Electrical and chemical characteristics of probe-induced two-dimensional SiOx protrusion layers

Three two-dimensional SiOx (x ≡ O/Si content ratio and x > 2) protrusion layers of ∼0.5, ∼4, and ∼6 nm high were induced on a native SiO2 layer by atomic force microscopy (AFM) probes. X-ray photoemission spectroscopy (XPS) was used to reveal the elemental quantity of the photoelectrons, Si 2p core-levels, and Si oxidation states in the three SiOx protrusion layers and native SiO2 layer. Pt-coated conductive AFM probes were also exploited to acquire the rectifying current-voltage (IV) characteristics of the three SiOx protrusion layers and the native SiO2 layer, indicating all the three SiOx protrusion layers to be good Schottky diodes.