arXiv subjects

Etienne Gheeraert

Publications and source records attributed to Etienne Gheeraert.

4 recordsLinked to original sources

arXiv2026

Maskless Electron Beam-Induced Etching of Diamond in Air: A Secondary Electron-Driven Mechanism

We report a direct, maskless electron beam-induced etching (EBIE) process for diamond in air, enabling high-precision patterning without lithography or plasma processing. Through a comprehensive analysis of electron-gas, electron-diamond, and gas-surface interactions in the SEM environment, we demonstrate that etching is predominantly governed by low-energy secondary electrons, which drive gas dissociation and radical generation. The resulting oxygen- and nitrogen-based radicals chemisorb on the diamond surface, form volatile carbon-containing species, and desorb under continued electron irradiation, enabling controlled material removal. The process exhibits two distinct regimes: a molecule-limited regime governed by gas flux and an electron-limited regime controlled by current density. Etch depths up to 212 nm and lateral resolution down to 200 nm are achieved. Time-dependent anisotropy is observed, with (100) surfaces transitioning to (111)-faceted morphologies, enhancing etch yield. These results establish a general secondary electron-driven mechanism for EBIE in gas environments, providing a maskless, damage-free nanofabrication route for diamond semiconductor and other chemically inert materials.

cond-mat.mtrl-sci↗

arXiv2026

First Plasma Atomic Layer Etching of Diamond via O$_2$/Kr Chemistry

We report the first plasma atomic layer etching (ALE) process for diamond using a cyclic plasma sequence composed of two separated steps: oxygen surface modification and krypton ion removal. The process is implemented in an inductively coupled plasma reactor using alternating O$_2$ plasma exposure and low-energy Kr ion bombardment. This cyclic process exhibits the characteristic self-limiting behavior of ALE and enables controlled material removal with atomic-scale precision. An etch depth per cycle of \SI{6.85}{\angstrom} was achieved. Surface analysis reveals that the etched diamond surfaces exhibit lower roughness than the pristine material, while XPS confirms the preservation of the diamond bonding structure and indicates essentially damage-free etching. These results demonstrate that plasma ALE based on O$_2$/Kr chemistry provides a viable route toward damage-controlled nanoscale processing of diamond, opening new opportunities for advanced device fabrication in power electronics, photonics, quantum sensing and quantum computing technologies.

cond-mat.mtrl-sci↗

arXiv2006

Magneto-optical spectroscopy of (Ga,Mn)N epilayers

We report on the magneto-optical spectroscopy and cathodoluminescence of a set of wurtzite (Ga,Mn)N epilayers with a low Mn content, grown by molecular beam epitaxy. The sharpness of the absorption lines associated to the Mn$^{3+}$ internal transitions allows a precise study of its Zeeman effect in both Faraday and Voigt configurations. We obtain a good agreement if we assume a dynamical Jahn-Teller effect in the 3d$^{4}$ configuration of Mn, and we determine the parameters of the effective Hamiltonians describing the $^{5}T\_{2}$ and $^{5}E$ levels, and those of the spin Hamiltonian in the ground spin multiplet, from which the magnetization of the isolated ion can be calculated. On layers grown on transparent substrates, transmission close to the band gap, and the associated magnetic circular dichroism, reveal the presence of the giant Zeeman effect resulting from exchange interactions between the Mn$^{3+}$ ions and the carriers. The spin-hole interaction is found to be ferromagnetic.

cond-mat.mtrl-sci↗

arXiv2004

Dependence of the superconducting transition temperature on the doping level in single crystalline diamond films

Homoepitaxial diamond layers doped with boron in the 10^20-10^21 /cm3 range are shown to be type II superconductors with sharp transitions (~0.2K) at temperatures increasing from 0 to 2.1 K with boron contents. The critical concentration for the onset of superconductivity is about 5-7 10^20 /cm3, close to the metal-insulator transition. The H-T phase diagram has been obtained from transport and a.c. susceptibility measurements down to 300mK. These results bring new quantitative constraints on the theoretical models proposed for superconductivity in diamond.

cond-mat.supr-con↗