Determination of SiO_2 Thickness at the Interface of ZnO/Si by Ellipsometry

摘要

When a ZnO thin film was deposited on a Si substrate and annealed, a thin layer of silicon oxide was formed at the interface. To determine the thickness of this silicon oxide layer, a four-phase model was used in the ellipsometric fittings. The effect of the layer thickness d_(SiO_2) on the spectral fittings was studied. The result shows that, after annealing at 900 ℃, d_(SiO_2) could be approxiamtely 1.5 nm, which decreases the calculated refractive index (n) by 0.06-0.07.