Durable diamond-like carbon templates for nanoimprint lithography

Diamond-like carbon (DLC) films were investigated as an alternative material not only for coating but also for direct fabrication of nanoimprint templates. A plasma enhanced chemical vapor deposition system was configured to deposit 20 nm--1 mum thick DLC films on silicon and quartz substrates. These films were verified using Raman spectroscopy, and characterized using nanoindentation, contact angle measurements, atomic force microscopy, and optical transmission measurements. DLC films deposited can provide high hardness (18-23 GPa), low surface energy (30-50 mJ/m2) and tunable UV transmittance with smooth surface (∼0.2 nm RMS). Besides, DLC films on quartz templates are shown to have better chemical and physical stability than fluorinated self assembled monolayer employed as template release coatings. DLC templates with 40 nm∼1 um features were fabricated using e-beam lithography followed by Cr lift-off and plasma etching. Both thermal and UV nanoimprints demonstrate good pattern transfer fidelity and easy template-resist separation.