Surface texture of single-crystal silicon oxidized under a thin V2O5 layer

Abstract

The process of surface texturing of single-crystal silicon oxidized under a V2O5 layer is studied. Intense silicon oxidation at the Si–V2O5 interface begins at a temperature of 903 K which is 200 K below than upon silicon thermal oxidation in an oxygen atmosphere. A silicon dioxide layer 30–50 nm thick with SiO2 inclusions in silicon depth up to 400 nm is formed at the V2O5–Si interface. The diffusion coefficient of atomic oxygen through the silicon-dioxide layer at 903 K is determined (D ≥ 2 × 10–15 cm2 s–1). A model of low-temperature silicon oxidation, based on atomic oxygen diffusion from V2O5 through the SiO2 layer to silicon, and SiOx precipitate formation in silicon is proposed. After removing the V2O5 and silicon-dioxide layers, texture is formed on the silicon surface, which intensely scatters light in the wavelength range of 300–550 nm and is important in the texturing of the front and rear surfaces of solar cells.