• Senior, Jorden
• Prunnila, Mika
• Viisanen, Klaara L.
• Bohuslavskyi, Heorhii
• Generalov, Andrey A.
• Ma, Jian
• Ferreira, Bernardo R.
• Möttönen, Mikko

Abstract

Publisher Copyright: © 2024 Author(s). | openaire: EC/H2020/824109/EU//EMP | openaire: EC/H2020/101053801/EU//ConceptQ | openaire: EC/HE/101113946/EU//OpenSuperQPlus100 ; Electrostatically tunable Josephson field-effect transistors (JoFETs) are one of the most desired building blocks of quantum electronics. Applications of JoFETs range from parametric amplifiers and superconducting qubits to a variety of integrated superconducting circuits. Here, we report on graphene JoFET devices fabricated with wafer-scale complementary metal-oxide-semiconductor (CMOS)-compatible processing based on chemical-vapor-deposited monolayer graphene encapsulated with atomic-layer-deposited Al2O3 gate oxide, lithographically defined top gate, and evaporated superconducting Ti/Al source, drain, and gate contacts. By optimizing the contact resistance down to ∼170 Ω μm, we observe proximity-induced superconductivity in the JoFET channels with different gate lengths of 150-350 nm. The Josephson junction devices show reproducible critical current I c tunablity with the local top gate. Our JoFETs are in the short diffusive limit with the I c reaching up to ∼3 µA for a 50 µm channel width. Overall, our demonstration of CMOS-compatible two-dimensional (2D) material-based JoFET fabrication process is an important step toward graphene-based integrated quantum circuits. ; Peer reviewed

Topics

• impedance spectroscopy
• semiconductor
• two-dimensional
• superconductivity
• superconductivity