Nanometer spaced electrodes using selective area atomic layer deposition

Abstract

Nanoelectrodes with spacing controlled between 1 and 10nm with subnanometer increment have been achieved using atomic layer deposition. Field emission and metal-vacuum-metal tunneling are used to characterize the electrode properties in situ during growth. The current-voltage data is modeled and gives electrode spacing of 1.0±0.2nm, a barrier height of 4.5eV, and electrode radius of 10nm. Temperature variation from 26to235°C changes the spacing by 0.05nm, as calculated from electrical data. This is close to 0.1nm expected from thermal expansion. Exposing to air reduces the barrier height to 2.15eV, which is explained by the growth of a thin metal oxide layer.