In the replication of nanostructures by hot embossing it is necessary to provide a non-sticking interface between the nanostructured master and the thermoplastic to be embossed. This allows demolding without degrading the replication fidelity. Adhesion during the mold release can cause damage to the replica. Further, residual polymer structures can contaminate the surface of the mold. A prerequisite for a successful imprint process is that the mold used should be chemically and mechanically stable and also adhere poorly with polymers to avoid sticking thereof to the mold.
R. W. Jaszewski, et al disclose in Microelectronic Engineering 35 (1997) 381-384 covering the surface of the mold with an ultra-thin anti-adhesive layer comprising a polytetrafluorethylene (PTFE) film. The film is deposited according to two kinds of techniques, i.e. plasma polymerization and ion sputtering from a plasma. Jaszewski et al allege in the above article that the quality of the film is degraded during the embossing process. Thus, it seems that the anti-adhesive layer according to Jaszewski et al is not sufficiently stable.
USPTO Backgrounds
USPTO Backgrounds