Plasma treatments and photonic nanostructures for shallow nitrogen vacancy centers in diamond

Abstract

We investigate the influence of plasma treatments, especially a 0V-bias, potentially low damage O${}_2$ plasma as well as a biased Ar/SF${}_6$/O${}_2$ plasma on shallow, negative nitrogen vacancy (NV${}^{-}$) centers. We ignite and sustain using our 0V-bias plasma using purely inductive coupling. To this end, we pre-treat surfaces of high purity chemical vapor deposited single-crystal diamond (SCD). Subsequently, we create $\sim$10 nm deep NV${}^{-}$ centers via implantation and annealing. Onto the annealed SCD surface, we fabricate nanopillar structures that efficiently waveguide the photoluminescence (PL) of shallow NV${}^{-}$. Characterizing single NV${}^{-}$ inside these nanopillars, we find that the Ar/SF${}_6$/O${}_2$ plasma treatment quenches NV${}^{-}$ PL even considering that the annealing and cleaning steps following ion implantation remove any surface termination. In contrast, for our 0V-bias as well as biased O${}_2$ plasma, we observe stable NV${}^{-}$ PL and low background fluorescence from the photonic nanostructures.

accepted for publication in Optical Materials Express