NV-doped microstructures with preferential orientation by growth on heteroepitaxial diamond

Abstract

For the wafer-scale fabrication of diamond devices, the growth of diamond substrates by heteroepitaxial chemical vapor deposition is the most promising option currently available. However, the transfer of growth and also structuring processes from small homoepitaxial to larger heteroepitaxial samples is not straightforward and requires adaptation. In this study, we present an approach for the fabrication of functional microstructures including pyramids and mesas as well as more complex structures with hollow centers. The associated methods were previously demonstrated by homoepitaxial growth and are now evaluated on heteroepitaxially grown diamond films. After optimizing the growth procedures to ensure a sufficient quality of the bare diamond substrates, precursor structures for overgrowth were fabricated by e-beam lithography and plasma etching. In the overgrowth of nanopillars, a truncated pyramidal shape was achieved. The characterization with scanning electron microscopy revealed the growth of higher-index facets. Nevertheless, photoluminescence spectroscopy reveals localized doping on the sides of the microstructures. In addition, optically detected magnetic resonance reaches a contrast of 6% of one preferred nitrogen vacancy orientation per facet and a transverse relaxation time T2∗ of 96 ns.

Comparative X-ray photoelectron spectroscopy analysis of nitrogen atoms implanted in graphite and diamond

“…The experimental results described in Section 3 demonstrate the importance of using complementary material characterization techniques to provide the best possible understanding of the fundamental processes involved in materials development involving the implantation of low-energy N atoms, specifically in diamond. In this sense, implantation of low-energy (≤2,500 eV) N + ions in EGSCD may enable C-atom ejection from diamond lattice points within 8-10 nm, which is required to form the subsurface NV centers that are currently being intensively explored to produce a transformational new generation of quantum physical electronic devices (Weippert et al, 2023). In addition, diamond-based nano-electronic devices may require producing diamond structures with electrically conductive surface/subsurface nanoscale regions.…”