Controlling and manipulating quantum information using advanced nanoelectronic technologies represents a major challenge currently undertaken by CEA-LETI and its partners. A key objective of this project is to achieve the integration of quantum devices within Fully Depleted Silicon-On-Insulator (FD-SOI) technology on a 300 mm platform. The success of this integration critically depends on the development of superconducting interconnects, which are essential for ensuring the thermomagnetic isolation of quantum devices in addition to ensuring the electrical continuity of the device.

The proposed integration scheme builds on a CEA-LETI patent that enabled the fabrication of TaN/TiN-based superconducting interconnections, exhibiting a critical temperature (Tc) on the order of one kelvin [1]. The goal of this research project is to explore the integration of superconducting materials with higher critical temperatures (around ten Kelvins) in order to enhance thermomagnetic isolation and improve overall device performance. This postdoctoral project aims to investigate the potential of newly developed high-temperature superconducting materials — such as ZrN, HfN, and NbTiN — produced by ICPMS-CNT and CEA-LETI, as well as their integration into the existing process flow. Using an innovative direct etch approach, the postdoc will study the impact of the process step on the superconducting properties. The influence of line dimensions on the superconducting properties such as critical temperature and current density of the materials will be also investigated. Based on the results obtained, process and integration adjustments will be proposed to optimize performances.

The postdoc will carry out structural and morphological characterizations (X-ray diffraction, TOF-SIMS, AFM, and microscopy) of the selected superconducting materials. In the second phase, she or he will work on integrating these materials in the fabrication of interconnexion lines and vias in CEA-LETI 300 mm cleanroom[1].   Once fabrication is complete, measurements of the critical temperature and magnetic field will be performed on the superconducting lines using a cryostat outside the cleanroom.