# Nitrogen-vacancy centers created by N$^+$ ion implantation through screening SiO$_2$ layers on diamond

## TL;DR

This paper introduces a SiO$_2$ screening mask technique for ion implantation that precisely controls NV center depth and density in diamond, significantly reducing dose and enabling near-surface NV creation with good coherence times.

## Contribution

The study presents a novel SiO$_2$ screening method to suppress ion channeling and optimize NV center placement without additional etching, improving control and efficiency.

## Key findings

- Suppresses ion channeling effectively
- Reduces implantation dose by over three orders of magnitude
- Creates near-surface NV centers with tens of microseconds coherence time

## Abstract

We report on an ion implantation technique utilizing a screening mask made of SiO$_2$ to control both the depth profile and the dose. By appropriately selecting the thickness of the screening layer, this method fully suppresses the ion channeling, brings the location of the highest NV density to the surface, and effectively reduces the dose by more than three orders of magnitude. With a standard ion implantation system operating at the energy of 10 keV and the dose of 10$^{11}$ cm$^2$ and without an additional etching process, we create single NV centers close to the surface with coherence times of a few tens of $\mu$s.