Charging and Coulomb staircase effects in silicon nanodisk structures fabricated by defect-free Cl neutral beam etching process

A defect-free nanometer-scale silicon disk (nanodisk) on thin SiO2 film was precisely fabricated by using Cl neutral beam etching of a 3.5–4-nm-thick polycrystalline silicon on 1.4–3-nm-thick underlying SiO2 with a 7-nm-diameter ferritin iron core mask. Kelvin force microscope observations revealed that nanodisks could maintain injected positive and negative charges. Additionally, Coulomb staircases were observed by I-V measurement of a nanodisk at a temperature of 25K. These results indicate that the nanodisk fabricated in this research had a precise quantum effect structure and attained the single electron property. This process has great potential in the development of future quantum effect devices.