Two‐Step Reactive Ion Etching Process for Diamond‐Based Nanophotonics Structure Formation. Issue 5 (8th June 2020)

• Record Type: Journal Article
• Authors: Golovanov, Anton V.; Luparev, Nikolay V.; Troschiev, Sergey Yu.; Tarelkin, Sergei A.; Shcherbakova, Viktoriia S.; Bormashov, Vitaly S.
• Other Names: Krueger Anke guestEditor.; Pobedinskas Paulius guestEditor.
• Is Part Of: Physica status solidi. Volume 218:Issue 5(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-06-08
• Subjects: anisotropic reactive ion etching -- etching selectivity -- interface structures -- microfabrication -- synthetic diamond; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.202000206
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : Diamond surface modification is one of the most important technological challenges in the creation of diamond quantum photonics devices. It is necessary to fabricate different 3D structures on the crystal surface with both vertical and V‐shaped etching grooves for waveguides, grating couplers, and mesastructures. Herein, the applicability of SF6 ‐based plasma for diamond processing is studied. SF6 plasma etches diamond five times faster than commonly used Ar/O2 3:1 at the same pressure and bias, but it cannot provide vertical diamond structures due to the ion scattering. Herein, the two‐step plasma processing method is developed with Molybdenum protective masks that provide steep diamond 3D structures with sidewall roughness less than 40 nm and is, therefore, suitable for nanophotonics and other diamond applications. Mo can be chemically patterned by low‐power SF6 plasma and then used as a hardmask for anisotropic etching of diamond in Ar/O2 plasma with a selectivity of 27. Unlike common methods of diamond processing, the proposed two‐step method does not require chlorine. Abstract : Reactive ion etching (RIE) of synthetic monocrystalline diamond in SF6 and Ar/O2 mixtures plasma is investigated. Diamond etch rate and degree of anisotropy for different plasma compositions are determined. Selectivity of Al, Ni, and Mo metals to diamond is measured. A new two‐step chlorine‐free RIE method for diamond microfabrication is proposed.