Maskless and targeted creation of arrays of colour centres in diamond using focused ion beam technology

TL;DR

This paper demonstrates a maskless, focused ion beam technique for precise, targeted creation of colour centres in diamond, enabling high-resolution defect placement for quantum and photonic applications.

Contribution

It introduces a novel focused ion beam method using ECR plasma source for targeted, maskless creation of NV centres in diamond with approximately 100 nm precision.

Findings

Focused nitrogen ion beam achieves ~100 nm resolution.

The method enables targeted defect creation in diamond structures.

Switching gas source to xenon allows standard FIB milling within the same setup.

Abstract

The creation of nitrogen-vacancy centres in diamond is nowadays well controlled using nitrogen implantation and annealing. Although the high-resolution placement of NV centres has been demonstrated using either collimation through pierced AFM tips or masks with apertures made by electron beam lithography, a targeted implantation into pre-defined structures in diamond may not be achieved using these techniques. We show that a beam of nitrogen ions can be focused to approximately 100 nm using focused ion beam (FIB) technology. The nitrogen ion beam is produced using an electron cyclotron resonance (ECR) plasma source. Combined with a scanning electron microscope, the nitrogen-FIB offers new possibilities for the targeted creation of single defects in diamond. This maskless technology is suitable for example for the creation of optical centres in the cavities of photonic crystals or in diamond tips for scanning magnetometry. Finally, we further show that by changing the gas source from nitrogen to xenon, standard FIB milling capabilities are also available within the same tool.