EUV SiMOS spin qubits fabricated in a 300 mm pilot line

We report on the characterization of spin qubits fabricated in imec's 300 mm pilot line using extreme ultraviolet (EUV) lithography for the patterning of the critical device layers. All-optical lithography enables scalable, high-throughput manufacturing, marking a key step toward industrially viable quantum processors. In this work, we perform a preliminary investigation of the performance of our overlapping-gate EUV-fabricated spin qubits. We present data collected on several two-qubit devices fabricated on an isotopically purified ²⁸Si/SO₂ gate-stack. We investigate the presence of low-energy excited valley states and show that high fidelity single- and two-qubit operation can be achieved with our devices. Excited valley states are probed by measuring the magnetic field dependence of coherent singlet-triplet oscillations at the decoupled single-qubit operation point. We measure the exchange interaction through exchange oscillations and splitting of the ESR spectrum to determine the range in gate space where single- and two-qubit operation is possible. Our preliminary results demonstrate the feasibility of using EUV lithography for scalable quantum device fabrication.