CHARACTERIZATION OF SILICON NATIVE-OXIDE FORMED IN SC-1, H2O2 AND WETOZONE PROCESSES

The structures of silicon native oxides formed in the SC-1, H2O2 and w et ozone processes were characterized using X-ray photoelectron spectr oscopy (XPS), transmission electron microscopy (TEM) and Fourier trans form infrared spectroscopy (FT-IR). Spectral simulation was performed to clarify the FT-IR spectra, assuming that the native oxide was pure silicon dioxide. Effective medium theories were applied to understand deviations of the observed spectra from the calculated ones. The devia tions between the native oxide thickness evaluated by XPS and the abso lute thickness obtained by TEM were also discussed. These deviations c an be explained if the void is incorporated in the native oxides and t he interface between the native oxide and the basal silicon-obtained b y the wet ozone process has a relatively smooth surface and a structur e more similar to that of pure silicon dioxide, compared with that obt ained by SC-1 or H2O2 treatment.