Nano-oxidation and in situ faradaic current detection using dynamic carbon nanotube probes

Carbon nanotube-attached atomic force microscope probes were successfully used without nanotube bending to make simultaneous precision nano-oxidation and faradaic current measurements in the dynamic mode. Probe oxidation on H-passivated Si(001) surfaces was carried out by two methods involving vector-scan and raster-scan with a much higher resolution and precision compared to the nanofabrication by standard cantilevers. Faradaic current of the order of a sub-picoampere was detected during nano-oxidation using a carbon nanotube probe, accurately reflecting the subtle difference in the oxidation reaction. The minute current detection through the AFM tip is sensitive enough for the detection of very thin oxides and small-sized features. The dimension of the meniscus during nano-oxidation, which is indispensable for establishing the mechanism model, was evaluated, based on the in situ faradaic current detection and edge broadening.