Structural transformations and silicon nanocrystallite formation in SiOx films

Abstract

The results of a comprehensive study by the methods of IR absorption, Raman scattering, photoluminescence (PL), and electron spin resonance (ESR) of SiOx films prepared by thermal evaporation of SiO in a vacuum are presented. The nature of structural transformations occurring on annealing the films is determined. Annealing in the temperature range 300–600°C gives rise to a PL band at 650 nm, presumably related to structural defects in SiOx film. Raising the annealing temperature further leads to healing of such defects and quenching of the PL band. Silicon precipitates pass from the amorphous to the crystalline state on being annealed at T ann=1100°C, which gives rise to a new PL band at 730 nm. ESR spectra of P b centers were recorded at the interface between randomly oriented silicon nanocrystallites and SiO2.