . according to  claim 1  characterized by the fact that the layers to be embossed consist of thermoplastic polymers the glass temperatures of which preferably are below 150° C.  
     
     
         7 . according to  claim 1  characterized by the fact that the layers to be embossed consist of curable polymers.  
     
     
         8 . according to  claim 6  characterized by the fact that the curable polymers preferably consist of photo-reactive epoxy resins.  
     
     
         9 . according to  claim 6  characterized by the fact that the curable polymers preferably consist of cross-linkable allyl polymers.  
     
     
         10 . according to  claim 7  characterized by the fact that after hardening the embossed structures are used as embossing tools.