Structure and stability characterization of anti-adhesion self-assembled monolayers formed by vapour deposition for NIL use

Anti-sticking efficiency remains a key issue in nanoimprint lithography. In order to address this problem, a self-assembled monolayer (SAM) of a fluorinated silane release agent is generally applied to the stamp surface, either in wet or in vapour phase. We present here the study on vapour deposition of (tridecafluoro-1,1,2,2-tetrahydrooctyl)TriChloroSilane (F-13-TCS) and wet and vapour deposition of a commercial product, OPTOOL DSX (TM) from Daikin. They are both fluorinated silanes used for the formation of anti-adhesive layers in nanoimprint lithography. Results will be compared in term of anti-adhesion properties and homogeneity for the obtained layers. Characterizations are made by means of contact angle measurements, Fourier Transform Infra-Red analysis and Atomic Force Microscopy observations, The vapour phase deposition of F-13-TCS allows us to reach surface energies as low as 11mN/m without increasing initial roughness. OPTOOL DSX (TM) deposition in wet phase presents comparable results, but with an increased roughness mainly due to the deposition procedure. The durability of the formed layers was investigated as a function of number of prints. For both materials, a significant degradation of the anti-adhesion properties occurs after few imprinted dies.