Oxide growth and its dielectrical properties on alkylsilated native-SiO2/Si surface

The kinetics and mechanism of probe-induced oxide growth on an octadecyltrichlorosilane (OTS) self-assembled monolayer (SAM) passivated native-SiO2/Si surface have been investigated using atomic force microscopy (AFM). It was found that oxidation strongly depends on tip polarity and the local chemistry of OTS molecules. At negative tip voltage, oxide grows and the oxidation involves a decomposition and depletion of OTS SAM. While under positive tip bias, OTS molecules are partially degraded. The dielectrical properties of the oxide were characterized by I–V measurements using current sensing AFM. The barrier height of AFM grown oxide, in comparison with thermal oxide and OTS SAM, was determined. Current spikes relating to the release of single charge were also observed on the I–V curves of AFM oxide.