SINGLE-ELECTRON EFFECTS IN HEAVILY-DOPED POLYCRYSTALLINE SILICON NANOWIRES

We have observed single-electron charging effects in heavily doped pol ycrystalline silicon nanowires at 4.2 K. Wires of approximately 20 nm by 30 nm active cross section were defined by electron-beam lithograph y and thermal oxidation in standard polycrystalline silicon material. We have measured a Coulomb staircase and periodic current oscillations with gate bias, attributed to localized carrier confinement resulting from a statistical variation in the intergrain tunnel barriers. A sha rp change in the current oscillation period is seen and we speculate t hat it is due to electrostatic screening of the gate bias by grain bou ndary defect states. (C) 1998 American Institute of Physics. [S0003-69 51(98)02534-0]