Fig. 1. (a) O/Si atomic ratio x of #A samples obtained from the XPS measurements as a function of the OFR. (b) The ratio x of #B samples as a function of the argon flow rate. (c) The ratio x and (d) the deposition rate of #A and #B samples as a function of the oxygen content [O2/(Ar+O2) ratio].

Fig. 2. (a) Transmittance and (b) the refractive indices of SiOx films (#A samples) with various O/Si atomic ratios x values. (c) The refractive index and the extinction coefficient of SiOx films (#A samples) as a function of ratio x at 550 nm wavelength.

Fig. 3. XPS spectra of sample #A1, #A3, #A4, #A5, and #A9, corresponding to the O/Si atomic ratios x of 0.12, 0.63, 0.80, 1.42, and 1.84, respectively. On the left side, the red hollow circles represent the experimental data and the black solid lines are the fitted components (Si0, Si1+, Si2+, Si3+, and Si4+ peaks) of the Si 2p core level and the sum line of the peaks. On the right side, the red dots represent the relative intensities of the components in the Si 2p core level and the black squares are the components calculated according to the RBM model.