Reactive ion etching of nanocrystalline diamond for the fabrication of one-dimensional nanopillars

• The mechanism of oxygen RIE of nanocrystalline diamond films was studied
• The etch rate increases significantly with ICP and rf powers and decreases with pressure
• Arrays of diamond nanopillars were fabricated from nanocrystalline diamond films
• Electron beam lithography and reactive ion etching were employed

One-dimensional diamond nanostructures (diamond nanopillars) have been fabricated using nanocrystalline diamond films (NCD) as a starting material, and electron beam lithography (EBL) and reactive ion etching in an inductively coupled O2 plasma (ICP-RIE) as processing techniques. In a first step, the etch rates have been determined as a function of four major plasma parameters, namely the ICP power, the rf power applied to the substrate holder, the pressure, and the oxygen flow rate. These parameters have been varied in wide ranges. In order to get insight into the mechanisms of the etching process, etching experiments have been performed with unpatterned NCD films by varying the process times using rather short intervals. Finally, EBL has been applied prior to the etching to obtain one-dimensional pillars with diameters from 200 nm to 1 μm. Scanning electron microscopy has been employed to characterize the pillars. First results showed the process developed to be successful, and first examples will be presented.