Early stages of oxide growth in H-terminated silicon nanowires: determination of kinetic behavior and activation energy

Abstract

Silicon nanowires (Si NWs) terminated with hydrogen atoms exhibit higher activation energy under ambient conditions than equivalent planar Si(100). The kinetics of sub-oxide formation in hydrogen-terminated Si NWs derived from the complementary XPS surface analysis attribute this difference to the Si–Si backbond and Si–H bond propagation which controls the process at lower temperatures (T < 200 °C). At high temperatures (T ≥ 200 °C), the activation energy was similar due to self-retarded oxidation. This finding offers the understanding of early-stage oxide growth that affects the conductance of the near-gap channels leading towards more efficient Si NW electronic devices.