Fabrication of Nanopillars on Nanocrystalline Diamond Membranes for the Incorporation of Color Centers

A fabrication process of dense arrays of one‐dimensional diamond nanostructures (diamond nanopillars) integrated on nanocrystalline diamond (NCD) membranes is implemented with an etched‐through marker hole in the membrane in the center of the array. NCD films deposited on silicon substrates are used as starting material. The main fabrication steps consist of structuring the NCD film by electron beam lithography (EBL) applying aluminum as a hard mask and subsequent inductively coupled O2 plasma reactive ion etching (ICP RIE), followed by structuring of the silicon substrate from the backside to open a NCD membrane. The developed fabrication procedure for nanostructured membranes can be transferred to monocrystalline diamond and implemented for deterministic single ion implantation into the nanopillars for generation of nitrogen‐vacancy (NV) or silicon‐vacancy (SiV) centers. For this purpose, the etched marker hole can be applied for alignment in the implantation process. Such diamond nanostructures with integrated color centers could play an important role in the development of novel quantum memory devices. This work presents a technology for the fabrication of nanostructured nanocrystalline diamond membranes. The nanopillar arrays are implemented with a marker hole via electron beam lithography, O2 plasma reactive ion etching and wet chemical etching in potassium hydroxide. Optical characterizations indicate the presence of ensembles of SiV centers and enhanced photon collection efficiency out of the pillars.