Optical and interfacial layer properties of SiO2 films deposited on different substrates.

SiO2 films were deposited on fused silica, silicon, glass, germanium, and sapphire substrates by an ion beam sputtering technique. The optical properties of SiO2 films on different substrates and interfacial layer properties between SiO2 films and different substrates were researched by the spectroscopic ellipsometry technique. The refractive indices of SiO2 films deposited on different substrates are about 1.477 at the wavelength of 632.8 nm. The optical anisotropy property of SiO2 films on fused silica substrate is the best. The impact of thermal treatment on surface roughness and interfacial layer properties between SiO2 films and Si substrates were also investigated. When the annealing temperature is 550°C, the least surface thickness and thinnest interface layer thickness between v films and silicon substrate can be achieved. The results indicate that the surface and interface layer properties between SiO2 films and silicon substrate can be greatly improved when the optimum annealing temperature is selected.