Electroluminescence of SiO2 films grown on Si by thermal oxidation and plasma-enhanced chemical vapor deposition

Abstract

Emission of the silicon oxide films grown on Si by wet thermal oxidation at 900 °С and by plasma-enhanced chemical vapor deposition from the SiH4 + N2O mixture at 350 °С has been compared using electroluminescence. The electroluminescence spectra were recorded in electrolyte – insulator – semiconductor system. The intense band in the red range with a maximum at 1.9 eV dominates the electroluminescence spectrum of the thermal oxide film. It was concluded that this band is related with the existence of silanol groups (Si — OH) in the oxide matrix. Multiband emission in the UV range is observed in the electroluminescence spectrum of the oxide film formed by plasma-enhanced chemical vapor deposition. Additional investigations using IR and RS spectroscopy revealed that observed spectrum modulation is of an oscillatory nature and is not the result of interference. Presumably, the luminescence in the UV region is due to the presence of oxygen deficiency centers containing bonds with hydrogen atoms.