Formation of nitrogen-vacancy centers in homoepitaxial diamond thin films grown via microwave plasma-assisted chemical vapor deposition

A model for controlling the two-dimensional distribution of negatively charged nitrogen-vacancy (NV^- ) fluorescent centers near the surface of a diamond crystal is presented, using only a microwave plasma-assisted chemical vapor deposition (CVD) method. In this approach, a CVD diamond layer is homoepitaxialy grown via microwave plasma-assisted CVD using an isotopically enriched methane (¹²CH₄), hydrogen (H₂), and nitrogen (N₂) gas mixture on patterned diamond (0 0 1). When the surface is imaged by means of confocal microscope photoluminescence mapping, fine grooves are observed to have been generated artificially on the diamond surface. NV^- centers are found to be distributed selectively into these grooves. These results demonstrate an effective means for the formation of NV^- centers of selectable size and density via microwave plasma-assisted CVD, with potential application in the production of diamond quantum sensors.