We demonstrate highly tunable formation of nitrogen-vacancy (NV) centers using 20 keV 15N+ ion implantation through arrays of high-resolution apertures fabricated with electron beam lithography. By varying the aperture diameters from 80 to 240 nm, as well as the average ion fluences from to 2 × 1011 ions/cm2, we can control the number of ions per aperture. We analyze the photoluminescence on multiple sites with different implantation parameters and obtain ion-to-NV conversion yields of 6%–7%, consistent across all ion fluences. The implanted NV centers have spin dephasing times ∼ 3 μs, comparable to naturally occurring NV centers in high purity diamond with natural abundance 13C. With this technique, we can deterministically control the population distribution of NV centers in each aperture, allowing for the study of single or coupled NV centers and their integration into photonic structures.
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While amorphous carbon pockets formed during implantations are not repairable with annealing, these pockets would only form at the damage threshold of ∼10 vacancies/nm3. This would require an implantation fluence of at 20 keV, which is more than two orders of magnitude above our maximum fluence.
We note that we do not consider PL data from these sites after implantation due to the possibility of PMMA damage from SEM imaging.
