Room-temperature observation of large Coulomb-blockade oscillations from germanium Quantum-dot single-hole transistors with self-aligned electrodes

A single Ge quantum-dot (~10 nm) forms and self-aligns with source/drain electrodes via SiO₂ tunneling barriers using thermal oxidation of a SiGe-on-insulator nanowire. Thereby, a Ge single-hole transistor with self-aligned electrodes is experimentally realized based on FinFET technology and features with clear Coulomb staircase/negative differential conductance and large Coulomb-blockade oscillation behaviors at room temperature. This work provides a simple approach to alleviate this nanofabrication bottleneck and thereby reduce series resistances and increase design freedom for SETs.