Characterization of thin films of a-SiO_x(1.1<x<2.0) prepared by reactive evaporation of SiO

Abstract

Thin films of a-SiO x with values of x ranging from 1.13 to 1.89 were prepared by reactive evaporation of SiO in a controlled oxygen environment. The oxygen pressure in the deposition chamber was varied so as to obtain films with different values of x. The films were studied by x-ray photoelectron spectroscopy and optical spectrophotometry. An attempt was made to analyse the Si 2p corelevel spectra in terms of five chemically shifted components corresponding to basic Si bonding units Si-(Si 4−n O n ) with n = 0, 1, . . . , 4. The concentration of these bonding units as a function of oxygen concentration was in reasonable agreement with the random-bonding model, with the exception that the Si-(Si 3 O) component was almost completely suppressed for all stoichiometries. Films with x < 1.65 consisted of elemental Si and oxides of silicon, while those with x 1.65 were almost free of Si. Films containing Si have higher refractive indices and degrees of absorption in the visible region compared with those which were free of Si.The optical properties of the films approach those of fused silica (SiO 2 ) as the values of x increase. For the films with the largest value of x (=1.89), the refractive index is smaller than that of fused silica. The density of these films was estimated to be smaller than that of fused silica by about 13%.

Electronic state characterization of SiOx thin films prepared by evaporation

“…A lower density for SiO x ͑x Ͻ 2͒ compounds than that of Si and SiO 2 have been previously reported by several authors. 1,13,19,38 From the series of samples analyzed in this study, the low density in the asdeposited SiO x films proves the formation of a new phase, and discards the possibility of considering the SiO x thin films prepared here as a mixture of segregated Si and SiO 2 domains.…”

Characterization of Si-Based Nanoparticulates Produced by Carbothermic Reduction of Silica-Containing Slag

“…The first and third deconvolution peaks were identified using available reference data. 6) The second peak at $102:4 eV was assigned to Si 3þ according to the results of Durrani et al 7) They examined thin films of SiO x with values of x ranging from 1.13 to 1.89 by XPS and showed that film with x > 1:65 can include only two oxide components corresponding to Si 3þ at 102.7 eV and Si 4þ at 103.8 eV. The other authors 8) reported also that films of SiO 1:3 stoichiom- and Si 0 states, respectively.…”

Diagnostics of SiOx‐Containing Layers Deposited on Powder Particles by Dielectric Barrier Discharge

“…In pure silicon the binding energy of the Si 2p peak is 99.5 eV 31–35. By the binding of silicon to oxygen, the binding energy is shifted by around 1 eV per SiO bond to higher energy 32.…”

“…It is the same energy range in which the SiO bonds are localized. Also the C1s peak of carbon, which was fixed by calibration of the energy axis at 284.5 eV, does not permit a separation of SiO and SiC/H 31, 35. The CO bonds are shifted to a higher energy of 286.61 eV.…”

“…The CO bonds are shifted to a higher energy of 286.61 eV. According to the scheme of Durrani et al,35 consideration of SiC bonding is not necessary because SiO bonds are not included.…”