Integration of Co Nanomagnets for Localized EDSR in Scalable FDSOI Spin Qubit Architectures

This study validates the integration of thin cobalt nanomagnets in a FEOL compatible process for EDSR manipulation in Si spin qubits. We designed, fabricated and electrically characterized three compact spin qubit architectures with Co nanomagnets on Fully Depleted Silicon-on-Insulator. The gate-first integration is investigated using x-ray spectroscopy and diffraction, and high-low frequency capacitive characterization to explore key process integration parameters. Electron holography measurements confirmed the remanent magnetization of horseshoe nanomagnets as most suited for low field operation, in agreement with micromagnetic simulations. These findings demonstrate the feasibility of compact Co FEOL integration in nanowires, FinFETs, and planar spin qubit architectures.