We used 2μm of ultra-nanocrystalline diamond (UNCD) grown by chemical vapour deposition (CVD) on a ∼520μm silicon carrier wafer from Advanced Diamond Technologies Ltd. Detailed information about the material and the stamp fabrication can be found in our earlier paper [16]. The UNCD wafer was scribed into 1×1cm2 samples and subjected to RCA cleaning (SC-1), followed by ultrasonic solvent cleaning. Nanofeature stamps were then created from the samples using conventional electron beam lithography (EBL) with negative tone electron sensitive resist, hydrogen silsesquioxane (HSQ). An Al discharge layer was required above the resist to prevent e-beam deflection due to charge build-up on the surface [17]. Several stamps were produced with this process and the pattern written varied in design but consisted of arrays of circular pillars. After EBL and HSQ development, the HSQ was used as an etch mask for RIE with a mixture of oxygen and argon gas. The etched diamond nanopillars were typically 225nm high. Fig. 1 displays a scanning electron micrograph of some typical stamp features.
