Nanometer-scale recording on a superhard and conductive carbon film using an atomic force microscope

Nanometer-scale recording on a carbon film deposited by electron cyclotron resonance plasma sputtering (ECR-C) is demonstrated by locally changing the electrical resistance using an atomic force microscope. The recording mechanism is thermal annealing of the film surface due to Joule heat generated by the probe current. Such a recording without apparent topographic changes is considered to be possible due to the higher electrical conductivity of the ECR-C than those of conventional amorphous carbons. Namely, it enables us to modify the surface at a lower application voltage than the voltage above which topographic changes due to field-induced oxidation occur. High-density probe storage is demonstrated by applying pulse voltage rows to the ECR-C. The minimum size of the data bit is about 70 nm.