Description du sujet de thèse

Title: Focused Ion Beam by Correlated Electron Feedback (FIBback)
The detection, control, and manipulation of individual particles are crucial for the development of new technologies. With the advancement of nano-electronic devices, a true technological leap is necessary to address these ultimate dimensions. A significant limitation to this development is the fact that the analysis tools for manufacturing these printed circuits, such as standard Focused Ion Beams (FIB), currently do not have the necessary probe size. Thus, for semiconductor technology and many developments in quantum technology, a new analysis method is required. This is precisely the context of this internship and thesis project at the Laboratoire Aimé Cotton (LAC), which relies on collaboration with the company Orsay Physics (OP), a global specialist in focused ion beams.

The deterministic production of individual ions and the control of their trajectory ion by ion has been achieved for the first time at LAC [Lop19]. By using the correlation between the ion and the electron, resulting from the photoionization of cesium atoms, the LAC team has developed a rapid feedback system to control the trajectory of ions in real time. From the position of the electron, one can predict the arrival position of the correlated ion and act in real time on its trajectory to send it to the desired location on the target. This device thus overcomes the current resolution limits of the column developed by OP by adding to the current focusing of this column the correction of the individual trajectories of each ion.

Furthermore, thanks to the correlation between the electron/ion pairs of this deterministic source, the LAC team has also conducted ghost imaging experiments with ions and electrons [Tri20]. This ghost imaging allows observing what is on the path of the ion spot by exploiting the image obtained with the correlated electrons. It has been demonstrated at LAC that it is possible, using the imaging of the electron detector, to reveal details of structures inaccessible to the position resolution of the ion detector. The use of this technique in this project is highly relevant for improving the resolution of the imaging done with the FIB column. The imaging done with the measurement of secondary electrons from the impact of each ion on the sample is enriched by the position information of the electron correlated to each ion, allowing to achieve sub-nanometric resolution for this FIB column.

This project thus makes it possible to control the number and position of atoms (or ions) on a nanometric scale, a decisive step for the development of nano-electronics and future quantum technologies.

[Lop19] C. Lopez, A. Trimeche, D. Comparat, and Y.J. Picard; Real-Time Trajectory Control of Deterministically Produced Ions; Phys. Rev. Appl. 11, 064049 (2019) [arXiv:1812.09039v2]
[Tri20] A. Trimeche, C. Lopez, D. Comparat, Y.J. Picard; Ion and Electron Ghost Imaging; Phys. Rev. Research 2, 043295 (2020) [hal-02498878] [arXiv:2003.02186]

Contexte de travail

The Laboratoire Aimé Cotton, located in Orsay (Essonne), is a joint research unit (UMR 9025) of the CNRS and the University of Paris-Saclay. It hosts approximately 50 permanent and non-permanent staff members distributed across 4 research teams and the platform supporting experiments and instrumental development, Lac Tech'. The recruited person will be integrated into the "Correlated Cold Matter" team led by Daniel Comparat.
The position is in a sector subject to the protection of scientific and technical potential (PPST), and therefore, in accordance with regulations, your arrival must be authorized by the competent authority of the MESR.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

no risk