Stabilizing shallow color centers in diamond created by nitrogen delta-doping using SF$_6$ plasma treatment

TL;DR

This study demonstrates the creation of stable, shallow nitrogen-vacancy centers in diamond via nitrogen delta doping and SF$_6$ plasma treatment, with surface fluorination playing a key role in stabilization.

Contribution

It introduces a method for fabricating stable, shallow NV centers in diamond using nitrogen delta doping combined with SF$_6$ plasma surface treatment, highlighting the importance of surface fluorination.

Findings

NV centers are stabilized after SF$_6$ plasma treatment.

Surface fluorination is crucial for NV stability.

Detected NV depth is approximately 5 nm.

Abstract

Here we report the fabrication of stable, shallow (< 5 nm) nitrogen-vacancy (NV) centers in diamond by nitrogen delta doping at the last stage of the chemical vapor deposition (CVD) growth process. The NVs are stabilized after treating the diamond in $SF_6$ plasma, otherwise the color centers are not observed, suggesting a strong influence from the surface. X-Ray photoelectron spectroscopy measurements show the presence of only fluorine atoms on the surface, in contrast to previous studies, and suggests very good surface coverage. We managed to detect hydrogen nuclear magnetic resonance signal from protons in the immersion oil, revealing a depth of the NVs of about 5 nm