During annealing in vacuum and dry O 2 , the amount of suboxide, Θ s , in the 1000 Å SiO 2 films on Si(111) was measured as a function of the annealing time by angle-resolved X-ray photoelectron spectroscopy (ARXPS). From ARXPS spectra of Si 2p taken at two polar angles of 0° (bulk sensitive) and 75° (surface sensitive), it was clarified that during annealing in vacuum, Θ s increases with time underneath the surface more largely than on the surface, but annealing in O 2 atmosphere at 0.5 Torr reduces Θ s on the surface more significantly than underneath the surface. These indicate that SiO molecules outdiffusing from the SiO 2 /Si interface are oxidized by permeating O 2 in the SiO 2 films.
ASJC Scopus subject areas
- 化学 (全般)