Formation and electric property measurement of nanosized patterns of tantalum oxide by current sensing atomic force microscope

Abstract

Nanosized patterns of tantalum oxide were fabricated on a tantalum substrate by applying a potential pulse utilizing current sensing atomic force microscopy (CSAFM). The dimensions of the dots were strongly dependent on the bias applied, scan rate, and potential pulse duration. By controlling these variables, the minimum size nanodots with full width at half maximum of 35 nm was achieved. Immediately after pattern formation, the electrical properties of the Ta oxide nanodots were measured using CSAFM. The charge transport at the CSAFM tip and the nanosized Ta oxide dot can be described by Poole–Frenkel type conduction. The relative dielectric constant of the nanosized Ta2O5 dots was calculated to be 17.8–24.3, showing that the quality of the oxide was high. In addition, by controlling the substrate bias applied, pulse duration, and tip scan speed, nanosized Ta oxide lines with the desired dimensions were prepared.