Conduction in ultra-thin SOI nanowires prototyped by FIB milling

Abstract

This work describes a simple yet fast fabrication method to prototype silicon-on-insulator nanowires (SOINW) by using FIB milling and sacrificial oxidation on SOI substrate. Al-gated silicon wires with 8 nm diameter and 50–200 nm length are successfully demonstrated. The Si-wires are heavily implanted with phosphorus in between two oxidation steps, resulting in a film structure in which the hopping conduction mode occurs in the electron accumulation regime. Conduction oscillations are observed in 8 nm diameter Si-wires at room temperature, in contrast with large geometry samples where no oscillations are visible even at low temperature and where the conduction appears as being temperature activated.