title: Epitaxial top-gated atomic-scale silicon wire in a three-dimensional architecture.
abstract: Three-dimensional (3D) control of dopant profiles in silicon is a critical requirement for fabricating atomically precise transistors. We demonstrate conductance modulation through an atomic scale 3 nm wide δ-doped silicon-phosphorus wire using a vertically separated epitaxial doped Si:P top-gate. We show that intrinsic crystalline silicon grown at low temperatures (∼250 °C) serves as an effective gate dielectric permitting us to achieve large gate ranges (∼2.6 V) with leakage currents below 1 pA. Combining scanning tunneling lithography for precise lateral confinement, with monolayer doping and low temperature epitaxial overgrowth for precise vertical confinement, we can realize multiple layers of nano-patterned dopants in a single crystal material. These results demonstrate the viability of highly doped, vertically separated epitaxial gates in an all-crystalline architecture with long-term implications for monolithic 3D silicon circuits and for the realization of atomically precise donor architectures for quantum computing.
authors.affiliation: Centre of Excellence for Quantum Computation and Communication Technology and School of Physics, University of New South Wales, Sydney, NSW 2052, Australia. sarah.mckibbin@gmail.com
authors.forename: S R
authors.initials: SR
authors.lastname: McKibbin
authors.forename: G
authors.initials: G
authors.lastname: Scappucci
authors.forename: W
authors.initials: W
authors.lastname: Pok
authors.forename: M Y
authors.initials: MY
authors.lastname: Simmons
mesh_terms: D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D005740:Gases / Q000737:chemistry; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D005740:Gases; D046911:Macromolecular Substances; D012825:Silicon