- Institute of Physics
Thermal decomposition of SiO<inf>2</inf>on Si(110) was observed in real-time by using scanning tunneling microscope (STM) and X-ray photoemission spectroscopy (XPS). STM revealed appearance of the height-different region at the void periphery, and the appearance of this region depended on the diffusing Si density in the void. The combination analysis revealed that the increase in the abundance ratio of Si<sup>3+</sup>to Si<sup>4+</sup>during decomposition of the oxide layer coincide with an increase in the area ratio of the height-different region to the oxide layer. These results suggest that the region observed by STM corresponds to the intermediate state of SiO<inf>2</inf>decomposition.